真空预压后塑料排水板对地基承载力及沉降的影响

真空预压法是加固软粘土地基的有效方法之一，天津港地区成功的工程实例表明，采用塑料排水板结合抽真空的方法加固地基具有明显的优势和经济性，施工技术也比较成熟。但塑料排水板在地基加固完成后并不取出，这些留在地基中的塑料板对地基的承载力和沉降会产生一定的影响。本文采用极限平衡法和有限元法分析了塑料板对地基稳定性的影响及其规律性。研究结果表明，真空预压后排水板的存在对地基的承载力具有一定的提高作用，对地基承载力的贡献与塑料排水板的间距、基础的宽度以及排水板的抗拉强度有关。对于超载使用的地基，排水板的存在增加了地基的承载力但排水板越长地基的沉降就越大。

Influence of Plastic Vertical Drain on Bearing Capacity and Settlement of Subsoil after Vacuum Preloading

As an effective method to reinforce soft soil foundation, vacuum preloading method has distinct advantage and economic property, which has been proved by successful engineering practices, especially in Tianjin Port. Meanwhile the construction technology of the vacuum preloading method is relatively mature. However, the plastic vertical drains (PVDS), which are left in the foundation after the vacuum preloading construction, may exert influences on the bearing capacity and settlement of the subsoil. In this paper, the limit equilibrium method and the finite element method are applied to analyze the effect of PVDS on the subsoil stability. The analyzing results show that the left PVDS increase the bearing capacity of subsoil, which is related to the interval of the PVDS and the width of foundation. When the applied load is bigger than the design load, the PVDS will increase the subsoil bearing capacity and the foundation settlement will increase with the PVDS length.