Soil creep effects on ground lateral deformation and pore water pressure under embankments

Abstract

Analysing the behaviour of the soft ground under embankments is a challenging task and is of significant interest to practising geotechnical engineers. This paper revisits a well known case study of an embankment of Boston Blue Clay, which was thoroughly instrumented and measured with piezometers, settlement rods and inclinometers over a long time period during and after construction. The soil parameters were very comprehensively collected by both in situ and laboratory tests in several major test programs. The behaviour of the ground considering the modified Cam-Clay model including and excluding soil creep is simulated using finite element method. The analysed data are verified with field measurements and a parametric study is conducted to evaluate the influence of creep index on excess pore water pressures generated and the displacement of the ground under the embankment. It is observed that both horizontal displacements and excess pore water pressures of the ground under the embankment increased by the creep index. Thus effects of soil creep should be precisely considered in predicting the ground performance under embankments.

Keywords:

• soil creep
• secondary consolidation
• embankment
• settlement
• pore water pressure
• lateral deformation

Acknowledgments

The authors gratefully acknowledge the financial assistance from the Australian Research Council. The contributions and feedback from Menard Bachy Pty Ltd., particularly Mr. Daniel Berthier and Mr. Philippe Vincent, are very much appreciated.