真空-堆载联合预压法加固软基平面等效算法研究

Equivalent Calculation of Soft Soil Consolidation by Surcharge Preloading Combined with Vacuum Preloading

真空堆载联合预压法是地基处理有效方法之一。目前的数值计算方法是考虑平面应变情况,基于堆载的思路,将砂井地基转化为砂墙地基,对砂井间距和砂井渗透系数进行等效调整,以便于简化计算。文章针对真空预压和堆载预压在作用机理上有所不同,提出了真空堆载联合预压情况下平面等效算法,并采用修正剑桥模型,对某工程实例进行了平面应变有限元分析,计算结果表明,与实测值比较吻合,说明该方法是合理可行的。

Surcharge preloading combined with vacuum preloading is an effective method for soft soil consolidation. At present, plain strain analysis is taken into account in most calculation methods. By introducing an equivalent surcharge pressure, sand drain soil is transformed into sand wall soil by adjusting spacing between sand drains and its permeability. Considering the difference of the functioning mechanism of vacuum preloading and surcharge preloading, an equivalent method is presented under the condition of vacuum preloading combined with surcharge preloading. Plain strain FE analysis is conducted with Cambridge model adopted in an example, the results of which are in consistency with the practical value, thus the method is reasonable and feasible.