advance geotech engineering lecture notes .pdf

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1. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
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2. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Advanced Geotechnical
Engineering
Dr.-Ing. B.V.S. Viswanadham
Professor, Department of Civil Engineering
Indian Institute of Technology Bombay
Powai, Mumbai- 400 076, INDIA
Website: www.civil.iitb.ac.in/~viswam
Email: [email protected]

3. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Course Outline
Origin and the nature of soils as engineering materials;
Soil classification schemes; Clay mineralogy
Soil compaction; Soil-water interaction; Permeability
and Seepage
Consolidation behaviour of the soil and Methods for
accelerating consolidation of the soil.
The stress-strain-strength response of soils,
Earth retaining structures and stability analysis of
slopes
Buried structures, and
Geotechnical physical modelling

4. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
1.Soil composition
and soil structure
Soilformation;Typesofsoilsandtheir
characteristics;Particlesizesandshapes;
theirimpactonengineeringproperties;
Soilstructure;Claymineralogy;Soil-air-
waterinteraction;Consistency; Soil
compaction;Conceptofeffectivestress.

5. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
2.Permeability and
Seepage
Permeability;Seepageforceand
effectivestressduringseepage;Laplace
equationsoffluidflowfor1-D,2-Dand
3Dseepage,Flownets,Anisotropicand
non-homogeneousmedium,Confined
andUnconfinedseepage.

6. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
3.Compressibility
and Consolidation
Stressesinsoilfromsurfaceloads;
Terzagahi’s1-Dconsolidation
theory; Applicationindifferent
boundary conditions;Ramp
loading; Determination of
Coefficientofconsolidationc
v;
NormallyandOverconsolidated
soils; Compression curves;
Secondaryconsolidation;Radial
consolidation; Settlementof
compressiblesoillayersand
Methods for accelerating
consolidationsettlements.

7. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
4.Stress-strain
relationship and
Shear strength
of soils
Stressstate,Mohr’scircleanalysisand
Pole,Principalstressspace,Stress
pathsinp-qspace; Mohr-coulomb
failurecriteriaanditslimitations,
correlationwithp-qspace;Stress-
strain behaviour: Isotropic
compression and pressure
dependency,confinedcompression,
largestresscompression,Definitionof
failure,Interlockingconceptandits
interpretations,Drainageconditions;
Triaxialbehaviour,stressstateand
analysisofUC,UU,CU,CD,andother
specialtests,Stresspathsintriaxialand
octahedralplane; Elasticmodulusfrom
triaxialtests.

8. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
5.Earth
retaining
structures
Earthpressures; Stresschangesinsoil
nearretainingwalls;Earthpressure
theories-estimationofearth
pressures- drainedandundrained
loading.
6.Stability of
Slopes Stabilityanalysisofaslopeand
findingcriticalslipsurface;Sudden
Drawdowncondition,effectivestress
andtotalstressanalysis;Seismic
displacementsinmarginallystable
slopes;Reliabilitybaseddesignof
slopes,Methods forenhancing
stabilityofunstableslopes.

9. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
S.No. Module Contents
7.Buried Structures
LoadonPipes,Marston’sload
theoryforrigidandflexiblepipes,
TrenchandProjectionconditions,
minimumcover,Pipefloatation
andLiquefaction.
8.Geotechnical
Physical
Modeling Physicalmodeling methods;
Applicationofcentrifugemodeling
anditsrelevancetogeotechnical
engineering;Centrifugemodeling
ofgeotechnicalstructures.

10. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
GeotechnicalengineeringisthebranchofCivil
Engineeringconcerned withtheengineering
behaviourofearthmaterials. Geotechnical
engineeringusesprinciplesof*SoilMechanicsand
**Rock Mechanics toinvestigatesubsurface
conditionsandmaterials
*SoilMechanicsisthebranchofsciencethatdealswiththe
studyofthephysicalpropertiesofsoilandthebehaviourof
soilmasssubjectedtovarioustypesofforces.
**Rock mechanics is the theoretical and applied science of
the mechanical behaviour of rock and rock masses

11. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of geotechnical engineering construction
Natural
slope
Cut
slope
Embankment dam
Building
foundation

12. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of geotechnical engineering construction
Supported
excavation
Tunnel
Buried
pipe
Road
embankment
Geosynthetic
Reinforced wall
Building on pile
foundation

13. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of geotechnical engineering construction
Ash
Ash
Compacted
ash
Compacted
ash
Conventional/Bioreactor
landfills
Heterogeneous
Municipal Solid
Waste

14. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of geotechnical engineering construction
Offshore
foundation
Construction
on soft soil
Sea wall
Windmill foundation

15. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Typical geotechnical
failures…
Landfill
failure
Expansive soil
subgrade
Mud pumping
Landslide
Slope
failure
Track
subsidence

16. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
GeotechnicalEngineeringissimplythebranchof
engineeringthatdealswithstructuresbuiltof,orin,
naturalsoilsandrocks.
Thissubjectrequiresknowledgeofstrengthand
stiffnessofsoilsandrocks,methodsofanalysesof
structuresandhydraulicsofgroundwaterflow.

17. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
CourseContext
Anunderstanding oftheengineering
behaviourofthegroundandtheinteraction
betweenthegroundandanystructuresbuiltin
oronthegroundisessentialforallCivil
Engineers.

18. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
According to Karl Terzaghi (1883-1963):
“Unfortunately, soils are made by nature and not by
man, and the products of nature are always complex…
As soon as we pass from steel and concrete to earth, the
omnipotence of theory ceases to exist. Natural soil is
never uniform. Its properties change from point to point
while our knowledge of its properties are limited to those
few spots at which the samples have been collected. In
soil mechanics the accuracy of computed results never
exceeds that of a crude estimate, and the principal
function of theory consists in teaching us what and how
to observe in the field.”

19. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Selected References
Atkinson,J.(2007) .Themechanicsofsoilsand
foundations. Taylor&Francis,LondonandNewYork,
SecondEdition.
Aysen,A.(2005). SoilMechanics: BasicConceptsand
EngineeringApplications,Taylor&Francis,Londonand
NewYork,FirstEdition.
Craig,R.F.(2004). Craig’sSoilMechanics,SponPress
Taylor&Francis,LondonandNewYork,Seventh
Edition.
Das,B.M. (2008). AdvancedSoilMechanics. Taylor&
Francis,LondonandNewYork,ThirdEdition.

20. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Selected References
Fang,H-Y., andDaniels,J.L.(2006). Introductory
Geotechnical Engineering: an Environmental
Perspective. Taylor&Francis,LondonandNewYork,
FirstEdition.
Fredlund,D.G., andRahardjo,H.(1993). Soilmechanics
forunsaturatedsoils,JohnWiley&Sons,NewYork,First
Edition.
Holtz,R.D.,andKovacs,W.D. (1981) .Anintroductionto
geotechnicalengineering,PrenticeHall,NewJersey,
Kaniraj,S.R. (2008). Themechanicsofsoilsand
foundations,TataMcGraw-Hill PublishingCompany
Ltd.,NewDelhi,TenthReprint.

21. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Selected References
McCarthy,D.F.(2007).EssentialsofSoilMechanicsand
Foundations: BasicGeotechnics,PearsonPrenticeHall,
NewJersey,Ohio,SeventhEdition.
Parry,R.H.G. (2004) .Mohrcircles,stresspathsand
Geotechnics. SponPressTaylor&Francis,Londonand
NewYork,SecondEdition.
Wood,D.M.(2004). GeotechnicalModelling,SponPress
Taylor&Francis,LondonandNewYork,FirstEdition.

22. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•The rocks that form the earth’s surface are
classified as to origin as:
•-Igneous
•-Sedimentary
•-Metamorphic
Rock: The source of soils
Most of the nonroganic materials that are identified
as soil originated from rock as the parent material.

23. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
IgneousRocks
•arethoseformeddirectlyfromthemoltenstateofmagma.
Themoltenmagmathatcooledrapidlyatornearearthssurfacearecalled
extrusiveorvolcanictyperocks.Eg.Basalts,RhyolitesandAndesites.
Ifthemoltenrockcoolsveryslowly,thedifferentmaterialssegregateinto
largecrystalsformingacoarse-grainedorgranularstructure(Trappedat
deeperdepths)
Intrusiveorplutonictype,Eg.Granite(whichconsistsofquartzand
feldspar),Syerites,andGabbros
BecauseofhighsilicacontenttheserocksareclassifiedasACIDIC
Decomposestopredominantlysandyorgravelwithlittleclay.(Goodconstruction
materials!)
RockswhosemineralscontainFe,Mg,CaorNabutlittlesilicasuchasthe
Gabbros,Diabases,BasaltsareclassifiedasBASIC

24. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Igneous Rocks
Whenthesolutionofmagmaiscooledveryveryrapidlythe
mineralsdonotseparateintocrystalsbutsolidifyasamorphous
vitreousrock.
Such as, Volcanic Scoria, Pumice, and Obsidan
Rocktypesthatareintermediatebetweenacidicandbasic
includetheTrachytes,Diorites,andAndesites
Easilybreakdownintothefine-textured
soilsduetotheirmineralcomponents.
Theclayportionoffine-texturessoilistheresultofprimary
rockmineralsdecomposingtoformsecondaryminerals.
Notsmallfragmentsoftheparentrockminerals
Thepropertiesandbehaviourofclaysoilsaredifferentfrom
thoseofgravel,sand,andsiltsoils.

25. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Sedimentary Rocks
areformedfromaccumulateddepositsofsoilparticles
orremainsofcertainorganismsthathavebecome
hardenedbypressureorcementedbyminerals.
Cementing materialssuchassilica,Calcium
Carbonate,ironoxidesareabundant
For E.g., Limestones, *Dolomites, Sandstone, Shale,
Conglomerate andBreccia
*Dolomite is referred to both the rock forming
mineral CaMg(CO
3)
2 and sedimentary rock
(recent name is Dolostone)

26. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Sedimentary rocks
Shales are predominantly formed from deposited
clay and silt particles.
-Thedegreeofhardness=f(thetypeofminerals,thebonding
thatdeveloped,andthepresenceofforeignmaterials).
-Thehardnessismainlyduetoexternalpressuresandparticle
bonds,notduetocementingminerals.
-Whenexposedtoenvironment(waterorair),shalestendto
expandordelaminate(thelayersseparate)
-BreakdownofshalefragmentsofvaryingsizesClay
particlesizes

27. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Formation
of sinkholes
(Modified after:
http://geoservicesltd.com/Limestone
sinkholes.html)
Sedimentary rocksLimestone is predominantly crystalline CaCO
3
(Calcite) formed under water.
Limestone-Dolomite isreferencedasKarstor
Karsticterrain.
Sinkholes/cavitiescan
resultduetosolvable
naturewithingredients
presentingroundwater. 
Weathering of limestones
predominantly finer size
particles.

28. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•Metamorphic Rocks [Source: IR or SR]
-resultswhenanytypeofexistingrockis
subjecttometamorphism, thechange
broughtaboutbycombinationsofheat,
pressureandplasticflowsothattheoriginal
rockstructureandmineralcompositionare
changed.
[
Plasticflow–slowviscousmovement and
rearrangementwithintherockmassduetoexternal
forces]
Limestone MARBLE; ShaleSLATE or PHYLLITE;
Granite GNEISS; SandstoneQUARTZITE

29. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Metamorphic Rocks
Gneissisafoliatedrockwithdistinctivebanding
thatresultsfromthemetamorphosisofgranite.
DistinctionbetweenGneissesandSchistsisnot
alwaysclear
UponweatheringGneissandSchistdecomposeto
formsilt-sand mixtureswithmica.
Soilsfromphyllitesaremoreclayeyand
decompositionofquartziteproducessandsand
gravels.

30. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Typical example of metamorphism

31. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
ROCKS
(IGNEOUS, SEDIMENTARY, METAMORPHIC)
WEATHERING
(PHYSICAL/CHEMICAL)
TRANSPORTED
BOULDERS, GRAVEL, SAND, SILT AND CLAY
SOIL

32. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•Rocks whose chief mineral is quartz minerals
with high silica content, decomposes to
predominantly sandy or gravelly soil with little
clay. [Acidic rocks are light-coloured]
•Basic rocks decompose to the fine- textured silt
and clay soils.
-The clays are not small fragments of the original
materials that existed in the parent rock [result of
primary rock minerals decomposing to form
secondary minerals]

33. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Major soil types based on particle size
The major engineering categories of soil are gravel,
sand, silt and clay
Gravel and sands are considered coarse-grained
soils (with large bulk particle sizes)
Silt(verytinyparticlesofdisintegratedrock)andclayparticles
areconsideredfine-grainedsoilsbecauseoftheirsmallparticle
sizes.
-Claysoilisplastic(ifitcanberemoldedwithout
cracking/breaking)overarangeofwatercontentandsiltsoil
possesseslittleornoplasticity.
Particles larger than gravel are called cobbles or
boulders

34. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•Soils can be grouped into two broad categories
(depending on the method of deposition):
Residual –Formed from weathering of rock
and remain at the location of their origin.
[a material which may possess little mineralogical
resemblance to the parent rock]Transported –those materials that have been
moved from their place of origin
-by agencies like, gravity, water, glaciers, or
man- either singularly or in combination

35. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•Characteristics of Residual soils are
dependent on:
Climatic conditions -humidity, temp.,
rainfall)
Natural drainage pattern
Form and extent of vegetation cover
[Awarmandhumidclimateisfavourabletothe
formationofresidualsoilsandnatureofresidualsoil
differsmarkedlyatdifferentdepthsbelowground
surfaceandconstantlychangeswithtime]
-SoildepositsinDeccanPlateau

36. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
•Transported Soils are classified according to the
transporting agency and method of deposition:
Alluvial – transported in running water [rivers]
Lacustrine – deposited in quiet lakes
Marine – deposited in sea water
Aeolin – transported by wind
Glacial – by ice [Glaciation –
massive moving sheets of ice
Colluvial –deposited through action of landslide
and slope wash

37. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of Transported soils:
LOESS – Wind blown deposit with very uniform fine
silt particles (possesses slight cementation
properties)
–Formed in Arid and Semi-Arid regions
with yellowish light brown colour
Tuff – Fine-grained slightly cemented volcanic
ash [by wind/water]
Glacial till – Heterogeneous mixture of boulders,
gravel, sand, silt and clay [Hilly regions]

38. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Examples of Transported soils:
Varved Clay – Alternate layers of silt and clay
deposited in fresh water glacial lakes.
-One band of silt and clay deposited each
year [each layer is approx. 10 mm thk.]
Marl – Very fine grained soil of marine origin
[impermeable, greenish colour]
Peat – A highly organic soil consisting almost
entirely of vegetable matter in varying stages
of decomposition, Fibrous, brown to black in
colour and highly compressible

39. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Major soil deposits:
f( Ambience, Geography and Topography)
Expansive –High shrink-swell characteristics
(attributed to the mineral)
Colour- Black (presence of Fe, Mg and Ti)
Marine – Very soft and may contain organic matter
Laterite – Red in colour due to Fe
2O
3(Laterization-
Leaching of Silica –due to intense chemical
weathering)
Alluvial – Alternate layers of Sand, Silt and Clay
Desert – Wind blown, Uniformly graded
Glacial – Boulder clay (all ranges of particle sizes)

40. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Distribution of predominant Soil
deposits In India
Marine soil
deposits
Expansive soil deposits
Desert soils

41. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Constituents of the soil mass
-Formation of soils from the weathering of the
parent rock
-Wide range of sizes of soil solids
Behaviour of soil mass under stress is a function
of material properties, such as:
(i) size and shape of grains, (ii) gradation, (iii)
mineralogical composition, (iv) arrangement of grain, (v)
inter-particle forces, etc.)

Material properties f(constituents of the soil mass)

42. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Soil is a particulate material,
whichmeansthatasoilmassconsistsofaccumulationof
individualparticlesthatarebonded togetherby
mechanicalorattractivemeans,thoughnotstronglyasfor
rock.
-Spaces in between solid particles Voids or pore space
Constituents of the soil mass
In soil (in most rock), voids exist between particles,
and voids may be filled with a liquid, usually water or
gas, usually air.

43. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Water surrounding
particles and at points
of contact between
particles, and filling
small void spaces
Air in irregular spaces
between soil particles
Actual soil bulk consisting of soil particles, water
and air

44. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Constituents of the soil mass
Soil is inherently multiphase material
(Generally consists of three phases)
-
Solid phase
-Liquid phase
-Gaseous phaseIt can also be TWO PHASE material:
-With solid + Gaseous (DRY STATE)
-With solid + Liquid (SATURATED STATE)

45. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
3 –Phase system
SOLIDS
LIQUID
GAS
Idealization

46. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Solid phase consists of:
Primary rock forming minerals (Size > 2µm, Poor
Reactivity, Prone to disintegration)
Clay minerals (Basic materials that form the soil
mass, Size < 2µm, High Reactivity)
Cementing material (Carbonates)
Organic matter (High water absorption,
Compressible, unstable)

47. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Liquid phase consists of:
WATER DISSOLVED SALTS
Pure
water
Polluted
water
Water
soluble
Water
insoluble
Water soluble-Chlorides, Sulphates, Bicarbonates
(Not capable of binding solid grains)

48. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Gaseous phase consists of:
2 –phase system; Dry soil
AIR GASES
Solids
Air
Solids
Water
2 –phase system; Saturated soil

49. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
3 –Phase system
W
a = 0
Weight
=
SOLIDS
WATER
AIR
Volume
V
a
V
w
V
s
V
V
W
w
W
s
V = V
S+V
W+V
a W = W
S + W
W
Partially Saturated Soil

50. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
3 –Phase system
W
a = 0
Weight
=
SOLIDS
WATER
AIR
Volume
V
a
V
w
V
s
V
V
W
w
W
s
V = V
S+V
W+V
a W = W
S + W
W
Partially Saturated Soil

51. Prof. B V S Viswanadham, Department of Civil Engineering, IIT Bombay
Self evaluation
i)Listthesoiltypesincludedincoarse-grain
categoryandthefine-grain category
ii)Whythereisadifferenceinbehaviourofnatural
claysandothersoiltypessuchassandsandsilts?
iii)Whatdoesthetermplasticmeaninrelationto
claysoils?
iv)Whatarelaterites(orlateriticsoils)andwhyare
suchsoilsconsideredinthecategoryofrequiring
specialconsiderationonconstructionprojects?
v)Fromanyboreholedatainyourlocation,listsoil
typeandrocktypes