基坑开挖的试验研究与Plaxis结果的比较讨论

基坑开挖与支护是一个三维空间问题。我国对软土深基坑支护工程的研究已取得一些成果，但对非饱和土地区的深基坑支护工程而言，由于非饱和土中存在负孔隙水压力(基质吸力)，使得其与饱和土在性状上有显著的不同。因而软土深基坑支护工程的许多成功经验不适用于非饱和土。对非饱和土基坑开挖的研究，尚存在许多问题有待解决，其中最主要的问题是挡墙上土压力的分布及变形。采用国际先进的Plaxis程序，将计算结果与室内大型模型试验结果进行对比分析，得出挡墙上土压力的分布及变形规律，以期完善土压力理论。

Comparing with Results between the Test Date and PLAIXS Program Calculation

Pit-retaining structure is a three-dimensional space. In China, many progresses had been maken in pit-retaining structure of soft soil. But there is negative pore water pressure, that is matrix suction, in unsaturated soil. The characters of unsaturated soil are very different from saturated soil. For unsaturated soil, many succeed experiences which are made in soft soil pit excavation area could not be used. There are many problems should be solved, and the main problems are earth pressure and deformation on the pit-retaining structure. Using PLAIXS finite element program, the earth pressure and deformation on pit-retaining structure will have been calculated. The results are compared with the model test, and hoping to perfect the earth pressure theory.