about the convention

8/20/2019 about the convention

1/31

Date: -27th feb 2016

ACKNOWLEDGEMENT

At every step, an engineer has to encounter earth andearth, as a material or as construction site. So it provesthe importance of geology to civil engineeringprofessionals. He or she must go through the inner coreof engineering geology for his/her perfection and forprofessionalism.

The trip was really fruitful to us and certainly we got a

lot of knowledge about the rocks and its structures. Thank you kamal sir and sir for sharing a part of hisbrain and to help us in eld and giving completesuggestions. e also e!press our deep sense of gratitude to lab ko sir ko naam for guidance during eldvisit. Also thanks for driver dai ko naam for taking ussafely to the spot. At last, we would like to thank all ourfriends of other groups who cooperate kindly in team

work """""""""...All of you did a wonderful #obto lay out these pages.

At last, we would like to e!press our gratitude to ourcollege, $athmandu %ngineering &ollege. e are proudto be students of $athmandu engineering college

'ibek Silwal ()*+bce)+-

'ikalpa Subedi()*+bce)-

'ikesh $armacharya()*+bce)-

'ikram hungana()*+bce)0-

'ipin 1.&.()*+bce)2-


2/31

TABLE OF CONTENT

)+.3ntroduction""""""""""""""""""""""""".

3ntroduction

4b#ective of the study

5ocation of study area

). Study of mass movement and study of preventive andcorrective measures"

6ass movement

&auses

&lassication

7revention and corrective measures

escription of each location

Sketches and photographs

). 6easurements of attitude of planar features of rock""""""""

Types of geological compass

Handling of geological compass

8ock outcrops

%!posures

7lanar features and Attitude of planar features

4bserved data in the eld


)0. 3dentication of rocks in theeld"""""""""""""""""

8ock and its classication


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8ock and its identication

Types of rock identied in the eld

escription of each location

%ngineering signicance of the rock

Sketches and photographS

)2. 1eology of studyarea"""""""""""""""""""""

8egional geological framework

1eological formation

8ock types in the formation

)9. Study of geological structures in theeld"""""""""""

1eological structures

Types of geological structures

1eological structures observed in the eld

&ivil engineering signicance of the geologicalstructures


)*. Study of river channelmorphology"""""""""""""""

8iver morphology

Types of river morphology

:eatures developed by river channel

&ivil engineering signicance of river channel

Sketches, photographs, description of thelocation


4/31

);. %ngineering geological studies of the rockyoutcrop""""""""

ene engineering geological data

7arameters of engineering geological data

%ngineering geological data observed in the eld

&ivil engineering signicance of the geologicaldata

)


5/31

The two days tour from we were taken to 6alekhu forgeological study. :irst day, we were taught to handlethe geologist compass to measure dip and strike andwe got ideas about river morphology, identication of rock and di?erent geological units of lesser Himalayaand $athmandu nappy. However the two days trip wasnot su@cient to fulll the thirst of us.

1.2 Ob(e&t')e* #f the +t%$,

To measure strike of bedding plane

To measure the dip direction and dip amountof the bedding planes and #oints

To identify the rock type and its property.

To be clear enough about #oints, faults and

folds.

1. L#&at'#! #f *t%$, a"ea

6alekhu lies on lesser Himalayan unit of epal. 3thas peculiar geological features within a small range of area. The 6alekhu B..&. of hading district lies about*) $ms south west of $athmandu valley and is locatedat latitude of *o 2)C ;CC to *o 02C 2)CC and longitude

of 0o0


6/31

. Mea*%"ee!t #f Att't%$e #f /a!!e" Feat%"e*Of R#&

.1 T,e* #f a** a"e a* f##3*:

1. Clinometers compass:

The compass, which can measure bearing andorientation with two sets. Since it doesnDt consist thesprit level, it should leveled by appro!imation and maynot be accurate.

2. Burnton compass:

3t consists of sprit level and can measure bearingand inclination with relatively less error.

3. Clar compass:

3t can read both inclination and bearing at once.8elatively easier to handle.

4. Digital compass:isplays digits as reading. %asy to handle.

5. Digital PC compass:

The compass directly connected to the computer.o not need to booking.

.2 4a!$'!5 #f 5e##5'&a a**:

A geological compass is used to measure theattitudes of the geological features. The compass wasmainly used for measuring the bearing of ob#ect withrespect to north and to measure inclination .The mainoperation of geological compass consists of openingthe compass carefully, leveling the spirit level andplacing the compass on the planer feature for

measurement.


7/31

. R#& #%t&"#*:

4utcrop is a 5e##5'&a term referring to theappearance of be$"#& or *%e"&'a

$e#*'t* e!posed at the surface of the %arth. 3n mostplaces the bedrock or supercial deposits are coveredby a mantle of *#' and vegetation and cannot be seenor e!amined closely. However in places where theoverlying cover is removed through e"#*'#!, the rockmay be e!posed, or crop out. Such e!posure willhappen most freGuently in areas wheree"#*'#! is rapidand e!ceeds the3eathe"'!5 rate such as on steep

hillsides, river banks, or tectonically active areas.'edrock and supercial deposits may also be e!posedat the earthCs surface due to human e!cavations suchas Guarrying and building of transport routes.

4utcrops allow direct observation and sampling of thebedrock '! *'t% for geologic analysis andcreating 5e##5'& a*. I! *'t% measurements are

critical for proper analysis of 5e##5'&a h'*t#",andoutcrops are therefore e!tremely important forunderstanding earth history. Some of the types ofinformation that can only be obtained from bedrockoutcrops, or through precise drilling and coringoperations, are> *t"%&t%"a 5e##5,featuresorientations (e.g. bedding planes, f#$ a!es, f#'at'#!-,depositional features orientations (e.g. paleoFcurrent

directions,grading, fa&'e* changes-,ae#a5!et'& orientations.4utcrops are also critically important for understandingfossil assemblages, paleoFenvironment, and evolutionas they provide a record of relative changes withingeologic *t"ata.

. Mea*%"ee!t* #f att't%$e #f a!a" feat%"e*#f "#&* '! the e$

http://en.wikipedia.org/wiki/Geologyhttp://en.wikipedia.org/wiki/Bedrockhttp://en.wikipedia.org/wiki/Superficial_depositshttp://en.wikipedia.org/wiki/Superficial_depositshttp://en.wikipedia.org/wiki/Soilhttp://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Weatheringhttp://en.wikipedia.org/wiki/In_situhttp://en.wikipedia.org/wiki/Geologic_maphttp://en.wikipedia.org/wiki/In_situhttp://en.wikipedia.org/wiki/Geological_historyhttp://en.wikipedia.org/wiki/Structural_geologyhttp://en.wikipedia.org/wiki/Fold_(geology)http://en.wikipedia.org/wiki/Foliationhttp://en.wikipedia.org/wiki/Facieshttp://en.wikipedia.org/wiki/Paleomagnetichttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Bedrockhttp://en.wikipedia.org/wiki/Superficial_depositshttp://en.wikipedia.org/wiki/Superficial_depositshttp://en.wikipedia.org/wiki/Soilhttp://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Weatheringhttp://en.wikipedia.org/wiki/In_situhttp://en.wikipedia.org/wiki/Geologic_maphttp://en.wikipedia.org/wiki/In_situhttp://en.wikipedia.org/wiki/Geological_historyhttp://en.wikipedia.org/wiki/Structural_geologyhttp://en.wikipedia.org/wiki/Fold_(geology)http://en.wikipedia.org/wiki/Foliationhttp://en.wikipedia.org/wiki/Facieshttp://en.wikipedia.org/wiki/Paleomagnetichttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Geology


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L#&at'#! N#- L1:

About +))m far from the old (broken- bridge along7rithvi Highway.

S.N. Dip Direction

(degree)

Dip Amount

(degree)

Attitude Plane Remarks

Observed By Bisnu Prasad Devkota

! "#$ #% #%&"#$ '.P

" !! # #&!! B.P

$ $* + +&$* '.P '.P,'oint

Plane* % *" *"&% '.P

+ %% !* !*&%% '.P B.P,Bedding

Plane# %+ !$ !$&%+ B.P

"#+ +# +#&"#+ B.P

%- $" $"&%- '.P

- !+ " "&!+ B.P

!% $+# !- !-&$+# '.P

Observed By ari Prasad Poudel

! %-% $# $#&%-% '.P

" "#+ +% +%&"#+ '.P

$ !% # #&!% B.P

* "*+ #+ #+&"*+ '.P


9/31

+ ""% $ $&""% '.P

# %" +$ +$&%" '.P

!#+ &!#+ B.P

%% + +&%% '.P

- "+" +* +*&"+" '.P

!% %" " "&%" '.P

Observed By /osa Ra0 Rimal

! "! +! +!&"! '.P

" %" !* !*&%" '.P

$ !#" +$ +$&!#" B.P

* !" +# +#&!" B.P '.P,'ointPlane+ % "# "#&% '.P

# $** * *&$** B.P B.P,Bedding

Plane "#$ "% "%&"#$ '.P

!! # #&!! B.P

- !#* * *&!#* B.P

!% "! +$ +$&"! '.P

Observed By 1alan 2adav

! $*+ # #&$*+ B.P

" !% !" !"&!% '.P


10/31

$ !+ + +&!+ B.P

* %* !" !"&%* '.P

+ !#* + +&!#* B.P

# "#+ % %&"#+ '.P

"# #% #%&"# '.P

%# $# $#&%# '.P

- "++ $" $"&"++ B.P

!% "+# #- #-&"+# '.P

Observed By 3anisman Sakya

! "% + +&"% '.P

" "-+ #+ #+&"-+ '.P

$ $+% + +&$+% B.P

* !% &!% B.P

+ !" % %&!" B.P

# "% ++ ++&"% '.P

"#+ $% $%&"#+ '.P

"++ #" #"&"++ '.P

- !#$ * *&!#$ B.P

!% %-+ !% !%&%-+ '.P


11/31

. IDENTIFICATION OF ROCK+ INT T4E FIELD:

.1 R#& a**

3n 5e##5,, rock is a !at%"a, occurring aggregateof '!e"a* and/or'!e"a#'$*. The%arthCs 'th#*he"e is made of rock. 3n general rocksare of three types, namely, '5!e#%*,*e$'e!ta",,and eta#"h'&./et"##5, is the scientic study ofrocks.

.2 Ca**'&at'#! #f "#&*

1. +e$'e!ta", "#&*:

The sedimentary rocks, as the name indicates, arethose rocks which are derived from the consolidation ofsediments of the pree!isting rocks (igneous,sedimentary or metamorphic- under the inuence of

mechanical, chemical or organic activities of thedenuding agents (i.e. wind, running water, glacier etc.-

The products of wear and tear of the rocks due tonatural agencies like blowing wind, running water,percolating underground water etc when sub#ected,under favorable conditions to sedimentation andsubseGuent compaction results in the formation of rock

masses due to pressure and temperature conditionswhich are known as the sedimentary rocks. ell knowne!amples are sandstone, lime stone, shale etc.

2 Meta#"h'& "#&*:

The rocks formed from the preFe!isting rocks (igneous,sedimentary or metamorphic- by the processes ofmetamorphism (1reek, 6etaI&hange, morpheIform-.

http://en.wikipedia.org/wiki/Geologyhttp://en.wikipedia.org/wiki/Naturehttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Mineraloidhttp://en.wikipedia.org/wiki/Lithospherehttp://en.wikipedia.org/wiki/Igneoushttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Metamorphic_rockhttp://en.wikipedia.org/wiki/Petrologyhttp://en.wikipedia.org/wiki/Geologyhttp://en.wikipedia.org/wiki/Naturehttp://en.wikipedia.org/wiki/Mineralhttp://en.wikipedia.org/wiki/Mineraloidhttp://en.wikipedia.org/wiki/Lithospherehttp://en.wikipedia.org/wiki/Igneoushttp://en.wikipedia.org/wiki/Sedimentaryhttp://en.wikipedia.org/wiki/Metamorphic_rockhttp://en.wikipedia.org/wiki/Petrology


12/31

3t is a process by which e!isting rocks are modiedunder the inuence of heat pressure or both

The ultimate product of metamorphism of already

e!isting igneous, sedimentary or even metamorphicrocks incorporating temperature, pressure, stress,chemically active substances are called metamorphicrocks, e.g. Slate, 6arble, Schist, 1neiss, 7hyllite.

I5!e#%* "#&*

7rimary or rst formed rocks are called igneous (5atin,3gnisI:ire- rocks. 3t has been observed in deep wells,borings, mines, etc. that the temperature increaseswith the depth, generally there is an increase of +o & forevery 0)m. depth.

The consolidation of magma results in the formation ofigneous rocks e.g. of igneous rocks are granite, rhyolite.

The magma remains in the molten state> so long itsphysical and chemical environments remain

unchanged. 'ut whenever some changes (pressure,temperature etc- takes place> the magma no longerremains in molten state, but is changed into solid statecalled rock. Those rocks, which are formed directly bythe solidication of magma on the earthCs surface orbelow it, are called igneous rock.

. I$e!t'&at'#! #f "#& '! the e$

L#&at'#! !#.L2

About 0))m from the hanging bridge over the Trishuli8iver along Thopal $hola. Hanging bridge is about+))m from the 7rithvi highway towards north and alongthe way of Thopal $hola. The study of 8iver &hannel6orphology had done in this location which is describedlater.

L#&at'#! !#.L


13/31

About ))m from the hanging bridge over the Trishuli8iver along Thopal khola i.e. in between location 5 andthe hanging bridge. :ollowing things we observed inthis location

+. Slate 8ock

. Jnconformity

. 5imestone 8ock

+ate R#&:

escriptionK

S.N. Pysical Properties

! Sample number %!

" 4olor 5rayis

$ 6e7ture Non crystalline

* Structures 8oliation plane&slaty cleavage

+ 5rain si9e 8ine

# Sp. 5ravity 1o: to medium

Acid test No reaction

3ineral comp.

- Origin&rock type 3etamorpism

!% ;ngineering

properties

1o: strengt< sligtly :eatered<

slaty cleavage and soapy =eel

!! >denti=ication Slate


14/31

!" ?ses Roo=ing< in electrical industry as

s:itc board< bases and various

turned or saped parts due to its

insulating property

The attitude of this formation is,

StrikeK % to , %

ip directionK +2

ip amountK ;9

L'e*t#!e R#&:

escription


! Sample number %"

" 4olor @ite

$ 6e7ture 4rystalline

* Structures Bedding plane

+ 5rain si9e 3edium

# Sp. 5ravity 3edium to ig

Acid test igorously reacts :it 4l

3ineral comp. 4alcite

- Scratc test Scratced by ammer

!% Origin&rock type Sedimentary

!! ;ngineering Porous< permeable


15/31

properties

!" >denti=ication 1imestone

!$ ?ses Ra: material =or cement and

sometimes in =looring

The attitude of this formation is ,

StrikeK *)% to S 0)

ip directionK

ip amountK ;

L#&at'#! !#.L

Typical fold had observed in this location and isdescribed later.

L#&at'#! !#.L8

Typical fold had observed in this location and isdescribed later.

L#&at'#! !#.L6: Amphibolite

Amphibolite was found at this location.

escription


! Sample number %$

" 4olor Dark green


* Structures&cleavage 8oliation plane&slaty


16/31

+ 5rain si9e 8ine to medium

# Sp. 5ravity ig


3ineral comp. orn blend

- Origin&rock type 3etamorpism

!% ;ngineering

properties

ig strengt

!! >denti=ication Ampibolite

!" ?ses 4an be used as aggregates<

dimension stone and oter

constructional applications

6agma intrusion into the robang phyllite.

Hard, gave metallic sound when hammered.

6assive rock, couldnDt found any e!actorientation.

L#&at'#! !#.L7

phyllite was found at this location.

escriptionK


! Sample number %*

" 4olor Silver :ite



17/31

* Structures&cleavage 8oliation plane&slaty

+ 5rain si9e 3edium to coarse



3ineral comp.

- Origin&rock type 3etamorpic

!% ;ngineering properties

1o: strengt

!! >denti=ication Pyllite

!" ?ses

The attitude of this formation is

StrikeK 22% to S 22

ip directionK S 2 %

ip amountK 2)

L#&at'#! !#.L9

escription


! Sample number %+

" 4olor Dirty :ite

$ 6e7ture 4rystaline

* Structures&cleavage 8olliation plane&slaty


18/31

+ 5rain si9e 3edium

# Sp. 5ravity 3edium


3ineral comp. uart9


!% ;ngineering properties

ig strengt< durable

!! >denti=ication uart9ite

!" ?ses 8or making reeling in ome

applications


19/31



3ineral comp. 5arnet< clorite<

Cuart9


20/31


* Structures 8oliation plane

+ 5rain si9e 4oarse


Acid test igorous

3ineral comp. 4alcite


!% Origin&rock type 3etamorpic

!! ;ngineering

properties

ig strengt< less porous< as rust

due to iron o= pyrite

!" >denti=ication 3arble

!$ ?ses As =ace :orks like =looring< :all

panels< statue making< tabletops and

oter decorative :orks

L#&at'#! !#.L11: ;Granite”

The boulder of granite was found in this location nearlocation 5+.

escription


! Sample number %

" 4olor @ite



21/31

* Structures 8oliation plane

+ 5rain si9e 4oarse


Acid test igorous

3ineral comp. 3ost important is calcite and te

oters are olivine< garnet< grapite


!% Origin&rock type 3etamorpic

!! ;ngineering

properties

ig strengt

!" >denti=ication 5ranite

!$ ?ses As aggregates< =oundations in te

construction and as slab

L#&at'#! !#.L12: ;Gneiss”

1neiss was found at this location #ust near thelocation+.

escription


! Sample number %-

" 4olor @ite



22/31

* Structures Pre=erred orientation< gneisocity

+ 5rain si9e 4oarse

# Sp. 5ravity ig


3ineral comp. uart9< plagioclase< biotite<

muscovite


!% ;ngineering

properties

ig strengt< durable< nonporous<

impermeable

!! >denti=ication 5neiss

!" ?ses as =looring mill and =or building

stone or material

:urtherK

'ands of light and dark color minerals.

1neissocity is very high.

Have weak planes.

High shear strength.

7erfect foliation plane.

Thus all three types of rock we had found at our eldarea. 6ostly there were metamorphic rock and thensedimentary and lastly igneous. :or civil engineers,only identication of rock is not su@cient. He or sheshould have an idea about theengineering signicance

of specic rock type. e all had learnt on this basis andpartially we got it too.


23/31

8.0 GEOLOG< OF +TD< AREA

8.1 L#&at'#! #f *t%$, a"ea

6alekhu lies on lesser Himalayan unit of epal. 3thas peculiar geological features within a small range of area. The 6alekhu B..&. of hading district lies about*) $ms south west of $athmandu valley and is locatedat latitude of *o 2)C ;CC to *o 02C 2)CC and longitudeof 0o0


24/31

The study area starts from benighat slate, 6alukulimestone, robang formation (robang phyllite withdunga GuartEite- to raduwa formation ( garnetiferousshist-. This is the boundary between nawakot and$athmandu comple! and known as 6ahabharat thrust.

Then we had found the formation named bhainsedovanmarble.

6.1 Ge##5'&a *t"%&t%"e*

1eological structure is the study of the permanentdeformation and rock failure created by the changes in

stress through geologic time. 3t is by far the mostimportant aspect of geology for the engineer tounderstand. Tectonic processes are responsible for themany discontinuity planes (fractures, faults, #oints- thatpermeate rock masses controlling their strength, stressFstrain characteristics and the transmission and storageof uids.

6.2 /he!#e!#! #f 5e##5'&a *t"%&t%"e*

7henomenon of structures may be convenientlysubdivided into two groupsK

Brittle structures F recording the brittleFelasticfailure of rocks in the past. :aults and #oints fall inthis broad category.

Ductile structures F preserving the permanentviscoplastic deformation of rock throughoutgeologic time. :olds and metamorphic foliationsare the e!pression of this type of structure.

6. Ma(#" 5e##5'&a *t"%&t%"e*K

uring the course of trip to 6alekhu area, we cameacross varieties of structure like #oints, folds, fault, etc.

1. Joints


25/31

3t is a fracture, which is relatively planer along whichthere has been little or no obvious displacementparallel to the plane. The #oints were formed almostparallel, which are called a set of #oints.

Almost at all location, we found the #oints on theoutcrop of the rock mass. 3t can be easily predict. Andhave great signicance in engineering geology.

2. Folds

:olds are ductile deformation on the structure. They arethe strata permanently deformed either by buckling orfracturing, if sub#ected to stress in a rock mass, andthey cannot resist. Type of deformation depends uponmechanical properties of rocks and the nature of stresswhen applied slowly deep on the earth.

3. Fault

:ault is a rupture plane along which the opposite walls

are moved each other. This movement may vary from afew cm to many km depending upon the magnitudeand nature of the stress and the resistance o?ered bythe rocks. The faults are also caused due to earthGuakebut it is still a complicated geological problem, whichawaits satisfactory solution. hether the earthGuakesare caused due to faulting or faults are caused due toearthGuake. The fault is occurred due to the plate

movements, which creates the shear stress. Themetamorphic form of gauge and breccia is calledmylonite.

. !!f#"'t,:

An unconformity is a buried e"#*'#!surface separatingtwo "#& masses or*t"ata of di?erent ages, indicatingthat*e$'e!t deposition was not continuous. 3n

general, the older layer was e!posed to erosion for an

http://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Rock_(geology)http://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Sedimenthttp://en.wikipedia.org/wiki/Erosionhttp://en.wikipedia.org/wiki/Rock_(geology)http://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Sediment


26/31

interval of time before deposition of the younger, butthe term is used to describe any break inthe*e$'e!ta", geologic record

D'*!f#"'t,

An unconformity betweenparallel a,e"*of *e$'e!ta", "#&* which representsa period of erosion or nonFdeposition. A paraconformityis a type of disconformity in which the separation is asimple bedding plane> i.e., there is no obvious buriederosional surface.(A13, 99- A blended unconformity is

a type of disconformity or nonconformity with nodistinct separation plane or contact, sometimesconsisting of soils, paleosols, or beds of pebbles derivedfrom the underlying rock.

N#!!f#"'t,

A nonconformity e!ists between sedimentary rocksand eta#"h'& or'5!e#%* "#&* when the

sedimentary rock lies above and was deposited on thepreFe!isting and eroded metamorphic or igneous rock.

A!5%a" !!f#"'t,

Angular unconformity at =a'* =ae.

An unconformity where horiEontally parallel *t"ata ofsedimentary rock are deposited on tilted and eroded

layers that may be either vertical or at an angle to theoverlying horiEontal layers. The whole seGuence maylater be deformed and tilted byfurther #"#5e!'& activity.

/a"a!f#"'t,

An unconformity where beds above and below areparallel and no erosional surface is evident.7araconformity can only be recogniEed based on the

http://en.wikipedia.org/wiki/Sedimentary_rockshttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Sedimentary_rockshttp://en.wikipedia.org/wiki/Metamorphic_rockshttp://en.wikipedia.org/wiki/Igneous_rockshttp://en.wikipedia.org/wiki/Vallis_Valehttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Orogenyhttp://en.wikipedia.org/wiki/Sedimentary_rockshttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Sedimentary_rockshttp://en.wikipedia.org/wiki/Metamorphic_rockshttp://en.wikipedia.org/wiki/Igneous_rockshttp://en.wikipedia.org/wiki/Vallis_Valehttp://en.wikipedia.org/wiki/Stratumhttp://en.wikipedia.org/wiki/Orogeny


27/31

gap in the rock record when rocks of a particular ageare absent from the seGuence of rocks.

6. What '!$ #f 5e##5'&a *t"%&t%"e*> 3e f#%!$

at the a"ea?

L#&at'#! !#- L

A typical plunge fold was found at the left bank ofmalekhu khola #ust about ))m far from new 6alekhu'ridge.

escriptionK

'rown colored rock with plunging fold.

7lastic and ductile deformation.

Asymmetric fold.

A?ected by physical weathering.

Hard in hammering.

4ne should have an idea about the engineeringsignicance of folds.

Some of these areK

+. 8epetition of beds may give a surprise to anengineer.

. Shattering in rocks causing permeability contrast andloss in strength.

. The crest and trough have reasonably low strengththan other part.

0. :olds are more sensitive in tunneling.

L#&at'#! !#- L8


28/31

At this location, we have found an e!ample of fault . Thelocation lies about ))m from 6alekhu 'ridge. 3tconsists of fault breccia and fault gauge. :ault breccia isthe crushed and angular fragments .it was embeddedand cemented on the fault gauge. 1auge waspulveriEed clay like powdered rock mineral. 3t wasoccurred at the base of the faulted Eone. it was formeddue to the strong rubbing action on the rocks duringthe faulting process.

%ngineering considerations of the faultK

• The shear Eone and fault Eone serve as easypathways to water, which can cause leakage indam construction.

• The faulted rock is very weak in strength and canDt

be suitable for foundation.

• 4nce the shear Eones become reaching in water,

slippage is highly facilitated.

L#&at'#! !#- L

The location where the garnet ferrous schist was found,we also met the ma#or thrust Eone named asmahabarat thrust. Thrusts are reverse faults andcommonly dominate the structure of collision mountainbelts. Some thrusts have moved a long way F many

mountain belts have thrusts that have moved manytens of kilometers.

4nce upon a time, the top of mt.everest lies at thebottom of the Tethis Sea. 3t has been raised due tothrust resulting by tectonic activities.

The picture below is of the area from where themahabharat thrust passes. 3t was identied by the


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dipping of the boundary rock .it separates the nawakotcomple! with $athmandu nappe.

'esides these ma#or geological structures, we also

found some deformation structures likeK

BeinsK

Loints lled my ller material. sometimes, the strengthof ller material is more than the parent material.

5ensesK

Same as veins, only di?erence in shape. 3t looked likean optical lens.

'oudinageK

Bariation in width of vein.

Tension gasesK

eformation structures due to shear stress in the mass.

6.8 E!5'!ee"'!5 *'5!'&a!&e #f the 5e##5'&a*t"%&t%"e*

The most striking features of rocks as engineeringmaterials is that they are not simple, isotropic, elasticand continuous but very comple!, strongly anisotropic,inelastic discontinuous. 3t is virtually impossible to

deduce the stress history of rocks from their observeddeformation. There are always many ambiguousdeformation paths that could have been followed toproduce what is observed.

10.0 CONCL+ION+:

At last we had concluded the malekhu and itssurrounding is the answer for geological curiosity.Actually, the malekhu is small in area but it has large


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A Te!t 'ook of %ngineering 1eology

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