Soft Soil Engineering In Practice

Engineering development on soft soils has grown rapidly in recent years, spurred by an increasing demand on land space for infrastructure expansion. However, the combination of poor strength, high compressibility and low permeability characteristics inherent to soft soils form a problematic suite of conditions, placing overlying structures at risk of excessive deformation and instability. Managing these conditions is particularly challenging to designers and constructors. This paper presents a summary of the critical findings and conclusions gained through the author’s own experience in designing embankments over soft soils. Particular emphasis is placed on the interpretation of geotechnical parameters using empirical correlations to validate test results and design assumptions, and specific design considerations that may impact on the performance of embankments built on soft soils. This paper also discusses design criteria, methods for settlement and stability control, commonly used ground stabilisation techniques, and approach to manage soft soil risks. The purpose of the paper is to provide suggestions towards a holistic approach to soft soil engineering based on the author’s experience. Examples are also provided to illustrate the author’s views and findings, which are not intended to be exhaustive.