Analysis of consolidation of a soil layer with depth-dependent parameters under time-dependent loadings

Abstract

In this paper, a Laplace transform method is proposed to solve the one-dimensional consolidation problems considering depth-dependent parameters of the soil layer, which is subjected to complicated time-dependent loadings at ground surface. The coefficient of volume compressibility and the coefficient of permeability for the soil layer are continuous functions of vertical coordinate. The solution is obtained and described in detail. The characteristics of consolidation under suddenly imposed constant loading are analysed. The results show that the excess pore pressure distribution of a soil layer with depth-dependent parameters is dissimilar to the solution Terzaghi has proposed. The characteristics of consolidation under time-dependent loadings are also analysed and the influences of depth-dependent parameters are considered. The results also suggest that the effective stress develops with time under time-dependent loading follows the trend under suddenly-imposed constant loading but exhibit certain oscillations. The oscillation amplitudes of the effective stresses don’t decrease with time. Therefore, it is inaccurate to simplify the cyclic loading to constant loading.

Keywords:

• Non-linear consolidation
• clay
• Laplace transformation
• depth-dependent parameters
• time-dependent loading

Acknowledgments

Many people and organisations contributed to the success of this project. The financial supports from the National Key Basic Research Program of China (973 Program) (No. 2015CB057801), National Natural Science Foundation of China (NSFC Grant No. 51278449, NSFC Grant No. 51238009 and NSFC Grant No. 51338009), Major Academic and Technical Leaders Cultivation Program of Jiangxi Province China (No. 00351081430912120) are greatly acknowledged.