基于深基坑地下连续墙变形安全性分析

在基坑开挖过程中实时对整个基坑安全状态进行评判,动态地评判基坑的安全状态,对保证基坑安全具有重要的现实意义,其中如何在基坑开挖过程中获得围护墙的实际弯矩,成为评判围护墙内力安全状态的关键,根据深基坑工程中常规监测所得的围护墙体测斜变形曲线,通过多项式拟合的测斜曲线方程求解变形曲率,将计算得到的弯矩与通过钢筋混凝土单筋截面梁弯矩计算极限弯矩进行对比分析,来科学判断基坑的安全状态。同时基坑深层土体开挖会引起较大的围护墙位移和土体沉降,施工中应严格控制深层土体开挖无支撑暴露的时间,及时架设支撑及浇注混凝土底板,减小土体侧向位移及地表沉降,最后阐述了基坑监测数据产生异常的原因。

Security analysis of diaphragm wall deformation in deep foundation pit

A great deal of excavations comes up with the massive construction of subway station for urban railway transportation.How to evaluate the real-time status in the process of excavation is meaningful for the safety of deep foundation pits.And the key process is how to obtain the real bending moment of the retaining wall.According to the retaining wall deformation obtained by routine monitoring of deep foundation pit,the curvatures of the lateral deformation curves were obtained by derivation polynomial fitting equations.The accuracy of the method was analyzed with calculated total moment and reinforced stress,to determine the security status of deep foundation.Meanwhile,the deep soil excavation can cause large retaining structure displacement and earth settlement.Therefore,during the construction,the expose time of deep soil excavation should be strictly controlled when there has no support.Besides,it should be in time to construct support and deposit concrete floor,and to reduce soil side displacement and surface settlement.The causes of the abnormal monitoring data were explained at last.