Solutions Manual To Accompany PRINCIPLES OF GEOTECHNICAL ENGINEERING, 8TH EDITION BY BRAJA M. DAS & KHALED SOBHAN

Toc H INSTITUTE OF SCIENCE & TECHNOLOGY, ARAKKUNNAM DEPARTMENT
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OF CIVIL ENGINEERING
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QUESTION BANK j




IV SEMESTER
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CE208– GEOTECHNICAL ENGINEERING I
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BASEDj ON

A P J ABDUL KALAM TECHNOLOGICAL UNIVERSITY SYLLABUS
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2015jADMISSION

AcademicjYearj2017jPrepar

edjbyjAsst.Prof.AnniejJoy

, MODULEj –I
SYLLABUS
• Introductionjtojsoiljmechanicsj-MajorjsoiljdepositsjofjIndia
• Basicjsoiljpropertiesj-
jVoidjratio,jporosity,jdegreejofjsaturation,jairjcontent,jpercentagejairjvoids,jmoisturejc


ontent,jspecificjgravity,junitjweightj-jRelationshipjbetweenjbasicjsoiljproperties
• Sensitivityj–jThixotropyj-j numericaljproblems
Semesterj Examj Marksj %j -15
TWOj MARKSj QUESTIONS
1. NamejthejfatherjofjSoiljMechanicsjandjDefinejSoiljmechanics.jDr.
KarljVonjTerzaghijisjthejfatherjofjSoiljMechanicsj.
Soiljmechanicsjisjdefinedjasjthejapplicationjofjthejlawsjandjprinciplesjofjmechanicsjan
djhydraulicsjtojengineeringjproblemsjdealingjwithjsoiljasjanjengineeringjmaterial.
2. Definejdegreejofjsaturationjandjporosity.
‘Degreejofjsaturation’jofjajsoiljmassjisjdefinedjasjthejratiojofjthejvolumejofjwaterjinjthej
voidsjtojthejvolumejofjvoids.
‘Porosity’jofjajsoiljmassjisjthejratiojofjthejvolumejofjvoidsjtojthejtotaljvolumejofjthejsoilj
mass.
3. Drawjthejphasejdiagramjforjcompletelyjdryjandjfullyjsaturatedjsoiljmass.




(a)jfullyjsaturatedjsoiljmassj(b)jcompletelyjdryjsoiljmass

4. Differentiatejbetweenj‘residual’jandj‘transported’jsoils.
Soilsjwhichjarejformedjbyjweatheringjofjrocksjandjwhichjremainjinjpositionjatjthejplac
ejofjtheirjoriginjarej‘ResidualjSoils’.
Soilsjthatjgetjtransportedjfromjthejplacejofjoriginjbyjvariousjagenciesjsuchjasjwind,jwat
er,jice,jgravity,jetc.jarejtermedjas‘‘Transportedjsoil’’.

5. Definejspecificjgravity.
Thejspecificjgravityjofjajsubstancejisjdefinedjasjthejratiojofjitsjmassjinjairjtojthejmassjofja
njequaljvolumejofjwaterjatjreferencejtemperature,j4j°C.
G=γs/γw

, 6. Sketchjthejphasejdiagramjforjajsoiljandjindicatejthejvolumesjandjweightsjofjthejphas
esjonjit.




7. Definej‘Voidjratio’jandj‘Waterjcontent’.
‘Voidjratio’jofjajsoiljmassjisjdefinedjasjthejratiojofjthejvolumejofjvoidsjtojthejvolumejofjsol
idsjinjthejsoiljmass.
‘Waterjcontent’jorj‘Moisturejcontent’jofjajsoiljmassjisjdefinedjasjthejratiojofjthejweightjofj
waterjtojthejweightjofjsolidsj(dryjweight)jofjthejsoiljmass.
8.

THREEj MARKSj QUESTIONS
1. Ifjthejvolumejofjvoidsjisjequaljtojthejvolumejofjsolidsjinjajgivenjsoiljsample,jFindjVoidjra
tiojandjporosity.
IfjVv=Vs,thenjvoidjratioje=jVv/Vsj=1jHen
ce,porosityjn=e/(1+e)=1/2=0.5
2. Usingjphasejdiagram,jderivejthejrelationshipjbetweenjvoidjratiojandjporosity.

, 3. Distinguishjbetweenj‘BlackjCottonjSoil’jandj‘Laterite’jfromjanjengineeringjpointjofjview
.
Blackjcottonjsoil-
jexpansive,jhighjshrinkjandjswelljcharacteristics,jblackjinjcolourjduejtojthejpresencejofj


iron,jmagnesiumjandjtitanium,foundjinjcentraljindiajandjportionjofjsouthjIndia.
Lateritejsoilj-
jredjinjcolourjduejtojFe2O3jwhichjundergoesjajprocessjcalledjlaterization,found jinjcen


traljandjS.EjIndia.

4. Establishjthejrelationshipjbetweenjdegreejofjsaturation,jsoiljmoisturejcontent,jspe
cificjgravityjofjsoiljparticles,jandjvoidjratio.




5. Differentiatejbetweenjsensitivityjandjthixotropyjofjsoils.

Sensitivityj(St)’jofjajclayjisjdefinedjasjthejratiojofjthejitsjunconfinedjcompressionjstr
engthjinjthejnaturaljorjundisturbedjstatejtojthatjinjthejremouldedjstate,jwithoutjanyjc
hangejinjthejwaterjcontent:




Thixotropy
Whenjclaysj withjajflocculentj structurejarejusedjinjconstruction,j thesejmayjlose