Coupled Consolidation in Unsaturated Soils Based on Random Field Theory

doi:10.16183/j.cnki.jsjtu.2014.11.005

Abstract

Abstract:

Based on the random field theory, a random finite element model of coupled unsaturated consolidation in spatial random soils was established using the covariance matrix decomposition method and Monte Carlo simulation method. The effects of spatial variability of Young's modulus and saturated permeability were investigated. The results show that the mean and standard deviation of the settlement are significantly affected by the coefficient of variation of Young's modulus, and COV_E. When COV_E increases, the mean and standard deviation of the settlement increase, which means the uncertainty of the settlement are increased due to the spatial variability of Young's modulus. When the correlation length of Young's modulus δ_ln_E decreases, the standard deviation of excess pore water pressure and the surface settlement decrease due to the increased spatial averaging effect. The spatial averaging effect is more significant when the thickness of soil layer is smaller than δ_ln_E. In general, the effect of spatial variability of k_s is much less significant than that of elastic modulus, which mainly affects the unsaturated consolidation in process.

Key words: spatial variability, random field, unsaturated soil, hydro-mechanical coupling, Monte Carlo simulation

CLC Number:

TU432

CHENG Yan, ZHANG Lu-lu, ZHANG Lei, WANG Jian-hua. Coupled Consolidation in Unsaturated Soils Based on Random Field Theory[J]. Journal of Shanghai Jiao Tong University, 2014, 48(11): 1528-1535.

Figures/Tables 9

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参数	数值
ρ_w／（kg·m^-3）	1　000
g／（m·s^-2）	9.801
ρ_s／（kg·m^-3）	2.65×10³
β_w／（m²·kN^-1）	5×10^-7
α_c	1.0
n	0.45
E／MPa	19
k_s／（μm·s^-1）	34.7
ν	0.3
S_{w r}	0.07
α	1.0
β／m^-1	1.74
ε	2.5
a／m^-1	6.67
b	5.00