Acknowledgements :
It is an essential for an civil engineering student to have the fundamental
 aspect of the geology. Geology is nowadays taken as a major subject of civil 
engineering worldwidely. For any applied science only the theoretical knowledge 
is very flowering one. With the aim of what has been emphasized above a three 
day field trip has been managed by the I.O.E, we are indebted to the team of 
out lecturers and their colleagues for such a robust management and the 
fruitful compact field trip. 

Introduction :
General Introduction : 
A three field trip has been undertaken. The trip started from the Pulchowk 
campus and terminated on Malekhu. On the way, the different landslides, and 
river channels were studied as far as possible. On the periphery of Malekhu, 
different types of geological structures were studied. 


Objectives :

To be familiar with the various aspects of geo-engineering is our goal. To 
achieve our goal we have the following activities. 

(1)Dip and Strike measurements
(2)Study of the bedding, foliation and joints on the rock outcrop. 
(3)Handling of the compass for the documentation of the engineering geological 
area. 
(4)Study of the landslide. 
(5)Study of the weathering profile. 
(6)Morphology of the river channel. 
(7)Rock identification in the field. 
(8)Identification of different geological units of the lesser Himalayan and 
Kathmandu Nappe. 
(9)Engineering Geological study along the large scale geological discontinuity
(Mahabharat Thrust). 
(10)Study of the rock slopes along the road corridor. 
(11)The rock mapping techniques of the rock outcrops. 

1.3 Methodology : 

The method of the study during the field trip comprises the following: 

Field observation :

The different geological structures as far as possible were directly observed 
and recorded. 

Literature :

The significance of the different geological structures, the causes for their 
origin, and other related aspects of the observational thing were studied 
referring the different the different literature. 




3

Instrument : 
The basically used instrument for the field observation are the following:


Geological hammer :

The geological hammer was used for the collection of the rock samples, to 
expose the fresh surgace from the weathered sample and hence the identification 
of the rock sample is eased 

Bruton compass(Geological) :

Bruton compass was used to measure the dip and strike direction as well as dip 
amount. Hence the attitude of the different units were measured and included on 
the relevant positions. 

Location of the study area :

Engineering Geology

General Geology of Nepal :

The Geology of Nepal can be considered to be formed by the following main 
geological units. 

Gangetic plane : 
It is a narrow belt towards the southern most part of the kingdom being formed 
from the alluvial deposits of the Himalayan rivers. It has the no remarkable 
formation of sedimentary rocks neither the igneous rocks. 


Siwalik range :
The Gangetic plane have been separated from the Siwalik range by the main 
frontal thrust. It is the one of active thrust in this region. It separates the 
alluvial deposits from the sedimentary rocks. Siwalik range can be considered 
to be made of three zones the upper zone of conglomerate, the middle zone of 
mudstone and the lower zone of the sandstone. 

Lesser Himalayan range :
It comprises our trip area. Sometimes the height may eve reaches to 4000m. Main 
boundary thrust separates this zone from the Siwalik range. It has wide variety 
of metamorphic rocks with some variety of igneous an sedimentary rocks. 



Higher Himalayan range : 
The northernmost part of the Kingdom is separated rom the lesser Himalayan 
range with main central thrust called Higher Himalayan range. It has high grade 
metamorphic rocks. 

Inner Himalayan zone :
The leftist mountains of the world lie in this zone. It has the thetic 
sedimentary rocks and lime stone. 

4
 
General geology of Malekhu and adjacent area :
Malekhu lies on lesser Himalayan unit of Nepal. It has peculiar geological 
features within a small range of area. 


Topography :
The Malekhu V.D.C. of Dhading district lies about 70 Kms south west of 
Kathmandu valley and is located at latitude of 27 50' 38'' to 27 45' 50'' and 
longitude of 24 49'5'' to 84 50' 50'' . It is situated on the bank of Trishuli 
and Malekhu river. The Trishuli river is running from the eastern direction to 
the western diredtion and the Malekhu river from south to north which mingles 
into the Trishuli river. Also, the Malekhu river has a tributary namely the 
Apakhola which meets the Malekhu river at a distance about 3 kms from the 
Malekhu bazzar. Climatically Malekhu is a sub-tropical zone. Mainly the 
rainfall are during the monsoon.

Major rock types :
Literally, Malekhu can be assigned as the museum of the rocks. It consists of 
lower grade as well as higher grade metamorphic rocks. The igneous and 
sedimentary rocks are less than that compared with metamorphic rocks. The area 
is regionally metamorphosed and it has younging downward lithology pattern. The 
different rocks found in this area are quartzite, slate, limestone, dolomite, 
phyllite, schist and marble with some what specific names like Benighat slate, 
Malekhu limestone, Bhaisedoban marble etc. 


6

Major Geological structures :
Dip and strike are the two fundamental aspects in the study of the geology. 
However the dip direction and the dip amount are the most significant for the 
study of engineering geology. 

Dip direction :
It is the direction of the rock strata towards which it dips i.e. inclined and 
it always lies at right angle to the strike. Strike is the direction on sloping 
surface in which a horizontal line can be drawn. 


Dip amount :
It is the maximum angle of inclination of the rock strata with the horizontal , 
and is measured in vertical plane. 


Folds :
It is a bend or plication in bedding, foliation, cleavage or other planar 
features in socks. It is the product of deformation Fold on the basis of the 
dipping of the involved limbs can be considered to be of: 


Anticlianl type :
The type on which the dipping of the limb is away from each other 


Synclinal type :
The type of fold on which the limb dip towards each other. Field photo attached 
show the syncline and anticline fold. 


7

 
Benighat slate :
The name is derived from the village 'Benighat' at the confluence of 
Budhigandaki and Trishuli river. This formation consists of gray to black 
slate. In some places it is highly carbonaceous (graphitic). Intercalation of 
quartz vein 2-4 cm thick is also observed in some places. The beds are not 
thicker than 5-7 cm in this formation. 

Attitude of bedding plane :
Strike 270o 
Dip amount 81o 
Dip direction 175o 


Location :
Along Thopal Khola and Dhading road after 300 m from suspension bridge over 
Trishuli river. 

9

 
Malekhu Limestone :
The name is derived from the village "Malekhu" along Prithivi Highway. The 
Malekhu limestone has a transitional contact with Benighat slate near the 
suspension bridge along Malekhu Dhading road on he right band of trishuli 
river. 


It is composed of light yellow colored siliceous limestone of fine grained to 
dense, crystalline and massive. In the middle and top part of this formation, 
the dolomite limestone is observed bounding structure in quartz veins is also 
observed in limestone which shows contemporary pressure temperature conditions, 
Weathered rock is blackish is color and fresh exposure is brown in color. The 
average thickness of this formation is about 800 m along Malekhu khola towards 
upsteam. 


About 400 m far from the bridge over the Malekhu Khola, we observed nearly 
vertical beds of dolomites limestone of grayish white or elephant skin color. 



Attitude of bedding plane :
Strike 255o 
Dip amount 80o 
Dip direction 155o 


About 200 m from the previous location along Malekhu Khola towards upstream we 
observed a fault plane left side of the fault plane composed of limestone of 
whitish yellow colors and the right side of the fault plane composed of grayish 
white phyllitic limestone. The fault plane composed of mylonite bressia. Nearly 
200m from the fault plane, there is a transitional contact between Malekhu 
limestone and Robang formaton. 


Robang Phyllite with Dunga Quartzite :
The name is derived from the village 'Robang' in Dhading district along Malekhu 
Khola on the right bank about 500m from the Prithivi Highway near Malekhu 
bazaar contact between dolomitic limestone of Malekhu limestone and dark green 
phyllite of Robang Formation was observed from where river bends sharply. Main 
lithology is phyllite and yellowish quartzite called 'Dunga Quartzite' which is 
highly jointed. Phyllite is gradually replaced by massive yellowish quartzite 
towards south. Some phyllite bends are black in color due to graphite. Nearly 
middle part of the formation, we observed Amphibolites, a metamorphic product 
of basic intrusive rock-dolerite. The thickness of this formation is about 200-
1000 m. 


Along Prithivi Highway towards Gajuri :
About 500 m far from the Malekhu bridge, the contact between Robang Formation 
and Malekhu limestone is found which is transitional contact. 


Attitude of bedding plane :
Strike N 80 E � S 80 W 
Dip amount 75o 
Dip direction S 10 E 


About 100 m far from the contact , amphibolites a meta basic rock is observed 
which is weathered, and is olive and muddy in color with contact of meta basic 
rock and quartzite is observed . It may be Dunga Quartzite. 


10

Bhaisedoban marble :
The formation is named after the village 'Bhaisedoban' an the Tribhuwan 
Highway. 


Attitude of beds :
Strike :  N 70 E � S 70 W 
Dip direction :  S 20 E 
Dip amount : 70 


Granite :
It is lighy coloured plutonic rock. It has medium grainded and holocrystalline 
structure. Rock forming minerals presents in granite are quartz and orlthoclase 
feldspar. Other minerals presents are olivine, micas, amphoboles, pyroxzene 
etc. In Malekhu tour we observed a granite contained zenolith. Zenolith is that 
part of granite which was not totally digest when intrusion cuts country rock 
on its path or flow way. 


Engineering Geological structures :
In the various formation different types of geological structures were 
observed. They have great significance in the engineering. Presence of joints 
will greatly reduce the strength. If fault is present in the site, there is 
possibility of discontinuity of the rock beds. The structures found may not 
have strength as expected due to the metamorphism. If these is unconformity it 
will give unexpected result. Study of the attitude of the rocks will give the 
tentative idea at which direction there is possibility of finding some rocks. 
It will also helps to know the possibility of failure. 




12
Some important terms related to river morphology :
Delta :
The Deltas are alluvial deposits of roughly triangular shape, that are 
deposited by the river. This results in a large seale, almost total deposition 
of the load carried by the river at that place. This continual deposits results 
to development of Delta structures. 

Oxbow Lakes :
The isolated curved or loop shaped parts of a meandering stream often contain 
some supplies of water, which are called Oxbow Lakes. 

Construction material survey from river deposits :
As the river deposits have considerable economic and strategic importance the 
main concern of a civil engineer should always be to ascertain the true nature 
of the deposits. Alluvium is usually very porous and will be compressible if 
rich in clay and permeable if composed mainly of silt, sand or gravel. In 
excavations the zone of saturation may be met at a small depth below the 
surface of the alluvium. Running sands and other forms of instability can occur 
under these conditions unless ground water is controlled. The alluvial mud may 
be used as one of the raw material I the manufacture of cement. Valuable 
deposits of gravel and sand occur in these terrace gravels and are excavated on 
a large scale for supplies of aggregate an sand for concrete and mortar. 


14

 
Landslide 
Introduction :
In many region of the earth a instability of superficial rock masses either 
consolidated or un-consolidated is a great proglem. When these superfidial 
masses either move abruptly or slowly in downward gradient or vertically 
downward then it create a great problem. Such flow of superficial masses is 
either rapid slow, consolidated or unconsolidated, major or minor loose 
material and may take place in any manner and in manner and in any direction 
are properly grouped as land slides. 


Study of the different landslide during the field trip :


Landslide no. 1 : 
The landslide located at chain age 15+200 is of differential type. It was 
almost dry so there is no chances to have water pressure. Slide is near the 
highway so that one cause and predominant factor is the construction of roadway 
other cause are weathering and discontinuity in rocks. Gabion wall and dry 
stone masonry are used for safety r prevention. 


15


 
Landslide no. 2 :
The Chainage (16 + 850) was dipped toward south east. The color is also 
different in different part. The Landslide is initiated due to the following :


(0)Weather of rock color varying from red to black.
(1)Featured rock
(2)Foliattion plane unfavourabvle to tributary.


Landslide No. 3 :
Location :  Junge Khola 
Type:  Composite complex as flowage type 


The landslide is located on the side of Junge Khola . The lower part of the 
slide is on the river so there is no any debris collected at the lower part. 
The rock mass of the landslide is vary weak type and almost completely loosed 
the cohesion being wet of water. 


16

 Landslide No. 4: 
Location : approximate 45 km.

The landslide is very esteem type and may be hazardous. This slide is also 
called subsidence type at which vertical fall of mass is occurring. From the 
topography of the evolved area and the trend of slide we came to conclude that 
neither the retaining wall nor the infilling is the proper treatment. 



17
Landslide No. 5 :
Location : 500 m ahead from Dhading Bridge
Type: rock fall

This is the rock fall and is extending in wide range. The slope is almost 
vertical the rock mass is heavily jointed and fractured. The main cause of the 
rock fall is due o the Kulo that constructed on the another side of the hill. 



Solution aspect of landslide :
Location : Dhading bridge

Various safety measures are found to be applied on the construction site of the 
Dhading bridge to control landslide and river cutting. Various types of safety 
measures applid are as follows:


18

 
Slope protection :
Following measures were applied to protects slope.

(0)Reshaping :
The possible area of land slide was reshaped so as to decrease the steepness. 
The site is also terraced. 

(1)Vegetation :
Vegetation protects from absorption of water and also facilitates flow of water 
it also provides some stability of the surface. 
(2)Diversion of water :
Diversion of water will prevent from erosion due to the water flow and it also 
helps to reducxe the absorption of water. 

Slope Stability :
To stabilize the slope various structures are used they are retaining wall, 
gabion wall, anchoring, bolting etc. Gabion walls are used where water pressure 
is created. 


19

Hosted by www.Geocities.ws