Book Description

The Lambeth Group underlies the London and Hampshire Basins. While of limited outcrop, it is of considerable relevance to infrastructure developments in central London, particularly those of tunnelling and deep foundations. Its complex stratigraphy has recently been clarified which, in turn, has led to a better engineering description and classification. An improved understanding of the engineering behaviour and properties of its component units has been gained from several recent major projects in central London with high-quality ground investigations and laboratory testing.

This book draws together this new information, coupling it to a review of case histories of construction in the Lambeth Group. It provides guidance about the relation between engineering properties and the group’s widely different lithologies, about the hazards they pose for construction, and appropriate ways to overcome them. This book provides recommendations for investigating these complex materials. In addition to case study data, the report is supported by a comprehensive reference list and bibliography.

210 pages

Contents: Summary, Acknowledgements, List of figures, List of tables, List of case studies, Abbreviations, Notation, 1 INTRODUCTION, 1.1 Background, 1.2 Scope and objectives, 1.3 Structure of the report, 2 GEOLOGY OF THE LAMBETH GROUP, 2.1 Regional setting, 2.2 Depositional environment, 2.3 Historical perspective, 2.4 Stratigraphy, 2.5 Depositional environment and processes, 2.6 Geophysical log characteristics, 2.7 Mineralogy, 2.8 Post-depositional features, 3 ENGINEERING HAZARDS, 3.1 Uncertainties stemming from the geology, 3.2 Engineering hazards, 4 ENGINEERING PROPERTIES, 4.1 Sources of data for the London Basin, 4.2 Sources of data for the Hampshire Basin, 4.3 Depositional environments and post-depositional processes,4.4 Generalised geotechnical descriptions, 4.5 Distribution, 4.6 Composition, 4.7 Soil plasticity, 4.8 Clay mineralogy, 4.9 Liquidity index, 4.10 Bulk density, 4.11 Groundwater conditions and in-situ horizontal stresses, 4.12 Undrained strength, 4.13 Effective stress strength parameters, 4.14 Stiffness, 4.15 Penetration resistance, 4.16 Consolidation parameters, 4.17 Permeability, 5 DESIGN, CONSTRUCTION AND PERFORMANCE, 5.1 Bored tunnels and shafts, 5.2 Deep excavations and cut-and-cover structures, 5.3 Groundwater control using dewatering techniques, 5.4 Slope stability, 5.5 Dredging, 5.6 Fill and pavement engineering, 5.7 Piled foundations, 5.8 Shallow foundations, 6 GROUND INVESTIGATION, 6.1 Desk study, 6.2 Stratigraphy and groundwater conditions, 6.3 In-situ testing, 6.4 Sampling methods, 6.5 Sampling effects, 6.6 Laboratory testing, 6.7 Best practice for ground investigations in the Lambeth Group, 6.8 Assessing engineering properties and selecting design parameters, 7 FURTHER WORK, 7.1 Characteristaion studies, 7.2 Case histories, REFERENCES, APPENDICES, A1 Bibliography, A2 Photographs of cores and exposures of the Lambeth Group, A3 Case history data