孔隙比变量一维固结方程解析理论

Analytical Solution for One Dimensional Void Ratio Consolidation Theory

经典Terzaghi固结理论假定固结沉降与超孔压消散间满足线性耦合关系,通过计算土体应力固结度与土体最终沉降量预测沉降发展过程。由于土体固结沉降与超孔压消散间存在不同步耦合效应,沉降发展快于超孔压消散,应用应力固结度预测土体沉降发展误差较大。以孔隙比变量作为固结方程控制变量,根据孔隙比边界条件求解土体固结沉降过程可以有效避开超孔压消散与土体沉降间的滞后耦合效应。以土体连续方程、达西定律、有效应力原理为基础推导孔隙比变量固结方程及边界条件,研究边界条件、土体自重、初始孔隙比分布、非瞬时加载等对土体固结过程与最终效果的影响,比较应力与应变固结度间差异。研究表明初始条件、土体自重等对孔隙比变量解答有较大影响,引起5%左右误差。

Classical Terzaghi consolidation theory assumes linear coupling relationship between settlement and excessive pore pressure dissipation to calculate consolidation degree, and according to the final settlement obtained beforehand to predict consolidation process. As the assumption that the linear coupling between settlement and ex-cessive pore pressure dissipation isn＇t simultaneous, settlement develops fast than pore pressure dissipation which will lead to great error by calculation consolidation with dissipation degree. Relatively, take void ration instead as the consolidation equation variable and get analytical solution according to the boundary conditions can avoid the nonlinear coupling effect. Based on soil constitutive relationship and Darcy seepage law, one dimensional consolida-tion equation and boundary conditions for void ratio variable can be determined. Considering the influences of boundary conditions, soil weight, initial void ratio distribution, long-term loading et al to consolidation, void ratio analytical solution shows that initial condition and soil weight affect the consolidation result more greatly which will lead to a 5% error.