多级线性加载下软土一维非线性固结分析

One-dimensional Nonlinear Consolidation Analysis of Soft Soil under Multi-stage Linear Loading

多级加载是一种常见的加载形式,目前软土一维非线性固结方面的研究鲜有考虑多级加载。为研究多级加载下软土一维非线性固结规律,构建考虑多级线性加载和土体非线性的固结模型。利用有限差分法获得固结方程的解答,并通过与现有解答对比验证了所得解答的正确性。进而分析荷载形式和土体非线性对固结特性的影响,结果表明:与瞬时加载或单级加载相比,采用多级线性加载可以充分让土体超静孔隙水压力消散并且可以降低超静孔隙水压力峰值。第一级荷载对土体固结影响最大,工程中采用多级荷载时,应控制第一级荷载的加载量及加载速率,以避免土体发生破坏。

At present,the research on one-dimensional nonlinear consolidation of soft soil rarely considers multi-stage loading,but multi-stage loading is a common loading form.In order to study the one-dimensional nonlinear consolidation law of soft soil under multi-stage loading,a consolidation model considering both soil nonlinearity and multi-stage loading was established.The finite difference method was used to solve the consolidation equation,and the correctness of the proposed solution was verified by comparing with the existing solution.Furthermore,the influence of load form and nonlinear parameters on the consolidation characteristics of soil was analyzed.The results show that compared with instantaneous loading or single-stage loading,multi-stage loading can fully dissipate the excess pore water pressure of soil and reduce the peak value of excess pore water pressure.Because the first stage load has the greatest influence on the consolidation of soil,the loading amount and loading rate of the first stage load should be controlled to avoid the damage of soil when the multi-stage load is used in engineering.