地铁车站围护结构地下连续墙作为桥梁桩基的竖向承载力分析

The Analysis of Vertical Bearing Capacity of Metro Station’s Retaining Structure Diaphragm Wall Function as Bridge Piles

为探讨基坑围护结构地下连续墙作为桥梁桩基的可行性,结合某一地铁车站与高架桥合建工程案例,基于俞式增长模型推导出地下连续墙竖向承载力计算公式,并进一步研究了初始水平变形对地下连续墙竖向承载力的影响。研究表明,所推导公式的计算结果较为准确,案例工程的地下连续墙竖向极限承载力约为82500kN,对应的墙顶竖向沉降约为30mm;而50mm的初始水平变形也仅使地下连续墙的竖向极限承载力减小约4.8%,其影响在工程实践中可忽略。因此,围护结构地下连续墙在基坑开挖结束回填后继续作为竖向承载基础是完全可行的。

To discuss the feasibility of retaining structure diaphragm wall function as bridge piles,combined with a joint construction case of a metro station and a viaduct,the calculation formula of vertical bearing capacity of diaphragm wall is deduced based on Yu’s growth model.Then the influence of initial horizontal deformation on the vertical bearing capacity of diaphragm wall is further studied.Conclusions can be drawn that the calculation results of the deduced formula are rather accurate.The ultimate vertical bearing capacity of the diaphragm wall from the case is about 82500kN,and the corresponding vertical settlement at the top of wall is about 30mm.Meanwhile,the initial horizontal deformation of 50mm only reduces the vertical bearing capacity of diaphragm wall by about 4.8%,which can be ignored in engineering practice.Therefore,it is completely feasible for the retaining structure diaphragm wall to continue to function as the vertical bearing foundation after the foundation pit is backfilled.