真空-堆载联合预压加固地基简化非线性分析

Simplified nonlinear analysis of subsoil improved by vacuum combined with surcharge preloading

针对真空-堆载联合预压加固地基的沉降性状,提出一种新的简化非线性分析方法。该方法考虑加固过程中地基模量变化的影响,将砂井地基在渗透性上等效为均质地基,通过常规压缩试验成果和割线模量法来反映地基模量的变化.基于Biot固结理论,推导了相应的简化非线性有限元分析方法,并给出具有快速收敛性的余量迭代算法.工程实例结果表明,由该方法得到的计算结果具有较高精度,该方法降低了传统分析的复杂性,具有一定的适用性和普遍性,可用于指导工程设计.

For calculating the settlement of subsoil improved by vacuum combined with surcharge preloading, a new simplified nonlinear method was proposed. Considering the effect of consolidation process on foundation modulus, sand-drain foundation was transformed into uniform ground according to its permeability, and the variation of foundation modulus was simulated by using the outcome of routine oedometer test and the secant modulus method. Based on Blot＇s consolidation theory, the corresponding simplified nonlinear finite element method was formulated with a rapid convergent of residual iteration algorithm. The experimental results show that the proposed method can increase the precision of analysis data, decrease the complexity of traditional method, and can be used for engineering design without loss of applicability and generality.