Analytical solutions for rheological consolidation of soft clays with consideration of threshold hydraulic gradients and nonuniform distribution of initial excess pore water pressure
LI Chuanxun1，MA Haotian1，ZHOU Enquan1，XIE Kanghe2
(1. Faculty of Civil Engineering and Mechanics，Jiangsu University，Zhenjiang，Jiangsu 212013，China；2. Research Center of Coastal and Urban Geotechnical Engineering，Zhejiang University，Hangzhou，Zhejiang 310058，China)
Abstract：The distribution of initial excess pore water pressure in clays caused by external load is usually non-uniform with depth，and the rheological characteristics of soft clays and the threshold hydraulic gradient in clays have also been recognized. However，an analytical solution for rheological consolidation of soft clays with consideration of threshold hydraulic gradient in clays and non-uniform distribution of initial excess pore water pressure has been rarely reported in the literature. In this study，the rheological characteristic of soft clays are described by Merchant three-element rheological model，and the governing equation for one-dimensional consolidation with consideration of threshold gradients and non-uniform distribution of initial excess pore water pressure with depth is developed，and analytical solutions for this consolidation model are derived by Laplace transform method. Based on the verification of analytical solutions，a large number of calculations are investigated by analytical method. The results show that：the larger the threshold hydraulic gradient is，the slower the speed of moving boundary is，and the smaller the average consolidation degree and the final settlement are. With an increase in the ratio(?) of the initial excess pore water pressure at the top surface( ) to that at the bottom surface( )，the speed of moving boundary and the final average degree of consolidation decrease，and the consolidation rate and the final settlement of clay layer increase. The ratio(a) of the elastic modulus of spring( ) in Kelvin body to the elastic modulus( ) of independent spring has little influences on the consolidation behavior in the early stage of consolidation. However，in the late consolidation stage，the greater the ratio a is，the larger the average degree of consolidation and the final settlement of the layer are. In the early stage of consolidation，the viscosity coefficient( ) has little influence on the consolidation characteristics of the soil. In the late stage of consolidation，the larger the value of ，the faster the consolidation rate and the settlement rate of the soil. But the viscosity coefficient has no influence on the final settlement of clay layer.
李传勋1，马浩天1，周恩全1，谢康和2. 考虑初始孔压非均布及起始坡降的黏土流变固结解[J]. 岩石力学与工程学报, 2019, 38(S2): 3859-3869.
LI Chuanxun1，MA Haotian1，ZHOU Enquan1，XIE Kanghe2. Analytical solutions for rheological consolidation of soft clays with consideration of threshold hydraulic gradients and nonuniform distribution of initial excess pore water pressure. , 2019, 38(S2): 3859-3869.
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2019, Vol. 38 
