4
Ministry of Mines, Energy and Water Resources 
Land and Water Studies Agency
BIRETE DAM PROJECT
\
SPECIFICATIONS AND BILL OF 
QUANTITIES
ADDIS ABABA
May 1981ACC-• J6g
Ministry of Mines, Energy and Water Resources
Land and Water Studies Agency
BIRETE DAM PROJECT SPECIFICATIONS AND BILL OF QUANTITIES
ADDIS ABABA
MAY 1981i
ABSTRACT
The report contains specifications for the construction of Birete Dam Project. It includes payment clauses. The specifications and the payment clauses have been tied with the items of the Bill of Quantities.
and the Bill of Quantities have been this document can form a part of the is let out on contract.
The specifications compiled in a way that
contract if the work11
ACKNOWLEDGEMENT
Specifications have been based on the standards of Water and Power Development Authority and National Engineering Services, Pakistan, incorporating modifications and changes to suit the
local site conditions • Bill of Quantities have been worked 
out by Ato Banteyehun Haile, engineer LWSA and Mr. Simon de Haan, Associate Export, UNDPe
NAFIS AHMAD
UN ENGINEERING ADVISERill
TABLE OF CONTENTS
Item
..........................................  1
..........................................  ±1
TABLE OF CONTENTS...............................................  .......................................... iii SPECIFICATIONS
SECTION         A,   Environmental Protection
n                    -         B,   Mobilization for Project Construction
Page
it
-        c,
Diversion and Caro of Water
during Construction,
ii
-      D,
Excavation
ii
-       E,
Construction of Earth and Rockfill
ii
-      F,
Concrete, Plain and Reinforced
ii
-      G,
Miacellaneous
BILL OF QUANTITIESBIRETE DAM PROJECT SPECIFICATIONS
SECTION A ENVIRONMENTAL PROTECTION
LANDSCAPE PRESERVATION
The Contractor shall take due precautions to preserve the natural surroundings and shall carry out his construction 
activities in such a manner as to avoid damage to or spoiling 
of the natural landscape around the area of the project. 
Clearing of trees, bushes, vegetation, grazing land, crops or property shall be limited to the areas of permanent works, approved construction roads and the areas of excavation operations. On completion of the project construction, all
work areas around the permanent structures shall be cleared and graded so as to blend with the natural landscape. The camp 
area shall be left in a clean condition and the abondoned 
borrow pits and quarry sites shall be dressed to stable slopes.
2    PREVENTION OF WATER POLLUTION
The Contractor shall carry out his construction activities in a manner that would prevent entrance or accidental spillage of solid matter, contaminants, objectionable pollutants, wastes, rQ Euse, garbage, sewage effluent, oil or other petroleum products into stream.
.-3 DUST ABATE MENT
During the construction of tho project the contractor shall carry out proper and efficient measures wherever and whenever necessary to reduce the dust nuisance.
1-4 MEASUREMENTS AND PAYMENTS
The cost of all work required by this section shall be
included      in      the      price      bid      in      the      schedule      for      other      items of work.
I:
D- 2
SECTION B
MOBILIZATION FOR PROJECT CONSTRUCTION
1     JORK INCLUDED
The work under this section consists of furnishing all
plant, labour, equipment, materials and superintendence, and other
services and facilities required to complete the Birete Dam
Project *
2     MEASUREMENTS AND PAYMENTS
B-2(l) General
The Contractor shall submit a breakdown of the
lump sum price bid for Item 101, Mobilization for
Project Construction, to the Engineer within thirty days
of the date of award of Contract. The breakdown shall
reflect in reasonable detail as determined by the
Engineer, the cost of each of the principal items of
work included for payment under the contract lump sum
price and, subject to such revision as the Engineer
may require, shall be used as a basis for partial and 
final payment as the work under Item 101, Mobilization 
for Project Construction, is performed and completed.
B-2(2) Measurement
Measurement       will       be       made       of       the       mobilization       of facilities          for          project          construction          and          work          related thereto,       all       as       mentioned       in       clause       B-2(3)       below,       as specified hereunder as a complete unit.
B-2(3) Payment
Payment will be made for the unit measured as provided above at the Contract lump sum price for Mobilization for Project Construction, and shall constitute full compensation for providing all facilities including camps, maintenance and services required in connection therewith as indicated, specified or otherwise required for the proper operation of the facilities and not included for payment under any other Contract Item, Payment under this Item will include but is not necessarily limited to, all costs incurred in connection with providing quarters for the Contractor’s personnel; Workshops, Warehouses, sheds and yards; and the Contractor’s administrative and field offices.3
SECTION C
DIVERSION AND CARE CF HATER DURING CONSTRUCTION
1 SCOPE
C-1(1) General
This section covers the construction, maintenance, and. the performance of all work necessary to care for
river water, ground water, and local drainage in
connection with the entire Contract, so that such water
does not interfere with the progress or affect the
quality of the construction.
C-1(2) Work included
The work includes but is not limited to the following:
(i)         Diversion and care of river during construction.
(ii)        Unwatering and handling of water behind Coffer dams, in conduit and all other parts of the work.
(iii)        Such design as may be necessary to supplement
that shown on the Drawings and carry out the intent of this section,
C-1(3) Structures
The structures include but are not limited to, 
are Upstream and Downstream Cofferdams, and the Diversion R.C.C. Structure including inlet, conduit and outlet, Work in connection with each of these
structures not covered in this section shall be
performed in accordance with the applicable requirements of the various Sections of the Specifications for the particular work involved,
•2 DIVERSION SJHEME
C-2(1) General
The Construction of dam will require a diversion to permit preparation of foundation and placing of
fill materials in dry, River diversion will be accomplished by constructing the Upstream and Downstream Cofferdams, and diverting the river flows through the Diversion Structure. The Diversion is
to be accomplished in two stages.a)
Stage I*
In the first dry season, it is intended to construct,
i)
the Diversion structure,
ii)
the spillway, and
iii)
the Intake Structure.
iv)
It is also intended to simultaneously construct the dam
from both sides to the full height leaving a gap in the embankment as shown in the Drawing to enable the high flows during the rainy season after the first dry season to
pass.
b)         Stage II
In the next dry season, it is intended to construct,
i)
the Upstream Cofferdam,
ii)
the Downstream Cofferdam,
iii)
the diversion of the river through the Diversion
Structure, and
iv)
closing of the gap in the Main Dam continuing construction upto the full height.
3     CLEARING AND STRIPPING OF FOUNDATIONS
All areas under the Cofferdams, Diversion Structure, Spillway, Intake Structure and the main Dam shall be cleared.of trees, vegetation and any other objectionable materials. 
Cleared material shall be disposed of by the Contractor from
the site of work in a waste area designated by the Engineer.
4     EXCAVATION FOR FOUNDATIONS
Excavation for foundations of Cofferdam, Diversion Structure, Spillway, Intake Structure and the Main Dara shall
be carried out in accordance with the Drawings and as specified in Section D-EXCAVATION.
5     COFFERDAMS
C-5(l) Materials
Materials for cofferdam fill shall be obtained from required excavations or from borrow as selected by the Contractor and approved by the Engineer. The different zones of cofferdams shall be constructed with the material gradation as shown on the Drawing.5
The shells of thG cofferdams will bo constructed with 
random rockfill obtained from the excavation with maximum size particles not exceeding 25cm.
C-5(2) Placement and Compaction
The random rockfill in the shells of the cofferdams shall be placed in 35 cn loose—depth lifts and compacted with at least four passes (complete coverage) of a 10 
short ton vibratory roller. The impervious zone and 
the transition material fill in the Upstream Cofferdam
shall be placed and compacted in accordance with relevant clauses of Section E for the Main Dam impervious and transition fills.
C-5(3) Demolishing Downstream Cofferdam
After the construction of the Main Dan has boon completed, the .Downstream Cofferdam or such portions of this Cofferdam as directed by the Engineer shall be demolished and the material so demolished shall be dis posed of in the aesignatod spoil areas as directed by 
the Engineer.
5 APPROVAL OF CONTRACTOR'S PUN OF OPERATIONS
Within thirty days after receipt of notice to proceed with the Contract, tho Contractor shall submit his proposed plan of operations for all Stage I and Stage II works under this Section for approval of the Engineer, including!
a)       Description of mothod including layout of unwatering system for cofferdams, excavation areas, and other parts of the work.
b)       Details including capacity of unwatering equipment, for unwatering cofferdams, excavation areas, and other parts of the work.
7 PROTECTION OF PERMANENT VCi<K
The Contractor shall provide such means as are necessary to supplement tho approved schemes for diversion, oare of
river, and unwatering during construction for the protection of the permanent work.- 6 -
UNWATERING AND CARE OF WjiTER
The Contractor shall provide, install, operate and maintain 
approved unwatering systems (including sufficient standby 
equipment) to unwater and keep dry all areas of construction 
that are below the stream or ground water elevation during 
construction operations and as required to keep excavated 
foundation and underground areas and side slopes stable. A11 
fill material shall be placed in the dry.
MEASUREMENTS AND PAYMENTS
C-9(l) Item No. 102. River Diversion and Care of Water.
a)       Measurement.
Measurement        will        be        made        of        all        work        acceptably performed        under        this        item,        which        is        not        included        for payment under another item, as a complete unit.
b)       Payment.
Payment will be made for the unit measured above at the Contract lump sum price for River
Diversion and Care of Water and shall constitute
full compensation for all costs related to diversion 
and care of water and other water for which payment
is not made under other items including repair or replacement of damaged work due to flood and other waters, expense incidental to overtopping of
cofferdams, dewatering, re-excavation and all
other work related to the item.
C-9(2) Items No. 103-a, 104-a, and 201 Clearing and 
Stripping of Foundations.
a)       Measurement,
Measurement will be made for the number of square metres projected vertically to a horizontal
plane of the foundations area acceptably cleared, stripped and graded.
b)       Payment.
Payment will be made for the number of square metres as measured above for clearing, stripping 
and grading and shall constitute full compensation for clearing, stripping and grading of all material- 7 -
related to this item including disposal of stripped 
material in the approved spoil area.
C-9(3) Items No. 103-C, 103-d, 103-e, 104-b, 
Rockfill, Transition Material fill, and Impervious fill
in Upstream and Doimstream Cofferdams.
a)       Measurement.
Measurement under these items will be made by actual measurement method for the number of cubic metres of each material in place and acceptably 
in the cofferdam fill to the lines, grades and 
cros§ions shown on the Drawing or established by the Engineer,
b)       Payment.
Payment will bG made for the number of cubic metres measured as provided above for the Contract unit price per oubic metre for these items. Payment shall constitute full compensation for constructing the cofferdam fills from required excavation, stock piles and borrow areas including enervation,hauling, rehandling, processing, moistening, placing and compacting the materials as specified and all other work related to the Items.
C—9(A) Item No. 105. Demolishing of Downstream Cofferdam.
a)       Measurement.
Measurement will be made for the number of cubic meters of fill acceptably demolished and removed from the Downstream Cofferdam as specified in clause C-5(3)„
b)       Payment.
Payment will be made for the number of cubic metres of fill demolished from the Downstream Cofferdam as measured above and shall constitute full compensation for excavation, demolishing, and disposal of excavated material in the approved 
areas and grading, leveling and clearing tho Downstream Cofferdam site in an approved manner,
10^-c. Random8
iri    of water from Foundations.
C-9(5) Itera No. 1o6’ PuniP  S
a) Measurement.
Measurement will be made for the number of 5 litres per second per hour of water removed (excluding water supplied for construction purposes) from all
work areas whenever required by pumping regardless of head against which it is purapea, acceptably performed, and as a complete unite Measurement will be made by acceptable devices provided by the Contractor and acceptable to the Engineer.
b) Payment.
Payment will be made for the number of 5 litres per second per hour measured as above at the Contract unit price per 5 litres per second per hour for
pumping of Water from foundations and shall constitute full compensation for the work related to pumping of water as described in clauses C-7 and C-8.
SECTION D EXCAVATION
1 SCOPE
This section covers excavation for Cofferdams, Diversion Structure, Spillway, Intake Structure and the Main Dam;
borrow areas; dental excavation; other excavation not specified in other sections; and disposal of all excavated materials except as the placement of material is covered in other sections.
X
•2 CLASSIFICATION OF EXCAVATION MATERIALS
D-2(l) General
The terms Rock, Random Rock, Formation and Earth are hereby defined when used for the purpose of
classifying excavated materials for payment under
the various Items.
D-2(2) Rock
Hock shall mean all in place bGds or Ledges of solid mineral matter sound and intact and as so classified by the Engineer. Processing and utilization of rock shall be required in the construction of the Main Dam.9
D-2(3)          Random-Rock
Random Rock shall mean in place solid mineral
material weathered to a reasonable degree having 
pieces of rock sound and intact, and as so classified 
by the Engineer.
D-2(U)         Transition Material (Weathered Basalt), Formation.
Formation of igneous material generally called 
rock but not meeting the classification requirements for
Rock or Random Rock as in clauses D—2(2) and D-2(3) respectively, and being in such a weathered condition 
that it can be effectively loosened or broken by 
ripping, and as so classified by the Engineer.
0-2(5)           Earth
Earth shall mean all materials except Rock, Random Rock and Formation as defined above in clauses
D-2(2), D-2(3), and 0-2(4). Earth shall include, 
but not necessarily be limited to, all geologically recent materials overlying rock such as alluvium and talus; all layers of earth which are cemented so that the earth becomes conglomerate, shall be considered as Earth.
EXCAVATION OPEN CUT--------- GENERAL
D-3(l) Excavation Methods
The Contractor shall perform all opGn cut excavation and grading to the final elevation lines
and grades shown on the Drawings or approved by the Engineer• Excavation shall be performed by approved methods. The Contractor shall make such trial excavations as are necessary to indicate the
adequacy of the excavation methods. The rock excavation in the foundation area of structures shall be done by such careful methods as Line Drilling Pre Splitting or Cushion Blasting. The Contractor shall plan his excavation operations in the rock area in such a manner that the bulk of material produced is of (—) 30cm size. The responsibility for the success of the excavation method shall rest with the Contractor regardless of approval by the Engineer.- 10 -
In general for th© earth and quarried rock materials
the Engineer will use his best endeavours to advise
the Contractor at the loading areas regarding the suitability of excavated materials for use in embankment based on the Engineer’s examination prior to transportation to points of placement and stock piling will not bo paid for. Rock excavation from
the dam and other structures’ foundation area shall be stockpiled as per instructions of the Engineer. The quality requirements of the materials are specified 
in clause E - 4 D-3(2) Excavation Extent
, Materials.
Excess excavation performed by the Contractor for any purpose or reason, except that ordered in writing 
by the Engineer, shall be at the expense of the Contractor. All excavation for structures shall be
carried to foundation material satisfactory to the Engineer regardless of whether the elevation thereof
is higher or lower than the elevation shown on the Drawings. All necessary precautions shall be taken 
to preserve the material below and beyond the lines
of all excavation in 3ound undisturbed conditions. 
All over excavations required by the Engineer to be backfilled shall be backfilled by the Contractor in accordance with the instructions of the Engineer}
over—excavation in rock below or against concrete structures and impervious fill shall be backfilled 
with concrete or as directed by th© Engineer; if over excavation is unauthorized it shall be backfilled at the Contractor’s expense. Except where the use of other materials is specifically approved by the Engineer, unauthorized excessive excavation along the sides of structures in rock and in earth where
side forms are not used shall be backfilled with concrete at the Contractor’s expense. Materials for use in the work shall be carefully excavated to produce the material in form suitable for the work;
additional measures such as secondary blasting and mixing shall bo used, if necessary, to make tho
-----------------11-
excavated material suitable for the required use.
Excavations through overburden into rock shall be
performed in a manner to result in seperation of the
rock from the overburden so that the maximum practicable amount of suitable embankment and fill material will
be produced. Stripping of bushes, shrubs, topsoil shall
be done prior to start of excavations in the area,
in accordance with clause C—3 hereof.
D-3(3) Excavation Tolerances
Excavation shall be performed within the tolerances for excavation limits indicated on the Drawings. Where
no tolerances are indicated, excavation shall be
performed to tolerances established by the Engineer
as acceptable for the design and type of work involved. 
In case where the structure or other governing criterion permits, the Engineer may relax the tolerance to 
facilitate construction.
D-3(U) Excavation Line to Suit Field Conditions
The character and desired dimensions of the proposed excavations are in general indicated on the Drawings. The. Engineer, however, shall have the right
to:
a)       Vary the depth, width, and the length of the excavations and to increase or decrease the slopes including berms of the excavations; and
b)       Require the use of berms of dimension as instructed in permanent slopes where none are shown on the Drawings, if conditions require or permit such modifications for the purpose of obtaining more stable or economical slopes and/or foundations. The Engineer shall have the right to vary the excavation lines after excavation has been commenced.
D-3(4) Contact Excavation for Core
Beneath the impervious core of the Main dam embankment within limits as shown on the Drawings all Earth materials shall be excavated, rock surfaces shall be prepared and impervious material shall be12
placed as required for the control of under-seepage. Excavation shall be carried to reasonably sound rock, suitable to receive the impervious core material. 
Contact length between the impervious core and rock 
at the Main Embankment Dam shall be as shown on the Drawings. The suitable material excavated will be
allowed to be placed in the shells of the main dam as directed by the Engineer, and the Contractor may stockpile such suitable material for further use. The payment for placement of suitable material will be
made separately according to other shell material in 
the dam. The unsuitable material will be disposed of
in the designated spoil area, and no additional
payment will be made for stockpiling and disposal work.
D-3(5) DENTAL EXCAVATION
Zones of unsatisfactory material below the foundation levels shown on the Drawing which will require excavation, may be encountered. All such material, regardless of character, shall be removed 
and disposed of as directed by the Engineer. Dental excavation shall consist of the removal of earth such 
as talus or alluvium or unsound rock such as soft, 
friable or highly weathered rock from below the foundation or other base excavation lines indicated on the Drawings or directed by the Engineer for
Structures and for impervious earth—rock contact, and from locations such as joints, fissures*pockets and between rock beds, where the use of power excavation equipment is not practicable• Dental excavation shall
not include removal of materials by pressure washing and shall not include excavation which is classified by 
the Engineer and paid for under another Contract Item. Excavated areas covered in this clause shall be
cleaned as specified and provided with dental treatment as specified in clause D-8(l)e3
t
13
D-3(6) Clearing and Stripping for Quarries
The areas from which Rock, Random-Rock, Transition Material, and Earth is to be excavated for fill in the
Dam, shall be cleared and stripped of all bushes, 
trees, shrubs, top unsuitable soil or material as
directed by the Engineer. Blasting and Excavation work 
in the quarries shall start only after the stripping 
and clearing has been completed to the satisfaction of
the Engineer and the stripped surface has been 
approved by the Engineer. The stripped material shall
be disposed of in the waste areas as directed by the Engineer.
D-3(7) Measurement and Payment
The measurement and Payment for excavation shall be made according to the type of excavation that is Rock or Random-Rock or Transition Material(Weathered Basalt) or Earth, as classified in the field by the
Engineer. The item rate for payment of Excavation shall include the disposition of material in the specified manher.
ROCK QUARRIES
D-4(1) General
The material for rock-fill will be obtained from the approved Rock Quarries as indicated on the Drawing or as selected by the Contractor and approved by the Engineer. The Contractor shall exploit, develop and maintain the approved quarries and pits in a suitable condition for the extraction and removal of the
required materials in a manner satisfactory to the Engineer, so as to obtain at all tiroes thG greatest practicable yield of suitable materials in the
deposit. The fact that the Employer has approved the
site and location from which material for rock-fill
I
may
the
be obtained shall not be construed as constituting approval for use of all material extracted from
■
.4.
the
for
quarries and the Contractor shall be responsible thG specified quality and grading of such produced
material. For quality and gradation of rock-fill
y'U
material the clause E - 4 materials shall be
<
applicable.
-- 14 -
-U(2) Blasting and Excavations
a)       The Contractor shall plan his quarrying and blasting operations in such a manner that bulk of
material produced is of (-) 30cm size. The (-) 30cm
rock material from the approved area and quarried in approved manner shall be used in the rockfill shells
of the embankment.
b)       For riprap material to be used on the upstream face, separate quarrying and salvaging shall be
required. The gradation of riprap is specified in 
clause, E-4(2)
D-4(3) Measurement and Payment for quarriod material.
The processed madterial from the rock quarries
shall be placed and compacted in the dam as per clauses E-5, E-6, E-7 and E-8 which items shall include the entire
cost of processing, separating, grading, handling, placement and compaction of this material. No seperate payment shall be made for the excavation of the material under this clause,
TRANSITION MATERIAL QUARRY
D-5(1) Excavation
The transition material will be obtained from the approved weathered Basalt areas as indicated on the Drawing or as selected by the Contractor and approved by the Engineer. The Contractor shall plan his ripping, excavation and quarrying operations in such a manner that the material produced is of (-) 8cm size, and 
shall be responsible for the specified quality and grading of transition material produced. For quality and gradation of transition material the clause
E-4(4) Materials shall be applicable. The (-) 8cm size material from the approved area and quarried in approved manner shall be used in the transition zones of the Embankment.15 -
D-5(2) Measurement and payment
The transition material from the quarry shall be
placed       and       compacted       in       the       dam       as       per       clauses       E-5       to       E-8 which items shall include the entire cost of
processing, seperating, grading, handling, placement and compaction of this material. No seperate payment shall be made for the excavation of the material
under this clause.
EARTH BORROW AREAS
D-6(1) General
Borrow area for earth material in the permanent work shall be the borrow area shown on the Drawing, other borrow area designated by the Engineer and other borrow area selected by the Contractor subject to approval by the Engineer. The outline of the borrow area shown on Drawing is general and schematic, the actual borrow excavation may be entirely within the area or partially outside of and beyond the indicated outline of borrow area. If the Contractor proposed to use borrow area other than that shown on the drawing, he shall make such investigations at his expense and furnish such evidence for approval of the Engineer, as will indicate that the borrow area can be used as a source of material suitable for the embankment.
D-6(2) Operation of Borrow Areas
In the earth borrow areas the Contractor shall perform selective excavation to necessary depth and extent in the dry, draining of borrow areas, prewetting of material in the borrow areas, dressing of borrow area during and after completion and disposition of materials to obtain and make the materials suitable for use in the work.
7 DISPOSITION OF MATERIALS
The Contractor shall be permitted to use all suitable materials from required excavation in the work shown on the drawings  Suitable materials from borrow areas and quarries
e
shall be used in the work shown on the Drawings; materials- 16 -
from borrow and quarries that are designated by the Engineer as unsuitable shall be neatly disposed of in approved locations
at no expense to the Employer. The Contractor shall be
responsible for making and maintaining all haul roads
required for transport of the materials from the Borrow Areas, Excavation and Quarries to their required destinations. No 
soperate payment will be due to the Contractor for the haul
roads and all costs related to this shall be included in the
unit prices of the materials as provided in the Bill of
Quantities•
FOUNDATION preparation
D-8(1) Preparation of Contact Surface between Kock and 
Impervious Core—Dental Treatment.
Exposed rock surface within the rock-core contact areas shall be cleaned by brooming and compressed air to permit inspection. Surface treatment shall be performed if necessary, to ensure that no open or
loosely filled fissures, joints or bedding planes are present which might permit seepage concentrations along the rock-core contact areas. Unsatisfactory material in pockets, seams and fissures shall be removed, if so ordered by the Engineer, Fissures, seams and shear zones exposed in the cleaning process shall be immediately filled with concrete, as directed by the Engineer,
D-8(2) Structures-Foundation Surface between Rock and Concrete.
Exposed rock surface within the foundation 
against which concrete is to be placed shall be
cleaned and broomed and the surface and undulations shall be covered and filled with a layer of blinding concrete as directed by the Engineer. The Blinding Concrete shall be provided according to Specifications in Section F for Concrete,17
MEASUREMENT AND PAYMENTS
D-9(1) Excavation from Earth Borrow Areas,
No seperate payment will be made to the Contractor
for clearing, stripping, watering and excavation from
the earth borrow areas, All excavation works from
earth borrow areas shall be included for payment under
the item which covers the placement of this material.
D-9(2) Items No, 103-b, 202. Earth Excavation in foundations.
a)       Measurement
Measurement for Earth Excavation of foundations will be made in cubic metre measure of unsuitable material in original positions acceptably removed 
to the satisfaction of the Engineer.
b)       Payment
Payment will be made for the number of cubic metres measured as provided above at the contract
unit price per cubic metre and shall constitute
full compensation for removing all unsuitable
material including disposal in the waste areas.
D -9(3) Item No. 203. Random-Rock Excavation in foundations.
a)       Measurement
Measurement for Random-Rock Excavation in foundations as defined in Clause D-2(3) shall be
made in cubic metre measure of Random-Rock in original position acceptably excavated.
b)       Payment
Payment will be made for the number of cubic metres measured as provided above at the contract unit price per cubic metre and shall constitute
full compensation for removing all unsuitable material to the waste areas and suitable material for stockpiling.- 18 -
D-9(M Item No, 204, Rock Excavation in foundations
a). Measurement
Measurement of Rock Excavation in foundations as defined in Clause D-2(2) shall be made in cubic
metre measure of Rock in original position 
acceptably excavated by means of line drilling, 
pre-splitting, cushion blasting or by other
approved methods, within the lines and grades
provided by the Engineer and stockpiled as
specified and directed by the Engineer,
b) Payment
Payment will be made for the number of cubic metres measured as above at the contract unit price
for excation of Rock from the foundation area, including full compensation for stockpiling of this material as specified.
D-9(5) Rehandling of Rock from the Approved Stockpiles
No separate payment will be made for rehandling 
of rock from the approved stockpiles and this work will
be included for payment of item which covers the
placement of material.
D-9(6) Rock from Quarrying
No separate payment for quarrying, stockpiling, sorting and mixing of rock material will be made to 
the Contractor, The measurement and payment for
Rockfill and Riprap material from the quarry will be
made in the fill under the items which cover the placement of rockfill and riprap material,
^-9(7) Item 205, Surface Dental Treatment of Foundation for
Core-Rock Contact-Dental Concrete,
a) Measurement
Measurement will be made for the number of cubic metros of Dental Concrete acceptably placed in the foundation for treatment of fissures, seams and shear zones as specified in clause D-8(l). 
No separate measurement will be made for cleaning work required in connection with dental
treatment.19 -
SCOPE
b) Payment.
Payment for dental concrete will be made for the number of cubic metres as measured above at the contract unit price per cubic metre of Dental concrete and shall constitute full compensation for filling up the cleaned fissures, shear zones with concrete and all work related to this item.
SECTION E
CONSTRUCTION OF EARTH AND ROCK FILL The work covered by this section consists of construction 
of the Main Dam, the cofferdams, and other Miscellaneous fills.
DEFINITION
The term fill as used in Section E of these Specifications
is defined as the earth and rock fill portions of the main 
dam and cofferdams structures and all other fill, riprap, 
filter and transition materials for these dams and as used in 
connection with other structures.
GENERAL PROVISIONS
E-3(l) Equipment and Methods
Before proceeding with any of the work specified in this section, the Contractor shall furnish the construction sequence and material utilization scheme
he proposes to use in fill construction to the
Engineer as further information for approval.
E-3(2) Lines and Grades
Fill shall be constructed to the lines, grades
and cross-sections indicated on the Drawings, nniftsa otherwise directed by the Engineer. Materials Conforming to the requirements specified in clause
E-4 Materials, shall be placed and compacted within the indicated zone limits. The Engineer reserves
the right to increase or decrease the foundation 
widths, the embankment slopes or the zone limits or
to make such other changes in the embankment sections as may be deemed necessary to produce safe structures,- 20
or for efficient utilization of materials from
required excavation. Settlement of embankment for
the post construction period will be provided for
by increasing the height of the sections. Required 
height increases will be determined ano specified by 
the Engineer from settlement observation made as the work progresses.
3(3) Conduct of Work
a) Maintenance, Protection and Tests.
The Contractor shall maintain and protect the Main Dam in a satisfactory condition at all times
until final completion of all work under the
Contract. The Engineer will establish a programme
of testing cf in—placo fill to insure that the
work is being performed in conformance to the requirements of theso specifications. The Engineer will also perform tests of materials at their
source and during their prossessing and handling 
as nccc-ssary for quality control and the Contractor shall adjust his methods as required for the improvement of tho product to meet Specification requirements. Tests of materials and embankment construction will bo made at regular intervals and the Engineer will notify the Contractor of any deficiencies in materials and/or construction when the results of tests are known. Deficiencies shall
be remedied by such measuros as th© Engineer may direct. The Contractor may bo required to romove, at his own expense, any fill placed outside of tho prescribed slops lines where such placement is
not authorized by the Engineer.
b) Haul Hoads
Haul roads shall be located and constructed as approvod by tho Engineer. They shall be designed to maintain th© intended traffic safely, without endangering embankment stability drutng tho embankmont construction period and shall bo constructed in a manner to preclude contamination or alteration of materials forming th© ombankmont- 21
section. All roads located on enbankcient slopes shall
be removed at the completion of embankment construction. Haul or construction roads shall be provided and will
not be measured for payment.
MATERIALS
E-4( 1 ) General
Fill materials shall be obtained from required excavations, from the borrow areas and from rock quarries as indicated on the Drawings and as specified in Section D. All materials shall conform to the requirements of the Specifications, and their disposition in the dam shall bo as shown on the Drawings except as otherwise directed by the Engineer.
E-4(2) Riprap
Material for riprap slope protection on the upstream of the dam shall be angular, sound, durable blocky Rock, free from cracks, seams or other defects which would tend to increase unduly its deterioration from natural causes, Material for riprap shall conform to the following general gradation of rock sizes.
Gradation            Requirement for Riprap Material
Material
Size
Percent Finer Than, By Weight
70 cm                                                   100
60 ” 15 ”
8 ” E-4(3) Rock-fill shells
80 to 90
10 to 20
Not Exceoding
Average Weight
175 kg 110 "
10 " 1 n
Material for upstream and downstrocm rock—fill shells shall be angular, sound, durable blocky rock, 
well graded within the following gradation limits.
Gradation Requirements for Rock-fill Material
Material
Size
30 cm
No. 4 siovo
Percent Finer Than
By Voight
100
(4.75mm)                  Not Exceeding 25 NO. 200 siovo
(O.O74mra)
5- 22 -
Oversize rocks produced in the required excavations or brought from the quarry shall be pushed towards
the outer slopes of the rock—fill shells®
E-4(4) Transition Material
Material for compacted transition upstream and downstream of clay core shall be weathered Basaltt angular, sound and durable as specified in clause
D-2(4) and quarried by means of ripping and scraping to a gradation within the following limits.
Gradation Requirements for Transition Material
Material Size
8 cm
2 "
No. 4 sieve (U.75mm) No. 200 Sieve (0.07^mm)
E-4(5) Impervious Core
Percent Finer Than By Weight
TOO 50 - 80 25 - 50
5—15
Material for compacted impervious core shall be the natural deposits of clay designated as borrow
area
3A              on Drawing No. DE 101.
PLACEMENT
E-5(1) General
No fill shall be placed on any part of the dam
or other structure foundations until such area has
been inspected and approved. Materials of the several
types and qualities required shall be deposited and 
distributed within the zone limits shown on the
Drawings and to the slopes indicated within the tolerances specified bolow. The gradation and distributier
of materials in the zones of the dam shall be such as to produce in each zone a reasonably wall graded mass. Fill material shall be handled and placed by such methods an will minimize segregation, in lifts
sizes of material within zones of rockfill are placed towards the clay core, and the larger sizes towards
the outor- 23 -
faces. inhere rockfill and riprap slopo protection 
are placed on permanently exposed enbanknont slopes, 
the placing of fill shall be such as to obtain surfaces
within a tolerance of plus 15cm and minus 8cm except
that the extreme minus tolerance shall not be
continuous over an area greater than 20 scuare metres. 
For all other zones not specified above, or elsewhere, material shall be placed as close as practicable to 
the lines shown on the tzrawings as approved by the Engineer. Bridging in the fill, and all slabs or
slabby rock shall bo broken down.
E-5(2) Rate of placement
Unless otherwise indicated or directed, the top 
of each embankment zone, including the riprap, shall
be maintained at approximately the same lc-vcl throughout each embankment construction stage regardless of the number of typos of materials being placed, except as
may bo required to prevent mixture of embankment materials. Material shall be delivered in proper
sequence and distributed over the surfaces of the
fills at such rate as will ensure the completion of
each embankment zone and stage thereof within the spccifiod time.
E—5(3) Slope protection placement
Riprap material shall be placed by dumping on the embankment within the limits indicated in such a
manner as to produce a well graded mass of rock with the minimum practicable percentage of voids, and shall bo constructed within the specified tolerance
to the lines and grades shown on the Drawings or staked in the field* The larger stones shall be well distributed and the finished riprap shall bo free
from objectionable pockets of small stones and clusters of largor stones* The desirod distribution of the various sizes of stones throughout the mass shall
be obtained by selective loading of the material at
its source and by controlled dumping of successive loads during final placing* Roarranging of individual
■■2U
stones by mechanical equipment or by hand will be required to the extent necessary to obtain a reasonably well graded distribution.
E-5(4) Impervious Fill Placement
The Impervious fill for clay core 3hall be placed in the Embankments within the limits indicated for impervious core. If in the opinion of the Engineer
the rolled surface of any layer of impervious fill is
too dry or smooth to bond properly with the layer of material to be placed thereon, it shall be moistened 
and worked with a bitrow or scarifier in an approved manner to sufficient depth to provide a satisfactory bonding surface before the succeeding layer of impervious material is placed. If in the opinion of Engineer the rolled surface of any layer of in-place impervious fill is too wet for proper placement of the layer to be placed thereon, it shall be removed or scarified or harj e*/ed to reduce the water content to 
the required amount before the succeeding layer is placed thereon. No impervious fill shall be placed below water.
The Impervious fill for clay blanket upstream of the dam to cover exposed rock shall be placed in the same manner as specified above.
E-5(5) Rock-fill Placement
The upstream and downstream rockfill zones material shall be placed in thG embankment within the limits indicated on the Drawings. Rearrangement of individual stones by mechanical equipment or by hand methods will be required to the extent necessary to produce a level, smooth and even finish at the Berm.
E-5(6) Transition Material Placement
The transition material shall be placed immediately upstream and downstream of the impervious core within the limits shown on the drawings. Caro shall be taken that transition material does not get mixed with the impervious fill. 
' JrThe loading and handling of the transition material
shall be done in such a manner that segregation will
be minimized. If considered necessary by the Engineer, 
some mixing by scarifying or wetting of material
before hauling shall be done in order to create a
homogeneous layer.
SPREADING
After depositing, the material shall be spread by 
approved means in approximately horizontal layers of uniform
thickness over placement area. The layers of the impervious
material after spreading in uniform layer shall be scarified 
by harrows to break any lumps of material and to ensure proper
and uniform compaction. Except as otherwise directed by the
Engineer as a result of the tests conducted during construction, 
the thickness of each compacted layer of impervious core
material shall not exceed 15cm, the compacted thickness of
transition material shall not exceed 25cm and the compacted 
thickness of rockfill material shall not exceed 30cms. The
Contractor shall determine by making test sections, the loose
lift thickness required in order to attain the compacted 
thickness opooifled herein^-
As soon as practicable after commencement
of construction of impervious zone, the fill surface shall be
sloped with a transverse slope of not less than 3 percent
throughout construction. During dumping and spreading the
Contractor shall provide at all times adequate facilities for
removal of all unsuitable and/or oversize material. Unsuitable
materials shall be removed from the embankment and disposed of
in an approved manner. The entire surface of any section of
embankment under construction shall be maintained in such
condition  that construction  equipment can  travel on of the section.  Ruts in  the surface of any  layer s' filled satisfactorily before compacting. • 4
MOISTURE CONTROL
E-7(1) Impervious Material (clay core)
Control of moisture content will be placing and compacting material in the c
So far as practicable, the material shall be delivered and spread in moisture range of 2.0 percent below- 26
standard optimum to standard optimum. coluturo content by irrigating or drying within the borrow areas. On 
the basis of tests conducted during construction the Engineer reserves the ri ht to srnko notification in 
the required range of moisture for this ante rial. Only such raoisture control ns nu<dod for minor adjustment of moisture changes caused by evaporation curing handling and placement or iron rainfall shall bo accomplished on the fill. The moisture shall bo distributed uniformly throughout each layer nrior to compaction. Optimum moisture cont nt .".hall be determined in the laboratory by th- fngin^or by making standard corpaction tost. The optimum aolstura contents for the materials in the borrow area will bo furnished by the Engineer to the Contractor nt daiLy intervals
or at significant changes of material being placed.
E-7(2) Other Zones
No particular moisture control will be required for compaction of materials in other zonoi of th*> daa. Somo addition of moisture in the transition zones
material may bo required to reduce segregation tondencios, Tho addition of vatir Cor this purpose
shall be accomplished prior to handling.
COMPACTION
E-8(l) Equipment
Compaction equipment shall conform to the following rcQuirvinunta and shall be
in subsequent clauses and as determined and ordered 
by the Engineer as a result of the tests conducted 
during construction.
a)           Vibratory Rollers
Vibratory rollers shall have \ total static weight of approximately tvn short tons, with at least ninety percent of the weight tranaaltted 
to the ground through a single attooth drum when the roller is standing in a level position hitchod to the towing vehicle. The diameter of the dr» shall bo approximately five feet and width
a> proscribed27 -*
approximately six feet. The roller shall produce
a dynamic impact of approximately sixty thousand pounds at rated vibration frequency. The roller
shall be towed at speeds not to exceed U Km per
hour. The equipment manufacturer shall furnish sufficient data, dravzings and computations for verification of the above specifications, and the character and efficiency of this equipment shall
be subject to the approval of the Engineer.
b)           Tamping Rollers
Tamping Rollers shall be used for compacting Impervious fill# Each drum of the roller shall
have an outside diameter of not less than 5 foot
and shall not be less than 4 feet or more than 6 
feet in length# The space between the two drums
when on a level surface shall not be less than 12 inches or more than 15 inches# One tamping foot
shall be provided on the drum for at least 100 
square inch of drum surface# The length of each tamping foot from the outside surface of drum shall be not less than 9 inches# The cross-section area
of each tamping foot shall be not more than 10 square inches at a place normal to the axis of the
shaft six inches from the drum surface and shall be not less than 7 square inches at eight inches from
the drum surface# The weight of roller when fully loaded shall not toe less than 4,000 pounds per
foot length of drum# The loading used shall be as required to obtain the desired compaction# During the operation of rolling, the Contractor shall
keep the space between the tamping feet clear of materials which would impair the effectiveness of the tamping rollers#
c)           Special Compactors
Compaction of materials in areas where it is impracticable to use a roller or a tractor, as provided above, shall be performed by the use of compactors of the heavy-duty power-driven type.
• H
.A
•j28
They shall be capable of producing densities at
least equal to those produced by the equipment specified in sub-clauses (a) and (b) hereof. All
such equipment will be subject to approval by the Engineer. Compactors which do not obtain the required density with reasonable amount of coverage of each layer and at a production rate consistent
with the adjacent embankment, shall not be used in the work. Compacted layer thicknesses by this equipment shall not exceed 10 cms.
d)           Sprinkling Equipment
Sprinkling equipment shall consist of tank trucks, pressure-distributors, or other equipment designed to apply water uniformly and in controlled quantities to variable widths of surface. Tank trucks shall be equiped with positive shut off
valves so that no leakage will result from the nozzles when equipment is not operating. Leaks
shall be repaired immediately and any material rendered too wet because of faulty equipment shall be removed or reconditioned and no additional pay ment will be made thereof.
E-8(2) Compaction General
After a layer of fill material has been deposited, it shall be scarified, bladed or otherwise treated as necessary to produce a uniform material with respect
to moisture content and grain size distribution, in accordance with clause (E-7)  Moisture Control. Mixing 
t
shall be performed to the full depth of the layer if
so required. When the moisture content and condition of the layer is satisfactory the lift shall be
compacted. Portions of the fill which are not accessible to the roller shall be placed in lifts consistent with the material size and compacted with power tampers to a degree equal to that obtained on the other portions of the compacted fill by rolling as specified. Dumping, spreading, sprinkling, and compacting may be performed at the same time atdifferent points along a section of embankment when 
there is sufficient area to permit these operations to 
proceed simultaneously.
E-8(3) Compaction of fill material
Except as otherwise determined and ordered by the
Engineer fill materials shall be deposited in successive
layers of thickness as specified, and compacted as
follows:
a)             Each      layer      of      material      in      the      impervious      (clay) core      zone      shall      be      compacted      with      not      less      than ten passes of the specified tamping roller#
b)      In all other zones, each layer of material, except riprap slope protection shall be compacted with not less than four passes of the specified vibratory roller.
c)           One pass of the vibratory roller is defined as one complete coverage of the surface of the area being compacted, in which the drum of the roller comes in contact with the entire surface of the area. 
For the tamping roller, the same definition shall apply, no consideration being given to the spaces between the drums, the entire width between the outside walls of the outside drums being considered as a continuous drum.
(4)E-8(4) Additional Rolling
If it is so determined by the Engineer, that the desired compaction of any portion of the embankment is not secured by the minimum number of passes specified, additional complete passes to the extend directed by the Engineer shall be made over the
sur ^ace area of such designated portion.
* MISCELLANEOUS FILLS AND BACKFILLS
E-9(l) General
In addition to the embankment fill for the dam certain miscellaneous fills and backfills will b^ required for spillway and other structures. Material requirements for these backfills shall be specified on- 30 -
the Drawings and the type of* material for these fills
will be as specified in Clause E—4, Materials or as
directed by the Engineer.
E-9(2) Operations Adjacent to Tx.sting Structures
In general, no fill, backfill or other load shall
be placed on or against the surface of any concrete
structure earlier than is permissible with regard to 
the protection of the structure. At locations where
the safety of the structures might be endangered, such 
operations shall not proceed until the construction 
has been completed tc such extent and the concrete has
attained sufficient strength to withstand any stresses
that might develop incidental to the operations required. 
If so required the Contractor shall submit details of
the methods of placement, spreading and compaction he proposes to use for the protection of structures at
such locations for the approval of the Engineer. Within 
areas where rollers cannot be used, the material shall
be compacted by means of power tampers.
) MEASUREMENT AND PAYMENT
E-10(l) Items No. 301 through 306, Main Dam Fills.
a) Measurement
Measurement under these items will be computed by actual measurements methods and will be made of
the number of cubic metres of each material zone in place and accepted in the embankment fill to the lines, grades and cross-sections shown on the drawings or established by tho Engineer.
b) Payment
Payment shall constitute full compensation for constructing the embankment from required borrow areas, quarries and stockpiles including excavating, loading, rehandling, hauling, processing, moistening, placing and compacting the materials and all other work related to the Item.
A
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•i- 31
i)     Item No. 301, Riprap Slope Protection 
Payment will be made for the number of cubic meters measured as provided above at the Contract unit price per cubic metre for Riprap.
ii)        Item No. 302, Rockfill Zone
Payment will be made for the number of cubic metres measured as provided above at the Contract unit price per cubic metre for Rock
fill Zone.
iii)          Item No. 303, Transition Material Zone. 
Payment will be made for the number of cubic metres measured as provided above at the Contract unit price per cubic metre for Transition Material Zone.
iv)   Item No. 30^, Impervious Fill Zone (Clay core) Payment will be made for the number of
cubic meters measured as provided above at the Contract unit price per cubic metre for Impervious Fill Zone (Clay core).
v) Item No. 305, Impervious Fill for clay Blanket Payment will be made for the number of
cubic metres measured as provided above at the Contract unit price per cubic metre for Impervious Fill placed as Clay Blanket.
vi)  Item No. 306, Miscelleous Backfill
Payment will be made for the number of cubic metres measured as provided above at Contract unit price per cubic metre for Miscelleous Backfill behind retaining walls
and other structures and shall constitute full compensation for constructing the backfill with the materials obtained from the specified stockpiles including hauling, placing and compacting the material and all other works related to the iteip..SECTION F
CONCRETE, PLAIN AND REINFORCED
F-1 SCOPE
Thi n section covers the manufacture, forming, tran
sporting, placing, stripping of forms, finishing, and 
curing of concrete in the structures included in the
specifications.
F-2 COMPOSITION
Concrete shall be composed of Portland cement, water, 
fine and coarse aggregate.
P-3 QUALITY
The concrete mixture will be designed by the Engineer
who will determine the required quality of the concrete for
the structures covered by these specifications.
F-4 CEMENT
P-4(1)
Cement shall be furnished packaged as approved by the Engineer. It shall be Portland Cement and shall conform to British Standard 12:1958, Portland Cement (ordinary) or to
ASTM Designation C 150-64, Standard Specification for Port land Cement, for Type I cement.
P-4(2) Test Requirements
Cement shall be sampled at storage site and tested at the expense of the contractor, in accordance with the ASTM requirements. Additional tests will be made by, or under33
the supervision of the Engineer, and at the expense of the Employer. No coment shall be used until notice has been given by the Engineer that the test results are satis
factory. If tests prove that a cement which has Deen 
delivered is unsatisfactory, it shall be promptly removed 
from the site of work. Cement which has been in storage
at the project site longer than four months shall not be
used until retest proves it to be satisfactory.
F-4(3) Transportation of Cement
Transportation of cement to the storage or to the site
of work shall be accomplished in such a manner that cement
to 
is completely protected from exposure' moisture. Cement which has been adversely affected by moisture as determined by the Engineer, shall be rejected.
F-4(4) Storage
Immediately upon receipt at the site of the work, cement shall be stored in a dry weather-tight and properly ventilat
ed structure. All storage facilities shall be subject to 
approval and shall be such as to permit easy access for inspection and identification. Sufficient cement shall be in storage at the work site to complete any lift of concrete started. The Contractor shall use cement in the approximate chronological order delivered at the site in order that
cement may not become widely aged.
F-5 AGGREGATES
F-5(1) Composition
Pine aggregate shall generally consist of natural sand, however, use of manufactured sand or a combination of natural and manufactured sand will be permitted on the approval of the Engineer. Coarse aggregate shall consist of natural- 3^ -
gravel, or crushed gravel or a combination thereof.
F-5(2) Source
The Contractor shall bring concrete aggregate from approved natural deposits or shall produce crushed aggregate from approved locations. The Contractor shall be responsible for ascertaining the extent of work, including type of equipment required and amount of weste involved in producing a sufficient quatity required of acceptable aggregate irom
the sources finally selected by him and approved by the Engineer,
F-5(3) Sampling and Testing
Curing construction, aggregates will be sampled as delivered to the mixer to determine compliance with specification provisions. The Contractor shall provide facilities as may be necessary for the ready collection of representative test samples. The Engineer will obtain and test such samples, at the expense of the Employer, using appropriate standard test methods selected by the Engineer. Tests and analysis of aggregates at various Btages in the processing and handling operations will be made at the discretion of the Engineer. Testing of concrete aggregates by the Engineer shall not relieve the contractor of his responsibility to maintain control, to ensure the production, stock piling and handling of both fine and course aggregates in accordance with these specifications.
F-5(4) Processed Aggregate
Aggregates, as delivered to the mixers, shall consist of olean, and uncoated particles. Where directed by the35
Engineer dust shall be removed from the coarse aggregate by adequate washing. The aggregates shall conform to the following specific requirements.
a) Fine aggregate
The grading and uniformity of fine aggregate as delivered to the mixers shall conform to the following requirements.
Sieve Designation U.S. Standard Square Mesh
3/8"
No. 4
No. 8
No. 16
No. 30
No. 50
No. 100
Percent Passing
100
95   to   100 80  to    100 50  to   85 25  to   60 10  to    30
2  to    10
In addition to the grading limits the fine aggregate as delivered to the mixer, shall have a fineness modulus
of not less than 2,30 nor more than 3.10.
b) Coarse aggregate
The grading of the coarse aggregate shall conform to the following requirements as delivered to the mixer.
U.S. Standard Sieve Size
1 in X in % in No. 4
Percentage by Weight Passing Individual Sieve
100 90 - 100 20 - 40C) Part icle Shape.
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The shape of the particles.in the fine aggregate and in the coarse aggregate- shall, be generally spherical or cubical. The .quantity of'fldt. and elongated particles in the course aggregate, as defined and, determined by standard tests.approved by the Engineer shall hot exceed 25 percent. A flat particle is one having a retio of width to thickness greater than three. An elongated particle is one having a ratio of length to width greater than three, 
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F-5(5) ’Storage
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Aggregates shall be stored atf'the site of work in 
such a manner as to prevent the inclusion of /foreign ?'7 materials in concrete. Sufficient aggregate shall be maintained at the site at all times to permit contijirious placement and completion of any lift of concrete started, 
F-5(6) Moisture Control
All fine aggregates and course aggregate shall-roinain 
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in free-draining storage at the site for atleaat 72 hours . immediately prior to use. Under no conditions shall ths aggregates be delivered to the mixers dripping wot.
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Water for washing aggregates and for mixing arid curing concrete shall be fresh water free from' injurious asouitts, of oil,acid, salt, alkali, organic matter. Or ether delptericas
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aubatanoos as determined by standard tears, selected by the
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Engineer*
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F-7 PROPORTIONING OF CONCRETE
F-7(1) Control
Trial mixes and tests will be made by the Engineer during the course of the work for the purposes of designing the mixes and for quality control. The proportions of all material entering into the concrete shall be as directed by 
the Engineer. The proportions will be changed whenever
such change is determined necessary to maintain the standard of quality required for the structures covered by these specifications and to the varying conditions encountered during construction. The Contractor will be entitled to no compensation additional to that included in the prices for
the applicable tender items in the Bill of quatities because
of such changes.
F-7(2) Cement Content
The cement content of concrete for various parts of the structure will range from 2OOkg per cubic metre to 365kg per cubic metre depending on the structural requirements.
F-7(3) Water Content
a) Water Cement Ratio.
In general, the Engineer’s design of mix will provide for water cement ratio by weight (exclusive of water absorbed by the aggregates) which will be determined on the basis of producing concrete having suitable vzorkability, density, impermeability, durability and the required strength without the use of excessive amount of cement. It is expected that water cement ratios will vary from 0.45 to 0.6, depending 
on the strength of concrete and the type of structure.- 38 -
b) Conistency
The amount of water used in the concrete shall be regulated as required to secure concrete of proper con
sistency. Addition of water to compensate for stiffening 
of the concrete befor placing will not be permitted. 
Uniformity in concrete consistency from batch to tatolr
will be required.
F-7(4) Strength of Concrete
Concrete for the several structures and parts therof
shall have compressive or flexural strengths at least
equal to the minimum allowable strengths shown on the Drawings, except us otherwise directed by the Engineer.
F-7 (5 ) Slump
The slump of the concrete after concrete has been deposited but before it has been consolidated shall not
exceed 3 inches (8 cms). The Engineer reserves the right
to require a lesser slump whenever such slump is practicable. Slump will be determined in accordance with AST?,1! Designat ion C - 143-53, standard method of test for slump of
Protland Cement Concrete.
F-8 TEST OF CONCRETE
Strength tests of the concrete placed during the course of the work will be made by the Engineer.The Contractor shall provide such facilities as may be necessary for procuring and handling representative test samples. Cylinders will be tested by the Engineer in accordance with the applicable requirements of ASTM- 39
Designation 639-64, standard Method of Test for compressive strength of Molded concrete cylinders, or cubes will be
tested in accordance with the applicable British Standard Specifications. The test results will be based on the
average of the strength of the test specimens. The
standard age of test will be 28 days, but 7 days test may 
be used at the discretion of the Engineer, based on the
relation between the 7 days and 28 days strengths of concrete
as established by tests for the materials and proportions used. The frequency of tests will be determined by the Engineer on the basis of p]a cement rate and the structure to assure
himself that the concrete being placed conforms to the speci fications and design requirements.
F-9 MIXING
F—9(1) Capacity
The Contractor shall provide concrete mixing arrangement having sufficient capacity to produce concrete at such a rate
as will enable the completion of monolith pours and will
assure the completion of concrete structures in accordance
with the requirements of the construction schedule.
F-9(2) Location
The concrete mixers              shall be installed at the site of work at locations selected by the Contractor and approved
by the Engineer.
i- 40 -
F—9(3) Arrangement
Seperate bins or compartments shall be provided for each classification of aggregate. The compartments shall be
of ample size and so constructed that the materials will be maintained seperated under all working conditions. All materials shall be preferably batched by weight. Batching 
by volume may be allowed by the Engineer.
F-9(4) Water Batches
A suitable water measuring device shall be provided by the Contractor which will be capable of measuring mixing water within the specified requirements for each batch to control water cement ratio. The water shall be delivered to the mixer ensuring that no leakage occurs.
F- 9(5) Mixers
Suitable mixers shall be provided by the Contractor. Each mixer shall be capable of combining the materials into 
a uniform mixture and of discharging this mixture without segregation. Mixers shall not be charged in excess of the capacity recommended by the manufacturer on the name plate. Excessive overmixing requiring additions of water will not
be permitted. The mixers shall be operated at a drum speed designated by the manufacturers on the name plate. The mixers shall be maintained in satisfactory operating condition, and mixer drums shall be kept free of hardened concrete. Mixer blades shall be replaced when worn down more than 10 percent of their depth.F-10 CONVEYING
Concrete shall be conveyed from mixer to forms as rapidly as practicable, by methods which will prevent segregation or loss of ingredionts. Any hopper through 
which the concrete passes shall be conical in Bhape. There
shall be no vertical drop greater than 1.5 metre except
where suitable equipment is provided to prevent segregation and where specifically authorized. Chutes or other similar equipment will not be permitted for conveying concrete except where the use of such equipment is approved in writing by the Engineer in advance of any use.
F-11 PLACING
F-11(1) General
No concrete shall be placed in the structure until the methods of placement have been approved by the Engineer. Approval of the method of placement proposed will not relieve the Contractor of responsibility for its adequacy. Concrete
shall be worked into the corners and angles of the forms and around all reinforcement and embedded items without per mitting the material to segregate. Concrete shall be deposited 
as close as possible to its final position in the forms.
The depositing of concrete shall be
regulated so that the concrete may be effectively compacted v/ith a minimum of lateral movement
into horizontal layers, approximately 30 to 45 cms in thickness. Not more than two cubic metres may be deposited in one pile for compaction. The surfaces of constructionjoints shall be kept continuously wet for at least
eighteen hours during the twenty four hour period prior to placing concrete except as otherwise directed by the Engineer All free water shall be removed and the construction joint shall be dry of surface water prior to placement of concrete. Concrete placement will not be permitted, when, in the opinion of the Engineer weather conditions prevent proper placement and consolidation.
F-11(2) Time Interval Between Mixing and Placing
Concrete shall be placed within thirty minutes, after
it has been mixed, unless otherwise approved by the Engineer. 
P-11(3) Lifts in Concrete
The depth of concrete placed in each lift will be as shown on the Drawings or as directed by the Engineer. The placement shall be carried out at such a rate that formation 
of cold joints will be prevented. SlabB shall be placed in 
one lift unless otherwise authorized or directed. In walls, slabs and other structures lift shall terminate at such 
levels as will conform to structural details.<
P-11(4) Vibration of Concrete
Concrete shall be compacted with mechanical vibrating equipment supplemented by handBpading and tamping. In no case shall vibrators be used to transport concrete Inside
the forms. The vibrating equipment shall be of the internal’ type and shall at all times be adequate in number of units and power of each unit to properly consolidate all concrete. Borm or surface vibrations shall not be used unless speci—fically approved. Internal vibrators shall maintain a
frequency when submerged in the concrete of not less than 7,000 impulses per minute. The intensity (amplitude) of
vibration shall be sufficient to produce satisfactory 
consolidation. The duration of vibration shall be limited 
to that necessary to produce satisfactory consolidation. Excessive surface working will not be permitted.
F-11(5) Placing Concrete Through Reinforcement and in Spillway a)     In placing concrete through reinforcement care shall
be taken that no segregation of the coarse aggregate occurs,
b)     The unformed portions of ogee crest at spillways, chute slab placed on slope>the flip bucket at the spillway 
end which are to be finished, shall be placed according to 
the grade and finished by accurate screeding. In general, 
chute slab of spillway shall be divided into strips consisting 
of square blocks with construction control joints except some pours which will be odd sizes. Each strip of the chute slab shall be placed in a single continuous pour and in the direction from down slope upwards and in a sequence strip by strip. If, for any reason, placing any of the strips is interupptedbefore completing its full length, a construction-control joint shall
be provided at the temporary end of the strip. Unless other wise shown on the Drawings or directed by the Engineer, the maximum differential in height between adjacent mass concrete monoliths shall be 3 metres.F-11(6) Placing Concrete on Rock
Rock surface upon which concrete is to he placed shall be clean free from oil, standing or running water, mud, drumy 
rock, coatings, debris, loose or semi detached or unsound 
fragments. Faults and seams shall be cleaned to satisfactory 
depth and to the firm rock on the sides. Immediately before
concrete in placed, all rock surface shall be throughly cleaned 
by use of air water jets or other approved methods. All rock 
surfaces shall be kept' continuously wet for at least 24 hours immediately prior to placing concrete thereon.
F-12 CONSTRUCTION JOINT TREATMENT
F-12(1) General
As a lift a s completed, the top surface shall be i rnmedi r tel y and carefully protected from any condition that will damage or adversely affect the hardening of concrete.
F-12(2) Cleaning
Horizontal construction joints on lifts shell be prepared for receiving the next lift by cleaning with air-water cutting. The surface shall be cut with a high pressure air—water jet to remove all laitance and to expose clean, sound aggregate, but not so as to undercut the edges of the larger particles
of the aggregate. The air pressure used in the jet shall be 100 PBi plus or minus 10 Psi and the water pressure shall be
just sufficient to bring the water into effective influence
of the air pressure. After cutting, the surface shall be washed and rinsed as long as there is any trace of cloudiness of the wash water. The surface shall again be washed with Qh air-water jet just prior to placing the succeeding lift.b) Polyvinylchloride Water Stops
Polyvinylchloride water stops shall be extruded from
an elastomericplastic compound the basic resin of which sail be polyvinylchloride (PVC).
F-14 CURING AND PROTECTION
a)     All concrete shall be cured for a period of not less than fourteen (14) consecutive dayB by an approved method or combination of methods. The contractor shall have all equipment needed for adequate curing and protection of the concrete available at site before actual concrete placement begins. The curing methods shall be approved by the Engineer. Unhardened concrete shall be protected from rain and flowing water. All concrete shall be adequately protected from damage.
b)      Concrete shall be moist-cured by maintaining all surfaces continuously (not periodically) wet for the duration of the entire curing period. Water for curing shall be clean and free from any elements which will cause staining or discolouration of the concrete. The quality of curing water shall be the same as given in clause F-6. Where forma of wood lagging are used and left in place during curing, the lagging shall be kept wet at all times. Horizontal construct ion joints and finished horizontal surfaces cured with sand shall be covered with a minimum uniform thickness of 5 cme of sand which shall be kept continuous saturated during the entire curing period.y-15 forms
F-15(1) General
Forms shall be true to line and grade within allowable tolerances for concrete surfaces, mortartight and sufficiently rigid or prevent objectionable deformation under load. Where forms for continuous surfaces are placed in successive units, care shall be token to fit the forms over the completed sur
face so as to obtain accurate alignment of the surface and 
to prevent leakage of motar. Responsibility for their ade
quacy shall rest with the Contractorj however, the type, 
shape, size, quality, and strength of all materials of which 
the forms are made shall be subject to specific approvel of
the Engineer. All forms shall be so constructed that they 
can be removed without damaging the concrete. All exposed joints, edges, and external corners shall be chamfered to 
provide a neat and uniform appearance unless otherwise di reefed by the Engineer.
F-15(2) Coating
Forms for exposed surfaces shall be coated with on approved nonstaining form oil which shall be applied shortly before the concrete is placed. After oiling, surplus oil
on the form surfaoes and any oil on the reinforcing steel
or other surfaces requiring bond with the concrete shall be removed. Forms for unexposed surfaces may be thoroughly wettttd in lieu of oiling immediately befor placing of concrete.F-15(3) Removal of Forms
Forms shall not be removed without prior approval of Engineer and all removals shall be accomplished in a manner
which will prevent damage to concrete. Forms shall not be removed before the expiration of the minimum time indicated below, except as otherwise directed or specifically authorized.
Slabs and conduit = 7 days
Walls = 2 days
F-16 TOLERANCE FOR CONCRETE CONSTRUCTION Variation in alignment, grade and dimensions of the
structures         from the established alignments, grade and dimensions      shown on the       Drawings shell be within the
tolerances        specified in
the following table.
1)     Variation from          the plumb a) In the lines and surfaces
of walls and in arrises
b) For exposed corners, joint groves and others
2)   Variation from the level
or from the grades indicated on the drawings.
3)   Footings
a) Variation of dimensions in plan
In 3
metres....0.5cm
In 6     metres.1.Ocm
In12
In 6
In12
In 3
metres....2.0cm
metres...,0.5cm
metreB.... 1.0cm
metres....0.5cm
Minus Plus
1,0cm
5.0cmb Reduction in thickness at any point
Minus
2%
of Specified thickness
. *
4) Conduit
d) Departure from established grade and level.
b)   Variation in thickness at any point.
c)   Variation from inside dimension.
Total length.♦»1.Ocm
Minus..................... 0 cm
Maximum...............1%
F-17 FINISHING
Immediately after removal of forms, all unsightly ridges or lips shall be removed and undesirable local buldging on the surfaces to be permanently exposed shall be remedied. Excessive rubbing of formed surfaces will
not be permitted. Voids and holes left by the removal of tierods in all permanently exposed surfaces and surfaces
to be exposed to water shall be reamed and completely filled with dry patching mixed in the proportions directed. Defective concrete shall be repaired by cutting out the unsatisfactory material and placing new concrete which shall be secured with keys, dovetails or anchors. Concrete for patching shall be drier than the usual mixture and shall be thoroughly tamped into place. All finishing shall be per- formed immediately after the forms are removed. All un-» formed surfaces of concrete that are not to be covered by 
•additional concrete or backfill, shall have a wood float
finish unless a steel trowel finish is specified, without additional mortar and shall be true to elevation as shown 
on the Drawings. Care shall be taken to see that all free
water which has accumulated at the surface is removed before making any finish. Every precaution shall be tc-ken by the Contractor to protect finished surfaces from steins or abrasions. Surfaces or edges likely to be damaged during 
the construction period shall be properly protected. The length of the template will be 1.5 m for testing of formed surfaces and 3.0 m for testing of unformed surfaces.
F-18 REPAIR OF CONCRETE
Concrete that is damaged from any cause; concrete that is honeycombed, fractured or otherwise defective; and concrete which, because of excessive surface depressions, must be excavated and build up to bring the surface to the prescribed lines; shall be removed and replaced with drypack, mortar, 
or concrete. Repair of concrete shall be performed only 
by skilled workmen and within 24 hours of removal of forms. All fillings shall be bonded properly to the surfaces and 
shall be sound and free from shrinkage cracks and drummy areas after the fillings have been cured and have dried. Repairs shall be made in accordance with procedures approved by the Engineer. All materials used in the repair of concrete shall conform to the applicable requirements of this section of the specifications. Concrete, mortar
and drypack filling shall each be mixed in proportions approved by the Engineer to produce a repair atleast- 51
equivalent in strength and durability to the concrete in 
v/hich the repair is required.
f-19 furnishing and placing steel reinforcement
F-19(1) General
The Contractor shall furnish, cut, bend, and place all steel reinforcement including rods, bars and structural
shapes as indicated on the Drawings or otherwise required. All reinforcement shall be, when surrounding concrete is placed, free from loose, flaky rust, and scale, and free form oil, grease or other coating which might destroy or reduoe
its bond with concrete. All placing shall be in accordance with Drawings furnished or as approved by the Engineer.
F-19(2) Cutting and Bending
Steel reinforcement may be cut and bent in the field. All bending shall be in accordance with standard approved practice and methods.
F-19(3) Quality
The steel reinforcement shall conform to the following requirements.
a)  Reinforcement bars (rods) shall be deformed bars of intermediate grade billet steel in accordance with the ASTM Designation A—15-65, or equivalent.
Yield point = 40,000'lbs/sq.inch Tensile strength = 70,000 ibs/sq.inch- 52
b)   Deformation of bars shall be in aocordanoe with ASTM Designation A-305-65.
F-19(4) Splicing
All splicing in reinforcement shall be in accordance
with ACI standard "Building Code Requirements for Reinforced Concrete."
F-19(5) Supports
All reinforoement shall be secured in place by use of metal or concrete supports, spacers or ties, as approved. Such supports shall be of sufficient strength to maintain 
the reinforcement in place throughout the concreting operation. The supports shall be used in such a manner that they will not be exposed or contribute in any way to the discolouration or deterioration of the concrete.
F-20 EMBEDDED ITEMS
Beforce placing concrete, care shall be taken to determine that all embedded items are firmly and securely fastenened in place as indicated on the Drawings, Embedded material shall be free from oil and other foreign matter such as loose coatings of rust, paint or coales. The embedding of wood and other foreign material in concrete shall not be allowed.53 -
F-21 BLINDING LAYER (CONCRETE)
Foundations of spillway shall be provided a concrete blinding layer as directed by the Engineer to achieve an approximately smooth surfaoe before laying and binding of steel reinforcement. The estimated range of cement in this concrete shall be 200kg per cubic metre.
F-22 DENTAL CONCRETE
Dental concrete shall be placed in dental excavation such as joints, fractures, cracks, fissures, pockets and 
between rock beds. It shall also be 'rovided in other below grade excavations.
F-23 MEASUREMENT AND PAYMENT
a) Item No.401, Furnish Portland Cement (ordinary)
i) Measurement.
Measurement for bagged cement will be made of the number of tons of bagged cement acceptably used in the per manent works for which items for measurement and payment are included in the Bill of Quantities. The quantity to be paid 
for will be based on the number of bags and standard weight per bag as detemined by the Engineer of cement acceptably used at the mixer.
ii) Payment.
Payment will be made for the number of tons measured aa provided above at the Contract unit price per ton for furnished Portland Cement (ordinary) which price shall include all costs associated with providing cement at the mixer. No payment will be made for cement used as follows:cement   used   in   concrete   that   is   wasted;   cement   used   in   the replacement   of   damaged   or   defective   concrete;   cement   that is   otherwise   wasted;   cement   used   in   extra   concrete   placed outside    the    concrete    paylines,    unless    such    extra    concrete is   required   as   a   result   of   written   order   of   the   Engineer; and   cement   used   in   concrete   placed   by   the   Concractor   in excavation    intentionally    performed    by    the    Contractor    to facilitate his operations.
b) Item No.402, Furnish and Install Reinforcing Steel
i) Measurements.
Measurement will be made of the number of killo-grams
of reinforcing steel acceptably placed on the basis of the
lengths of bars installed in accordance with approved
Drawings or bar schedules or as directed,  converted  to weights for the size of bars listed  by  the use of unit weights per linear metre.
Steel in laps indicated on the Drawings or required by the Engineer will be paid for at the Contract Unit Price. No measurement for payment will be made for the additional steel in laps which are authorized for the convenience of
the Contractor.
ii) Payment
Payment will be made for the number of killo-grams measured us provided above at the applicable Contract unit * prices per killo-gram and shall constitute full compensation for furnishing, delivering, handling, cutting, bending, cleaning, placing, binding and supporting the bars and all other work related to the Items.- 55
c)      Item No. 403, Furnish and Install Water Stop.
i) Measurement
Measurement will be made of the number of linear metres of water stops acceptably placed in the work based on the applicable unit linear metre for material. In computing 
lengths no allowance will be made for laps.
ii) Payment
Payment will be made for the number of linear metres measured as provided above at the Contract unit price to 
furnish and install water stops, and shall include full compensation for splicing material and all other work
related to the Item.
d)     Measurement and Payment of Concrete.
General
Except as otherwise specified here^under, measurement
of concrete will be made on the basis of actual volume of
concrete in place within the neat lines of the structures as indicated on the Drawings or as otherwise established by the Engineer. Measurement for payment will not be made of concrete, nor any ingredients including cement in concrete which is
placed outside of the lines shown on the Drawings, Measurement of concrete placed against the sides of any excavation without the use of intervening forms will be made only within the pay ’ lines of the structure. Unless otherwise specified payment
for concrete will be made at the respective Contract Unit Prices per cubic metre for the various Items of the Bill of Quantities, which price shall include the cost of ell labour,- 56 -
materials, and the use of all equipment and tools required 
to complete the batching, mixing, transporting, placing, protecting, curing and other concrete work; except the cement, reinforcement, and embedded parts which are specified to be paid for seperately. The Contract unit price per cubic metre
for concrete will include the cost of formwork, form oils, aggregates, water, preparation of joints, joint fillers, 
specified cleaning, preparation of surface to receive concrete, finishing and all other work required to complete the concrete structures. No measurement or payment for patching or repair ing faulty concrete by any method will be made. The Items
for the Concrete work are specified hereinafter.
e)        Item No, 206, 404, Dental Concrete.
Dental concrete includes concrete required to be placed in the dam foundation, spillway, diversion structure, and 
intake structure as directed by the Engineer in accordance
with the requirements of Clause F-22 Dental Concrete.
i)      Measurement
Measurement will be made of the number of cubic metres of concrete acceptably plaoed us directed by the Engineer in dental excavation as specified above.
ii)     Payment
Payment will be made for the number of cubic metres measured as provided above at the Contract Unit Price per cubic metre for Dental Concrete, and shall constitute full compensation for all work related to the Item.f)         Item No. 405, Blinding Concrete,
Blinding concrete includes concrete within limits as directed by the Engineer, except Dental Concrete. 
Payment
Payment will be made for the number of cubic metres measured as provided in Clause F-23(d) at the Contract
Unit Price per cubic metre for Blinding concrete and Bhall constitute full compensation for all work related to the
Item in accordance with Clause F-21.
g)     Item No. 406, Plain Concrete.
This Item includes concrete in Approach channel of Diversion Structure and Approach channel of Intake Structure as shown on the Drawings.
Payment.
P Qyment will be made for the number of cubic metres measured as provided in Clause F-23(d) at the Contract Unit Price per cubic metre for concrete laid in position and shall constitute full payment for all work related to the Item
h)   Item No. 407, Reinforced Concrete
This Item includes concrete in Spillway, Diversion, and and Intake Structures as shovzn on the Drawings.
Payment.
Payment will be made for the number of cubic meters measured as provided in Clause F-23 (d) at the Contract
Unit Price per cubic meter for concrete laid in the structures and shall constitute full payment for all work related to the Item.G—1 SCOPE
58 -
SECTION G MISCELLANEOUS
This section covers furnishing and installing of
structural drains, Gates, Steel pipe for Intake Structure, 
valves, and other miscellaneous works connected with the
structures.
G-2 structure drains
G—2(1) Qeneral
Under drainage will be provided for the Spillway Structure downstream of the toe of downstream rock—fill zone of the dam along the side walls of the chute as
shown on the Drawing. It will also be provided under
the downstream toe of the dam as shown on the relevant Drawings•
G-2(2) Materials
a)     Pipes.
Concrete pipes of the internal diameter sizes as specified on the Drawings shall be used. Each 
piece shall be 30 cms long with straight ends and shall be laid dry, Pieces of pipe shall be laid keeping 3 to 4 mm apace between the ends.
b)    Material around the pipes.
The material around the pipes shall consist of gravel clean and well graded from No. 4 U S. 
t
standard sieve size to three quarter inch size, as approved by the Engineer.
G-2(3 ) Installation
a) Trenching
Widths and depths of the trenches for drains shall be as indicated on the Drawings and where not indicated shall be of minimum width necessary for proper laying of pipe. Excavation for trenching shall be performed by barring and wedging or any other approved method which will not damage the rock in the foundations.59 -
b)        Pipe Installation
Each pipe shall be carefully inspected before it is laid. Any defective or damaged pipe shall be rejected. The laying of pipe shall proceed upgrade beginning at the lower end of the pipe line. Under
no circumstances the pipe shall be laid in water
and pipes shall not be laid when the trench conditions are unsuitable for such work. Full responsibility for dewatering of trenches during construction shall be born by the Contractor. 
Pipes shall be laid to the lines and grades as
shown on the Drawings. When pipe laying is inter rupted the Contractor shall seal the ends of the
pipe line to prevent the entry of foreign matter. 
No backfill shall be placed over or around the
pipe untill the installation is approved by the Engineer.
c)        Backfilling
Before pipes are laid, graded gravel material as specified above shall be placed to the depth as shown on the Drawings or as directed by the Engineer Care shall be taken to ensure thorough compaction of the fill under the pipe. Material shall be
placed along the side of the pipe in layers not exceeding 10cm in the depth and shall be compacted by hand tamping,
BULKHEAD GATES AND TRASH RACK
G-3(1) General
The Contractor shall furnish, assemble, install and test the following:-
a)        Two bulkhead gates, one for Diversion Structure and the other for Intake Structure; hoists; anchorage assembly, hoist stems or chains, track bars, seals, sill and other embeded items shown 
on the drawings and required for satisfactory operation of gate.- 60 -
b)  Trash rack including anchorage and arrangements required for satisfactory installation.
G-3(2) Material Specifications
All material used shall be of highest grade, free from defects and imperfections, all material shall
be of recent manufacture and unused and of classificatio and grade designated on the Drawings, The rubber
seals for gates shall be moulded only.
G-3(3)         Workmanship
a)   General
Workmanship and finish shall be first class and equal to the best practice in modern fabrication and machine shops. Before laying out, cutting 
or fabricating the work in any way, the material shall be thoroughly straightened by methods that will not result in damage, except that sharp
kir.ks or bends in members to be straightened will be cause for rejection. Finished members shall be free from kinks, bends, or winds. Shearing 
shall be accurately done, and all portions of the work neatly finished. Bends, except for minor details, shall be made by approved dies or bending rolls. Where heating is required, precautions
shall be taken to avoid overheating the metal and 
it shall be allowed to cool in such a manner as
not to destroy the original properties of the
metal. Holes for drainage shall be provided in 
such horizontal or inclined members as may be subject to retention of entrapped water.
b)   Dimensional Tolerances for Structural Works.
i) Structural work fabricated under this
Contract and delivered to the work site in sub-assemblies will have been fabricated to, and shall be assembled in accordance with the dimensional tolerances herein specified.- 61
ii)        Unless otherwise specifically authorized the major dimensions of any structure fabricated of structural steel shall be within 3 mm
of the dimensions shown on the Drawing. Dimensions shall be measured by means of an approved calibrated steel tape of the
same temperature as the structure at the time of measurement. Unfairness of platework shall be held to a practicable minimum.
c)  Welding
i)         All welding and work related thereto shall comply with the requirements of the American Welding Society or the ASME Code as applicable to the equipment being welded. All welds shall
be continuous unless otherwise approved by the Engineer and shall be made in such a manner thr.t residual shrinkage stresses will be reduced 
to a minimum.
ii)        Members to be joined by welding shall be cut accurately to size. The edges of the members shall be sheared, flame cut or machined to 
suit the type of welding. The cut surfaces shal’’ expose sound metal free from defects. The surfaces of plates to be welded shall be free
from rust, grease and other foreign matter
for a distance of at least 2 cms back from the edge of the weld.
iii)  All welding shall be performed by the electric
arc method. After being deposited, welds shall
be cleaned of slag and shall show uniform sections, smootheness of weld metal, feather edges without overlap and freedom from porosity and clinkers. All pinholes, cracks and other defects shall be repaired by chipping or
grinding the defects to sound metal and rewelding.iv)       Arc welding equipment shall be of a type approved by the Engineer that will produce proper voltage, amperages and polarity for all uses and positions for which the electrodes are suitable. Electrode shall conform to ASTM Designation A-233 or similar.
d)        Inspecting and Testing during Manufacture,
The Engineer shall be entitled at all times during manufacture to inspect, examine and test on the place of manufacture the materials and the workmanship of all equipment to be supplied under the Contract. Such examination or testing if made shall not release the Contractor from any obligation under the Contract.
G-3(4) Installation
a)  General
- The Contractor shall assemble, install and test the bulk head gates including seals, track bar, sill assembly and trash rack in accordance with the details shown on the Drawings or as directed by the Engineer. Seals and guide assemblies shall be installed to true vertical planes within tolerance
of plus or minus 1.5mm in over all height, or over all width as applicable, no deviation from
straight line exceeding 1.0mm in any 3.00 metres length. The distance across bearing surface and 
seal plates shall be maintained to a tolerance not exceeding plus or minus 1,0mm from the dimension shown. After adjustment to the tolerance required assemblies shall be concreted in accordance with the applicable requirements of Section F.
b)  Erection Equipment and Supplies,
The Contractor shall furnish all equipment including but not limited to, lifting and erecting devices and welding machines and supplies necessary for the errection of the gates and trash rack. The Contractor shall furnish temporary supports, blocking bracing, jacks, anchor bolts- 63 -
and all similar items necessary for the support of equipment. The Contractor shall lubricate all parts requiring lubrication before operating any equipment.
C-4 PAINTING
All metal surfaces except those to be embedded in concrete shall be painted in accordance with the provisions of this
clause or as directed by the Engineer. All painting and surface preparation work shall be carried out at the site. Surfaces
to be painted that will be inaccessible after installation 
shall be completely painted prior to installation. All oil, 
grease, dirt and rust preventive compound shall be removed 
from the surfaces by the use of a suitable solvent and clean wiping meterial. Following the solvent cleaning, surfaces to 
be painted shall be cleaned of all rust, mill scale, dirt
and other foreign substances. Immediately after cleaning, the surfaces shall be given the first coat of priming paint. 
Surfaces of metal items which are not submerged in water shall
be given one coat of priming paint and two coats of Aluminium finish paint. Structural steel and miscellaneous metal works
that will be submerged in water shall be given two coats of
Red Lead priming paint and two coats of Phenotic resin Aluminium finish paint.
No separate payment will be made for any of the painting of metal work performed under these Specifications and all
costs therefor shall be included in the rate or amount tendered 
for the item to which the painting is appurtenant.
G "5 INTAKE STRUCTURE STEEL PIPES AND VALVES
G-5(1) Scope
The work to be done under this item consists of providing and installing steel pipes, butterfly 
valves and other fittings complete as shown on the Drawings or as directed by the Engineer*
G-5(2) Pipes
a)        All pipe and fittings shall be fabricated, shop tested, delivered to the site, Installed and tested in place. Pipe diameters, lengths of straight runs, special fittings, anchors, and- 63
and all similar items necessary for the support of equipment. The Contractor shall lubricate all parts requiring lubrication before operating any equipment.
PAINTING
All metal surfaces except those to be embedded in concrete shall be painted in accordance with the provisions of this
clause or as directed by the Engineer. All painting and surface preparation work shall be carried out at the site. Surfaces
to be painted that will be inaccessible after installation 
shall be completely painted prior to installation. All oil, 
grease, dirt and rust preventive compound shall be removed 
from the surfaces by the use of a suitable solvent and clean wiping meterial. Following the solvent cleaning, surfaces to 
be painted shall be cleaned of all rust, mill scale, dirt
and other foreign substances. Immediately after cleaning, the surfaces shall be given the first coat of priming paint. 
Surfaces of metal items which are not submerged in water shall
be given one coat of priming paint and two coats of Aluminium finish paint. Structural steel and miscellaneous metal works
that will be submerged in water shall be given two coats of
Red Lead priming paint and two coats of Phenotic resin Aluminium finish paint.
No separate payment will be made for any of the painting of metal work performed under these Specifications and all costs therefor shall be included in the rate or amount tendered for the item to which the painting is appurtenant.
INTAKE STRUCTURE STEEL PIPES AND VALVES
G-5(1)
0-5(2)pertinent dimensions shall be as shown on the Drawings. Pipe and fittings shall be fabricated 
from steel plate in accordance with American Water Works Standard Specifications.
b)  Welding shall be performed as specified in clause G~3(3) C, and in accordance with AWWA Standards.
c)  The exposed steel pipe shall be painted as specified in Clause G-4.
d)  Materials.
i)       Steel plate for the welded steel pipe and appurtenances, and for welded steel plate
special fittings shall conform to the requirements of ASTM Designation A283, Grade B or equivalent. Any laminations or other defects in the plates shall be cause for
rejection whenever in the opinion of the Engineer such laminations or defects will impair the quality of the pipe.
ii)      All studs for steel flanges connections shall be threaded full length and shall be furnished each with two nuts for flang bolting. Studs shall be of such length that about hO cm shall project through the nuts when drawn tight.
iii)     Gaskets for flanged joints shall be full face gaskets made of asbestos composition sheet packing, graphited both sides.
5(3) Butterfly Valves
Butterfly valves of size and of standard manufacture shall be provided in the Pumphouse as shown on the Drawing, and having the following specifications:
a)        Butterfly valves shall be in accordance with AWA Specification 0504. The valves shall be
rubber seated, tight closing type.b)
- 65 -
Valve bodies shall be constructed of close grain, high tensile strength cast steel, ASTM A126, class B, with one piece stainless steel shaft. Valve ends shall be flanged for connecting to the pipe.
c)   Valve discs shall be constructed of alloy cast
iron ASTM A4J6, class B with 14 percent nickel, 6 percent copper, 2^ percent chromium.
d)   Valve seats shall be natural rubber of the moulded type cemented and clamped or bonded into the
body for complete immovability under all operating conditions.
e)   Shaft bearings shall be self lubricating sleeve type
of bronze construction impregnated with oil.
f)   Valves shall have manual operating mechanism having permanently lubricated totally enclosed gearing 
with head wheel diameter and gear ratio to 
require not over 40 pounds pull to meet the
torques required for- operating valves. Operating mechanism shall be equiped with hand-wheel, position1 indicator, and locking device. Hand-wheel shall
turn counter-clockwise to open the valves.
g)    Valves shall be set plumb, A clear and clean distance of 1.25 metres around each valve shall be maintained during installation. Valves shall have the interiors cleaned of all foreign matter before installation. Before installation the stuffing boxes shall be tightened and the valves shall be inspected in opened ^nd closed positions to ensure that all parts are/working condition.
v
The Contractor shall remove and replace at his
own    cost does not
any   item   — operate in a
,em that does not seat tight or
satisfactory manner.
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it.G-5(4) Handling and Transporting Pipe
The Contractor shall take every precaution during loading, transportation, and unloading to prevent damage to the pipe. The pipe shall be handled only 
by means of approved hooks on the ends, or by means of belt slings. Trucks or trailers used for transportation of pipe shall be provided with padded bolsters curved to fit the outside of the pipe Pipe
shall be supported on the ground in an approved manner. Any pipe section that becomes damaged shall be repaired as directed by the Engineer, if in his opinion a satisfactory repair can be made otherwise it shall be replaced with an undamaged section at the expense of the Contractor.
G-5(5) Installation of Fabricated Steel Pipe.
a)  Just prior to installing any section of pipe with field welded joints, all foreign matter of every nature shall be removed from the surfaces that are to be in contact at joints, so as to leave
thoroughly clean surfaces for metal to metal contact. Pipe trench shall be kept free of water
at all times during pipe laying operations.
b)  Each section of the pipe shall be accurately laid to the required line and grade. In placing pipe
in the trench, the pipe shall be held by the sling 
at the balancing point of the sections The longitudinal welded seems shall be staggered with adjacent pipe sections. The Contractor shall
make such excavation outside of the specified trench section as are needed for field welding.
c)   The pipe shall be laid above the ground by supporting it on specially constructed steel bar pedestals. The supports shall be provided at intervals as directed by the Engineer. The pipe shall be encased in reinforced concrete as shown in the Drawings and as specified in Section F.“'-•; .■-■■■■
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iLj&iL' i IS- SI-SGjGHHS’t'xh 9’5i)         Measurement
Measurement will be made for the Bulk Head Gates at Diversion and Intake Structures acceptably provided and installed according to the Specifications and Drawings as a seperate complete unit for each of the Diversion and Intake Structures.
ii)        Payment.
Payment will be made for each complete unit measured as provided above at the Contract unit price per unit for Furnish, Install and Test Bulk Head Gates and shall constitute full compensation for manufacture, transportation to the site, installation, testing of the Gates including its accessories and 
all other works related to the Item.
d)  Item No. 506. Furnish and Install Trash-rack at the Intake Structure.
i)            Measurement
Measurement will be made for a Trash-rack acceptably provided and installed according to the. Specifications and Drawings as a complete unit in the Intake Structure,
ii)           Payment
Payment will be made for a complete unit measured as provided above at the Contract unit price per unit for Furnish and Install Trash-rackr and shall constitute full compensation for manufacture, transportation to the site, and installation including painting and all other works related to the Item.
) Item No. 507. Supply and Laying of 50 cm dia steel pipe
for intake structure.
i) Measurement
Measurement will be made in linear metres along the centre line of the pipe from inle
the pump house acceptably supplied and install
• e- directed by the Engineer* shown on the Drawings or dirii) Payment
- 69 -
Payment will be made for the number of linear
metres of pipe as measured above at the Contract
unit price per linear metre for supply and laying 
of pipe and shall include full compensation for supply, laying, installing of the specified steel
pipe including fittings, anchors and all other
works related to Item.
f) Items Nos. 508, 509, 510 and 511. Supply and Install Bell
mouth at inlet, and bifurcations and bends in the pump 
house.
i)          Measurement
Measurement will be made for each Item of Bell mouth, bifurcations and bends acceptably provided and installed according to the Specification and Drawings as a separate complete unit.
ii)         Payment.
Payment will be made for each complete unit measured as provided above at the. Contract unit price per unit for Supply and Install and shall
constitute full compensation for manufacture, transportation to site, installation including its accessories and all other works related to the
Item.
g)     Item Nos. 512 and 513. Furnish, Install and Test Butterfly Valves.
i) Measurement
Measurement will be made for the number of 50 cm and 30 cm diameter Butterfly Values acceptbly provided, installed and tested in the pump house
of Intake Structure, as provided in the- 70 -
BILL OF QUANTITIES
Description
Quantity
Unit
Rate
Birr
Total Amount
Birr
SECTION B-MOBILIZATION Mobilization for Project
Construction
L.S.
Sub-Total
for Mobil:
>
SECTION C-DIVERSION AND CARE 0? WATER River     Diversion     and     Care     of
zatio: 1
ha
L.S. Sq,
Cu.
m
m
r
it
fi
it
3000 1500
3010
490
1850
. •
I
r
-b
-c
Water
Upstream Cofferdam
Clearing       and       Stripping       of foundation
Earth Excavation of
foundation
Random Rockfill Zone
Transition Zone
Impervious Core Zone
Downstream Cofferdam
Clearing       and       Stripping       of foundation
Random Rockfill Zone
Impervious Zone
Demolishing        of        Downstream Cofferdam
Pun >ping     of     Water     from foundations
Sq. m
Cu
e
it-
ra
II
140
91
26
117
L
5LPS/Hr     800hrs.
Sub-Total for Diversion and Care of water e
^£ctiqn_d EXCAVATION oaring and Stripping of 
f°undations.
Earth Excavation in foundationa
udom-Rock Excavation in f°undations
••
*
»q. m
Cu. m
‘I
•1
if
55200
43200
20000
!<
's-71
4
5
Description
Rock Excavation in
foundations
Surface Dental Treatment of
Unit
Quantity
Unit
Rate
Birr
Total Amount
Birr
Cu, m
4050
Foundation for
Contact-Dental
Core-Rock Concrete
n
5770
Surface Dental             Treatment
upstream of core-Dental
Concrete
Sub - Total for
SECTION E-CONSTRUCTION OF EARTH Main Dara Fills
Riprap Slope Protection Rockfill Zone
Transition           Material Zone
it
Excavation
AND ROCKFII
I
J
7700
—
,L
Cu* m
11
11
Impervious core)
Fill Zone (Clay
11
Impervious         Fill for clay
Blanket
Miscellaneous Backfill
Sub-Total for Construction of
SECTION F-CONCRETE       PLAIN AND REINFORCED Furnish Portland Cement
11
11
8744
123500
28000
48000
128000
30000
•
Earth and Rockfill »
(Ordinary Type-l)
Furnish and Install
Reinforcing Steel
Furnish and Install Water Stop Dental Concrete in Spillway, Diversion, and Intake Structures foundations.
Blinding Concrete under
Spillway chute slab, and under inlets of Diversion and
Intake Structures
Tons
Kg* m*
130 126630
390
Cu.m
40- 72 -
Item N   o I                           Description
Unit
Quantity
Unit
Rate
Birr
Total ’ Amount
Birr
4o6         I Plain concrete in Approach 
j channels of Diversion and Intake
I Structures
407               Reinforced Concrete in
Spillway, Diversion and Intake
I Structures.
Sub - Total for Concrete,
SECTION G-MISCELLANEOUS
4
Cu. m
ii
Plain and
158
•
1600 Reinforce
d =
I Structure drains
501          i Rock Excavation
502 Furnish and Install 15 cm
1 concrete pipe drain
503 Furnish and Install 20 cm
concrete pipe drain
Bulk Head Gates
Cu. m
Lin. m
ii          ii
120
322
500
•
504               Furnish, install and test Bulk Head Gate for Diversion
Structure
Per unit
>05
Furnish, install and test Bulk 
Head Gate for Intake Structure
ii              ii
06 !             Furnish and Install Trash-rckck at the Intake Structure
Steel pipes for. Intake Structure
ii              ii
One
One
One
07 Supply and Laying of 50 cm
dia steel pipe.
38
Supply and Install bell mouth
at inlet
<
Lin. m           j Per unit
>9       '    Supply      and      Install      50      cm bifurcation for by-pass
0               Supply         and         Install         reduction bifuration to 30 cms.
ii               ii
ii              n
49.2
one
One
One73
[item No
Description
Unit
Quantity
Unit
Rate
Birr
Total Amount
Birr
511
512
513
Supply and Install 30 cm
bends
Furnish, install and test
50cm, Butterfly valve
Furnish, install and test
30 cm. Butterfly valves
Sub - Total for Miscellaneous
GRAND TOTAL, Tender
1
Per unit
II H
2
One
2
Items =
Price c
?
«
?

Summery

Birete Dam Project Summary

Birete Dam Project Specifications and Bill of Quantities

Project Overview

The Birete Dam Project document contains detailed specifications for construction and a comprehensive bill of quantities. Prepared by the Ministry of Mines, Energy and Water Resources (Land and Water Studies Agency) in Addis Ababa, May 1981.

Key Features:

Environmental protection measures including landscape preservation and water pollution prevention
Two-stage river diversion scheme during construction
Earth and rockfill dam construction with multiple material zones
Concrete structures including spillway, diversion structure, and intake structure
Miscellaneous works including drainage systems, gates, and steel pipes

Main Project Sections

Section A: Environmental Protection

Landscape preservation requirements
Water pollution prevention measures
Dust abatement procedures

Section B: Mobilization for Project Construction

Contractor's responsibilities for facilities and services
Payment structure for mobilization work

Section C: Diversion and Care of Water During Construction

Two-stage diversion scheme description
Cofferdam construction specifications
Water management procedures

Section D: Excavation

Classification of excavation materials (Rock, Random Rock, Formation, Earth)
Excavation methods and tolerances
Foundation preparation requirements

Section E: Construction of Earth and Rockfill

Material specifications for different dam zones
Placement and compaction procedures
Moisture control requirements

Section F: Concrete, Plain and Reinforced

Concrete composition and quality requirements
Formwork, placing, and curing specifications
Reinforcement steel standards

Section G: Miscellaneous

Structural drainage systems
Bulkhead gates and trash rack installation
Steel pipes and valves for intake structure

Key Material Specifications

Dam Construction Materials

Material Zone	Description	Key Requirements
Riprap	Upstream slope protection	Angular, sound, durable rock blocks (70-8cm size range)
Rockfill Shells	Upstream/downstream shells	Angular, sound rock (max 30cm size)
Transition Material	Adjacent to impervious core	Weathered basalt (max 8cm size)
Impervious Core	Clay core	Natural clay deposits from designated borrow area

Concrete Requirements

Component	Specification
Cement	Portland Cement conforming to BS 12:1958 or ASTM C 150-64
Aggregates	Graded natural or manufactured sand and gravel/crushed rock
Water-Cement Ratio	0.45 to 0.6 depending on structure requirements
Curing Period	Minimum 14 consecutive days

Bill of Quantities Highlights

Major Quantities

Item	Quantity	Unit
Rockfill Zone	123,500	m³
Impervious Fill (Clay core)	48,000	m³
Impervious Fill (Clay blanket)	128,000	m³
Reinforced Concrete	1,600	m³
Reinforcing Steel	126,630	kg
Portland Cement	130	tons

Key Structures

Diversion Structure with bulkhead gate
Intake Structure with trash rack and bulkhead gate
Spillway structure
49.2m of 50cm diameter steel pipe for intake
Butterfly valves (50cm and 30cm)

Construction Methodology

Diversion Scheme

The construction will follow a two-stage diversion approach:

Stage I (First Dry Season):
- Construct diversion structure, spillway, and intake structure
- Build dam embankment from both sides leaving a central gap
Stage II (Next Dry Season):
- Construct upstream and downstream cofferdams
- Divert river through diversion structure
- Close gap in main dam and complete construction

Dam Construction

Compaction requirements:
- Impervious core: ≥10 passes with tamping roller
- Other zones: ≥4 passes with vibratory roller
Layer thicknesses:
- Impervious material: ≤15cm compacted
- Transition material: ≤25cm compacted
- Rockfill: ≤30cm compacted

Quality Control & Measurement

Testing Requirements

Regular testing of materials and embankment construction
Concrete strength tests at 7 and 28 days
Aggregate grading and quality checks
Moisture content control for impervious fill

Measurement Methods

Earthworks: Actual measurement of materials in place
Concrete: Volume within neat lines of structures
Pumping: Measurement of water removed (5 liters/sec/hour)
Reinforcement: Based on lengths installed converted to weights

Payment Structure

Lump sum payments for mobilization and river diversion
Unit rate payments for most construction items
Separate payments for cement, reinforcement, and embedded items