Birete Dam Geological Investigation Report Summary

MINISTRY OF MINES, ENERGY AND WATER RESOURCES
LAND AND WATER STUDIES AGENCY
BIRETE DAM PROJECT
GEOLOGICAL INVESTIGATION REPORT
I
February 1981 A0DI5 ABABAMinistry of Mines, Energy and Water Resources
Land and Water Studies .Agency
BIRETE DAU PROJECT GEOLOGICAL INVESTIGATION REPORT
by
Nafis Ahmad, UN Engineering Adviser Aklilu Assefa, Senior Geologist, EIGS Banteyehun Haile, Engineer, LWSA
February, 1981 ADDIS ABABA1
BIRETE BAM PROJECT
GEOLOGICAL INVESTIGATION REPORT
ABSTRACT
The geological investigation report covers the geological mapping for the Birete Bam site and includes
a geological cross-section along the axis of the dam. 
Nine boreholes have been logged and the permeability tests are conducted in four holes. The foundation is assessed 
as competent for building the dam. Prospecting for construction materials was carried out and the test results are appended. Recommendations are included regarding the use of construction materials.2
TABLE OF CONTENTS
Item
£££
ABSTRACT ,.............................................................................................  1
TABLE OF CONTENTS .........................................................................    2
Introduction...............................................................................................   3
!.      Basin discription.........................................................................................  3
I.      Previous work.............................................................................................. 4
General Geology of the Area....................................................................    4
•      Dam Site Geology....................................................................................    5
. Drillings ............................................... .. .............................. . .. . 6
.      Permeability tests»...................................................................................... 7
.      Construction materials................................................................................ 8
.       Recommendations .................................................................................... 10
. Appendixes....................... ................. ................. ............ »»•«,... .....14- 3 -
1.   Introduction
The Birete Pam study was initiated by building material comoration in collaboration with the Ministry of Mines, Energy and Water Resources.
Engineers from Land and Water studies agency and geologist from the Ethiopian Institute of Geological Surveys closely investigated the Birete river basin to identify all the
possible dam and reservoir sites so that sufficient water will be stored. The investigation was not limited to the indicated requirement of water 2000m^/day for the cement plant but also considered other needs and uses of water inorder to have the optimum utilization of the water which could be stored in the reservoir.
2.   Basin Discription
Birete river, is one of the tributaries of sodoble river
which drains into Mugher river tributary of Blue Nile river, The basin extends between latitudes 9° 25'N and 9° 29'N and longitudes 38° 03'E and 33° 20'E and covers an area of 33 square kilometres. Birete river orginates near Wajuturie village about 10km north of water-shed divide of Blue Nile and Awash rivers. The altitude in the oatchement area varies from 2450-2670 metres above sea level and is characterized by undulating topography gradually sloping to the north. The top soil which is a residual weathering product of the basalt, covers most of the catchement area and outcrops are rare. More than 95% of the area is an open grass land most of which is used for agriculture and posture. Bora and Likimsa are the main tributaries and join Birete river one kilometre south (upstream) of the dam site.- 4 -
3.   Previous Work
Reconnaissance geological map of the area has been prepared by D.H.Jebsen and M.J.Athearn, U.S. Department of State Agency International development in 1963* Hydrogeophysical and geological investigations of the area were carried by Ethiopian Institute of Geological Surveys in 1978 and 1979 respectively. The preliminary Hydrogeophysical study revealed that the under ground water potentiality is limited and the geological investigation indicated the geological condition 
of the Dam site and construction materials.
Pitting
Thirty four pits were dug along the two previously proposed dam axis designated as profile I-I and II-II in the geological report of December 1979- Profile It I is very close to the final dam axis. The average thickness of overburden in profile I-I for 16 pits is about 2.50 metres and in profile
II-II for twelve pits 2.90 metres.
General Geology of the Area
The area is located in the central Ethiopian plateau series of basalts which consistsof the following stratigraphic successions.
a)    upper basic volcanites
b)    ignimbrites
c)    lower basic volcanites
The basic unit is predominant in Birete river basin and is underlain by thin createceous sandstone, limestone with gypsum, shale and marl intercalation at the base. The Triassic sandstone is exposed further north at theconfluence of sodoble and Mugher river♦ Different lava
flows with poleasoil formation are observed in the dissected part of the plateau#
Along the bank of Birete river the rocks are not well
exposed and almost all the rocks in the surrounding ridges
are highly weathered and altered^ The deep weatharlryj of the basalt has resulted in the formation of residual clays
2t>5metres thick.
Major faults are not observed in the vicinity of the Dam
Bite, however according to D.H.Jebsen and Murray J.Athearn one major fault is shown further north (downstrearn) from
the Dam site.
5• Darn’Site Geology
The dam site is situated about two to three kilometres
south west of the cement plant site, the area at the Dem
site and considerable areas down and upstream of it were mapped on the scale 1:2000.95% of the mapped area is povettd by soil, as a result of detailed geological study in the
three patches of basaltic out crops, the following joint direction and intensities were observed.
Outcrop
Strike
Dip
Set
Spacing
I
110-120°
40-55
NE
1
l5-25am
II
210-220°
vertical
to
4° 2
15-30<Jm
300-320°
III
290-310°
20 E
2
15-50cm
220°-230°- 6 -
The width of the columnar joint varies from few millimeters to eight millimetres on the surface which is probably due
to weathering. The joints are mainly filled by calcite
or clayey material as observed in the boreholes. Due to 
the scarcity of outcrops it was impossible to calculate
the coefficent of jointings.
6.   Drillings
In order to under-stand the exact nature of the dam site
nine bore holes, were drilled along the dam axis, to 
a total of 173.40 linear meters, the cores were systematically logged. Bore logs are shown in appendix I. Field permeability tests were conducted in boreholes No 3,4,7 and 8. Results
of permeabilities at various locations appear in appendix II. The subsurface features of the dam site were interpreted as to whether grouting is needed or not. Disturbed and undisturbed samples from the boreholes were submitted to the Building college and the physico-mechanical test results are shown in appendix III.
Thin sections of the core sample revealed the following minerallogical            composition.
Phenocrysts            ofplagioclose, 
ground mass
plagioclase
pyroxene
pyroxene and Augite 45%
40%
Accessory                  othopyroxene
magnetite (opaque)
According        to        the        above        mineralogical        composition,        the rock is augite basalt.- 7 -
As depicted in drawing No. SW 101 and cross-section in figure I along the dam axis, the following information were deduced:
1.    The centre part of the valley is deeply weathered and consists from top to bottom of clay gravel and highly weathered basalt, the valley slopes (sides) are covered with clayey detrital materials and weathered basalts.
2.    At least two lava flows have taken place within the drilled deDth (30 metre) and the paleosoil formation with indication of peat and silty clay stone suggests that the area was swampy before the last flow.
3.    As shown in the cross section along the Dam axis an average of about 2.50 metres depth of clayey material has to be stripped off.
4.    There is a confined shallow artesian ground water on the western terrace (left bank) of the river at and 
in the vicinity of Borehole No. 8 where the water was overflowing for several days. The water encountered in the other borehole and pits has no relation with it.
7.   Permeability tests
J
Permeability tests were carried out in four boreholes
(3,4,7, and 8) by pumping in test method where water
is forced into the section of borehole under test through 
drill rods (pipe equiped with rubber packers). The
interval of testing and the pressure applied varied
according  to  the materials under test.  It depended  on the compactness of the material under test to  hold  the packer tightly  in  the borehole and  it also  depended  on the weight of the material above the length of hole
t- 8 -
2
undertest. The minimum pressure applied was 0.3 kg/cm 2
and the maximum 2kg/cm .
Due to the chysical condition of the material encountered
at
certain 
depths
und
ertest, 
not
performed 
at
those
depth 
the following:
Borehole No
3
4
7
8
The permeability coefficient
water pressure tests were intervals and are listed in
Interval
15.8-18.00m
0.00-14*00m
0.00-5.00m
0.00-4.00m
results are shown in appendix II
8i Construction Materials
a)    Rock
The exposed basalt at Likimsa river 500 metres south west of the dam site could be used for quarry. It covers an 
area of 3800 square metres and can be quarried with open pit to 10 metre death. The other exposure of basalt is
700 metres north of the dam site. It can also be easily quarried to 10-12 metres depth.
b)   Clay
Three localities have been investigated in the vicinity 
of the dam site.
i)          Plant Site
In order to use the clay to be excaveted from the plant
site physico mechanical tests on the clay samples had been carried at the Building College but the clay type is net suitable for the construction of the dam. Test resultsare attached as Appendix IV
ii)     Kotcha Creek
The clay area near kotcha creek 1J kilometre north east
of the dam site was investigated and was found to be
satisfactory as a core material for dam purpose* The borrow
area is designated as 3-A in the drawing. Test results are
included as Appendix V. Relevant sample numbers are 118418 and 118078.
iii)       Hud-gebeya
The clay occurrence near hud-gebeya is situated 3km north 
west of the Dam site and could be used as core material
for dam. This borrow area is designated as 33 in the drawing. Relevant laboratory test results for this borrow area are
also given in Aopendix V bearing sample Nos* 113417 and 118079
c)  Transition Materials
i)    Weathered Basalt
The weathered basaltic rocks at Biyo, area 7A and near the church at Mekoda, area 7B in the drawing DE 101, can be used as transition material.
ii)     Tumtu Sgaflgt+ne
The friable sandstone which can be easily made into sand available at Tumtu, 14km south of the dam, can be used as a filter layer next to the impervious core.
iii)       Sodoble River Alluvial Deposit
The river sand in the sodoble valley has been investigated by pitting with an average depth of 2 metres. The sand 
is mixed with gravel, boulder and silty materials in the following proportions.10 -
Boulder 50%, Gravel 30%, Sand 15%, Silt 5%. Grain size analysis revealed that the material could be used as a transition material after processing but the sand proportion of the material which can be only obtained by screening is fine and is not considered suitable for making concrete.
9. Recommendations
a) Foundation
i)    Perusal of the bore logs shows that the bed rock would provide a suitable foundation for the dam. There is no serious weak spot in the foundation area. Localized thin peat layer is encountered at a depth of 30m below the foundation level. The dam is about 20.5m high and considering load dispersion for the depth at which peat layer is encountered, its presence is not considered of
any serious consequence.
ii)     Permeability in the boreholes 3,4,7 and 3 shows that in hole No.4 at depth 18.50m and in hole No.8 at depth 
-4 
22m, it is 6.96 x 10 and 5.42 x 10 cm per second 
-4
respectively. Artesian flow was also experienced in hole No. 8. In hole No. 4 permeability tests could not be conducted from 0 to 14m depth. In the light of the above information it is suggested that the area between horizontal distance 240 to 310 from the left abutment should be provided with a single line grout curtain for a depth of
18 metres.
In case the physical notential for grouting is not available the area from the impervious core to the upstream toe of the dam could be provided with dental treatment and than the dental treated area could be tied with a clay blanket11
upstream. Tying of upstreom clsy blanket with the core
is not suggested in view of the very low shear paracetres
of the clay available.
b) Materials
i) Clay material for core
Clay material has been tested in the Building College
laboratory. The facility for triaxiel testing is not
available. The values of internal shear angle indicated 
are based on the direct shear tests.
Test results of clay samples from the plant area (Appendix IV) indicate internal shear angles of 3° and 5°. This material
is unsuitable for th6 clay core.
Test results of clay samples from Borrow area, Kotcha creek 
(3A) and Hud-gebeya (3B) appear in Appendix V and internal shear angle values show a large variation. Two samples
No. 118417 from 3B Borrow arGa and No. 113413 from 3.4 Borrow area were tested earlier. Since the sample No. 113417 
which had higher percentage of fines smaller than 2 microns and had higher liquid., limit and plasticity index showed higher internal friction angle compared to sample No. 118418 it was considered advisable to get new samples from the
two Borrow areas end run the teat3 again. The tests ware repeated by a different engineer. The new results are higher in both cases. A comparision is shown below:-12 -
Sample
No
Borrow
area
L. It
P.I
Angle of
shearing 
resistance
Cohesion 
k/cm
unified soil
classification 
group symbol
118417
118418
3B
3A
70
64
43
36
23.0
15.0
0.10
0.16
CH
CH
118078
118079
3A
3B
76
75
49
46
26.5
26.0
CH
CH
Since the variation in the results is so much it was considered advisable to use average values as given in table 8, chapter
V of the book, "Design of Small Dams by U.S. Bureau of Reclamation." The following shear parametres were adopted for the design of Birete Dam Embankment.
Angle of internal friction, / = 15°
2
cohesion = 0.05 kg/cm
ii) Transition material
Grain size curves from area 7 A sample No 118077 and area 7B, sample No 118080 are shown in Appendix VI. Though it is not a well graded material and is deficient in finer fractions
it is considered that during transport and compaction it would produce finer fractions that would improve its quality as
a transition material. The material from the area near the church is considered better, it is also nearer to the dam site
and may be used.
iii)      Rock
Rock can be obtained, for constructing the rock-fill zones, from two locations, one from 500 metres upstream and the other- 13 -
700 metres downstream of the dam. The upstream location, though near, is within the reservoir area. Rock quarry from that site would expose all the joints, fissures etc., which 
can be a source of leakage from the reservoir, unless the
quarry area after the completion is properly dressed and 
is covered with a clay blanket. In view of the above it is recommended that the downstream location which is about 700 metres north of the dam site may be exploited as a rock quarry.J
APPENDIX I BORE LOGSLocality BERETE
BH Nol
Elevation 121-4
Depth In meter
Form
To
Graphic log
Descrptlon
core
Recovery%
/
water
struck
static
water
level
Remor k
0 00
4 -Om
O-IOOm block clay 100 - 400 m grey silty cloy
95
85mm
4 00
610
a" 2T a
-A- A—A
6-10
6-40
—ffK—
6-40
13-50
”p~" P~P PPP
PPP
PPP
PPP
PPP
PPP
Brown clay with basalt fragments
•
-----ureen ciaYkcnioriTig highly weathered basalt wittj silty clay Llmonltlc stains, are observed along cracks (Joints)
--------212 90
CD
75mrr
7-30
6-50
13*50
150
XXX
XXX
XXX
weathered jointed
basalt
95
65
'       1   1  1  1 1 ''III
1     11   1      1 1
1    1 1   1  1  1 1
1    1 1   1  1  1 1Locality BERETE
Depth in meter
B H No 2
Elevation
From
To
Graphic log
Description
core Recovery%
•
e
o
water
struck
static
water
level
Remark
0-00
2 30
A — A* A
A - A*-A
Grey sticky cloy
inter mixed with
basalt fragments
90
75
•
-A r A- A
2-30
5 76
XXX
XXX
XXX
jointed Dasalt.the joints ore filled by calci te
98
75Locality Birete
B H No 3
Elevation 1147
Jnjnti
JL£
From
To
Gta phic log
Description
core
R e covery%
/
water
struck
static     I water
level
Remork
0-00
>2
A      AA —      --
A      AA
— — —
Brownish black- clay with weal he* red basal! frog-
men ts
90
-i
mm
85
2
8
1/      V V
k      VV
V      VV
V      VV
V       VV
V      VV
weathered    joint ed basalt* joint
•pocing 0-5-3-5 cm and calcite
fillings
80
85
mm
-
6
II
——
p      VV —   — —
z     ry
V    pp
highly weathered basalt with black silty clay
75
85
mm
9*30- 9 90no
core
r*
II
17-50
V       VV
V      ZV
V       VV
V      VV
V       VV
V      VV
V— V /
weathered     vesi cular jointed ba- salt with clay, the joints ore filled
by calcite
95
85
mm
17-50
30-55]
X    XX
X     XX
X     XX
X     XX
X      XX
X      XX
X     XX
x     XX
X   • X X
X      XX
X       XX
X      XX
X x x;
jointed basalt with calcite filli-
ngsjolnt spacing 0 3- 40 cm
95
65
•
__________________ 1Locality BERETE
B'H No 4
Elevation 110 2
Depth in meter
From      To
------------ -----------
Graphic log
Description
Core Recovery (%)
/
water
Struck
static
waler
level
Remark
0
3
------ —
,         Dark brown Sticky cloy
96
85
AA
AA
3
13-6
AA
AA AA AA AA a" a AA
~A~
Dark brown
Silty clay
with gravels
pebbles and
angular frag ments of basalt
95
13-6
19
k k 
k v
k v
k v
k V
weathered ves icular basalt
the core is ma inly crushed and the recovery 70% sludge,30-
% basalt
60
mm
75
r
•
•
19
A_ _ A
206
A~A
Brown silty
Clay with bas alt fragments
mm
75
19m
1-50
watetrlevel
changes with
20-6
27 8
XXX XXX
xxx
xxx
xxx 
xxx
xxx 
xxx
xxx
xxx 
xxx
xxx
xxx
7~~
Jointed massive basalt joint spa cing varies from few centi meter to I6cms,27-35- 27-80vesicular
basalt
95
mm
75
1
- ———— ——  -,
27-6
30 95
Grey silty
Clay stone
98
75
23-30-23-47 /
......
31-35 Sl-44X X X X X
---------- BJLflJ__________ Basalt
r
______-____ L
*
1Locality BERETE
B H No-5
Elevation 1115
Depth  n mete
ir
Form
To
Graphic log
Description
core Recovery%
e
.o
O'
water
struck
eta tic
water
level
Remark
0
2-50
—
0 00- 1 black cot ton clay* Dark gr ey sticky cloy
90
100
2 00
3
90
3
10-90
PPV VVV
7     7V 7     77
7.77
PPP
PPP
PPP
J
Dark grey cloy with weathered basalt
fragments
Highly weathered jointed basalt with silty cloy material
10-15%
*
90
100
10-90
15-50
xxx
XXX
XXX
XXX
Fine graind jointed
basalt
95
85
tLocality BERETE
B H No-6
Elevation
Depth inmeter
From      To
*
Graphic log
Description
core
Recovery%
Remark
e’
0
0-50
—
Dark grey clay soil
95
O-5O
5-50
v77
7     7v VVV 7.     7 7 7     77
Highly weathered basalt frgmtnti intermixed with
silty clay
70
100
5-50
8
Highly weathered jointed vesicular ba salt along joints lim- onitic stains
85
100
8
15 52
XXX
XXX
XXX
XXX
XXX
XXX
XXX
>
jointed vesicular basalt joint spacing
5- 10 cm
90
85
75
<-< <<
__ <__BERETE
B H No-7
Elevation 113 4
Graphic log
Description
Sticky dark browncfo
core Recoevery°/<
er
struck
static
water
level
52
PPP
PPP
P7P
_V V V
Highly weathered
basalt with clay
VVV
VVV
V VV
VVV
Weathered jointed basalt with clayey
material Thert-are calcite filling along
the joints
Clay mixed with peat
jointed basalt
-.--
—,--------- ----- ---------- -------------ocolity BERETE
B H No 8
Elevation III )
Depth In meter
: orm
To
Graphic log
Descrptlon
core Recovery^1
,o
q"
> water
struck
static
water
level
Remork
0
2 60
Sticky brownish biuck cloy
90
3-340    undistur bed sample
_
A           AA
26
13
—
— — —
A           AA
A           AA
A          AA
A           AA
A          AA
A          AA
A           AA
A          AA
A          AA
Brown silty clay with basalt frogm-
ents (5mm)
95
85
•
13
14
aQ 0  ***
0 0 Oq
a  0 <J
Sludge
25
14
16 15
V VV
V VV
weathered     Jointed basalt
90
a   • •
16-15
17 60
• \
•
V
• v,v
•
Sludge withcrushe d basalt
50
17 6C
23-27
23 27
23 32
V V V-
V          VV
V          VV
V         VV
V        •V V
V           VV
weathered jointed basalt   Joint   epoch nig 6cm-filled by
calclt
90
75
/
23 32
27
4
'/•/
•/
/' • / ■
------------ Peat-----------------------
Silty clay-stone greyish block in
colour
95
75
24 20
water was ov for*-, .rak
er flowing the weH
lays
.............i
4
27
28 6Q
X         XX
X         XX
X          XX
jointed basolt,joint
spacing 2-8 mm
95
75
Illi 1  1 111111
till 1
1Locality BERETE
B H No 9
Elevation 119-7
Deptn Form
in men To
r
Graphic log
Description
core
Re co ver/7c
h
c
c
G
c
3
water
struck
static
water
level
Remark
0
2 30
Greyish block
Sticky clay
90
85
2 30
10 00
»J
A ~a" "a~a
AAA
_A__   A   A ’’ A~ A A
AAA
AAA
Dark brown silty clay with basalt
fragments
95
85
-
LQ .
10-30
*
silty clay st one
10-30
12 60
PPP
PPP
Clay     with     basalt fragments
95
12 60
15
XXX
XXX
Fine grained jointed basalt Joints are fill ed by calcite
98
75
1 1 1 1 1
1 1 1 11
1 1 1 1  1 11111APPENDIX II FIELD PERMEABILITY
TEST RESULTSComputation, of Permeability Values
1
2
3
4
5
6
BH
No
Bore Hole
Depth (M)
Water.
Loss Q
/sec)
Water Loss (gPM)
Applied Pump      Press-' ure             9 Hi(Kg/cm )
z
Applied Pump     Press ure
Hi(PSI)
3
4.67x10-6 1.67x10“6
2.0 x10~5
1.33x1 O'5
9 x 10“6
7.4x10"2
2.64x10“2
0.32
2.11
0.14
0.5
0.8
1.0
1.2
1.3
7.1
11.38
14.23 '
17.07
18.49
fl
If
fl
H
—
4
7
2.50-5.0
4.5 -7.2
7.20-10.40
10.40-13.05 13.05-15.80
15.80-18
18.0 -22.20
14-17.36
17.36-20.80
20,80-24.54 24.54-27.56 27.56-30.12
5.0 - 8.0
8-11.0
11.0 -15.0
4.0 - 7.0
7.0 -10.20
10-13
13-16
16-19
19-22
22-25
-
3.0 x10-5
4 x10-4
4.5 x10"5
3.3 x10“7
4.67x10-6
5.67x10"5 7.83x1O’5
-
1.57x1O"5
1.67x10~5
3.33x1O-5
1.21x10“4 3.13X1O"5 8.33x10_b 3.03x1o“4
-
0.46
6.34
7.24x10"1 5.28x1O-3 7.4 x10~2 8.98x10"1
1.24
—
8
2.48x10_1
2.64x1O“1
5.28x10~1
1.92
4.97x1 O'1
1.32x10-1
4.81
-
0.5
1.2
1.5
1.8
2.0
0.4
0.5
0.5
0.7
1.0
1.2
1.5
1.5
1.3
7.1
17.07
21.33
25.60
28.45
5.69
7.1
7.1
9.96
14.23
17.07
21.33
21.33
18.49
XComputation of Permeability Values
7
8
9                     10
11
12
Applied. Pump 
Pressure
x 2.31 (PSIx2.31)
Head 
of Water
H2
Peet of Water H
( ft)
Length of
The column 
Tested
L ( ft )                 L         10r
°p^los? for
K=C  Q pp H
cm/sec
16.43
11.5 I
26.29         |     22.15
27.58
48.44
8.2            I 6.19x10-3
8.86 5.81x10-3
1,66x1O-5
3.17x1O“6
32.87
32.0
64.87
10.5
5.13x10"3
2.53x10-5
39.43
42.49
81.92
8.69
6.19x10-3
1.59x10-4
42.71
52.33
95.04
9.02
5.97x1O“3
8.79x10“6
n
1!
If
fl
ff
11
16.43 39.43 49.27 59.14 65.72
13.14
16.43
16.43
23.0 32.87 39.43
49.27
10.04 8.46
7.05
7.15
7.15
22.77
32.81
7.71 14.11 13.45 15.26
14.93
26.47 46.86 56.32
66.29
73.44
35.91
49.24
24.14
37.11
46.32
54.69
64.2
11.06
5.25x10-3
10.96                 5.15x1O-3
11.38                 5.02x1O-3
9.91                 5.52x1O“3
8.14                 6.60x1 O’3
9.84                 5.45x1O"3
9.84         i       5.45x10~3
9.84                 5.45x1O"3
10.5                  5.13x1O~3
9.19                 5.67x10~3
9.84                  5.59x10"3
9.84                  5.59x10-3
9.12x10"5
6.96x1o'4
6.45x1O"5
4.4 ±10"7
6.65x10“6 1.36x10~4 1.37x1O"4
5.6 xIO-3
3.65x1O-5
6.46x1 O’5
1.96x1O"4
4.33x10“5
49.27
12.8
62.09
9.84 
;
5.59x10"3
1.19x1O-3
42.71
9.68
52.39
9.84 
'
5,59x1O-3
5.42x10“4PRESSURE TEST
ETHIOPIAN BUILDING MATERIALS CORPORATION BIRETI DAM SITE - NEV/ MUDAER
BORE HOLE No. 3
DEPTH
(M)
CONSUMPTION M3
From
To
Pump
Pressure
Kg/cm2
Start
End
Water
Lose m3
1
2
3
4
5
6
2.50 m.
5.00 m.
0.3 kg/cm2
<1
If
fl
II
11
1!
If
If
If
II
II
If
n
ii
ii
n
0.5 kg/cm2
if
if
If
If
4.50 m.
0.8 kg/cm^
1!
II
7.20 m.
fl
11
11
n
10.40 m.
7.20 m.
11
11
II
If
1?
If
ci
10.40 m.
0.6 kg/cm
2
II
If
II
11
II
it
ii
II
If
11
11
1.0 kg/cm2
If
11
11
11
11
11
11
11
13.05 m.
1.2 kg/cm2
If
11
11
If
If
ft
II
11
11
II
11
11
13.05 m.
n
18,00 m.
15.80 m.
1.3 kg/cin
If
11
If
II
II
II
11
11
22.20 m.
II
it
1.8 kg/cm
1!
II
It
11
230.5552
230.5578
230.5598
230.5612
230.5626
230.5640
230.5654
230.5668
230.5705
230.5717
230.5724
230.5729
230.5734
230.5739
230.5748
230.5753
230.8725
230.8800
230.8867
230.8927
230.8987
231.8315
231.8750
231.9157
231.9557
231.9957
232.1830
232.1875
232.1905
232.1932
232.1959
232.2905
232.2905
232.2905
230.5578
230.5598
230.5612
230.5626
230.5640
230.5654
230.5668
230.5682
230.5717
230.5724
230.5729
230.5734
230.5739
230.5748
230.5753
230.5758
230.8800
230.8867
230.8927
230.8987
230.9047
231.8750
231.9157
231.9557
231.9957
232.0357
232.1875
232.1905
232.1932
232.1959
232.1986
232.2905
232.2905
232.2905
0.0026
0.0020
0.0014
0.0014
0.0014
0.0014
0.0014
0.0014
0.0012
0.0007
0.0005
0.0005
0.0005
0.0009
0.0005
0.0005
0.0075
0.0067
0.0060
0.0060
0.0060
0.0435
0.0405
0.0400
0.0400
0.0400
0.0045
0.0030
0.0027
0.0027
0.0027
0.0000
0.0000
0.0000ETHIOPIA# BUILDI#G MAZERXALSCORPORAZICJf BIRETI BAH SITE - HE" KUTAET:
BORE HOLE No,3
the
DATE
Start
End
Duration
(Min.)
1          REMARK
Start
Completed
'7
8
9
10
11
12 -_____________
3:20
3:25
3:30
3:35
3:40
3:45
3:50
3:55
2:00
2:05
2:10
2:15
2:20
2:25
2:30
2:35
2:50
2:55
3:00
3 :05
3:10
3:40
3:45
3:50
3:55
4:00
12:50
12:55
1 :00
1 :05
1:10
10:05
10:1n
10:15
3:25
3:30
3:35
3:40
3:45
3:50
3:55
4:00
2:05
2:10
2:15
2:20
2:25
2:30
2:35
2:40
2:55
3:00
3:05
3:10
3:15
3:45
3:50
3:55
4:00
4:05
12:55
1 :00
1 :05
1 :10
1 :15
10:10
10:15
10:20
5  mine
27/8/80
ii
ii
ii
n
n
n
n
Hole diameter 100 cm. H-3.4(ta.*0.3
L « 2.50 a.
n
H«3.4C3. *0.5ks/cs
, 2
ii
rt
n
ii
•1
n
5  min.
28/S/80
it
if
ii
ii
i:
ti
ti
TI
II
n
ii
1!
It
11
27/8/90
IT
n
n
tr
tl
n
23/8/S0
t:
1
it
it
n
it
n
it
5  min.
29/8/30
It
II
II
II
It
11
It
II
29/8/80
M
It
tt
II
5  min.
30/8/80
30/8/80
11
II
II
II
II
II
It
II
tt
M
II
5 min.
i»
1/9/80
ii
ii
ii
It
II
It
•I
It
1/9/30
n
H
ii
5  min.
ii
it
3/9/80 
3/9/30
H
II
It
tt
Hole diameter 100mm. H»6.75m.*0.Skg/em-
L • 2.70 a.
*>
H-6.75c.*O.acg/c=:
Hole diameter 100sa.
L*9.75x3- -1 .Okg/cmr
L 3.20 a.
Hole diameter S5=m.
L • 2.65 a.
Hole diameter 85:33. H»15.95m.  ♦ 1.  JJtg/w- L w 2.75  .
a
Hole diameter T5sra #■21.95m.  >1.3kg/ca* I w 4.20 m.
T^To    V*ater    pressure    test    was    not    performed    at    depth 
from
15.90 
*. 
y? I ;
8 00                                            Be  auee
(i.e from 15.80 to 18.00 depth) is found to be the same oa
°     the Dhyeical condition or the colusn
previously tested column (i.e. from 13.05 - 15.80), there fore the column not tested it taken to be the same as there is ir
previously tested column, 
’1’
........... 2/GROUND WATER LEVEL 1.18 m,.
BORE HOLE No. 4
depth (m)
3
CONS UUPTION (M )
From
To
Pump
Pressure
Kg/cm2
Start
End
Water
Loss m3
1
.2
3
4
5
6
14,00 m. 
fl
17.36 m.
fl
fl
Cl
t!
fl
11
fl
fl
11
fl
:i
0.5 kg/cm2
fl
11
11
,J              2
0.8 kg/11cm
11
11
it
ci
11
11
17<36 m.
1.0 kg/cm
2
1!
II
II
11
20.80 m.
11
II
11
11
ii
n 
ci
ci
ci
20.80 m.
n
ii
11
II
n
ci        2 1.2 kg/cm
fl
11
11
fl
IT
11
24.54    m.
If
ti
11
II
ii
ii
17
II
11
11
If
11
1.2 kg/cm2
fl
11
b2
1.5 kg/cm ■
It
11
If
24.54 m. 
fl
11
11
fl
11
27.56 m.
27.54  m.
11
11
11
II
II
30.12 m.
1.4   kg/cm2
11
11
1.8 kg/cm2
fl
fl
ti .        2 1.5   kg/cm
II
It
It
11
fl
fl
H
11
11
11
11
fl
11
11
11
2.0 kg/cm2
11
11
224.9940 
225.0038 
225.0132 
225.0222 
225.0312 
225.0402 
225.0505 
225.0605 
225.0705
225.3710 
225.4960 
225.6170 
225.7380 
225.9240 
226.0475 
226.1700 
226.2900
226.4100
226.5695 
226.5808 
226.5908 
226.6008 
226.6160
226.6313 
226.6450 
226.6587
226.6785 
226.6790 
226.6790 
226.6795 
226.6795 
226.6802
226.6809 
226.6890 
226.6915 
226.6927 
226.6939 
226.6956 
226.6970 
226.6984
225.0038 
225.0132 
225.0222 
225.0312 
225.0402 
225.0505 
225.0605 
225.0705 
225.0805
225.4960 
225.6170 
225.7380 
225.8590 
226.0475 
226.1700 
226.2900 
226.4100 
226.5300
226.5808 
226.5908 
226.6008 
226.6008 
226.6313 
226.6450 
226.6587 
226.6724
226.6790 
226.6790
226.6790 
226.6802
226.6790 
226.6809 
226.6816 
226.6915 
226.6927 
226.6939 
226.6951
226.6970 
226.6984 
226.6998
0.0098
0.0094
0.0090 
0.0090 
0.0090
0.0103 
0.0100
0.0100
0.0100
0.1250 
0.1210
0.1210
0.1210
0.1235
0.1225
0.1200
0.1200
0.1200
0.0113 
0.0100
0.0100 
0.0100
0.0153 
0.0137 
0.0137 
0.0137
0.0005 
0.0000
0.0000
0.0001
0.0000
0.0001
0.0001
0.0025 
0.0012
0.0012
0.0012
0.0014
0.0014
0.0014GROUND WATER LEVEL 1.18m
BORE HOLE No. 4
TIME
DATE
Start
End
Duration
(min,)
Start
REMARK
Completed
11:30
11:35
11 :40
11 :45 
11:50
11:55
12:00
12:05
12:10
10:40
10:45
10:50
10:55
11105
11 :10
11:15
11:20
11:25
4:15
4:20
4:25
4:30
4:40
4 :50
4:55
5 :00
2:20
2:25
2:30
2:40
2:35
2:45
2:50
9:25
9:30
9:35
9:40
9:50
9:55
10:00
11:35
11:40
11:45
11:50
11:55
12:00
12:05
12:10
12:15
10:45
10:50
10:55
10:00
11 :10
11:15
11:20
11 :25
11 :30
4:20
4:25
4:30
4:35
4:45
4:55
5:00
5:05
2:25
2:30
2:35
2:45
2:40
2:50
2:55
9:30
9:35
9:40
9:45
9:55
10:00 10:05
5 min.
fl
If
fl
If
II
fl
II
fl
5/7/80
5/7/80
11
11
fl
II
II
11
II
11
fl
11
11
If
II
n
ft
11
Hole diameter 85 mm. H=3.06m. +0.5kg/cnr L ■ 3.37 m.
H=3.06m.+0.8kg/cm2
5 min.
II
1!
If
II
II
fl
II
fl
7/7/80
II
fl
11
11
11
fl
11
11
7/7/80
If
fl
II
fl
II
11
II
If
5 min.
II
If
If
fl
fl
t:
8/7/80
If
11
fl
fl
II
fl
fl
8/7/80
If
II
fl
11
11
II
11
5 min.
11
fl
fl
II
II
11
9/7/80
II
II
fl
II
II
fl
9/7/80
fl
11
11
II
11
5 min. 
fl
If
11
11
fl
11
10/7/80
11
fl
II
it
11
11
10/7/80 
11
If
fl
II
11
n
Hole diameter 85 mm. H =r 2.58m.+1. Okg/cm^
L 0 3.34 m.
H e 2.58m.+1.2kg/cm2
Hole dimeter ■= 85mm, L = 2.15m.+1.2kg/cm2 
D = 3,74m.
. .
H = 2.15m.+1.5kg/cm2 Hole 0 = 85mm.                  Q
H ■= 2.18m.+1.4kg/cnr L <3 3.02 m.
H=2.18m.+1.8kg/cm2
Hole dimeter' ■=>85mm.
H 2.18m.+1,5kg/cm “
L a 2,56 m.
H-2.18m.-2.Okg/crn2
£o
I!7
8
—2 1
10
11
l£ “BORE HOLE No. 7
DEPTH (M)
C01
TSUMPTION (
m3)
From
To
Pump
Pressure
kg/cm^
Start
End
Waters
Loss m
1
2
3
■4
5
6
5.00 m.
8.00  m.
0.2 kg/cm
o
11
fi
ti
ti
II
11
11
ii
n
” 2
0.4 kg/cm
n
ii
it
ii
;           ii 8.00 m.
11
11
H
II
H
11
11
11
11
11.00  m.
11
n
ii
ii
I!
11
11
It
1!
II
11
n
n
it
n
0^3 kg/cm2
ft
ft
Cl
II
ii
2
n
u
0.5kg/ 11cm
1!
ti
11.00 m.
n
15.00 m.
(1
11
11
11
II
11
It
11
11
Ci
11
17
11
11
CT
0.8 kg/cni
n
it
ii
1.0 kg/cm
9
11
11
11
H
227.1285
227.1433
227.1560
227.1690
227.1820
227.1980
227.2162
227.2340
227.2510
227.2680
227.3810
227.4045
227.4272
227.4495
227.4718
227.5025
227.5265
227.5502
227.5737
227.5972
227.8953
227.8957
227.8957
227.8957
227.8957
227.8960
227.8960
227.8960
227.8960
227.1433
227.1560
227.1690
227.1820
227.1950
227.2162
227.2340
227.2510
227.2680
227.2850
227.4045
227.4272
227.4495
227.4718
227.4941
227.5265
227.5502
227.5737
227.5972
227.6207
227.8957
227.8957
227.8957
227.8957
227.8960
227.8960
227.8960
227.8960
227.8960
0.0148
0.0137
0.0130
0.0130
0.0130
0.0182
0.0178
0.0170
0.0170
0.0170
0.0235
0.02*7 :
0.0223
0.0223
0.0223
0.0210
0.0237
0.0235
0.0235
0.0235
0.0004
0.0000
0.0000
0.0000
0.0003
0.0000
0.0000
0.0000
0.0000BORE HOLE No. 7
time .
DATE
Start
End
Duration 
(min.)
REMARK
Start
Completec
7
8
9
10
11
12
9:30
9:35 
9:40
9:45
9:50
10:00
10:05
10:10
10:15
10:20
2:25
2:30
2:35
2:40
2:45
2:55
3:00
3:05
3:10
3:15
3:45
3:50
3:55
4:00
4:05
4:10
4:15
4:20
9:35
9:40
9:45
9:50
9:55
10:05
10:10
10:15
10:20
10:25
2:30
2:35
2:40
2:45
2:50
3:00
3:05
3:10
3:15
3:20
3:50
3:55
4:00
4:05
4:10
4:15
4:20
4:25
5  min.
29/7/80
29/7/80
11
11
11
ti
if
fi
it
1!
ii
11
11
11
n
w
ti
i?
it
ft
11
11
If
11
It
fl
tf
If
11
diamet er=1OOmm?
Hole
H =   6.94m.+0.2kg/cm
L =   3.00 m.
2
H =   6.94m.+0.4kg/cm
5  min.
1/8/80
1/8/80
ii
it
H
ti
n
11
ft
fl
11
It
If
fl
1!
11
11
fl
It
11
11
fl
11
11
n
if
n
it
it
Hole      diameter=100mm.o H =   10.00m.+0.3kg/cm
L =   3.00 m.
H =   10.00m.+0.5kg/cm
_ 2
5  min.
3/8/80
3/8/80
11
11
11
If
11
11
11
11
11
n
ii
n
n
1!
If
11
11
11
If
11
11
•
Hole      diameter=100mm.? H =  12.2 5m. +0.8kg/cin L =   4.00 m.
H =  12.25m.+1.2kg/cm
■
pBore Hole No, 8
Q
Depth (M)
Consumption (nr)
From
To
Pump
Pressure
Kg/cm2
Start
End
Water ,
Loss m'
1
2
3
4
5
6
4.00 m.
7.00 rn.
0.3     Kg/cm2
ii
n
it
it
it
ti
ii
ii
ii
it
it
ii
it
it
ii
it
ti
tt
n
0.5           it
ii
ti
ti
it
7.00 m.
10 .20m•
0.5           it
1!
fl
It
It
II
t!
ii
ii
ii
it
ii
11
0.7           ti
11
1!
ii
ii
ti
ti
ii
ii
ii
ii
ii
ii
tt
it
10.00mf
13.00,
0.8        it
ii
11
it
ii
II
II
ii
ii
ii
It
11
II
ti
11
II
II
tt
h
ii
tt
ii
1.0         it
ti
it
ti
it
13.00m.
16 ,00m.
II
ii
1.0         ii
ii
tt
If
11
II
ft
If
1.2
it
ii
ii
it
228.3645
228.3708
228.3756
228.3810
228.3858
228.3906
228.3972
228.4023
228.4070
228,4725
228.4807
228.4860
228.4913
228.4963
228.5013
228.5116
228.5169
228.5219
228.5269
228.6510
228.6257
228.6352
228.6447
228.6537
228.6627
228.6820
228.6930
228.7035
228.7135
228.7235
228.7415
228.7730
228.8038
228.8330
228.8622
228.8967
228.9330
228.9693
228.3708
228^3756
228.3810
228.3858
228.3906
228.3954
228.4023
228.4070
228.4117
228.4807
228.4860
228,4913
228.4963
228.5013
228.5063
228.5169
228.5219
228.5269
228.5319
228.6257
228.6352
228.6447
228.6537
228.6627
228.6717
228,6930
228.7035
228.7135
228.7235
228.7335
228.7730
228.8O38
228.8330
228.8622
228.8914
228.9330
228.9693
229.0056
0.0063
0.0048
0.0054
0.0048
0.0048
0.0048
0.0051
0.0047
0.0047
0,0082
0.0053
0.0053
0,0050
0.0050
0.0050
0.0053
0.0050
0.0050
0,0050
0.0107
0.0095
0.0095
0.0090
0.0090
0.0090
0.0110
0.0105
0.0100
0.0100
0.0100
0.0315
0.0308
0.0292
0.0292
0.0292
0.0363
0.0363
0.0363Time
Date
Start
End
Duration 
(Min)
Start
Comp.
7
8
9
10
11 •
12:35
12:40
12:45
12:50
12:55
1 :00
1:10
1 : 15
1:30
12:35
12:40
12:45
12:50
12:55
1:00
1 :10
1:15
1 :20
1 :25
6:50
6:55
7:00
7:05
7:10
7:15
7:25
7:30
7:35
7:40
7:45
1 :10
1:15
1 :20
1 :25
1 :30
1 :40
1 :45
1 :50
12:40
12:45
12:50
12:55
' 1:00
1:05
1 : 15
1:30
• 1:35
12:40
12:45
12:50
12:55
1 :00
1 :05
1 :15
11:20
1 :25
1:30
6:55
7:00
7:05
7:10
7:15
7:20
7:30
7:35
7:40
7:45
7:50
1:15
1 :20
1 :25
1 :30
1 :35
1 :45
1:50
1:55
5 min.
10/8/80
10/8/80
11
if
11
11
11
11
11
11
11
ji
11
it
11
11
11
it
11
11
11
11
11
11
11
it
11
it 1
11
it
11
11
it
it
11
it
11
11
II
11
II
H
II
It
tt
II
11
II
II
11
II
II
It
II
11
Remark
12
Hole 0 = 100 mm. 
H    =    2.35    m.    +    0.3    Kg/cm L = 3.00 m.
2
2
11/8/80
11/8/80
2
II
II
II
II
II
II
If
It
II
11
It
II
11
II
11
II
II
II
H = 2.35 m. + 0.5 Kg/cm
Hole 0 s 100 mm, 
H    =    4.30    m.    +    0.5    Kg/cm L = 3.20 m.
16/8/8O
16/8/8O
II
11
II
11
It
11
11
II
II
II
II
II
II
11
II
II
It
11
11
II
Hole 0 ss 100 mm. 
2
H     =     4.10     m.     +0.8     Kg/cm L = 2.80 m.
H = 4.65 m. + 1.2 Kg/cm2
18/8/80
11
II
It
II
11
II
It
18/8/80
II
II
II
II
II
II
II
Hole 0 = 85 mm. 
2
H    ss    4.65    m.    +    1.0    Kg/cn> L a 3.00 m.
H = 4.65 m. +                1.2 Kg/cm2■
Depth (m)
Cons uni p t i on (m )
From
To
Pump
Pressure
kg/cm2
Start
End
Water        ~ Loss m
1
2
3
4
5
6
16.00m.
19.00m.
1.2 Kg/cm2
ii
ii
ti
ii
ii
ii
ti
ii
ii
ii
ii
n
it
ii
it
0
n
n
II
II
fl
II
II
19.00m.
n
22.00m.
ii
ii
ii
ii
II
If
It
If
11
22.00m.
25.00m.
11
It
It
If
11
H
If
II
1.5
It
II
II
1.5
II
II
II
11
II
*
1.3
tl
ft
II
It
229.0170
229.0252
229.0324
229.0392
229.0452
229.0512
229.0635
229.0735
229.0829
229.0923
229.1907
229.1942
229.1972
229.2000
229.2025
229.2050
229.2260
229.3310
229.4270
229.5160
229.6070
229.0252
229.0324
229.0392
229.0452
229.0512
229.0572
229.0735
229.0829
229.0923
229.1017
229.1942
229.1972
229.2000
229.2025
229.2050
229.2075
229.3310
229.4270
229.5160
229.6070
229.6980
0.0082
0.0072
0,068:/
0.0060
0.0060
0.0060
0.0100
0.0094
0.0094
0.0094
0.0035
0.0030
0.0028
0.0025
0.0025
O.Q025
0.1050
0.0960
0.0910
0.0910
0.0910
NOTE:
On bore holes Ni . 3,4,6 &. 8 permeability tests were not performed at the following depths respectively. From 0.00 to 2.50 m. , 0.00 to l4.00ipe0.00 to 5.00 m. 
and 0.00 to 4.00 m. , due to softness of the over-burden.APPENDIX III BOREHOLES SAMPLES
TEST RESULTS'T 
...
. - ' < ' ’■ .
buildinat
I.
ca .l«   >dd:°6    • 
Certificate No. 767« Sample Mo. 36706-709
p 0. o°*
T«U. 44 TO 30 • 4
„
I
I
MATERIALS research and testing department
faculty of technology
ADDIS ABABA UNIVERSITY .
Addis Ababa
.•
Client:
R^t Objects:
SflAipled by:
Dale Received:
i ' •,
.□Calion:
Test Specified by;
Cine! of test:
lerliirks: <
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2.2J
0.06
«n®lo®wtoo Jlo. 1-Lthe building MATERIALS
research ANL) TESTING department
/\QPlS ABABA_______________________
GRAIN SIZE DISTRIBUTION
CERT No. ENCL No LAPPENDIX IV CLAY TEST RESULTS
PLANT SITE0UILDINST
Certificate No 7416
Sample No. 34494*495
MATERIALS research and testing department
FACULTY OF TECHNOLOGY
ADDIS ABABA UNIVERSITY
Addis Ababa
licnt:                                   Ethiopian Building Materials Corporation, Addis Ababa.
est Objects:
.mpled by:
ate Received:
jcalion:
•st Specified by:
nd of test:
marks:
Soil samples
The olient (c/o Ato Banteyehun Haile)
January 4» 19^0
Bireti - New Mager
Ato Banteyehun Haile
Attarberg limits, grain size analysis, free-swell, shrinkage limit and compaction (modified AASHO)
TEST B B S U L T S
Sample
No.
SiU
Client’s marking
sample description
L.L. P.L. P.I. Ereo-swell
%
Shrinkage
limit
4
Optimum
moisture
content
■/
34494
"495
' 1-1
B-l
105 33 72
115 30 85
110
125
8.4
7.8
28.4
28.5
Client’s marking
sample description
Maximus
dry density
3
d (kg/d. )
Cohesion
C - kg/om^
Angle of shearing
resistance
0 - (degrees)
A-l
1.49
0.16
3.0
B-l
1.52
0.14
5.5
°  grain size distribution, please aee enolosure No. 1.
r
or n°i«tur»_den.ity relationship ourv.s, pl .as. se. .nclosur.s No. 2 and. 3
4di * A^aba, Maroh 24, 1980
_
hfL
'-^1 kA. (
ndw°“B«a M.ngi.t.
^7
Tewodxoa Philip•7HE building MATERIALS --------------------------~ research and testing department
aoois ABABA
GRAIN SIZE distribution
CERT No. .74.1.6
ENCL No                   3---
1
• ->1•
• * . ft A - F<
f
-
•
•*<
-
‘ AS.
•
•;’X
APPENDIX V
CLAY TEST RESULTS
KOTCHA CREEK - BORROW AREA 3A Samples 118418 &118078
HUD - GEBEYA - BORROW AREA 3B
*
Samples 118417 & 118079buildinst
Ccriifieuie No. 7>9X Sample No. 35734-735
MATERIALS RESEARCH and testing department
FACULTY OF TECHNOLOGY
ADDIS ABABA UNIVERSITY
Addis Ababa
lienl:
. bl Objects:
miplcd by:
a ie Received:
nation:
;s t Specified by:
nd of test:
.marks:
Ethiopian Building Materials Corporation, Addis Ababa.
Soil samples
The client (c/o Ato Banteyehun Haile)
April 15, 198c
New-Huger
Ato Banteyehun Haile
Atterberg       limits,       grain       size       analysis,       free       swell,       specific       gravity, direct shear, shrinkage limit and compaction modified AASHO.
TEST    RESULTS
Cl t Sample Test
ent’s, marki pit
ng
Samole
L.L.
7J
P.L.
P.I.
£
Shrinkage
limit
Free swell
No. 
’To.
depth (m.)
II8417 
1
0-1.50
d°
27
43?
14.6
40
118418 
2.
0-1.50
64
28
36
14.7
40
1
’ajijle No.
Cli en t  s mark.3 ng
Test pit                Sample Ko.             depth (m.)
1                c-1.50
2 0-1.50
Cohesion
C - in kg/cm
0.10
0.16
2
I84I7
i8.<ig
Angle of shearing 
resistance
0 - degrees
23.0
15.0
Specific gravity
2.72
2.72
—
38.0
—
— 
Client’s m ark i r?. g
Maximum
Optimum moisture
s a!.'i.jle
Test pit
Sample
Eo. 
Mo.
depth /m.)
dry-density
’ d-kg/dm^
content
d
F
H8417 
T
C-1.50
1.65
28.0
U8413 
I
or
or
2
0-1.50
1.67
27.6
distributions, AASHO compaction
,               August 27, 1980 Mengiste
enclosures 1-2
see enclosures 2-4• Eshetu Muhez
n
<eUlLDINST
Cciiiiicaie No. 7768 Sample No. 37407-408
MATERIALS research and testing department
FACULTY OF TECHNOLOGY
ADDIS ABABA UNIVERSITY
Addis Ababa
Client
Ethiopian Building Materials Cor>., Addis Ababa.
Test Objects:                   Soil samples
Suniploi by:                     The client (c/o Ato Banteyehun Haile)
Dale Reived:
Location:
Tesi Specified by:
Kind of test:
J
Remarks:
February 6, I98I
New Muger (Bireti)
Ato Banteyehun Haile
Atterberg limits, grain size analysis, free swell and. direct shear.
TEST RESULTS
Client’s marking 
Q . *>
T T t. t
Free-
Angle    of    shearing
Jj. I). A •
* Pit No. Depth, m.
•veil
resistance
degrees
118078 . -
-
76 27
49
46
55 
26.5
118079 ' -
-
75 29
50 
26.0M.I.T CRAIN SIZE SCALE
o
ro
SlZL Of OPENING -INS                      USS SIEVE SIZE - ME SUES/IN.
/7a“ V
140 200
c X >
z
— xxx —
—  — go
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GRAIN SIZE - MM
0?
g I COARSE ^MEDIUM | FINE COARSE
C09B1.E
MEDIUM
PINE
SIZc
GRAVEL SIZE
SAND SIZE
FINE GRAINEDJILDING MATERIALS
the apCH ano testing department
------------------------------------------------------------
LERT Nd.
ENCL No
grain size DISTRIBUTION
I I
1
i
1
i
_
___ .... L_ 1
}__ _ :__ i _  __
!
f- thTsUILDING MATERIAL^------------------- — ^search a^ testing DEPARTMENT
AD DlS_ABft£^ —■ •-
^|lN SIZE DISTRIBUTION
CERT        No.        \?-
ENCL N<.
/
percent finer THAN
t
* W/aa/ guiLb/MG
' DATE
, APPROVE*?;
£[~TE.~: UW &UGG&
i———— -------- z- .APPENDIX VI TRANSITION MATERIALr-ABLE ADDRESS i
p. O BOX 518
T EL. 44 70 30-4
BUILOINST
IcHificale No. 769?’ Sample No.      36816—819
materials research and testing department
FACULTY OF TECHNOLOGY
ADDIS ABABA UNIVERSITY
Addis Ababa
Client:                               Building Materials Corporation, Addis Ababa
Test Objects:
2 samples of coarse aggregates
Sampled by:
The client (c/o Ato Aklilu Assefa)
Date Received:
November 16, I98O
.ocation:
New Mugher
lest Specified by:
Ato Aklilu Assefa
Cind of test:
Sieve analyses
Remarks:
Teat Results;
Sieve size (AS1M)
Sieve   analyses test results, > (by weight)
Coarse  aggregate No. 118077
Coarse aggregate No. II8O8O
As received
After      48-hrs+ immersion and drying
As received
After 48-hrs+ immersion  and drying
$
3"
2”
1^”'
1”
3/4”
i”
3/8*
Ko. 4
No. 8 
No. 16
No. 30
No. 50
No.100
No.200
100
89
77
55
43
32
25
12
7
4
3
2
1
1
100
96
88
69
57
41
31
15
8
5
4
3
2
1
100
96
95
90
73
57
42
35
22
14
9
6
3
2
1
100
99
98
93
78
54
40
24
15
10
71 
RJ
1
w
2
according to the client’s request.mo Zm
z      z op
COBBLE
SIZE
[coarse 1 MEDIUM | FINE
-
COARSE
MEDIUM
SAND SIZE
FINE
SILT SIZE
CLAY SIZE
GRAVEL SIZE
fine grained
AN ° TESTlNG DEPARTMENTI0
V.

Summery

Date: February 1981

Location: Birete River Basin, Ethiopia (9°25'-9°29'N, 38°03'-38°20'E)

Prepared by: Nafis Ahmad (UN Engineering Adviser), Akiliu Assefa (Senior Geologist), Banteyehun Haile (Engineer)

1. Project Overview

The Birete Dam study was initiated to store water (2000m³/day) for a cement plant while considering other water utilization needs. The investigation included geological mapping, borehole drilling, permeability tests, and construction material assessment.

2. Basin Description

38 km² catchment area in the Ethiopian plateau
Altitude: 2450-2670 meters
Main tributaries: Bora and Likimsa rivers
Topography: Undulating with gradual slope to the north
Surface: 95% covered by residual clay from weathered basalt

3. Geological Findings

Stratigraphy

Upper basic volcanites
Ignimbrites
Lower basic volcanites (predominant)
Underlain by Cretaceous sandstone, limestone with gypsum, shale, and marl

Dam Site Geology

Highly weathered basalt with 2-5m thick residual clay
Joint patterns observed in outcrops (3 sets with 15-50cm spacing)
Two lava flows identified within drilled depth (30m)
Paleosoil formation indicates former swampy conditions
Average 2.5m clayey overburden to be stripped

Borehole Findings (9 holes, 173.4m total)

Key Findings	Details
Core Recovery	70-98% recovery rates
Mineral Composition	Augite basalt (45% plagioclase, 40% pyroxene)
Water Conditions	Shallow artesian groundwater at left bank (BH No.8)

4. Permeability Tests

Tests conducted in boreholes 3, 4, 7, and 8 using pumping-in method (0.3-2 kg/cm² pressure):

Critical Findings:

High permeability at BH No.4 (18.5m depth): 6.96×10⁻⁴ cm/sec
High permeability at BH No.8 (22m depth): 5.42×10⁻⁴ cm/sec
Areas requiring grout curtain: Horizontal distance 240-310 from left abutment (18m depth)

5. Construction Materials

Recommended Sources

Material	Location	Distance from Dam	Notes
Rock	Downstream quarry	700m north	Avoids reservoir leakage issues
Clay (core)	Kotcha Creek (3A) and Hud-gebeya (3B)	1.5km NE and 3km NW	Shear parameters: φ=15°, C=0.05 kg/cm²
Transition Material	Mekoda church area (7B)	-	Better graded, closer to site

6. Recommendations

Foundation: Bedrock is competent but requires:
- Grout curtain (240-310m from left abutment, 18m depth)
- Alternative: Dental treatment + upstream clay blanket
Materials:
- Use downstream quarry (700m north) for rock
- Clay from Kotcha Creek (3A) and Hud-gebeya (3B)
- Transition material from Mekoda church area (7B)
Special Considerations:
- Peat layer at 30m depth not considered critical
- Artesian flow at BH No.8 requires attention

7. Appendices Included

Bore logs (Appendix I)
Permeability test results (Appendix II)
Borehole sample test results (Appendix III)
Clay test results (Appendices IV-V)
Transition material analysis (Appendix VI)