basic soil presentation ima 2012.ppt
DESCRIPTION
Basic Soil PresentationTRANSCRIPT
BASIC SOIL MECHANICS
Prof.(Dr.) SUDHENDU SAHA
Chartered Professional Engineer
Civil Structural Geotechnical Consultant
Formerly
Professor and Head of The Dept. of Civil Engineering,
DEAN of Research Consultancy & Industry Institute Interaction,
Bengal Engineering and Science University, Sibpur
SOIL IS A COMPLEX MIXTURESOIL IS A COMPLEX MIXTURE
OF OF
PARTICLES OF DIFFERENT SIZESPARTICLES OF DIFFERENT SIZES
DIFFERENT ORIGINDIFFERENT ORIGIN
DIFFERENT MINERALSDIFFERENT MINERALS
DIFFERENT PROCESS OF FORMATIONDIFFERENT PROCESS OF FORMATION
DIFFERENT STRESS HISTORYDIFFERENT STRESS HISTORY
SOIL AS THREE PHASE SYSTEM
VOID RATIO ,
MOISTURE CONTENT,
DENSITY
PARTICLE SIZE DISTRIBUTIONPARTICLE SIZE DISTRIBUTION
UNIFORMITY COEEFICIENT
EFFECTIVE SIZE
COEFFICIENT OF CURVATURE
% OF SAND SILT & CLAY
Soil Classification Soil Classification based on particle sizes :based on particle sizes :
Boulder over 300 mmBoulder over 300 mmCobble 80 to 300Cobble 80 to 300
Gravel 4.75 to 80Gravel 4.75 to 80 C Coarse Sand 2.00 to 4.75oarse Sand 2.00 to 4.75 Medium Sand 0.425 to 2.00Medium Sand 0.425 to 2.00 Fine Sand 0.075 to 0.425Fine Sand 0.075 to 0.425 Silt 0.075 to 0.002Silt 0.075 to 0.002
Clays < 0.002 mmClays < 0.002 mm
Soil Classification according to Plasticity Index of clayey soils :
Plasticity Index Classified as
0 Non-Plastic < 7 Low Plastic 7 – 17 Medium Plastic
> 17 Highly Plastic
when, Plasicity Index = Liquid Limit – Plastic Limit
BROAD CLASSIFICATION OF SOILSBROAD CLASSIFICATION OF SOILS
COARSE GRAINED SOILSCOARSE GRAINED SOILSGW, GP, GM, GCGW, GP, GM, GCSW, SP, SM, SCSW, SP, SM, SC
FINE GRAINED SOILSFINE GRAINED SOILSML, CL, OLML, CL, OLMI, CI, OIMI, CI, OI
CH, OH, PtCH, OH, Pt
SOIL INVESTIGATIONSOIL INVESTIGATION
PLANNING SOIL INVESTIGATION PROGRAMME
DEPTH & NUMBER OF BORE HOLES
BORING & SAMPLING
FIELD TESTS OF SOILS
STANDARD PENETRATIUON TESTS
VANE SHEAR TEST
PLATE LOAD TEST
PLANNING SOIL EXPLORATION PROGRAM
DEPTH OF BORE HOLES
STANDARD PENETRATION STANDARD PENETRATION TESTTEST
N-Value vs Angle of Internal Friction of Soil
STATIC CONE STATIC CONE PENETRATION TESTPENETRATION TEST
Angle of Internal Friction of Soil
Static Cone Resistance
VS
Angle of Internal Friction Of Soils
LABORATORY TESTS OF SOILSLABORATORY TESTS OF SOILS
PARTICLE SIZE DISTRIBUTIONPARTICLE SIZE DISTRIBUTIONTRIAXIAL SHEAR TESTSTRIAXIAL SHEAR TESTS
CONSOLIDATION TESTCONSOLIDATION TESTSPECIFIC GRAVITY OF SOILSSPECIFIC GRAVITY OF SOILS
ATTERBERG’S LIMITSATTERBERG’S LIMITS
PROCTOR’S COMPACTION PROCTOR’S COMPACTION TESTTEST
TRIAXIAL SHEAR TESTSTRIAXIAL SHEAR TESTS
TYPICAL MOHR-COULOMB FAILURE CURVE
COULOMB’S EQUATION
S = C + ( - u) tanFAILURE CRITERIA
SRELATIONSHIP OF PRICIPAL STRESSES AND
SHEAR PARAMETERS
1 = 3 tan2 (450 + / 2 ) + 2C tan (450 + /2)
TYPICAL COMPACTION CURVESTYPICAL COMPACTION CURVES
COMPACTION CHARACTERISTICS OF FINE
GRAINED SOILS
COMPACTION CURVE FOR SANDS
DETERMINATION OF STRESSES
AT DIFFRRENT DEPTHS BELOW FOUNDATION LEVEL
CONTACT PRESSURE DISTRIBUTION BELOW FOUNDATION
DETERMINATION OF VERTICAL STRESS AT ANY DEPTH BELOW
UNIFORMLY LOADED RECTANGULAR AREA
VERTICAL STRESS AT ANY POINT BELOW UNIFORMLY LOADED
CIRCULAR AREA
NEWMARK CHART
DETERMINATION OF STRESSES AT DIFFERENT DEPTHS BELOW
FOUNDATION AREA OF ANY SHAPE
IMMEDIATE SETTLEMENT
4
21)( I
EqbaverageSe
CONSOLIDATION SETTLEMENT
Sc = . h . mv . p
0
0
0
ln1 p
ppC
e
hS cc
MODES OF SHEAR FAILURE BELOW FOOTING
ENGINEERING APPRECIATION
PERFORMANCE CRITERIA
EFFECTS OF TOTAL AND DIFFERENTIAL SETTLEMENTS
SEISMIC RESPONSE OF SOILS
(a) In Seismic Coefficient Method : h = . I .0
(b) In response Spectrum Method : h = . I. F0 Sa /g
HORIZONTAL SEISMIC COEFFICIENT
SHEAR WAVE VELOCITY
LIQUEFACTION
FACTOR OF SAFETY AGAINST LIQUEFACTION
F.S. = CRR / CSR
SEISMIC EFFECTS ON STRUCTURES WITH UNEVEN LOADS
DESIGN OF SHALLOW FOUNDATIONS
LOCATING NEW FOUNDATION NEAR EXISTING FOUNDATION
EFFECT OF STRESS FROM ONE FOUNDATION TO ANOTHER
SPECIAL FOUNDATIONS
TYPICAL FOUNDATIONS
FOR
OIL STORAGE TANKS
REINFORCED EARTH FOUNDATIONS
GEOSYNTHETICS
APPLICATIONS
REINFORCEMENTS
SEPARATION
EROSION CONTROL
FILTRATION
DRAINAGE
TRANSMISSION
IMPROVEMENT OF BEARING CAPACITY
INTERACTION OF REINFORCEMENT WITH FAILURE WEDGES
MODES OF FAILURE
SHEAR FAILURE OF SOIL AGAINST REINFORCEMENT
REINFORCEMENT PULLOUT FAILURE
REINFORCEMENT TENSION FAILURE
TYPICAL SECTION OF A REINFORCED EARTH
RETAINING WALL
TYPICAL SECTION OF A REINFORCED EARTH BRIDGE
ABUTMENT
DESIGN OF
MACHINE FOUNDATIONS
MODES OF VIBRATION
DESIGN CRITERIA
THEORY OF VIBRATION
DYNAMIC PROPERTIES OF SOILS
VIBRATION ISOLATION
GROUND IMPROVEMENT METHODS
COMPACTION
DENSIFICATION
STABILISATION
GROUTING
USE OF GEOSYNTHETICS
PRELOADING WITH VERTICAL DRAINS
IMPROVEMENT OF SOFT CLAY SOILS
USE OF VERTICAL DRAINS
FOLLOWED BY
VERTICAL DRAINS LIKE
1. SAND DRAINS
2. SAND WICKS
3. PREFABRICATED DRAINS
4. STONE COLUMNS
THEORETICAL CONSIDERATIONS
U% = f(T)
Ur = Cvr.t / de2
Uv = Cv.t / de2
U = 1 - ( 1- Ur) (1-Uv)
TIME FACTOR
VS
DEGREE OF CONSOLIDATION
DESIGN AND CONSTRUCTION OF
STONE COLUMNS
LOAD TRANSFER MECHANISM IN PILE AND
STONE COLUMN
LOAD BEARING CAPACITY
OF STONE COLUMN
NCK
qZK
dP su .421
34
.00
2
LOAD BEARING CAPACITY OF TREATED GROUND
A
PqAAq safespsafe
SETTLEMENT ANALYSIS OF GROUND TREATED WITH
STONE COLUMNS
PILE FOUNDATIONS
RANGE OF APPLICATIONS
TYPES OF PILES
CONSTRUCTION METHODS
EFFECTS OF INSTALLATION
NEGATIVE SKIN FRICTION
LOAD BEARING CAPACITY OF PILES
ULTIMATE LOAD CAPACITY
Qu = Qp + Qf
Qp = Ap {Nc Cp + Pd Nq + 0.5 d N}
Qf = d { C l + K l Pz tan }
BEARING CAPACITY FACTOR N9
PILE GROUP CAPACITY
PILE GROUP MAY AFFECT THE SOIL STRATA AT DEPTH
INTERACTION BETWEEN PILES IN A GROUP