Handbook of Tropical Residual Soils Engineering

Residual soils are found in many parts of the world. Like other soils, they are used extensively in construction, either to build upon, or as construction material. They are formed when the rate of rock weathering is more rapid than transportation of the weathered particles by e.g., water, gravity and wind, which results in a large share of the soils formed remaining in place. The soils typically retain many of the characteristics of the parent rock. In a tropical region, residual soil layers can be very thick, sometimes extending to hundreds of meters before reaching un-weathered rock. Unlike the more familiar transported sediment soil, the engineering properties and behaviour of tropical residual soils may vary widely from place to place depending upon the rock of origin and the local climate during their formation; and hence are more difficult to predict and model mathematically. Despite their abundance and significance our knowledge and understanding of these soils is not as extensive as that of transported sediment soil. Written by residual soil specialists from various parts of the world, this unique handbook presents data, knowledge and expertise on the subject. It provides insight into the engineering behaviour of tropical residual soils, which will be applicable to small or extensive construction works worldwide on such soils. This book covers almost all aspects of residual soils, from genesis, classification, formation, sampling and testing to behaviour of weakly bonded and unsaturated soil, volume change and shear strength. It features chapters on applications in slopes and foundation, as well as dedicated parts on residual soils in India, Hong Kong and Southeast Asia. A large number of graphs, tables, maps and references throughout the text provide further detail and insight. This volume is intended as a reference guide for practitioners, researchers and advanced students in civil, construction and geological engineering. Unique in its coverage of the subject, it may serve as a standard that benefits every engineer involved in geological, foundation and construction work in tropical residual soils.

Table of Contents:
1 Introduction 1.1 Aim and scope 1.2 Soils 1.3 Residual soils 1.4 Geographical occurrence of residual soils 1.5 Climate, classification systems and regions 1.6 Distribution of tropical residual soils 1.7 Engineering peculiarities of tropical residual soils References 2 Formation and classification of tropical residual soils 2.1 Introduction 2.2 Residual soils 2.2.1 Origin and general features of residual soils 2.2.2 Formation of residual soils 2.3 Formation of tropical residual soils 2.4 Characteristics of tropical residual soils 2.4.1 Development of a weathered profile 2.4.2 Chemical alteration and composition of the weathered profile 2.5 Pedogenetic classification of tropical residual soils 2.6 Definition and classification of tropical residual soils in civil engineering practice 2.6.1 Definitions of residual soils 2.6.2 Pertinent aspects of classifications of tropical residual soils for engineering practice 2.7 Examples of residual soils over different rock types 2.7.1 Profiles over igneous rocks 2.7.2 Profiles over sedimentary rocks 2.7.3 Profiles over metamorphic rocks 2.8 Conclusions References 3 Sampling and testing of tropical residual soils 3.1 Introduction 3.2 Sampling 3.3 Laboratory testing 3.4 In-situ tests 3.5 Summary and conclusions References 4 The behaviour of unsaturated soil 4.1 Introduction 4.2 Suction 4.2.1 Components of suction 4.2.2 Axis translation 4.2.3 The suction scale 4.2.4 Limiting suctions 4.2.5 Suction measurement 4.3 Water retention behaviour 4.4 Shear behaviour 4.4.1 Stress state variables 4.4.2 The extended Mohr-Coulomb failure criteria 4.5 Volume change 4.5.1 Shrinkage 4.5.2 Swelling 4.5.3 Combining changes in volume and water content 4.5.4 Collapse 4.6 Permeability 4.6.1 Water permeability (hydraulic conductivity) 4.6.2 Air permeability (air conductivity) References 5 Volume change of tropical residual soils 5.1 Introduction 5.2 Swelling and shrinkage 5.3 Collapsible residual soils References 6 Shear strength model for tropical residual soil 6.1 Introduction 6.2 Development of soil shear strength models 6.3 Laboratory measurement of shear strength using triaxial apparatus 6.4 Conclusions References 7 Slopes 7.1 Introduction 7.2 Geological factors of slope behaviour 7.3 Geology and mode of slope failure 7.4 Landslide classification 7.5 Landslide triggering mechanisms 7.6 Stability analyses 7.7 Remedial measures for soil and rock slopes References 8 Foundations: Shallow and deep foundations, unsaturated conditions, heave and collapse, monitoring and proof testing 8.1 Introduction 8.2 Direct (shallow) foundations 8.2.1 Solutions to foundations on residual soils – factors that affect the concept 8.2.2 Particular conditions in residual soils 8.2.3 Main demands for the guarantee of structural limit state conditions 8.3 Foundations on unsaturated soils 8.3.1 Shallow foundations on collapsible soils 8.3.2 Deep foundations on collapsible soils 8.3.3 Mitigation measures 8.3.4 Recent research and developments for dealing with collapsible soils 8.3.5 Shallow foundations on expansive soils 8.3.6 Characterisation by swell strains 8.3.7 Types of foundation that are used in expansive soils 8.3.8 Mitigation and preventive measures 8.3.9 Case histories 8.4 Indirect (deep) foundations 8.4.1 General concepts 8.4.2 Pile design References Standards, government and official publications Bibliography 9 Residual soils of Hong Kong 9.1 General descriptions of decomposed rocks in Hong Kong 9.2 In-situ test sites and sampling locations 9.3 Sampling methods and preparation procedures 9.4 Stress-dependent soil–water characteristic curves (SDSWCC) 9.5 In-situ permeability function 9.6 Small strain shear stiffness 9.7 Shear strength of unsaturated saprolites 9.8 Summary References 10 Residual soils of India 10.1 Introduction 10.2 The Archaean group 10.3 Climate 10.4 Distribution of residual soils 10.5 Physico-chemical properties 10.6 Geotechnical engineering data References 11 Residual soils of Southeast Asia 11.1 Introduction 11.2 Residual soils of Malaysia 11.2.1 Engineering applications and problems 11.3 Residual soils of Thailand 11.3.1 Engineering applications and problems 11.4 Residual soils of Singapore 11.4.1 Engineering applications and problems References