This document provides a geotechnical report for the Arja-Tian-Dhalkot Hydropower Project in Azad Kashmir, Pakistan. It summarizes the geological conditions and subsurface investigation conducted at the project site. Boreholes were drilled at various locations, including the dam site and power house site. Rock cores were analyzed to determine properties like rock quality designation, core recovery, and lithology. Laboratory tests were performed on rock samples to evaluate physical properties like moisture content, porosity, and density. The geology of the area consists of Siwalik Formation and Murree Formation rocks. Quaternary deposits like alluvium and conglomerate are also present.

2. GEOTECHNICAL REPORT OF ARJA-TIAN-
DHALKOT HYDROPOWER PROJECT
AZAD KASHMIR(BAGH)

3. INTRODUCTION
 M/S Geo-con were awarded the project of
sub soil investigation with geological
mapping, topographic survey, seismic
survey and interpretation of Harighal-
Dhalkot hydropower project

4. INTRODUCTION CAN’T
 In ARJA-TIAN-Dhal kot hydropower project
the small reservoir is located on Mahel River
upstream. The objective of this small dam is
to provide the hydropower downstream the
river around the loop through an underground
tunnel for power generation

5. LOCATION AND ACCESSIBILITY
 The project area is approximately 10 km from
Bagh towards Rawalpindi
 The approach of this project area is very easy
on Rawalpindi-Bagh main metalled road
 In our project area the right abutment of the
dam is in district Bagh and the left abutment
is in district Poonch and power house is in
district poonch

7. INVESTIGATION PLANE
 A programme of subsurface investigation was
conducted according to instruction by
consultant M/s RENCON, ISLAMABAD
 The programme consisted of geological
mapping, seismic refraction survey of dam site
and power house site as well as collecting
subsurface data.
 The subsurface data has been collected by
drilling and coring in bore holes

8. INVESTIGATION PLANE
Sr. No. BOREHOLE NO. DEPTH
1. RA#01 30m/Right abutment
2. RA#02 30m/Right abutment
3. RA#03 30m/Right abutment
4. NB#01 30m/Bed of river
5. NB#02 30m/bed of the river
6. LA#01 30m/Left abutment
7. PH#01 30m/power house

9. GEOLOGY OF THE AREA
LITERATURE REWIEW
TWO TYPE OF FORMATION ARE PRESENT IN
THIS AREA
 SAWALIK FORMATION
 MURREE FORMATION

10. SIWALIKS GROUP
 The left abutment of the project have siwalike
formation
 In this area lower siwaliks and lower part of
middle siwalike are exposed. The siwaliks of
this area however appears similar throughout.
They are petro graphically indistinguishable.
The sand stone are coarse grained massive and
even pebbly. They are interbeded with hard
and compact shaly/clayly rock

11. STRATIGRAPHIC COMMITTEE OF PAKISTAN
(1973) HAS FORMALIZED SIWALIKE GROUP AND
DIVIDED IT INTO FOLLOWING FORMATION

12.  Soan formation Pleistocene
 Dhok phatan formation Pliocene
 Nagri formation upper Miocene
 Chinji formation middle Miocene

13. MIDDLE SIWALIKE NAGRI STAGE
 Orange and brown incoherent sandstone with
harder cores within, weathering in uneven
pitted surface. Soft red shale's with buff or
grey plant bearing shale's. Hard semi nodular
pale red clay, Rhinocerotid and ungulate
bones

14. CHINGI AND NURPUR STAGES
 Fine grain, blue grey nonmicaceous sand stone
pseudo-conglumerate at interval, massive and
thick bedded. Grey coarse, soft micaceous
sand stone with pebbles at places almost
conglomerates. Strata rudely bedded with
laminated shale's hard, indicated, reddish
purple, semi concretionary, thickly veined
with calcite few calcareous red clays,
weathering in hummocky surfaces proportion
of sand stone to shale is about equal

15. KAMLIAL AND LOWER CHINJI
 Fewer shale of grey blue, purple and red
colors, with carbonized leaf impressions
limonitised woody tissues. Hard semi-nodular
sand stone blue grey with purple stains,
containing kankar like nodules and
limonitoised woody tissues (coniferous)
proportion of sandstone to shale

16. RECENT ALLUVIUM
 The gentle slopes and flat plains of the area
contains stream. River and wind blow the
deposits of recent age. The surrounding
area of this dam is situated over the alluvial
deposits of Mahl river these deposits are
composed of clay fine silt and sands with
boulders and pebbles of varying size and
composition the boulders are usually sub
angular to sub rounded the alluvial deposits
provide fertile land for agriculture purpose

17. MURREE FORMATION:
 Lithology, the widely exposed rocks of
Murree formation is composed of
alternating beds of clays, shale, siltstone
and sandstone. This formation is well
exposed in Rawalakot, Bagh and Hajera
areas.

18. MURREE CLAYS AND SHALE
 The Murree clays and shale are red, brown,
purple and grey in color, soft, sticky and
slightly silty and places
 The clay stone is well stratified, brownish grey
to dull red, soft to medium hard and
interbeded with silt stone and sandstone beds.

19. MURREE SILTSTONE
 The siltstone is greenish grey to pale and
yellowish brown on weathered surface
 Greenish grey to brownish grey on fresh
surface
 Thin to medium bedded, at places lens form,
soft to medium hard, sheared and fractured.

20. MURREE SANDSTONE
 It is greenish to brownish grey and purplish on
weathered surface
 Dull down to red and light green to grey on fresh
surface
 It is massive too thin bedded, fine to medium
grained, well sorted and at places cross bedded. It
is medium hard to hard, well jointed and
fractured
 The block size ranges from 2-3m. Joints are
mostly closed and packed with secondary clay
material. Calcite veins are occasionally present.

21. QUATERNARY DEPOSITS
 The Quaternary deposits include the stream
channel deposits, alluvium and some exposures
of Mirpur Conglomerate. The stream channel
deposits comprise sand, silt, gravel and boulders
of unsorted and heterogeneous nature occupying
the nala beds and flood plain area. The alluvium
consists of mainly clay and silt intermixed with
talus and detrital material which is dusky grey to
light brown in color. Valleys are filled with alluvial
material which is dominantly clay. The slopes
have been developed into alluvial terraces

22. QUATERNARY DEPOSITS
 The Mirpur conglomerate is exposed in Bagh
area along the Mahl River. It is poorly sorted
and consists of pebbles and boulders of
sedimentary, igneous and metamorphic rocks
indurated in sandy and clayey matrix. These
deposits rest with an angular unconformity on
Murree formation.

23. TECTONICS OF THE AREA
Himalayan
seismic zone
Suliamn-
Kirthar
Seismic
Zone
Kuchch
Seismic
Zone
Makran Seismic
Zone
Chaman-
Hindukush
Seismic Zone

28. PROJECT
AREA

29. PHASING AND OBJECTIVE
 The investigation for Arja-Tian-Dhalkot
hydropower project and its associated
structures may initially be directed at
choosing the more favorable site. This involve
geology and geotechnical study and other
aspects

30. OBJECTIVE
FOLLOWING OBJECTIVE WERE UNDER
CONSIDERATION
 Engineering parameters, suitability of weir
foundations, and its probable settlement
which can occur
 Seepage problems under the weir and
abutments, and to determine the parameters
require accessing the volume of seepage, the
accompanying pressure distributions, reduce
seepage etc.

31.  To examine the water tightness of the reservoir
area and stability of the surrounding slopes under
submergence and draw down.

32. INVESTINGATIONG AT SELECTED SITE AND DATA
EVALUATION OF BOREHOLE LOGS
WEIR SITE:
BORE HOLE RA-01
 In borehole RA-01 rocks are slightly
fragmented
 Slightly too closely jointed
 Slightly to moderately weathered
 RQD values range from 0 %-78%.
 Core recovery range from 60%-97%

33. RQD IN BORE HOLE RA-01
 The RQD value of the upper mudstone is 0-
53%
 In the lower mudstone bed it is 53%
 In upper sandstone bed it is 53-60%
 In lower sand stone bed it is 69-72%

34. CORE RECOVERY IN BORE HOLE RA-01
 Core recovery in upper sandstone bed is 60%
 Core recovery in lower sandstone bed is 80-
97%
 Core recovery is 60% in the upper mud stone
bed and 63% in the lower mudstone.

35. LITHALOGY OF BORE HOLE RA-01
 The lithology varies as upper shale brownish
fine gained
 Sandstone is brownish to grayish brown, fine
to medium grained and moderately weathered
 The middle mudstone is dark brown, fine
grained, loose and disintegrated at water
contact

36. BORE HOLE RA-02
 Rocks were highly fragmented
 Weathered
 Highly jointed
 The joints were closely spaced
 Core recovery value range from 57%-97%
 RQD values range from 30%-81%

37. RQD IN BORE HOLE RA-02
 The RQD value of the upper sandstone is 0-
68%
 In the lower sandstone bed it is 71-77%
 In upper mudstone bed it is 41-76%
 In lower mudstone bed it is 53-81%

38. CORE RECOVERY IN BORE HOLE RA-02
 Core recovery in upper sandstone bed is 77-
85%
 Core recovery in lower sandstone bed is 66-
82%
 Core recovery is 73-93% in the upper mud
stone bed and 75-98% in the lower mudstone.

39. LITHALOGY OF BOREHOLE RA-02
 Top 1.5m is overburden brownish, grayish brown,
coarse grained, gravels, cobbles, pebbles, and
some shaly clay
 The middle part Reddish brown to brown fine
grain highly fractured, freshly weathered s.st.1.5-
5m
 From 5-15.5m Fractured, medium Compacted,
Low strength Mud stone Fractured, jointed and
contact of gray Fragmented Mud stone Highly
jointed

40. BORE HOLE RA-03
 The rock was slightly to highly fragmented
 the joints spacing was moderately to closely
the joints direction was along the direction of
strike.
 Core recovery value range from 32%-97%
 RQD values range from 0%-78%

41. RQD IN BORE HOLE RA-03
 The RQD value of the sandstone is 13-76%
 The RQD value of mud stone is from30-33%

42. CORE RECOVERY IN BORE HOLE RA-03
 Core recovery of sand stone is from 34-97%
 Core recovery of mudstone is from 53-63%

43. LITHALOGY OF BORE HOLE RA-03
 1-2m is overburden which is reddish brown
clay and some cobble
 2-27.5m there is highly fractured, weathered
reddish brown to brownish fine to medium
grain sand stone which is low to medium hard
 27.5-30 there is mixture of mudstone and clay
that mudstone is medium to highly fractured

44. BORE HOLE NB-01
 The rock was fragmented moderately to
highly
 Joint spacing was moderately to closely
 weathering was slightly to highly

45. RQD IN BORE HOLE NB-01
 The RQD value of the sandstone is 40-75%
 The RQD value of mud stone is from 64-84%

46. CORE RECOVERY IN BORE HOLE NB-01
 Core recovery of sand stone is from 82-97%
 Core recovery of mudstone is from 86-91%

47. LITHALOGY IN BORE HOLE NB-01
 From 1-16.75m there is gravel poorly sorted and
poorly to well rounded
 From 16.75-28.2m there is sandstone which is
which is jointed, weathered and medium hard
 From 28.2-30m there is mud stone which is
medium hard

48. BORE HOLE NB-02
 The rock was fragmented moderately to
highly
 Joint spacing was moderately to closely
 weathering was slightly to highly

49. RQD IN BORE HOLE NB-02
 The RQD value of the sandstone is 40-82%
 The RQD value of mud stone is from 39-45%

50. CORE RECOVERY IN BORE HOLE NB-02
 Core recovery of sand stone is from 79-96%
 Core recovery of mudstone is from 70-77%

51. LITHOLOGY OF BORE HOLE NB-02
 1-20m there is gravel which is poorly to well
sorted and medium to well rounded
 From 20-27.90m there is sand stone which is
medium to fine grained and highly fractured
and weathered, color is grey to brownish
 From 27.90-30m there is fine grain and highly
mud stone whose strength is medium to high

52. BORE HOLE LA-01
 The rock was highly fractured and freshly
weathered
 Core recovery value range from 32%-93%
 RQD values range from 13%-81%

53. RQD IN BORE HOLE LA-01
 The RQD value of the sandstone is 0-81%
 The RQD value of mud stone is from34-55%

54. CORE RECOVERY IN BORE HOLE LA-01
 Core recovery of sand stone is from 34-93%
 Core recovery of mudstone is from 77-83%

55. LITHALOGY OF BORE HOLE LA-01
 1-2m is overburden which is reddish brown
clay and some silt
 2-28m there is highly fractured, weathered
reddish brown to brownish grey fine to
medium grain sand stone which is low to
medium hard
 28-30 there is mixture of mudstone and clay
that mudstone is medium to highly fractured

56. POWER HOUSE SITE
In power house site only one hole was drilled
named as PH-01
BORE HOLE PH-01
 Silty sandstone ,freshly weathered and highly
fractured,
 Core recovery value range from 24-93%
 RQD value range from 0-81%
 Highly fractured mud stone is present which is
mixed with clay

57. LABORATORY TESTING OF DAM SITE
LABORATORY TESTING ON THE ROCK
SAMPLES
TESTING LABORATORY
 The laboratory testing on the rock sample
was got done from rock mechanics laboratory
of mining engineering department university
of engineering and technology Lahore

58. TEST TYPE
Two type of test were performed on rock sample
 Test For Physical Properties
 Test For Mechanical Properties

59. PHYSICAL PROPEERTIES TEST
Following properties was determine
 Moisture content
 Porosity
 Density

60. DISCUSSION OF PHYSICAL PROPERTIES OF ROCK
SAMPLE IN DIFFERENT BOREHOLES
BORE HOLE RA-01
 In bore holes RA-01 the average moisture
content was .509% average porosity measured
by helium porosimeter was 10.3%. Average
density was 2.601 gm/cc

61. BORE HOLE NB-01
 In bore hole NB- 01 the average moisture
content was .280% average porosity measured
by helium porosimeter was 4.47%. Average
density was 2.646 gm/cc

62. BORE HOLE LA-01
 In bore hole LA- 01 the average moisture
content was 0.530% average porosity measured
by helium porosimeter was 9.49%. Average
density was 2.610 gm/cc

63. MECHANICAL PROPERTIES
Following test was done for the mechanical
properties of the rock sample
 UNIAXIAL COMPRESSIVE STRENGTH

64. DISCUSSION OF MECHANICAL OF ROCK SAMPLE
PROPERTIES IN DIFFERENT BOREHOLES
BORE HOLE RA-01
 The average height of the sample was 110.00mm
and the average diameter was 43.75mm. height to
diameter ratio was 2.51 which is according to ISPR
standard
 Moisture conditions of the specimen at the time
of test were laboratory air dry. The equipment
used for this test was universal testing machine.
The unconfined compressive strength of the
sample was 107.985MPa

65. BORE HOLE NB-01
 The average height of the sample was 110.00mm
and the average diameter was 44,00mm. Height
to diameter ratio was 2.52 which is according to
ISPR standard
 Moisture conditions of the specimen at the time
of test were laboratory air dry. The equipment
used for this test was universal testing machine.
The unconfined compressive strength of the
sample was 81.281MPa

66. BORE HOLE LA-01
 The average height of the sample was 110.00mm
and the average diameter was 43.40mm. Height to
diameter ratio was 2.53 which is according to ISPR
standard
 Moisture conditions of the specimen at the time
of test were laboratory air dry. The equipment
used for this test was universal testing machine.
The unconfined compressive strength of the
sample was 79.897MPa

67. PETROGRAPHIC TEST ON ROCK SAMPLE
TESTING LABORTARY
MINERALOGY LAB PUNJAB UNIVERSITY
LAHORE

68.  Petrographic only done at the sample from
NB-01 at the depth of 20-21m. The core
samples have diameter 4cm and length 25cm,
weight 800gm. At the cut surface, the color of
the sample is medium grey, the sample show
mild effervescence at the surface on reaction
with cold dilute HCl. Megascopic assessment
of the sample revealed that the core sample is
fine grained sand stone.

69. DISCUSSION OF MINERALOGY OF ROCK SAMPLE
 Following is the mineralogical composition of
the sample
 QUARTZ 61%
 FELDSPAR 20%
 LITHIC FRAGMENTS 7%
 CALCITE 7%
 MUSCOVITE 3%
 MAGNETITE 2%

70. CHEMICAL ANALYSIC OF WATER SAMPLE
 Water sample was taken from NB-01 and NB-
02 of dam site. There chemical analysis shows
that water does not contain sulphates or any
other dangerous property in harmful quantity.
As such ordinary Portland cement may be
used in the foundation.

71. LABORATORY TESTING ON THE SOIL SAMPLES
Testing Laboratory
 The laboratory testing on the soil samples was
got done from the geo-technical engineering
Laboratory of civil department University of
Engineering & Technology Lahore.

72. COLLECTION OF SAMPLES
 Two samples of insitu soil were collected from
the site. One sample from RA-01 and other
sample from PH-01. The sample from RA-01
was collected from 2-3m depth below existing
ground level during July 2013. The sample PH-
01 was collected from 6-7m depth below
existing ground level during September 2013.

73. LABORATORY TESTING
 Both the samples were sent to university of
engineering & technology Lahore for soil
classification. Following tests were carried out
on these samples.
 Grain size analysis – ASTM D422
 Atterbergh limits – ASTM D4318

74. DISCUSSION ABOUT TEST RESULTS
 Both the samples were found to be non plastic
in nature. The sample of RA-01 is classified as
silty sand (SM) & sample of PH-01 is classified
as poorly graded sand with silt (SP-SM) as per
unified soil classification system ASTM D-
2487.

75. RECOMMENDATIONS
 Sandy soil is a good bearing material provided
that it is properly compacted & confined. In
open areas without confinement, this type of
material is subjected to erosion. Without
proper confinement erosion cannot be
avoided. It is therefore suggested that proper
confinement of this material be done to avoid
the direct hit of water.

76. FIELD TEST IN DRILL HOLE
 Permeability in rock strata has been
determined during drilling operation using in-
situ water pressure test in drill hole for weir
and operational structure

77. CONCLUSIONS AND RECOMMENDATIONS
 Geological investigations of ARJA-TIAN-
DHALKOT HPP suggest that site is feasible
taking into consideration the discontinuities
present
 To thoroughly investigate the geological and
structural conditions of the tunnel and dam
site area extra geotechnical study are require in
the tunnel site and dam site During
construction stages

78.  The grouting of Joints and fractures will
increase the stability of rocks.
 Seismicity of the area must be considered
during the design of foundations for dam.
 Construction material is available nearby dam
site so this will be economical for the
construction of dam, but for power house and
tunnel the accessibility of material will be
difficult

79.  Flooding in rainy season is very high in river,
the effects must be considered during the
design and after constructions of dam.
 Because of medium to high relief of
mountains, erosion effects are expected, so
sedimentation factor should be considered
while designing the dam

80.  Thick sandstone with subordinate siltstone and
shale is commonly exposed at the surface, or at
the shallow depth throughout the area. The
foundation therefore may be laid down on the
fresh rock. Overburden and weathered portion
should be removed
 Core recoveries and RQD value is good enough
and it reveals from laboratory results. That the
rock is hard enough to sustian the expected load
of the structure.

81.  Rocks of catchment area are belonging to
siwalike group, which is characterized by
alternate beds of sandstone and shale. The
later unit is soft, therefore siltation activity is
expected

82. THANK YOU
ANY QUESTION ?