Ch 2 Earth Pressure

8/17/2019 Ch 2 Earth Pressure

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EARTH

PRESSURE

Prepared By :Megha Desai

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Contents…..

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Introduction Types of lateral earth pressureRankine’s theory for active earthpressure

Rankine’s theory for passive earthpressureCoulomb’s theory for active earthpressureCoulomb’s theory for passive earthpressure

Types & design considerations for

retaining walls


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Earth pressure & retainingstructures

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• Retaining structureswhen su!cient space isnot available for mass ofsoil to spread and form

a safe slope" a structureis re#uired to retain thesoil or to keep the soil atdi$erent level.

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%oil engineering givesthe theories of earthpressure on retainingstructure.

Megha Desai, Civil dept., CSPIT,Changa


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Introduct ion

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Introduct ion

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Retaining structure ) to retain soil ) to bear soil

pressure

The pressure e*erted by soil on retaining structure is

called +ateral ,arth -ressure.


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Introduct ion

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To estimate the correct crosssection

of retaining structure" we have to

calculate the magnitude and direction

of lateral earth pressure.

Backfll :- /The soil retained by anyretaining structure is called back0ll1.


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Introduct ion

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-roper designing of retaining walls"

cantilever sheet pile walls" braces cuts

and other similar structures re#uires

proper estimation of +ateral ,arth

-ressure.

These all are the types of retainingstructures.


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Retaining Wall

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Cantilever Sheet Pile

Wall

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Braced Cuts

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Introduct ion

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The lateral earth pressure is function of2

Type & amount of wall movement ) i.e.

towards or away from the soil.

%hear parameters of soil ) i.e. C & Ø.

'nit weight of the soil.

3rainage condition at the back0ll ) in

cohesive soil drainage is poor & vise

versa" & lateral earth pressure is

di$erent in both cohesive & noncohesive

soils.


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Typ es o Wal l! o v e " e n t s

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! The wall have tendency to move" upon

the action of lateral earth pressure of

soil. %o based on that there may be

three di$erent conditions of wall

movement2

4all cannot move i.e. at rest condition

4all move away from soil

4all move towards soil


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Type s o #a te ra l Ea r thP r e s s u r e

! 5ased on the wall

movements" upon the

action of lateral earth

pressure of soil" there are

basic three di$erent types

of lateral earth pressure2

6t rest earth pressure"

6ctive earth pressure" and

-assive earth pressure.

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t R e s t E a r t h P r e s s u r e

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AT REST EARTH PRESSURE $% 4hen the soil mass is not

sub7ected to any movement or lateral yielding called at

rest earth pressure.

4all is restrained

from moving i.e. at

rest condition.

8h ) -ressure

e*erted by soil" on

retaining wall.


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c t i v e E a r t h P r e s s u r e

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ere the wall moves away from the

soil at the amount 9ΔH’.

6ssuming the failure wedge :as shown

in 0g.;" & wall may tilt away from the

soil retained backside of wall" it is the

active condition.


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c t i v e E a r t h P r e s s u r e

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ACTIE EARTH PRESSURE $% 6ctive earth pressure is

occur when the soil mass yields in such a way that it tends

to stretch hori


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P a s s i v e E a r t h P r e s s u r e

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The wall is moving towards the soil at

the amount 9ΔH’.

6ssuming the failure wedge :as shown

in 0g.;" & wall may be pushed in tothe soil retained backside of wall" it is

the passive condition.

ere with su!cient wall movement"

soil wedge will fail" which is called as

passive condition.


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P a s s i v e E a r t h P r e s s u r e

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PASSIE EARTH PRESSURE $% 6 state of passive

pressure e*ists when the movement of wall is such that

the soil tends to compress hori


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L a t e r a l E a r t h P r e s s u r e

a t R e s t

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Considering any soil element at depth

9=’ from the e*isting ground surface.

>n this element. 3ue to overburden of

soil above vertical stress 98v’ will act in

vertical direction" and hori


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L a t e r a l E a r t h P r e s s u r e

a t R e s t

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,C, Ø

>4 T> 6?6+@%, TI% 98h’AAAAA


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Reerences'(

Books:• 6rora" B.R." %oil echanics & (oundation ,ngineering

• -unamia" 5.C." %oil echanics & (oundation ,ngineering

• urthy" D.?.%." %oil echanics & (oundation ,ngineering

• Denkatramaiah" C." Eeotechnical ,ngineering

Internet:• httpFFwww.engr.uconn.eduFGlanboFC,HJ+ect4KK%lopestabi

lityK.pdf

• elearning.vtu.ac.inFKJFenotesFJLCDLF'nitL%D3.pdf

• http://nptel.ac.in/courses/105108075/module8/Lecture30.pdf

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• httpFFpeople.eng.unimelb.edu.auFstsyFgeomechanicsMte*tFChKKM%lope.pdf

• httpFFstep.ipgp.frFimagesFeFeNFJOMJKM+imitMe#uilibriumMslopeMstability.pdf

• httpFFcivilwares.free.frFEeotechnicalPHJengineeringPHJPHJ-rinciplesPHJandPHJ-racticesPHJofPHJ%oilsPHJechanicsPHJandPHJ(oundationPHJ,ngineeringFChapterPHJKJ.pdf

• httpFFsite.iuga


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http://site.iugaza.edu.ps/wp-content/uploads/Lesson%2006-Chapter%206%20Slope%20Stability.pdfhttp://site.iugaza.edu.ps/wp-content/uploads/Lesson%2006-Chapter%206%20Slope%20Stability.pdfhttp://civilwares.free.fr/Geotechnical%20engineering%20-%20Principles%20and%20Practices%20of%20Soils%20Mechanics%20and%20Foundation%20Engineering/Chapter%2010.pdfhttp://civilwares.free.fr/Geotechnical%20engineering%20-%20Principles%20and%20Practices%20of%20Soils%20Mechanics%20and%20Foundation%20Engineering/Chapter%2010.pdfhttp://civilwares.free.fr/Geotechnical%20engineering%20-%20Principles%20and%20Practices%20of%20Soils%20Mechanics%20and%20Foundation%20Engineering/Chapter%2010.pdfhttp://step.ipgp.fr/images/e/e7/05_01_Limit_equilibrium_slope_stability.pdfhttp://step.ipgp.fr/images/e/e7/05_01_Limit_equilibrium_slope_stability.pdfhttp://people.eng.unimelb.edu.au/stsy/geomechanics_text/Ch11_Slope.pdfhttp://people.eng.unimelb.edu.au/stsy/geomechanics_text/Ch11_Slope.pdf

Ch 2 Earth Pressure

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