CV201 Engineering Geology

8/11/2019 CV201 Engineering Geology

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B.E (CIVIL) /S3

CV201 ENGINEERING GEOLOGY

QUESTION BANK

UNIT I

What is meant by continental drift?

The movement of continents relative to one another. This is a

hypothesis put forward by Alfred Wegener in 1912. According to this,

there was only one continent called Pangaea and during the Carboniferous

period this single continent was broken up and drifted in different

directions to occupy the present positions.

Explain the theory of plate tectonics.

The rigid and solid crustal layers are called plates. The study of the

whole mechanism of evolution, nature and motions of plates, deformation

within plates and interactions of plate margins with each other is

collectively called plate tectonics.

What is Mohorovicic discontinuity?

There is sudden increase in the velocity of seismic waves at the base

of lower crust (about 6.9Km/sec), but it suddenly becomes 7.9 to 8.1

Km/sec. This trend of seismic waves denotes discontinuity between the

boundaries of lower crust and upper mantle. This discontinuity was

discovered by A. Mohorovicic and so it is called as Mohorovicic

Discontinuity or Moho discontinuity.

What is meant by weathering?Weathering is the disintegration and decomposition of rocks in situ.

Explain spheroidal weathering.


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It is a complex type of weathering characterized by breaking of the

original rocks into spheroidal blocks. Both physical and chemical processes

operate in this. The rock is divided into blocks by heat effects. Then the

blocks get rounded at the edges due to chemical decomposition there by

developing spheroidal shaped boulders.

Describe exfoliation.

It is the peeling off of concentric shells of rocks due to combined

effect of heat and wet conditions experienced in sub-tropical and monsoon

lands.

What is chemical weathering?

Decomposition and disintegration of rocks due to chemical reactions

is called chemical weathering. Water is the media which activate various

types of chemical reactions within rocks.

What is a delta?

The depositional feature of almost triangular shape at the mouth of a

river is called delta. Almost every large river forms a delta.

Give an account of alluvial fans.

Alluvial fans are semicircular or arcuate shaped accumulation of

sediments deposited by streams at the base of hills or mountain ranges.

They have gentle slopes. The size of alluvial fans vary considerably.

Explain dendritic drainage pattern.

The relationship of streams with one another and with the region as

a whole give rise to the drainage pattern. A drainage pattern in which the

tributaries and the main stream have the shape of branching tree is called

dendritic pattern.What is a waterfall?

A waterfall is a vertical drop of water of enormous volume from a

great height in the long profile of rivers.


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What is cuesta?

It is an erosional feature produced by rivers. It is a term given to a

combined set of escarpment and dip slope occurring adjacently.

Explain hogback.

Hogback is an erosional feature developed by river erosion. It is an

outcrop of a hard resistant rock that is very steeply inclined.

Give an account of barchan.

Barchans are sand dunes of crescentic shape having two horns. The

windward side have a gentle slope and is convex in plan, while the leeward

side is concave in plan with steep slope.

What are ventefacts?

Wind faceted rock boulders, pebbles etc are called ventefacts. They

are products of wind erosion. When three faces are developed then they are

called dreikanters.

Describe an atoll

An atoll is amore or less circular coral reef enclosing a lagoon, but

without land inside.

What are bars?

The ridges, embankments or mounds of sands formed by

sedimentation through sea waves parallel to the shore line are called bars.

What is an aquifer?

An aquifer is a geological bed or formation which can hold and

transmit water and from which considerable amount of water can beextracted. Eg: sand, sandstone.

What is an aquiclude?


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Earth material or geological formation which is porous but not

permeable is called an aquiclude. Eg: Clay bed.

What is a confined aquifer?

An aquifer which is underlain and overlain by impermeable layers

or aquicludes is called as a confined aquifer.

Explain an unconfined aquifer?

An aquifer underlain by an impermeable bed (aquiclue) the upper

part which is generally the unsaturated zone. The upper surface of the

water or the water table is under atmospheric pressure.

What is water table?

The upper surface of the zone of saturation is called water table. It

generally fluctuates depending on several factors especially recharge and

discharge.


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UNIT -2

Define a plane of symmetry.

A crystal has a plane of symmetry when for each face edge or solid

angle there is another similar face, edge or angle, which has a like position

on opposite side of this plane.

What is an axis of symmetry?

If a crystal is rotated through a certain number of degrees about

some line as an axis, if the same type of face occupies precisely the same

position as first, that axis is said to be an axis of symmetry.

Explain a centre of symmetry.

A crystal has a centre of symmetry if an imaginary line is passed

from some point on its surface through its centre, and a similar point is

found on the line at an equal distance beyond the centre.

What is mineral?

A mineral is a homogeneous inorganic substance with a definite

chemical composition and a certain characteristic atomic structure.

What is an ore?

It is an assemblage of ore minerals and gangue and from which ametal can be extracted profitably.

Explain a syngenetic deposit.


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It is a type of ore deposit which has been formed simultaneously

with the enclosing rock.

What are epigenetic deposits?

Those deposits that were formed subsequent to the formation of the

host rock.

What are fissure veins?

Mineral bodies of elongated or tabular shape deposited in pre-

existing fissures. The shape of the ore bodies resembles the original

fissures or fractures.

Describe ladder veins.

Mineral deposits generally found in some igneous rocks such as

dikes and consist of transverse, roughly spaced fractures that are filled with

deposits of economic minerals.

Explain cleavage of a mineral.

Cleavage is the tendency of a mineral to break more easily with

smooth surfaces along planes of weak bonding.

What are saddle reefs: They are mineralized cavities associated with the

folded rocks comprising of beds of competent and incompetent nature.

Describe beach placers: They are deposits of economic value accumulated

by waves along shores of water bodies like oceans.

What is meant by opalescence?

When minerals show milky appearance, the term Opalescernce is

used.What is streak?

It is the colour of the fine powder of the mineral.

What is luster of a mineral?


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It is due to the reflection of light from the mineral surface. It is a

measure of the reflectivity of the mineral surface.

What is meant by vitreous luster?

It is the luster exhibited by the broken glass eg: Quartz

What is meant by tenacity of a mineral?

Tenacity of a mineral denotes the character or degree of cohesion. It

is a consequence of its elasticity.

What is the hardness of corundum?

The hardness of corundum is 9.

What is meant by the fracture of a mineral?

The surface of breakage in any direction other than the cleavage is

known as the fracture surface.

What is the hardness of orthoclase?

The hardness of orthoclase is 6

Name three clay minerals?

The clay minerals are montmorillonite, illite and kaolinite.

What is the chemical composition of orthoclase?

The chemical composition of orthoclase is KAlSi3O8


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UNIT 3

What is a rock?

A rock is an aggregate of minerals.

What is a sedimentary rock/

A sedimentary rock is one formed by the deposition of solid

material which are the products of weathering and erosion and deposited by

agencies of transport.

What is magma?

Magma is the hot, molten rock material occurring beneath the earth.

What are lavas?

Lavas are extensive forms of molten magma which have been

poured out on the surface of the earth.

What are igneous rocks?

The igneous rocks are those which have solidified from a molten

condition.

Explain an intrusive igneous rock?

Intrusive igneous rocks are formed by the solidification andcrystallization of magma in the crust. They are generally coarse in grain

size. They alter the adjacent rocks on all sides.

Describe an extrusive igneous rock.


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Extrusive igneous rocks are those formed from lava erupted to the

surface. Because of the escape of the included gases vesicularity and

cindery surfaces are produced, especially in the upper parts of the flows.

Due to rapid cooling, grains are fire and glass may also be present.

How do we classify igneous rocks?

Igneous rocks are classified based on chemistry of the rocks (CIPW

norm), mineralogy, relative proportions of felsic and mafic minerals,

geologic occurrence and texture. A combination of these in the form of a

table gives the tabular classification.

What is meant by the texture of a rock/

Texture is the intimate mutual relationship of the mineral

constituents and glassy matter in a rock

What is a holocrystalline rock?

A rock composed entirely of crystals is said to be holocrystalline

Explain porphyritic texture.

In a porphyritic texture, the large crystals, or phenocrysts, are

enveloped in a groundmass which may be microgranular. Eg: Granite

porphyry.

Describe poikilitic texture.

Poikilitic texture is the converse of porphyritic. Smaller crystals are

enclosed in the larger ones without any orientation. Rock like syenite show

this texture.

What is ophitic structure?

The ophitic texture is a special case of poikilitic texture. In this

crystals of augite enclose memerous thin laths of plazioclaze. Thiscommonly occur in acid volcanic or hypabyssal rocks.

What is spherulitic structure?


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A type of structure seen in igneous rocks. It is a fibrous radiating

structure with the arrangement about a common centre. They commonly

occur in acid volcanic or hypabyssal rocks.

What is gabbro?

It is a plutonic igneous rock, Mafic minerals dominate, Clacic

plagioclase make up nearly half the rock while the pyroxenes make the

remaindes. Biotite, hornblende, ilmenite and magnetite are accessories. The

texture is usually coarse. Sometimes show ophitic texture.

Give an account of diorite.

It is a plutonic igneous rock. Quartz and potash felspars almost

absent. Consists dominantly of intermediate plagioclase felspars and lesser

amounts of mafic minerals. It is a coarse grained rock.

Describe a basalt.

It is a volcanic igneous rock with fine grained nature contains

augite, plagioclase, and occasionally olivine. Plagioclase feldspar and

mafic minerals occur in approximately equal amounts. They show sub

ophitic texture and vesicular structure.

Describe a sandstone

It is a clastic sedimentary rock. Sand when cemented becomes a

sandstone. The cementing materials may be calcareous, silicons,

argillaceous, or ferruginous. Some times some partly weathered felspars

grains may also be present.

Explain a limestoneIt is a non clastic sedimentary rock. Calcite is the dominant mineral.

Organic limestones are mainly due to biomechanical process and others are

formed by biomechanical process.


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Describe a shale

Clay deposits when compressed, gradually consolidate and with

varying degrees of cementation it is converted in to shale. They possess

fissility. This is called lamination.

Describe a quartzite

The metamorphic equivalent of sandstone and silt stone is quartzite.

Those when affected by a sufficient degree of heat, are merely

recrystallised into granoblastic aggregate, with the complete obliteration of

their elastic characters.

Give an account of slate

The dynamic metamorphism on argillaceous rocks produces slate.

The rock splits or cleaves readily along smooth, flat, closely spaced

surfaces of weak cohesion. Slates are mainly composed of finely divided

micaceous minerals. All minerals are flattened and elongated in the plane

of the cleavage.

Describe a schist

Schistose structure is due to the predominance in a metamorphic

rock of flaty, lamellas, tabular and highly cleavable minerals, such as mica,

chlorite, tale and amphiboles, under the dominant influence of directed

pressure, form layers or folia arranged in more or less parallel bands. This

is called foliation. When the foliation is closely spaced throughout the body

of the rock, so that almost any part of it can be split into flaty sheets, the

rock is called a schist.

What is a gneiss?

A metamorphic rock in which alternate bands of granular mineralsand micaceous and other ferromagnesian minerale are seen. The granular

minerals include quartz and feldspar and the ferromagnesian minerals


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include, biotite, hornblende and garnet. They are often granitic in

composition.

UNIT -4

Explain Dip and strike

The dip includes the direction of the maximum slope of a bedding

plane and the angle between the maximum slope and the horizontal . The

direction of dip is measured by its true bearing.

The strike of an inclined bed is the direction of any horizontal line

along a bedding plane. It is direction of the intersection of the bedding

plane with the ground surface. The dip dir direction is at right angles to the

strike. But the direction should be specified.

What are folds?

Folds are undulations seen in rocks. It is produced mainly due to thecompressive forces acting on them.

What is meant by the hinge of a fold?

Hinge is a continuous line on a folded surface connecting points of

maximum curvature. The amount of curvature of curvature may very

along the hinge.

What is an anticlinorium?

A series of anticlines and synclines so arranged structurallythat to get then they from a general arch or anticline is known

as an anticlinorium.

Explain a fold system


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A reverse fault that is characterized by a lour angle of

inclination with reference to a horizontal plane. This fur then

divided into over thrusts and under thrusts.

What are joints?

Joints are fractures along which three has been no relative

displacement. They may be open or closed in nature.

Describe columnar jointing.

This is seen in igneous rocks with uniform coo lip and

contraction in a homogeneous magma. The joints tend to take

on a regular columnar or prismatic form. They are

characterized by the development of four -, five-, or six-,

sided prisms, which may be intersected by cross- joints.

What are longitudinal or primary waves?

They are seismic waves in which motion of particles are

parallel to the direction of the direction of propagation. These

are the only waves used in seismic prospecting.

What is the principle used in seismic prospecting?

Because the elastic waves travel with different velocities

through different rocks they undergo both reflection and

refraction and behave like rays of light and they obey the

laws of reflection and refraction.

Mention the application of seismic method in civil engineering.

In civil engineering the method find application in foundation

problems, such as determination of depth to the bed rock,topography of basement rocks and presence of faults. In

groundwater investigations depth to water table can be

determined.


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What are the types of arrange ments of electrodes used in resistively

survey for groundwater exploration?

For ground water exploration wenner arragement and

Schlumberzer arrangement are used.

How is apparent resistivity calculated for wenner array?

Apparent resistivity is calaulated by using the formal =2aV/I.

Where a is the distance between adjacent electrodes in m, V is the potential

difference measured between the potential electrodes (volts)

and I applied current strength (amperes).

UNIT -5

Deserible remote sensing

Remote sensing is the science of acquiring information about

an object from a distance without coming into contact with it

using some sensors.

What is the type of measurement carried out in remote senting ?

The electromagnetic energy radicted by objects are

measured. The incident energy that is reflected by earth

surface features is measured as a function of the wavelength

and is called spectral reflectance.

Which part of the electromagnetic spectrum is usable for remote

sensing?

A large portion of the electromagnetic spectrum in the

visible mean- and middle infrared, and thenmal infrared

regions is usable for remote sensiy from space craft or

aircraft

What are the types of electromagnetic sensor systems?


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Two types of electromagnetic sensor systems are there. They

are passive systems and active systems.

How is remote sensing data useful in civil engineering?

On civil engineering contractions such as dams, tunnels high

ways etc. The topography, land ferns, depth of weathering,

soil types, lithology geologic structure and other details can

be obtained from aerial photographs and satellite imageries.

In hydrological otudies drainage characteristics can be

carried out. In connection with ground water exploration,

features aezociated with recharge zone, soil moisture and

geological aspects can be deciphered.

What is a spillway?

The spillway is a concrete structure that conveys floodwater

from the valley upstream from the dam to the downstream

with out damaging the structure.

What are the types of forces acting on a dam?

The types of forces acting on a dam are the static forces and

the dynamic forces.

What are the types of reservoir problems?

The reservoir problems include seepage and leakage and

ground water problem.

What are the terminology used soft- ground tunneling ?

The terms commonly used are raveling ground running

ground, ground, flowing ground, squeezing ground and

swelling ground.

In a stratified rock if a tunnel is constructed near a steep slope which will

be most unstable condition?

The most unstable condition arises when the beds are steeply

dipping in the same direction as the slope of the terrain.


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What happens if a tunnel is constructed below the water table?

The tunnel will act as a drain and water table will be lowered

causing depletion of water in the neigh hour hood .

Explain the application of geophysics in tunnel investigations.

The following information can be obtained by geophysical

methods. (1) the extent of faulting and fractures (2) depth of

bed rock under deep soil coven, and (3) location of particular

rock formations.

In the design of a bridge what are the factors to be considered?

The factors to be considered are the settlement of the bridge

and its stability.

What are landslides?

Land slides are sudden movement of soil, rock or sediments a

long a slope in hilly terrains.

What are the types of landslides?

The types of landslides are (1) slap slides and (2) rotational

slides.

Explain the types of coastal protection structures.

Structures made to prevent coastal erosion are coastal

protection structures. Only include construction of groins and

sea wall and aforestation.

What are the causes of land slides?In causes are external, internal and intermediate. These are

due to increase in shearing stress, decrease in resistance and

sudden drain down of strata along a slope.


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Unit I

6 Mark Questions

1. Explain the geology in construction job in scope of Engineering?

2.

Write a critical essay on the Age of the Earth.

3. Give a general view of the internal structure of the earth Discuss

briefly the importance of seismological studies in arriving at broader

conclusions about the structure of the Earth.

4. Write an essay on Weathering of Rocks and the significance in

Engineering construction.

5. Write a critical essay on the Origin of the Earth should we

consider the problem as solved? If yes how? If no why?

6. Explain the terms, Crust, mantle and core.

7.

Write a brief note on the atmosphere surrounding the earth.

8. What are the plate Tectonics in the earth? Explain briefly.

9. What are the Hypohesis principles adopted in the Internal structure

of the earth.

10.Explain Glaciers. What are the Geological work in Glaciers.

10 Mark Questions :

1. Explain the terms : (any five of them):

Weathering, crosion, denudation, deflation, abrasion, attribution,

saltation, overhang, blowout, ventifacts.

2. Give an account of geological work of wind explaining briefly some

major geological features produced by this agency on the land surface

due to erosion and deposition.

3. Give an account of geological work of running water explaining

briefly some major geological features produced by this agency on the

land surface due to erosion, Transport and deposition.

4. Write an essay on work of atmosphere and its significance in

Engineering construction.

5. Discuss the relevance of Engineering Geology in Civil Engineering

Profession.


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UNIT II

6 Marks Questions

1. Define a crystal, crystal symmetry, crystal form and a

crystallographic system

2. Give a detailed account of the elements of symmetry, forms

developed and minerals crystalling in any two of the following

system

i)Isometric system ii) Hexagonal system iii) Monoclinic

system

3. Write short notes on any three

i) Polysynthelic twinningii) Albite Law twinning

iii) Rhombohedron

iv) Crystallographic exes

4. Explain, in a tabular form, salient features of crystallographic

systems

5. Discuss processes of formation of minerals in nature. Which

group of minerals is most common in occurrence?

6.

What is rock forming mineral? Explain it

7. Give salient features and mention important properties of any

three of the following groups of minerals:

i) Pyroxene group

ii) Felspar group

iii) Amphibole group & (iv) Mica group

8. Write short note on any three

i)Minerals formed due to recrystallisation


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ii) Sheet structure

iii) Classification of feldspars

iv) cleavage in amphiboles and pyroxenes.

9. Match the minerals with their correct chemical composition and

hardness

Mineral Chemical composition Hardness

Calcite sio2 7

Orthoclase k A I SI308 3

Quartz caco3 6

Hypersthene MgAl204 2.5

Muscovite (Fe,mg) sio3 7.5

Spinel KAl2(Alsi3010)oH2 5.5

10 Marks Questions

1. Write an essay on Silicate Group of minerals giving an account of

their composition, atomic structure and classification.

2. What are the carbonate minerals which are very important in

secdimentary and metamorphic groups.

3. Explain the pyroxene Group of minerals in the igneous and

metamorphic rocks.

4. Explain importment physical properties of minerals that are

commonly studied for their Indentification.

5.

Explain the difference giving example

a) Colour and Lustre b) Cleavage, Parting and Fracture

a) Hardnex and tenacity d) Density and Specific gravity


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b) e) Vniaxial and biaxial minerals.

6. Write short notes on (any five):

a)

Cleavage b) Structure of minerals c) play of colours

c) Nicol prisms e) Briefringence f) Streak

g) opticalsign h) mots scale of Hardness.

UNIT III

6 Marks Questions

1. What are the difference between igneous, sedimentary and

metamorphic rocks?

2. Explain with neat sketch of phacoliths?

3. What are the structures of sedimentary rocks?

4. Explain any three of the following:-

d) Gneiss b) Schist c) Marble d)

Quantzile

5.

What are the engineering properties of rocks?

6. Explain Density and Abrassive Resistance?

7. What are rocks? How is it formed?

8. What are concordant bodies? Explain it?

9. Explain any three igneous rocks?

10.Classify the mode of formation or origin of the rocks?

10 Marks Questions


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1. How are igneous rocks formed? Describe the illustration the various

forms in which they occur?

2.

Give a simple classification of igneous rocks and mention the basisof such classification.

3. What are extrusive and instructive bodies? How the igneous rocks

are classified?

4. Give a brief account of the classification of sedimentary rocks and

indicate the importance of study of shape and size of grains of

sediments.

5. What do you understand by the term texture of a rock? Discuss the

various types of textures of sedimentary rocks.

6. Discuss the classification of metamorphic rocks and state the basis

of such a classification.

7. Describe important metamorphic rocks giving their uses as

engineering materials.

UNIT IV

6 Marks Questions1. What are folds? Give an outline of classification of folds?

2. Explain the following terms:

a) Dome and Basin b) conjugate c) Recumbent d)

Anticline and syncline

3. Describe, with the help of neat sketches, various parts of fault as

understood in structural geology.

4.

What are broadly accepted causes of faulting of rocks?

5. Write a brief note on joints in rocks, their causes and effects on the

engineering quality of rocks.

6. Write an essay an Volcasic Landforms with examples.


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7. Write short notes on any three :

(i) Rift valleys (ii) Block mountains (iii) Pedeplains (iv) Core

and crater.

8. Write the descriptive notes on any three :

(i) Origin of Lake Basin (ii) Coastlines of Submergence, (iii)

Classification of plains (iv) Plate Tectonics.

10 Mark Questions

1.

Give an account of mountains as physiographic features. Discuss

briefly latest theory about their origin.

2. Explain with the help of neat sketches, various types of valleys and

their origin. Give suitable examples.

3. Define a Fold : How Folds are classified? Explain with the help of

neat sketches, important types of folds as distinguished on the basin

of inclination of axial plane.

4.

Explain with the help of near sketches principal types of faults asrecognized on the basis of (i) apparent movement (ii) Actual

movement. (iii) Mode of occurrence.

5. Write illustrated notes on (any five)

(i) Thrust fault (ii) Horst and graben (iii) Master joints (iv)

Columnar jointing (v) Angular unconformity (vi) Inlier and

Outlier (vii) Rift valley.

Unit V

6Mark Questions :

1. What are the objection of Geological investigates on in engineering?


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2. What are the remote sensing Techniques evolved in the Geological

investigation?

3. What are the methods of remote sensing in the geological

application?

4. What are the advantages and limitations of remote sensing?

5. How will you determine the groundwater conditions in the region of

tunnel project?

6. What are the Remedial measured adopted in the mobility of

Landslides?

7. Explain briefly Sea Walls.

8. What are the Geological character for investigation?

9. Explain Dip and Strike of planes in the earth?

10.

What re the Geological Faults formed in the earth.

10 Mark Questions :

1. What are the classification and types of Land Slides according to the

characteristic features?

2. What are the Geophysical Investigation adopted in economically

exploration of subsurface geology?

3. What are coastal protection measures adopted in Indias Coastline?

4. Explain the methods of Geological investigations in Civil

Engineering.

5. What are the satellite remote sensing methods and explain the

advantages and disadvantages of the satellite remote sensing?

6. Explain the formation of tunnels and method of excavating

tunneling work in the geological considerations.


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CV201 Engineering Geology