变荷载下连续排水边界黏弹性地基一维固结性状分析

One-dimensional consolidation characteristics of viscoelastic foundation with continuous drainage boundary under time-dependent loading

在考虑软黏土流变特性的基础上,结合工程实际,引入连续排水边界条件,建立了变荷载下连续排水边界黏弹性地基一维固结模型。通过分离变量法与常数变易法,求得了变荷载作用及连续排水边界条件下的饱和软黏土一维固结模型的解析解,进一步研究了透水边界条件和土体参数对超孔隙水压力、有效应力的影响。研究结果表明:上下边界透水性的不同会直接影响超孔隙水压力的变化;越靠近透水性大的边界处的土体固结速度越快,且随着其离排水边界的距离减小,对固结速度的影响逐渐增大;另外,软土层的渗透系数、Kelvin体弹簧的弹性模量和黏滞系数等对土颗粒间的有效应力影响较大。

Considering the rheological properties of soft clay and the engineering practice, the continuous boundary condition is applied to construct a one-dimensional consolidation model for viscoelastic foundation under time-dependent loading condition. The analytic solution for one-dimensional consolidation of saturated soft clay under time-dependent loading and continuous drainage boundary is solved by using separation of variables and variation of constants methods. Furthermore, influences of boundary conditions and soil parameters on excess pore water pressure and effective stress are studied. It is found that the variation of excess pore water pressure is directly influenced by permeability of upper-and lower-boundary. The consolidation rate is larger at the location closer to the boundary with higher permeability, and with decreasing the distance from drainage boundary, the influence on consolidation rate increases gradually. Moreover, the effective stress is significantly influenced by permeability coefficient, elastic modulus of Kelvin model and viscosity coefficient.