饱和软黏土渗透特性及对一维大变形固结影响

摘要

通过室内渗压试验对广州南沙饱和软黏土在不同固结压力和不同渗透压力下的渗透特性进行系统研究,分析影响土体渗透性的各种加卸荷条件;归纳渗透系数与固结压力、渗透系数与孔隙比的经验关系;揭示了软黏土的渗透规律和渗透破坏特征.在试验成果分析基础上,根据大变形固结理论中以位移为控制变量的物质描述方程,进一步研究初始渗透系数对大变形固结的影响以及在软土地基大变形固结计算中考虑压缩系数和渗透系数的非线性的必要性和合理性.%Based on laboratory seepage pressure tests of saturated soft clays in Nansha,Guangzhou,the permeability of saturated soft clays under different consolidation and seepage pressures are systematically investigated. The effects of loading and unloading conditions on permeability are analyzed,and experience formulae are given to define void ratio and permeability coefficient. Testing results reveal the permeability law of saturated soft clays under different hydraulic gradients and the seepage failure characteristics. Based on experiments and large strain consolidation equations with displacement as variable,the effects of initial seepage coefficient on large strain consolidation are studied. It is shown that the nonlinear compressibility and permeability need to be considered in large strain consolidation calculation of soft foundation.