FOUNDATION ANALYSIS AND DESIGN
CO NTE NT S 1 GEOTECHNICAL ENGINEERING A HISTORICAL PERSPECTIVE 1 1 1 INTRODUCTION 1 1 2 GEOTECHNICAL ENGINEERING PRIOR TO THE 18TH CENTURY 1 1 3 PRECLASSICAL PERIOD OF SOIL MECHANICS 1700 1776 5 1 4 CLASSICAL SOIL MECHANICS PHASE I 1776 1856 6 1 5 CLASSICAL SOIL MECHANICS PHASE II 1856 1910 6 1 6 MODERN SOIL MECHANICS 1910 1927 7 1 7 GEOTECHNICAL ENGINEERING AFTER 1927 8 1 8 END OF AN ERA 13 REFERENCES 14 2 ORIGIN OF SOIL AND GRAIN SIZE 16 2 1 INTRODUCTION 16 2 2 ROCK CYCLE AND THE ORIGIN OF SOIL 16 2 3 ROCK FORMING MINERALS ROCK AND ROCK STRUCTURES 27 2 4 SOIL PARTICLE SIZE 28 2 5 CLAY MINERALS 30 2 6 SPECIFIC GRAVITY GS 38 2 7 MECHANICAL ANALYSIS OF SOIL 39 2 8 PARTICLE SIZE DISTRIBUTION CURVE 48 2 9 PARTICLE SHAPE 55 2 10 SUMMARY 57 PROBLEMS 57 REFERENCES 63 3 WEIGHT VOLUME RELATIONSHIPS 64 3 1 INTRODUCTION 64 3 2 WEIGHT VOLUME RELATIONSHIPS 64 3 3 RELATIONSHIPS AMONG UNIT WEIGHT VOID RATIO MOISTURE CONTENT AND SPECIFIC GRAVITY 68 3 4 RELATIONSHIPS AMONG UNIT WEIGHT POROSITY AND MOISTURE CONTENT 72 TABLE OF CONTENTS 3 5 RELATIVE DENSITY 80 3 6 COMMENTS ON EMAX AND EMIN 83 3 7 CORRELATIONS BETWEEN EMAX EMIN EMAX 2 EMIN AND MEDIAN GRAIN SIZE D50 85 3 8 SUMMARY 88 PROBLEMS 88 REFERENCES 94 4 PLASTICITY AND STRUCTURE OF SOIL 95 4 1 INTRODUCTION 95 4 2 LIQUID LIMIT LL 95 4 3 PLASTIC LIMIT PL 105 4 4 PLASTICITY INDEX 107 4 5 SHRINKAGE LIMIT SL 108 4 6 LIQUIDITY INDEX AND CONSISTENCY INDEX 113 4 7 ACTIVITY 114 4 8 PLASTICITY CHART 117 4 9 SOIL STRUCTURE 118 4 10 SUMMARY 123 PROBLEMS 124 REFERENCES 127 5 CLASSIFICATION OF SOIL 129 5 1 INTRODUCTION 129 5 2 TEXTURAL CLASSIFICATION 130 5 3 CLASSIFICATION BY ENGINEERING BEHAVIOR 132 5 4 AASHTO CLASSIFICATION SYSTEM 132 5 5 UNIFIED SOIL CLASSIFICATION SYSTEM 136 5 6 COMPARISON BETWEEN THE AASHTO AND UNIFIED SYSTEMS 139 5 7 SUMMARY 150 PROBLEMS 151 REFERENCES 155 6 SOIL COMPACTION 156 6 1 INTRODUCTION 156 6 2 COMPACTION GENERAL PRINCIPLES 157 6 3 STANDARD PROCTOR TEST 158 6 4 FACTORS AFFECTING COMPACTION 162 6 5 MODIFIED PROCTOR TEST 165 6 6 EMPIRICAL RELATIONSHIPS 167 6 7 STRUCTURE OF COMPACTED CLAY SOIL 177 6 8 EFFECT OF COMPACTION ON COHESIVE SOIL PROPERTIES 178 6 9 FIELD COMPACTION 181 6 10 SPECIFICATIONS FOR FIELD COMPACTION 186 6 11 DETERMINATION OF FIELD UNIT WEIGHT OF COMPACTION 188 6 12 EVALUATION OF SOILS AS COMPACTION MATERIAL 195 6 13 SPECIAL COMPACTION TECHNIQUES 195 6 14 SUMMARY 204 PROBLEMS 205 REFERENCES 210 7 PERMEABILITY 212 7 1 INTRODUCTION 212 7 2 BERNOULLI S EQUATION 212 7 3 DARCY S LAW 215 7 4 HYDRAULIC CONDUCTIVITY 217 7 5 LABORATORY DETERMINATION OF HYDRAULIC CONDUCTIVITY 218 7 6 RELATIONSHIPS FOR HYDRAULIC CONDUCTIVITY GRANULAR SOIL 226 7 7 RELATIONSHIPS FOR HYDRAULIC CONDUCTIVITY COHESIVE SOILS 232 7 8 DIRECTIONAL VARIATION OF PERMEABILITY 238 7 9 EQUIVALENT HYDRAULIC CONDUCTIVITY IN STRATIFIED SOIL 239 7 10 PERMEABILITY TEST IN THE FIELD BY PUMPING FROM WELLS 244 7 11 PERMEABILITY TEST IN AUGER HOLES 248 7 12 HYDRAULIC CONDUCTIVITY OF COMPACTED CLAYEY SOILS 250 7 13 MOISTURE CONTENT UNIT WEIGHT CRITERIA FOR CLAY LINER CONSTRUCTION 252 7 14 SUMMARY 253 PROBLEMS 254 REFERENCES 259 8 SEEPAGE 261 8 1 INTRODUCTION 261 8 2 LAPLACE S EQUATION OF CONTINUITY 261 8 3 FLOW NETS 263 8 4 SEEPAGE CALCULATION FROM A FLOW NET 265 8 5 FLOW NETS IN ANISOTROPIC SOIL 271 8 6 MATHEMATICAL SOLUTION FOR SEEPAGE 274 8 7 UPLIFT PRESSURE UNDER HYDRAULIC STRUCTURES 276 8 8 SEEPAGE THROUGH AN EARTH DAM ON AN IMPERVIOUS BASE 277 8 9 L CASAGRANDE S SOLUTION FOR SEEPAGE THROUGH AN EARTH DAM 280 8 10 PAVLOVSKY S SOLUTION FOR SEEPAGE THROUGH AN EARTH DAM 282 8 11 FILTER DESIGN 286 8 12 SUMMARY 290 PROBLEMS 290 REFERENCES 294 9 IN SITU STRESSES 295 9 1 INTRODUCTION 295 9 2 STRESSES IN SATURATED SOIL WITHOUT SEEPAGE 295 9 3 STRESSES IN SATURATED SOIL WITH UPWARD SEEPAGE 301 9 4 STRESSES IN SATURATED SOIL WITH DOWNWARD SEEPAGE 304 9 5 SEEPAGE FORCE 306 9 6 HEAVING IN SOIL DUE TO FLOW AROUND SHEET PILES 309 9 7 USE OF FILTERS TO INCREASE THE FACTOR OF SAFETY AGAINST HEAVE 315 9 8 EFFECTIVE STRESS IN PARTIALLY SATURATED SOIL 318 9 9 CAPILLARY RISE IN SOILS 319 9 10 EFFECTIVE STRESS IN THE ZONE OF CAPILLARY RISE 322 9 11 SUMMARY 325 PROBLEMS 325 REFERENCES 330 10 STRESSES IN A SOIL MASS 331 10 1 INTRODUCTION 331 10 2 NORMAL AND SHEAR STRESSES ON A PLANE 332 10 3 THE POLE METHOD OF FINDING STRESSES ALONG A PLANE 336 10 4 STRESSES CAUSED BY A POINT LOAD 338 10 5 VERTICAL STRESS CAUSED BY A VERTICAL LINE LOAD 341 10 6 VERTICAL STRESS CAUSED BY A HORIZONTAL LINE LOAD 343 10 7 VERTICAL STRESS CAUSED BY A VERTICAL STRIP LOAD FINITE WIDTH AND INFINITE LENGTH 345 10 8 VERTICAL STRESS CAUSED BY A HORIZONTAL STRIP LOAD 350 10 9 LINEARLY INCREASING VERTICAL LOADING ON AN INFINITE STRIP 354 10 10 VERTICAL STRESS DUE TO EMBANKMENT LOADING 356 10 11 VERTICAL STRESS BELOW THE CENTER OF A UNIFORMLY LOADED CIRCULAR AREA 360 10 12 VERTICAL STRESS AT ANY POINT BELOW A UNIFORMLY LOADED CIRCULAR AREA 362 10 13 VERTICAL STRESS CAUSED BY A RECTANGULARLY LOADED AREA 366 10 14 INFLUENCE CHART FOR VERTICAL PRESSURE 372 10 15 WESTERGAARD S SOLUTION FOR VERTICAL STRESS DUE TO A POINT LOAD 375 10 16 STRESS DISTRIBUTION FOR WESTERGAARD MATERIAL 378 10 17 SUMMARY 381 PROBLEMS 382 REFERENCES 389 11 COMPRESSIBILITY OF SOIL 390 11 1 INTRODUCTION 390 11 2 CONTACT PRESSURE AND SETTLEMENT PROFILE 391 11 3 RELATIONS FOR ELASTIC SETTLEMENT CALCULATION 393 11 4 IMPROVED RELATIONSHIP FOR ELASTIC SETTLEMENT 396 11 5 FUNDAMENTALS OF CONSOLIDATION 405 11 6 ONE DIMENSIONAL LABORATORY CONSOLIDATION TEST 409 11 7 VOID RATIO PRESSURE PLOTS 412 11 8 NORMALLY CONSOLIDATED AND OVERCONSOLIDATED CLAYS 415 11 9 EFFECT OF DISTURBANCE ON VOID RATIO PRESSURE RELATIONSHIP 419 11 10 CALCULATION OF SETTLEMENT FROM ONE DIMENSIONAL PRIMARY CONSOLIDATION 420 11 11 CORRELATIONS FOR COMPRESSION INDEX CC 422 11 12 CORRELATIONS FOR SWELL INDEX CS 424 11 13 SECONDARY CONSOLIDATION SETTLEMENT 431 11 14 TIME RATE OF CONSOLIDATION 434 11 15 CONSTRUCTION TIME CORRECTION OF CONSOLIDATION SETTLEMENT 444 11 16 DETERMINATION OF COEFFICIENT OF CONSOLIDATION 447 11 17 CALCULATION OF CONSOLIDATION SETTLEMENT UNDER A FOUNDATION 454 11 18 METHODS FOR ACCELERATING CONSOLIDATION SETTLEMENT 456 11 19 SUMMARY 459 PROBLEMS 460 REFERENCES 467 12 SHEAR STRENGTH OF SOIL 469 12 1 INTRODUCTION 469 12 2 MOHR COULOMB FAILURE CRITERION 469 12 3 INCLINATION OF THE PLANE OF FAILURE CAUSED BY SHEAR 471