m/ -
Ministry of Mines, Energy and Water Resources Land and Water Studies Agency
BIRETE DAM PROJECT SPECIFICATIONS AND BILL OF QUANTITIES
ADDIS ABABA May 1991Ministry of Mines, Energy and Water Resources Land and Water Studies Agency
BIRETE DAM FROJECT SPECIFICATIONS AND BILL OF QUANTITIES
ADDIS ABABA
MAY 1981The report contains
Birete Dam Project
ABSTRACT
specifications for the construction of 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 workii
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 Expert, UNDP.
NAFIS AHMAD
UN ENGINEERING ADVISERiii
TABLE OF CONTENTS
Item
ABSTRACT
ACKNOWLEDGEMENT..
TABLE OF CONTENTS
SPECIFICATIONS
SECTION •A- • Environmental Protection
ii
it
-     B,    Mobilization for Project Construction
-       c,
Diversion and Care of Water
during Construction.
ti
-      D,
Excavation
n
-     E,
Construction of Earth and Rockfill
it
-     E,
Concrete, Plain and Reinforced
ii
-      G»
Miscellaneous
BILL OF QUANTITIESBIRETS DAM PROJECT SPECIFICATIONS
I 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 9hall 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.
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, refuse, garbage, sewage effluent, oil or other petroleum
products into stream.
DUST ABATEMENT
During the construction of the project the contractor shall carry out proper and efficient measures wherever and whenever necessary to reduce the dust nuisance.
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.SECTION B
MOBILIZATION FOR PROJECT CONSTRUCTION
?fORK 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.
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 bo 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 costa 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 WATER DURING CONSTRUCTION
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(l) 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
t
through the Diversion Structure, The Diversion is to be accomplished in two stages.- U -
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 constructior upto the full height*
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 9ite of work in a waste area designated by the Engineer*
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.
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 the cofferdams will be 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 cm 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 Dam has been 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 designated spoil areas as directed by 
the Engineer.
APPROVAL OF CONTRACTOR'S PLAN OF OPERATIONS Within thirty days after receipt of notice to proceed with 
the Contract, the Contractor shall submit his proposed plnn of operations for all Stage I and Stag© II works under this Section for approval of the Engineer, including;
a)       Description of method 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.
F PROTECTION OF PERMANENT WORK
The Contractor shall provide such means as are necessary to supplement the approved schemes for diversion, care of
river, and unwatering during construction for the protection of the permanent work.6
UNWATERING AND CARE OF WjiTEJL-
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(1) 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,         104-c. Random
Rockfill,            Transition            Material in Upstream and Dowistrean Cofferdams.
a)       Measurement,
fill,            and            Impervious            fill
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 
cross-sections shown on the Drawing or established by the Engineer,
b)       Payment,
Payment will be made for the number of cubic metres measured as provided above for the Contract unit price per cubic metre for these items  Payment
3
shall constitute full compensation for constructing the cofferdam fills from required excavation, stock piles and borrow areas including s.—c^vation,hauling, rehandling, processing, moistening, placing and compacting the materials as specified and all other work related to the Items-.
C—9(4) 'Item No. 105* Demolishing of Downstream Cofferdam, 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)O
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 the Downstream Cofferdam site in an approved manner.
?C_9(5) Item No. 106. Pumping of water from Foundations.
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 pumped, acceptably performed, and as a complete unit. 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
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.
CLASSIFICATION OF EXCAVATION MATERIALS
D-2(l) General
The terms Rock, Random Rock, Formation and Earth are hereby defined when used fcr the purpose of
classifying excavated materials for payment under the various Items.
D-2(2) Rock
Rock shall mean all in place bods or ledges of solid mineral matter sound and intact and as so classified by tho 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(4) 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, anjd being in such a weathered condition that it can be effectively loosened or broken by 
ripping, and as so classified by the Engineer,
D-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 D-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 3hall perform all open 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 hio excavation operations in the rock area in such a manner that the bulk of material produced is of (-) 30cm size. The responsibility for the
sucoess of the excavation method shall rest with the Contractor regardless of approval by the Engineer.10
In general for the 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 be 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 
, Materials.
0-3(2)
in clause E — 4 Excavation Extent
Excess excavation performed by the Contractor for any pyrpose 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 sound 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 the 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 be used, if necessary, to make the11 -
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.
0-3(4) 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 be- 12
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 9hall
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).13
D—3(6) Clearing and Stripping for Quarries
The areas from which Rock, Random-Rock, Transition Material, and Earth is to he 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 times the 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
may be obtained shall not be construed as constituting the approval for use of all material extracted from
the quarries and the Contractor shall be responsible for the specified quality and grading of such produced material. For quality and gradation of rock-fill material the clause E - 4 materials shall be
applicable.- 14 -
D-4(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 U3od in the rockfill shells
of the embankment.
b)       For riprap material to bo 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) Moasuromont and Payment for quarried material.
The processed madterial from tlie 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 separate payment shall be made for the excavation of the material under this clause.
TRANSITION MATERIAL QUARRY
D-5(l) 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 tho 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 bo 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 evidenco for approval of the Engineor, as will indicate that the borrow area can be used as a source of matorial 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 an/! extent in the dry, draining of borrow areas, prewetting of material in the borrow areas, drossing of borrow area during and after completion and disposition of materials to obtain and make the materials suitable for use in the work.
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 shall bo used in tho 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 tho 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 
seperate payment will be cue 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(l) Preparation of Contact Surface between Rock and 
Impervious Core-Dental Treatment*
Exposed rock surface within the rock-core contact areas shall be cleaned by brooming and compressed air to permit inspoction. 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 dirocted 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 tho surface and undulations shall be covered and filled with a layer of blinding concrete as directed by the Engineer* The Blinding Concrete shall bo provided according to Specifications in Section F for Concrote*MEASUREMENT AND PAYMENTS
D-9(1)
D-9(2)
0-9(3)
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.
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 metros 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.
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 abovG 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.
0-9(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.
D—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 metres 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.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
SCOPE
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 thi9 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, unless otherwise directed by the Engineer. Materials Conforming to tho requirements specified in clause
E-U Materials, shall be placed and compacted within the indicated zone limits. The Engineer reserves
the right to increase or decrease the foundation 
widths, thG embankment slopes or the zone limits or
to make such other changes in the embankment sections as may be deemGd necessary to produce safe structures,- 20
or for efficient utilization of materials from
required excavation, Settlement of embankment for
the post construction period will bG provided for
by increasing the height of the sections, Required 
height increases will be determined and specified by 
the Engineer from settlement observation made as the work progresses.
E-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 of in—place fill to insure that the
work is being performed in conformance to the requirements of these specifications. The Engineer will also perform tests of materials at their
source and during their prossessing and handling 
as necessary for quality control and the Contractor shall adjust his methods as required for the improvement of the product to meet Specification requirements. Tests of materials and embankment construction will be made at regular intervals and the Engineer will notify vhe Contractor of any deficiencies in materials and/or construction when the results of tests are known. Deficiencies shall
be remedied by such measures as the Engineer may direct. The Contractor may be required to remove, at his own expense, any fill placed outside of the prescribed slope lines where Buch placement is
not authorized by the Engineer.
b) Haul Roads
Haul roads shall be located and constructed as approved by tho Engineer. Thoy shall be designed to maintain the intended traffic safely, without endangering embankment stability druing the embankment construction period and shall be constructed in a manner to preclude contamination or alteration of materials forming the embankment
| *tnnu /section. All roads located on embankment slopes snail
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 
f
in the dam shall bo as shown on the Drawings except as otherwise directed by the Engineer.
E—^(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
Average Weight
70 cm                                                    100                                        175
60 •• 15 "
8 •• E-4(3) Rock-fill shells
80 to 90
10 to 20
Not Exceeding
110 " 10 '•
1 ”
Material for upstream and downstream rock-fill shells shall be angular, sound, durable blocky rock, well (graded within the following gx'adation limits.
Gradation Roquiromonts for Rock-fill Matorial
Material
Percent Finer Than
Size
By Weight
30 cm
-100
No. 4 sieve
(4.75cim) Not Exceeding 25 NO. 200 sieve
(0.074mm)
11                    h                              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*
U(U) Transition Material
Material for compacted transition upstream and downstream of clay core shall be weathered Basalt, 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 (4.75mm) No. 200 Sieve (0.074mm)
£-4(5) Impervious Core
Percent Finer Than By Weight
100 50 - 80 25 - 50
5-15
Material for compacted impervious core shall be the natural deposits of clay designated as borrow
area
PLACEMENT E-5(1) General
3 A                    on Drawing No. DE 101.
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 below. The gradation and distribution of materials in the zones of the dam shall be such 
as to produce in Gach zone a reasonably well graded mass. Fill material shall be handled and placed by 
such methods as will minimize segregation, in lifts of depths as specified, and in general the smaller sizes of material within zones of rockfill are placed towards the clay core, and the larger sizes towards
the outer- 23
faces. [There rockfill and riprap 3lope protection 
are placed on permanently exposed embankment slopes, the placing of fill shall be such as to obtain surfaces
within a tolerance of plus 15cm ana minus 8cm except
that the extreme minus tolerance shall not be
continuous over an area greater than 20 square metres. For all other zones not specified above, or elsewhere, material shall be placed as close as practicable to 
the lines shown on the Drawings as approved by the Engineer. Bridging in the fill, and all slabs or
slabby rock shall be 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 level throughout each embankment construction stage regardless of the number of types of materials being placed, except as
may be required to prevent mixture of embankment materials. Material shall be delivered in proper
sequence and distributed over th^ surfaces of the
fills st such rate as will ensure the completion of
each embankment zone and stage thereof within the specified 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 be constructed within the specified tolerance
to the lines and grades shown on the Drawings or staked in the field. The larger stones shall bo well distributed and the finished I'iprap shall bo free
from objectionable pockets of small stones and clusters of larger stones. The desired distribution of the
various sizes of stones throughout tho 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- 24
stones by mGchanlcal equipment or by hand will be required to the extent necessary to obtain a reasonably well graded distribution.
5(4) Impervious Fill Placement
The Impervious fill for clay core shall 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 bo moistened 
and worked with a l.Bcrow 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 hari th’&Q to reduce the water content to the required amount before the succeeding layer is placed thereon. No impervious fill shall bo placed below water.
The Impervious fill for clay blanket upstream of the dam to cover exposed rock shall bo placed in the same mannor as specified abovet
E-5(5) Rock-fill Placement
The upstream and downstream rockfill zones material shall be placed in the embankment within the limits indicated on the Drawings. Rearrangement of individual stones by mechanical equipment or by hand methods will be requirod to the extent necessary to produce a level, smooth and even finish at the Berm.
E-5(6) Transition Material Placomont
The transition material shall bo placed immediately upstream and downstream of the impervious core within the limits shown on tho drawings, Caro shall bo taken that transition material docs not got mixed with tho impervious fill.- 25
The 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 a
before hauling shall be done in order to creaAeka * homogeneous layer. 
SPREADING
After depositing, the material shall be spread uy 
approved means in approximately horizontal layers of\uh.iform
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
Contractor shall determine by making
thickness specified 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 
' x \
l $ 
/
7-
k ( ■’
'i i■
// //
condition that construction equipment of the section. Ruts in the
filled satisfactorily before
MOISTURE CONTROL
E-7(1) Impervious Material
Control of moisture placing and compacting So far as practicable,
and spread in moisture
travel on a surface        of        any compacting.
core
will be material in the clay''*
.zone .
the material shall be delivered range of 2.0 percent below- 26
standard optimum to standard optimum moisture content by irrigating or drying within the borrow areas. On 
the basis of tests conducted during construction the Engineer reserves the right to mako modification in 
the required range of moisture for this material. Only 
such moisture control as needed for minor adjustment
of moisture changes caused by evaporation during handling and placement or from rainfall shall be accomplished on the fill. The moisture shall be
distributed uniformly throughout oach layer prior to compaction. Optimum moisture content shall be determined in the laboratory by the Engineer by making standard compaction test. The optimum mois tu.re, contents for the materials in tho borrow area will be furnished 
by the Engineer to the Contractor at daily intervals or at significant changes of material boing placed.
E-7(2) Other Zonos
No particular moisture control will be required for compaction of materials in other zones of the dam. Some addition of moisture in the transition zones material may be required to reduce segregation tendencies. The addition of water for this purpose
shall be accomplished prior to handling.
COMPACTION
E-8(l) Equipment
Compaction equipment shall conform to the following requirements and shall be used as prescribed 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 a total static weight of approximately ten short tons, with at least ninety percent of the weight transmitted 
to the ground through a single smooth drum when the roller is standing in a level position hitched to the towing vehicle. The diameter of the drum shall be approximately five feet and width27 -
approximately six feet. The roller shall produce
a dynamic impact of approximately sixty thousand pounds at rated viberation frequency. The roller
shall be towed at speeds not to exceed 4 Km per
hour. The equipment manufacturer shall furnish sufficient data, drawings 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 feet
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 be 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.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.
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 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 at
*29
different points along a section of embankment when 
there is sufficient area to permit these operations to 
proceed simultaneously.
£-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.
8(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 surface area of such designated portion^
9 MISCELLANEOUS FILLS AND BACKFILLS
E-9(1) General
In addition to the embankment fill for the dam certain miscellaneous fills and backfills will be required for spillway and other structures. Material requirements for these backfills shall be specified on■1
- 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 the 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.
r •
t. r -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*1, 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.- 32 -
SECTION E
CONCRETE, PLAIN AND REINFORCED
F-1 SCOPE
This section covers the manufacture, fo.rming, tran-
sporting, placing, stripping of forms, finishing, and. 
curing of concrete in the structures included in the
specifications.
E-2 COMPOSITION
Concrete shall he composed of Portland cement, water, 
fine and coarse aggregate.
P-3 QUALITY
The concrete mixture will he designed hy the Engineer
who will determine the required quality of the concrete for
the structures covered hy these specifications.
F-4 CEMENT
P-4(1)
Cement shall he furnished packaged as approved hy the Engineer. It shall he 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    he    sampled    at    storage    site    and    tested    at the   expense   of   the   contractor,   in   accordance   with   the   ASTM requirements. Additional tests will he made hy, or under- 33 -
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 been 
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.
p_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 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 appro-si mate chronological order delivered at the s’ite in order that
cement may not become widely aged.
P-5 AGGREGATES
,P-5(1) Composition
Fine 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 naturalgravel, 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 waste involved in producing a sufficient quatity required of acceptable aggregate from
the sources finally selected by him and approved by the Engineer.
F-5(3) Sampling and Testing
During 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 stages 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 coarse aggregates in accordance with these specifications.
F~5(4) Processed Aggregate
Aggregates, as delivered to the mixers, shall consist of clean, and uncoated particles. Where directed by the- 35 -
Engineer duet 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
Percentage by Weight Passing Individual Sieve
1 in
% in
% in
' No. 4
100
90 - 100 20 - 40
0-5- 36 -
c) Particle Shape
The shape of the particles in the fine aggregate
and in the coarse aggregate shall be generally spherical
or cubical. The quantity of flat and elongated particles
in the coarse aggregate, as defined and determined by 
standard tests approved by the Engineer shall not exceed
25    percent.    A    flat    particle    is    one    having    a    ratio    of    width to      thickness      greater      than      three.      An      elongated      particle      is one having a ratio of length to width greater than three.
P-5(5) Storage
Aggregates shall be stored at the site of work in 
such a manner as to prevent the inclusion of foreign 
materials in concrete. Sufficient aggregate shall be
maintained at the site at all times to permit continnous placement and completion of any lift of concrete started. 
P-5(6) Moisture Control
All fine aggregates and coarse aggregate shall remain 
in free-draining storage at the site for atleast 72 hours immediately prior to use. Under no conditions shall the aggregates be delivered to the mixers dripping wet.
P-6 WATER
Water for washing aggregates and for mixing and curing concrete shall be fresh water free from injurious amounts of oil,acid, salt, alkali, organic matter, or other deleterious substances as determined by standard tests selected by the Engineer.37
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 vri.ll 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 200kg 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 workability, density, impemeabllity, 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.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 tatoh 
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 as 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 oms). The Engineer reserves the right
to require a lesser slump whenever such slump is practicable Slump will be determined in accordance with ASTM Designat ion C - 143-5 8, standard method of test for sltunp of
Protland Cement Concrete.
F-8 TEST OF CONCRETE
Strength tests of the concrete pla.ced 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 a-rrnngeme-nt 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.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 Bhall 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 oharged 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 shape. 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
P-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 comers 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 with 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 construction- U2
joints 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 join, 
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.
F-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. Slabs 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.
F-11(4) Vibration of Concrete
Concrete shall be compacted with mechanical vibrating equipment supplemented by handspading 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. Form or surfaoe vibrations shall not be used unless spool-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.
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 excent some pours which will be odd sizes. Each strip of the chute slab shall be placed in a Bingle continuous pour and in the direction from down slope upwards and in a aequenoe 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.- 44
F-11(6) Placing Concrete on Rock
Rock surface upon which concrete is to be placed shall oe clean free from oil, standing or running water, mud, drurr.y 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 is completed, the top surface shall be immediately and carefully protected from any condition that will damage or adversely affect the hardening of concrete.
P-12(2) Cleaning
Horizontal construction joints on lifts shall be prepared for receiving the next lift by cleaning with air—water cutting. The surface shall be cut with a high pressure air—water jat 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 minuB 10 Psi and the water pressure Bhall be just sufficient to bring the water into effective influence
of the air pressure. After cutting, the aurfaoe aha.ll be washed and rinsed as long as there is any trace of cloudiness of the wash water. The surface shall again be washed with an air-water jot just prior to placing the succeeding lift.p _13 EXPANSION-CONTRACTION AND CONSTRUCTION JOINTS F_13(1) General
Joints shall be provided at the location indicated 
on the Drawings or as otherwise approved or directed by the Engineer. In no case any fixed metal embeded in concrete be continuous through an expansion-contraction joint.
F-13(2) Expansion-Contraction Joint Filler
Where indicated on the drawings expension-contraction joint filler shall be installed using material of type end 
quality indicated. Expansion—contraction joint filler will
consist of sponge rubber or self expending cork or any other material and type as directed by the Engineer meeting the requirements of ASTM Designation D1752.
F-13(3) Water Stops
Water stops of copper and polyvinylchloride (PVC) shall
be installed in joints as shown on the Drawings or otherwise directed. All joints of the metal water stop shall be braded 
or welded. All water stops shall be installed so as to form
a continuous water tight diaphram in each joint. Adequate provision should be made to support and completely protect the water stops during the progress of work. The Contractor shall replace or repair, at his expense, any water stop punctured or otherwise damaged befor final acceptance of the work.
a)        Copper
Copper water stops shall conform to the requirements of ASTM Designation B37O-66, standard specification for Copper Sheets and strip for Building Construction.- 46 -
b)        Polyvinylchloride Water Stope
Polyvinylchloride water stops shall be extruded from
an elastomericplastic compound the basic resin of which sail be polyvinylchloride (PVC),
p_14 CURING AND PROTECTION
a)     All concrete shall be cured for a period of not less than fourteen (14) consecutive days 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 P-6. Where forms 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 cms of sand which shall be kept continuous saturated during the entire curing period**■ 46 —
b) Polyvinylchloride Water Stops
Polyvinylchloride water stops shall be extruded from
an elastomericplastic compound the basic resin of which sail be polyvinylchloride (PVC).
4 CURING AND PROTECTION
a)     All concrete shall be cured for a period of not less than fourteen (14) consecutive days 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 forms of wood lagging are used and left in place during curing, th® 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 cma of sand which shall be kept continuous saturated during the entire curing period.- 47 -
F_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 taken 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 Contractor; however, the type, 
shape, size, quality, and strength of all materials of which 
the forms are made shall be subject to specific approval 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 directed 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 wetted in lieu of oiling immediately befor placing of concrete.- l>8 -
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 shall 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
In 3 metres....0.5cm
In 6 metres.... 1.0cm
In12 metres....2.0cm
In 6 metres....0,5cm
In12 metres.... 1,0cm
In 3 metres... .0.5cm
a) Variation of dimensions                         Minus..................... 1.0cm
in plan
Plus
..................... 5.0cmb Reduction in thickness at any point.
Minus
2%
4) Conduit
a)   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 by50
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 taken by the Contractor to protect finished surfaces from stains 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
°f concrete shall conform to the applicable requirements this section of the specifications. Concrete, mortar
and drypack filling shall each be mixed in proportions approved by the Engineer to produce a repair atleast51
equivalent in strength and durability to the concrete in 
which the repair is required.
5 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, v/hen 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 Bteel reinforcement shall conform to the fol1owi ng requirements.
a) Reinforcement bars (rods) shall be deformed bars °f“ intermediate grade billet steel in accordance with the ASM Designation A-15-65, or equivalent.
Yield point a 40,000?'.Ibs/sq.inch Tensile strength = 70,000 lbs/sq.inch- 52
b) Deformation of bars shall be in accordance with ASTM Designation A-305-65.
F-19(4) Splicing
All splicing in reinforcement shall be in accordance
v/ith ACI standard "Building Code Requirements for Reinforced Concrete.”
F-19(5) Supports
All reinforcement 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. Sknbedded 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
y_2l BLINDING LAYER (CONCRETE)
Foundations of spillway shall be provided, a concrete blinding layer as directed by the Engineer to achieve an approximately smooth surface 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 provided in other below grade excavations.
F_23 MEASUREMENT AND PAYMENT
1) Measurement.
Measurement for bagged cement will be made ot the . number of ions ot bagged cement acceptably used « the per manent works tor which items for measurement and paymen ar included in the Bill of Quantities. The quantity to 
tor will be based on the number ot bags and standard weig
t corainery)
per bag as detemined by the Engineer used at the mixer.
ii) Payment. 
_ rpment acceptably 
.
Payment will be made for the number of tons as provided above at the Contract uni p furnished Portland Cement (ordinary) which pri include all costs associated with providing cement a mixer. No payment will be made for cement used
• 4- nri ce per ton ton 
.- 5^ -
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) Measurement s.
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 ty the Engineer will be paid for at the Contract Unit Price, No measurement for payment will be made for the additional 0 teel in laps which are authorized for the convenience of
the  Contractor.
ii) Payment
Payment will be made for the number of killo-grams ae e.sured as provided above at the applicable Contract unit
f
60  P r killo-gram and shall constitute full compensation
e
Or  furnishing, delivering, handling, cutting, bending, lea hing, placing, binding and supporting the bars and all
°th
er
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. I  computing 
n
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 of    concrete    will    be    made
specified here^under, measurement on the basis of actual volume of
concrete      in      place      within  the neat lines of the structures as
indicated
Engineer.
on the Drawings or as otherwise established by the Measurement for payment will not be made of concrete, 
y ingredients including cement in concrete which is
Placed    outside    of    the    lines    shown    on of
the Drawings, Measurement
r ete placed against the sides of any excavation without
the  use of
:
lines of the Toj* p
^ntit
ip
intervening forms will be made only within the pay
J  structure. Unless otherwise specified payment
^ete will be made at the respective Contract Unit
cubic metre for the various Items of the Bill of
which price shall include the cost of ell labour,materials, and the use of a
- 56 -
^  equipment and tools required 
1
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 prioe 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,
1) Measurement
Measurement will be made of the number of cubic metres ° f Concrete acceptably pladed as directed by the Engineer in 
en tal excavation as specified above,
ii) Payment
Payment will be made for the number of cubic metres 6a sured as provided above at the Contract Unit Price per Ubic mefre for Dental Concrete, and shall constitute full
P h-sation 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 shall
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 yment will be made for the number of cubic • 
a
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
Payment.
Payment will be made for the number of cubic meters
^tures and shall constitute full payment for all work
rel ated to
the Item.58 -
SECTION G
MISCELLANEOUS
SCOPS
This section covers furnishing and installing of
structural drains, Gates, Steel pipe for Intake Structure, 
valves, and other miscellaneous works connected with the
structures.
structure drains
G-2(1) General
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 space between the ends.
b)     Material around the pipos.
The material around the pipes shall consist of gravel clean and well graded from No* 4 U,S. standard sieve size to three quarter inch size, as approved by the Engineer.
2 L) 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) PiP  Installation
e
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.
General ~~----------------------
Contractor shall furnish, assemble, install
XX
est the roiiowin
0
 bulkhead gates, one for Diversion Structure
«=-
b the other for Intake Structure; hoists; chorage assembly, hoist stems or chains, track
D <3. r’ SSoetals, sill and other embeded items shown drawings and required for satisfactory
deration of gate.G-^2^
G-3(3)
- 60
Trash rack including anchorage and arrangements required for satisfactory installation.
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 classification and grade designated on the Drawings, The rubber
seals for gates shall be moulded only.
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 
kirks 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.
Structural work fabricated under this Contract and delivered to the work site in sub-assemblies will have been fabricated , and shall be assembled in accordance with the dimensional tolerances herein speciii) 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 thtt 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 b0 suit the type of welding. The cut surfaces shall expose sound metal free from defects. The surfaces of plates to be welded shall be j.ree from rust, grease and other foreign matter
for a distance of at least 2 cms back from edge of the weld.
i-ii) All welding shall be performed by the ele arc method. After being deposited, welds be cleaned of slag and shall show unit sections, smootheness of weld metal, f itv edges without -overlap and freedom from p and clinkers. All pinholes, cracks ar. defects shall be repaired by chippi ^°
n
grinding the defects to sound metal rewelding.r'ti----1 ~ -I
I
•f
V*■
V
I
V
>
t
I*»• . , «•
I
■
i
»i
!
i
i
i
iX
i
4

Summery

Birete Dam Project Summary

Birete Dam Project Specifications Summary

Project Overview

Project: Birete Dam Project

Prepared by: Ministry of Mines, Energy and Water Resources, Land and Water Studies Agency

Location: Addis Ababa

Date: May 1981

This document contains specifications for the construction of Birete Dam Project, including payment clauses tied to the Bill of Quantities.

Main Specifications Sections

Section A: Environmental Protection

Landscape preservation requirements
Prevention of water pollution measures
Dust abatement procedures
Costs included in other work items

Section B: Mobilization for Project Construction

Includes all plant, labor, equipment, materials and services
Contractor must submit breakdown of lump sum price within 30 days
Payment covers all mobilization facilities including camps, workshops, and offices

Section C: Diversion and Care of Water During Construction

Two-stage diversion scheme (dry season construction)
Includes coffer dams, diversion structure, and gap closure
Detailed measurement and payment methods for various components

Section D: Excavation

Classification of materials (Rock, Random Rock, Formation, Earth)
Excavation methods and requirements
Rock quarries and transition material quarry specifications
Earth borrow area operations
Foundation preparation requirements

Section E: Construction of Earth and Rock Fill

Material requirements for riprap, rockfill, transition material, and impervious core
Placement, spreading, and compaction specifications
Moisture control requirements
Equipment specifications (vibratory rollers, tamping rollers)

Section F: Concrete, Plain and Reinforced

Composition and quality requirements
Cement specifications (British Standard 12:1958 or ASTM C 150-64)
Aggregate requirements and testing
Concrete mixing, placing, curing, and finishing specifications
Formwork and reinforcement requirements
Measurement and payment methods

Section G: Miscellaneous

Structural drains installation
Bulkhead gates and trash rack specifications
Material and workmanship requirements

Key Material Specifications

Riprap Material Gradation

Material Size	Percent Finer By Weight	Average Weight
70 cm	100	175 kg
60 cm	80-90	110 kg
15 cm	10-20	10 kg
8 cm	Not exceeding 10	1 kg

Rock-fill Material Gradation

Material Size	Percent Finer By Weight
30 cm	100
No. 4 sieve (4.75mm)	Not exceeding 25
No. 200 sieve (0.074mm)	Not exceeding 5

Transition Material Gradation

Material Size	Percent Finer By Weight
8 cm	100
2 cm	50-80
No. 4 sieve (4.75mm)	25-50
No. 200 sieve (0.074mm)	5-15

Measurement and Payment Highlights

Mobilization (Item 101) - Lump sum payment
River Diversion (Item 102) - Unit measurement
Clearing/Stripping (Items 103-a, 104-a, 201) - Per square meter
Excavation (Items 103-b, 202-204) - Per cubic meter by material type
Dam Fills (Items 301-306) - Per cubic meter by zone/material type
Concrete Work (Items 401-407) - Various measurement methods