Compressibility of Ultra-Soft Soil

by Myint Win Bo (DST Consulting Engineers, Canada)

This book describes the compression behaviour of ultra-soft soil upon additional load application. Various types of laboratory compression tests suitable for this type of soil are discussed, such as tests using small and large-scale consolidometers, hydraulic Rowe cells under different drainage conditions, constant rate of loading and constant rate of strain tests. It also explains how to determine the transition point, which differentiates the two distinct behaviours between slurry state and soil state deformation. Methods to determine the compression indices and coefficients of consolidation at different stress ranges, which are required for the predicton of magnitude of settlement and time rate of settlement, are developed. An equation for predicting settlement of ultra-soft soil in both the slurry and soil stages is elaborated upon. These proposed methods of characterization or analyses- which are validated against published data, laboratory measurements and a case study- serve as useful tools for designing and constructing embankments and for carrying out land reclamation on ultra-soft soil.

Contents: Sedimentation and Consolidation; Models and Analogy; Characterization of Physical Properties and Mineralogy of the Soil; Compression Tests with Large-Scale Consolidometer; Compression Tests on Slurry with Small-Scale Consolidometer; Compression Tests on Ultra-Soft Soil with Hydraulic Consolidation Cell; Continuous Loading Tests on Ultra-Soft Soil; Constant Rate of Strain Test on Ultra-Soft Soil; Verification of Proposed Formulae and Models with Laboratory Measurements; Case Study.

About the Author : Dr. M W BO (Bo Myint Win) is a Geoservices Director at DST Consulting Engineers, Canada. He is a Fellow of the Geological Society, London, UK and a Fellow of Institution of Civil Engineers, UK. He is also a professional geologist, charterd Geologist, Chartered Scientist, Chartered Engineer, Chartered Environmentalist, European Geologist and European Engineer. Dr Bo is a member of the panel of experts for the Federation of European Geologists and also a committee member of Technical Committee 39 for the International Society of Soil Mechanics and Geotechnical Engineering, committee member of Technical Committee for International Geosythetic Society and also a committee member of Soil and Rock Committee D-18 for American Society of Material Testing.