IES-GA IES- GATE TE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com 1.ORIGIN OF SOILS According to 1) Geologist: soil is top surface of the earth crest 2) Agricultural engineering: The upper layer of the mantila is useful for cultivation of crops Is called soil 3) Definition of soil: soil is an unconsolidated loose crest of the earth →
Note: un consolidated
having voids
→
rest of the earth
top surface of the earth !rigin of soil
Decomposition of organic matter
"eathering of roc#s
$!rganic soil or cumulose soil)
$Inorganic soil)
umulose soils: e%ample: peat& humus& muc#& etc'
(oil
!rganic soil $ormed *y decomposition
Inorganic soil $ormed *y "eathering of roc#s)
of organic matter)
+eathering of ,oc# $po"der of roc#)
-hysical +eathering
hemical "eathering
1) Due to physical effects li#e
Due to chemical action li#e
. Temp changes
. o%idation
. A*rasion
. hydration
. +edging action of ice
. ar*onation
. -enetration of plant roots
. (olution . /eaching . 0ydrolyses etc'
2) There is no change in chemical omposition of minerals present
!riginal roc# minerals are converted into lay minerals
!riginally in the roc# 3) $Type of soil finally) ,esults in coarse grained and non ohesive soils li#e
,esults in formation of fine grained and cohesive soils li#e
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com . Gravel
.lay
. (and
.-lastic silt
.Non plastic silt
Geological cycle: +eathering of roc# transportation deposition upheaval
-ic#up the correct one a) Transportation . Deposition "eathering upheaval *) 4pheaval transportation deposition c) +eathering transportation deposition upheaval
ans:c
lassification of soils: 1) ,esidual soils or sedentary soils: or sedentary soils: (oil particles resides over or near the parent roc# $i'e no transportation) 5%ample: 6lac# cotton soils& laterite soils
2) Transported soils $or) (edimentary soils: (oil particles created at one location& transported and finally deposited in another location Transportation of soil: 1) Due to flo"ing "ater: i) (oils deposited *y "ater in rivers are called Alluvial soil ii) (oils deposited in la#es are called lacustrine soils iii) (oils deposited in sea are called marine soils /acustrine soil →
lo"ing "ater
Alluvial soil 7arine soil
2) Due to "ind: (oils deposited *y "ind are called Aeolian soils 5%ample: sand dumes& loess $silt si8ed particle)
3) Due to glacier $slo"ly moving ice mass) (oils deposited *y glacier are called Glacier deposits
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com 5%ample: Drift& till etc: 9) Due to gravity: (oils deposited *y gravity care called olluvial soils 5%ample: Talus $means soil particles are deposited at the foot of the hill) 6lac# cotton soils:.It is a residual soil farmed *y chemical "eathering& parent $!rigin) roc# is 6asalt or trap 5%hi*its large s"elling and shrin#age due to the presence of montmorillonite clay mineral
Note: Gravitational forces $") *ody forces are predominant in coarse grained soils li#e gravel
φ and sand ( ; tan
"here ; is *ody force
(urface forces& chemical farces& electrical farces are predominant in clays e%ample: cohesion&
φ electric charge etc' (hear strength of soil ( c < ; tan
"here c cohesion'
In case of silt *oth gravitational forces and surface forces may *e present
=arved clay: ontains alternate thin layers of clay > silt& generally lacustrine deposit
IES-OBJECTIVE QUESTIONS ?1' 7atch list I "ith list II and select the correct ans"er /ist I
@I5(.2???
/ist II
A' /oess
1' Deposited from suspension in running "ater
6' -eat
2' Deposits of marine origin
' Alluvial soil
3' Deposits *y "ind
D' 7ari
9' !rganic soil A
6
D
a' 3
9
2
1
c' 9
3
2
1
A
6
D
*'
9
3
1
2
d'
3
9
1
2
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com 1' The collapsi*le soil is associated "ith a' Dune sands
@I5(.2??3
*' /aterite soils
c' /oess
d' 6lac# cotton soils
2' onsider the follo"ing statements:
@I5(.2??B
1' !*taining relia*le properties of soil is very important in geotechnical engineering' hun# samples o*tained from the field are the *est for this purpose' 2' hun# samples may easily *e o*tained at all depths *elo" ground level and for all types of soils' 3' 4ndistur*ed soil samples are enclosed in rugged containers' As such& they do not get distur*ed easily during transportation and handling' +hich of the statements given a*ove isCare correct a' 1& 2 and 3
*' 1 only
c' 2 and 3
d' 1 and 3
PRACTISE QUESTIONS 1' (oils are *asically (a) Organic Materials (b) Inorganic Materials (d) Organic and Inorganic Materials
(c) Mineral Materials Ans:d
2' ohesionless soils are formed *y $a) physical disintegration of roc#s $*) chemical "eathering of roc#s $c) consistent *lo"ing of "ind in the same direction $d) deposition in a delta region Ans:a 3' ETalusF is the soil transported *y $a) "ind $*) "ater $c) glacier $d) gravitational force Ans:d 9' E/oessF is silty clay formed *y the action of $a) "ater $*) glacier $c) "ind
$d) gravitational force
Ans:c
B' EDriftF is the material pic#ed up& mi%ed& disintegrated& transported and redeposited *y $a) "ind $*) gravitational force $c) glacier "ater $d) all Ans:c ' Non.cohesive soil is $a) sand $*)silt
$c) clay
$d)clay > silt
Ans:a
H' The soil transported *y flo"ing "ater is called $a) aeolian soil $*) marine soil $c) alluvial soil
$d) lacustrine soil
Ans:c
' The soil transported *y "ind is called $a) aeolian soil $*) marine soil
$d) lacustrine soil
Ans:a
$c) alluvial soil
J' /acustrine soils are those "hich are $a) deposited in sea "ater $*) deposited at the *ottom of la#es
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com $c) transported *y "ind
$d) deposited due to moving of ice sheets
1?' lay can *e classified as $a) highly cohesive soil
$*) limited cohesive soil
11' +hich of the follo"ing is cohesive soil $a) Kan#ar $*) 6lac# cotton soil
$c) cohesionless soil
$c) /oose coarse sand
Ans:*
Ans:a
$d) (and "ith clay Ans:*
12' +hich of the follo"ing "ill have highest L of loam& loess a)(andy clay loam *)'(ilty clay loam c)'lay
d)'(ilty lay
Ans:a
13' The inventor of the term soil mechanics& "as $a) Kray $*) Dr' Karl Ter8aghi
$d) ellenius'
Ans:*
$c) /eygue
19' -ic# up the correct statement from the follo"ing: $a) To an agriculturist& soil is the su*stance e%isting on the earthFs surface& "hich gro"s and develops plants $*) To a geologist& soil is the material in a relatively thin surface 8one "ithin "hich roots occur& and rest of the crust is termed as roc# irrespective of hardness $c) To an engineer& soil is the unaggregated and uncemented deposits of minerals and organic particles covering the earthFs crust $d) All the a*ove'
Ans:$d)
1B' Geologic cycle for the formation of soil& $a) 4pheavel
$*) +eathering
transportation
upheaval
$c) Transportation $d) +eathering
deposition "eathering
transportation
upheaval
transportation
"eathering
deposition
deposition
deposition
upheaval
Ans:$d)
1' hemical "eathering of soil is caused due to $a) o%idation
$*) car*onation
Ans:$e)
$c) hydration
$d) leaching
1H' Transporting and re.depositing soils& is done *y $a) "ater
$*) glacier
$e) all
Ans:e
$c) gravity
$d) "ind
$e) all
1' +ater formed transported soil is $a) alluvial
$*) marine
$c) lacustrine
$d) loess'
1J' ETalusF is the soil transported *y $a) "ind
$*) "ater
Ans:d
Ans:d $c) glacier
$d) gravitational force'
2?' In sedimentary soil the individual particles are created at one location& transported and finally a) Deposited in another location
*) ,edeposited in lo" lying areas
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com c) Deposited in lo" lying areas
d) Deposited in desert areas
Ans:a
21' A residual soil is one formed in place *y the "eathering of roc# at the location a) And transported to another location *) +ith little or no movement of the individual soil particles c) And deposited under la#e
d) And deposited under area
Ans:*
22' (oils are *asically a) !rganic materials
*) Inorganic materials
c) 7ineral materials
d) !rganic and inorganic materials
Ans:d
23' The *ehaviour of silts is normally governed *y: a) 7ass energy
*) (urface energy
Ans:c
c) 7ass and surface energy
d) None
29' The *ehaviour of clay is governed *y a) 7ass energy
Ans:c
*) (urface cum mass energy
c) (urface energy
d) riction
2B' ,esidual soils are formed *y: a) Glaciers
*) +ind
c) +ater
d) None
2' /acustrine soil is aMM'
Ans:d
$I5(.1JJB)
a) (oil deposited in sea
*) +ind *orne soil
c) (oil deposited in la#e
d) (oil formed *y vegetational matter
Ans:c
2H' hemical "eathering occurs *ecause of a) !%idation
*) ar*onation
c) 0ydration
d) All the a*ove
2' -hysical "eathering occurs due to a) Temperature changes
*) +edging action of ice
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Ans:d
IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com c) (preading of roots of plants
d) All the a*ove
Ans:d
3?' The term soil 7echanics "as coined *y a) Ter8aghi
*) assagrande
c) Ne"mar#
d) ,an#ine
Ans:a
31' ohesionless soils are formed due to a) !%idation or roc#s
*) /eaching action of "ater on roc#s
c) 6lo"ing of hot and cold "ind
d) -hysical disintegration of roc#s
Ans:d
32' -eat is composed of a) lay and (and
*) Decayed vegeta*le matter
c) Inorganic silt and silty clay
d) (ynthetic chemicals
Ans:*
33' Talus is the soil transported *y a) Gravitational force
*) +ater
c) Glacier
d) +ind
39' =arved clay is MMM
Ans:a Ans:c
a) A mi%ture of sand& silt& caly
*) A chemically *onded soil mi%ture
c) Alternate thin layers of silt and clay d) Decomposed volcanic ash deposit 3B' 6lac# cotton soil is a) A chemically "eathered residual soil
*) A physically "eathered residual soil
c) A olluvial soil
d) An organic soil
Ans:a
3' 6lac# cotton soil e%hi*its large s"elling and shrin#age due to presence of the follo"ing clay mineral $GAT5 J3& A-(56 J1) a) Kaolinite
*) llite
Ans:c c) 7ontmorillonite
d) 0alloysite
3H' +hen the product of roc# "eathering are not transported as sediments *ut remain in place a) Alluvial soil
*) Glacial soil
c) residual soil
d) Aeolian soil
3' Aeolian soils are MMMM' a) ,esidual soils
*) +ind deposits
Ans:c
$GAT5.1JJB) c) Gravity deposits
d) +ater deposits Ans:*
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com 3J' /oam means a) (andy lay "ith a little slit
*) (ilty lay "ith a little sand
c) (and& (ilt and lay
d) (and& (lit and Gravel
Ans:c
9?' ill is deposit made a) 6y transported soil
*) *y "eathering of roc# in one location
c) 6y deposition of transported soil
d) *y the activities of man
Ans:d
91' The maority of naturally occurring collapsing soils are a) Aeolian
*) -eat
c) Alluvial
d) 7arine Ans:a
92' Identify the non collapsing soil from the follo"ing a) dune sand
*) volcanic ash
Ans:d
c) loess
d) gravel or pe**le
93' -ic# up the correct seOuence of geological cycle for the formation of soil a) Transportation upheaval deposition "eathering *) Transportation deposition "eathering upheaval c) +eathering upheaval deposition transportation d) +eathering transportation deposition upheaval
Ans:d
99' The most erratic soil deposit is a) +in load deposit
*) river channel deposit
c) lood plain deposit
d) Glacial deposit
Ans:d
9B' The most uniform soil deposit is a) +ind laid deposit
Ans:a
*) Delta deposit
c) (hare deposit
d) glacial deposit
9' In *lac# cotton soils the seasonal moisture changes *ring in volume changes upto a ma%imum depth of a*out a) 1'?m
*) 1'Bm
c) 2'?m
d) 3'?m
Ans:*
9H' 7atch list I "ith list II and select the correct ans"er using the codes given *elo" the lists:
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IES-GATE ACADEMY SOIL MECHANICS www.iesgateonlinetest.com /ist I
$(oil deposit)
/ist II
$(oil Name)
A' Gravity
1' (tratified drift
6' /a#e
2' Talus
' Glacial
3' /oess
D' +ind
9' /acustrine
a) A 1& 6 3& 2& D 9
*) A 2& 6 9& 1& D 3
c) A 3& 6 9& 1& D 2
d) A 9& 6 3& 2& D 1
Ans:*
B?' /oess is a) a clay deposit c) silt si8e particles
*) ine sand si8ed particles d) colloidal particles
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(
Ans:c
