Originally published in the fall of 1983, Braja M. Das' Seventh Edition of PRINCIPLES OF FOUNDATION ENGINEERING continues to maintain the careful balance of current research and practical field applications that has made it the leading text in foundation engineering courses. Featuring a wealth of worked-out examples and figures that help students with theory and problem-solving skills, the book introduces civil engineering students to the fundamental concepts and application of foundation analysis design. Throughout, Das emphasizes the judgment needed to properly apply the theories and analysis to the evaluation of soils and foundation design as well as the need for field experience.
Table of Contents
1. GEOTECHNICAL PROPERTIES OF SOIL.
Introduction. Grain-Size Distribution. Size Limits for Soils. Weight-Volume Relationships. Relative Density. Atterberg Limits. Liquidity Index. Activity. Soil Classification Systems. Hydraulic Conductivity. Steady-State Seepage. Effective Stress. Consolidation. Calculation of Primary Consolidation Settlement. Time Rate of Consolidation. Degree of Consolidation Under Ramp Loading. Shear Strength. Unconfined Compression Test. Comments on Friction Angle, φ''.Correlations for Undrained Shear Strength, cu . Sensitivity. Problems. References.
2. NATURAL SOIL DEPOSITS AND SUBSOIL EXPLORATION.
Introduction. Natural Soil Deposits: Soil Origin. Residual Soil. Gravity Transported Soil. Alluvial Deposits. Lacustrine Deposits. Glacial Deposits. Aeolian Soil Deposits. Organic Soil. Some Local Terms for Soils.
Subsurface Exploration: Purpose of Subsurface Exploration. Subsurface Exploration Program. Exploratory Borings in the Field. Procedures for Sampling Soil. Split-Spoon Sampling. Sampling with a Scrapper Bucket. Sampling with Thin-Walled Table. Sampling with a Piston Sampler. Observation of Water Tables. Vane Shear Test. Cone Penetration Test. Pressuremeter Test (PMT). Dilatometer Test. Coring of Rocks. Preparation of Boring Logs. Geophysical Exploration. Subsoil Exploration Report. Problems. References.
3. SHALLOW FOUNDATIONS: ULTIMATE BEARING CAPACITY.
Introduction. General Concept. Terzaghi''s Bearing Capacity Theory. Factor of Safety. Modification of Bearing Capacity Equations for Water Table. The General Bearing Capacity Equation. Case Studies on Ultimate Bearing Capacity. Effect of Soil Compressibility. Eccentrically Loaded Foundations. Ultimate Bearing Capacity under Eccentric Loading – One-Way Eccentricity. Bearing Capacity with Two-Way Eccentricity. Bearing Capacity of a Continuous Foundation Subjected to Eccentric Inclined Loading. Problems. References.
4. ULTIMATE BEARING CAPACITY OF SHALLOW FOUNDATIONS: SPECIAL CASES.
Introduction. Foundation Supported by a Soil with a Rigid Base at Shallow Depth. Bearing Capacity of Layered Soils: Stronger Soil Underlain by Weaker Soil. Bearing Capacity of Layered Soil: Weaker Soil Underlain by Stronger Soil. Closely Spaced Foundations – Effect on Ultimate Bearing Capacity. Bearing Capacity of Foundations on Top of a Slope. Seismic Bearing Capacity of Foundation at the Edge of Granular Soil Slope. Bearing Capacity of Foundations on a Slope. Foundations on a Rock. Uplift Capacity Foundations. Problems. References.
5. SHALLOW FOUNDATIONS: ALLOWABLE BEARING CAPACITY AND SETTLEMENT.
Introduction. Vertical Stress Increase in a Soil Mass Caused by Foundation Load:
Stress Due to a Concentrated Load. Stress Due to a Circularly Loaded Area. Stress Below a Rectangular Area. Average Vertical Stress Increase Due to a Rectangularly Loaded Area. Stress Increase under an Embankment. Westergaard''s Solution for Vertical Stress Due to a Point Load. Stress Distribution for Westergaard Material. Elastic Settlement: Elastic Settlement of Foundations on Saturated Clay. Settlement Based on the Theory of Elasticity. Improved Equation for Elastic Settlement. Settlement of Sandy Soil: Use of Strain Influence Factor. Settlement of Foundation on Sand Based on Standard Penetration Resistance. Settlement in Granular Soil Based on Pressuremeter Test (PMT). Consolidation Settlement: Primary Consolidation Settlement Relationships. Three-Dimensional Effect on Primary Consolidation Settlement. Settlement Due to Secondary Consolidation. Field Load Test. Presumptive Bearing Capacity. Tolerable Settlement of Buildings. Problems. References.
6. MAT FOUNDATIONS.
Introduction. Combined Footings. Common Types of Mat Foundations. Bearing Capacity of Mat Foundations. Differential Settlement of Mats. Field Settlement Observations for Mat Foundations. Compensated Foundation. Structural Design of Mat Foundations. Problems. References.
7. LATERAL EARTH PRESSURE.
Introduction. Lateral Earth Pressure at Rest. Active Pressure: Rankine Active Earth Pressure. A Generalized Case for Rankine Active Pressure. Coulomb''s Active Earth Pressure. Active Earth Pressure Due to Surcharge. Active Earth Pressure for Earthquake Conditions. Active Pressure for Wall Rotation about the Top: Braced Cut. Active Earth Pressure for Translation of Retaining Wall – Granular Backfill.
Passive Pressure: Rankine Passive Earth Pressure. Rankine Passive Earth Pressure: Vertical Backfill and Inclined Backfill. Coulomb''s Passive Earth Pressure. Comments on the Failure Surface Assumption for Coulomb''s Pressure Calculations. Passive Pressure Under Earthquake Conditions. Problems. References.
8. RETAINING WALLS.
Introduction. Gravity and Cantilever Walls: Proportioning Retaining Walls. Application of Lateral Earth Pressure Theories to Design. Stability of Retaining Walls. Check for Overturning. Check for Sliding along the Base. Check for Bearing Capacity Failure. Construction Joints and Drainage from Backfill. Gravity Retaining Wall Design for Earthquake Conditions. Some Comments and a Case Study on Design of Retaining Walls. Mechanically Stabilized Retaining Walls: Soil Reinforcement. Considerations in Soil Reinforcement. General Design Considerations. Retaining Walls with Metallic Strip Reinforcement. Step-by-Step-Design Procedure Using Metallic Strip Reinforcement. Retaining Walls with Geotextile Reinforcement. Retaining Walls with Geogrid Reinforcement – General. Design Procedure for Geogrid – Reinforced Retaining Wall. Problems. References.
9. SHEET PILE WALLS.
Introduction. Construction Methods. Cantilever Sheet Pile Walls. Cantilever Sheet Piling Penetrating Sandy Soils. Special Cases for Cantilever Walls Penetrating a Sandy Soil. Cantilever Sheet Piling Penetrating Clay. Special Cases for Cantilever Walls Penetrating Clay. Anchored Sheet-Pile Walls. Free Earth Support Method for Penetration of Sandy Soil. Design Charts for Free Earth Support Method (Penetration into Sandy Soil). Moment Reduction for Anchored Sheet-Pile Walls. Computational Pressure Diagram Method for Penetration into Sandy Soil. Fixed Earth Support Method for Penetration into Sandy Soil. Field Observations for Anchored Sheet Pile Wall. Free Earth Support Method for Penetration of Clay. Anchors. Holding Capacity of Anchor Plates in Sand. Holding Capacity of Anchor Plates in Clay (φ = 0 Condition). Ultimate Resistance of Tiebacks. Problems. References.
10. BRACED CUTS.
Introduction. Pressure Envelope for Braced-Cut Design. Pressure Envelope for Cuts in Layered Soil. Design of Various Components of a Braced Cut. Case Studies for Braced Cuts. Bottom Heave of a Cut in Clay. Stability of the Bottom of a Cut in Sand. Lateral Yielding of Sheet Piles and Ground Settlement. Problems. References.
11. PILE FOUNDATIONS.
Introduction. Types of Piles and Their Structural Characteristics. Estimating Pile Length. Installation of Piles. Load Transfer Mechanism. Equations for Estimating Pile Capacity. Meyerhof''s Method for Estimating Qp . Vesic''s Method for Estimating Qp . Coyle and Castello''s Method for Estimating Qp in Sand. Correlations for Calculating Qp with SPT and CPT Results. Frictional Resistance(Qp) in Sand. Frictional (Skin) Resistance in Clay. Point-Bearing Capacity of Piles Resting on Rock. Pile Load Tests. Elastic Settlement of Piles. Laterally Loaded Piles. Pile-Driving Formulas. Pile Capacity for Vibration-Driven Piles. Negative Skin Friction. Group Piles: Group Efficiency. Ultimate Capacity of Group Piles in Saturated Clay. Elastic Settlement of Group Piles. Consolidation Settlement of Group Piles. Piles in Rock. Problems. References.
12. DRILLED-SHAFT FOUNDATIONS.
Introduction. Types of Drilled Shafts. Construction Procedures. Other Design Considerations. Load Transfer Mechanism. Estimation of Load-Bearing Capacity. Drilled Shafts in Granular Soil: Load-Bearing Capacity. Load-Bearing Capacity Based on Settlement. Drilled Shafts in Clay: Load-Bearing Capacity. Load-Bearing Capacity Based on Settlement. Settlement of Drilled Shafts at Working Load. Lateral Load-Carrying Capacity – Characteristic Load and Moment Method. Drilled Shafts Extending into Rock. Problems. References.
13. FOUNDATIONS ON DIFFICULT SOILS.
Introduction. Collapsible Soil: Definition and Types of Collapsible Soil. Physical Parameters for Identification. Procedure for Calculating Collapse Settlement. Foundation Design in Soils Not Susceptible to Wetting. Foundation Design in Soils Susceptible to Wetting. Expansive Soils: General Nature of Expansive Soils. Unrestrained Swell Test. Swelling Pressure Test. Classification of Expansive Soil on the Basis of Index Tests. Foundation Considerations for Expansive Soils. Construction on Expansive Soils. Sanitary Landfills: General Nature of Sanitary Landfills. Settlement of Sanitary Landfills. Problems. References.
14. SOIL IMPROVEMENT AND GROUP MODIFICATION.
Introduction. General Principles of Compaction. Field Compaction. Compaction Control for Clay Hydraulic Barriers. Vibroflotation. Blasting. Precompression. Sand Drains. Prefabricated Vertical Drains. Lime Stabilization. Cement Stabilization. Fly-Ash Stabilization. Stone Columns. Sand Compaction Piles. Dynamic Compaction. Jet Grouting. Problems. References.
ANSWERS TO SELECTED PROBLEMS.