基于综合分析法的深基坑安全性评估

Safety assessment of deep excavation basedon comprehensive analysis method

由于深基坑工程安全性受到多因素影响,因此,利用综合分析法对基坑进行安全性评估,通过分析原始设计资料、施工资料对既有基坑的现状进行初步了解,结合现场调查及检测数据对基坑各支护构件强度进行定量分析,并将支护方案复核计算结果与监测数据进行对比。采用Midas三维有限元软件对基坑开挖全过程进行数值模拟,有效地反映了基坑整体开挖过程中支护的变形趋势。结果表明:①支护结构混凝土强度、支撑梁及冠梁钢筋数量及间距、支护桩外侧土体密实情况均符合设计和标准要求;②基坑支护方案各个剖面位移变形、整体稳定性验算、抗倾覆验算均满足工程设计要求;③数值模拟结果表明,支护桩及支撑梁各阶段位移变形值均在基坑变形控制范围内,满足基坑安全使用要求。

Due to the multiple factors affecting the safety of deep foundation pit engineering,a comprehensive analysis method was used to evaluate the safety of the foundation pit.By analyzing the original design and construction data,a preliminary understanding of the current situation of the existing foundation pit was obtained.Combined with on-site investigation and testing data,a quantitative analysis was conducted on the strength of each support component of the foundation pit.The calculation results of the support scheme review were compared with monitoring data.The use of Midas three-dimensional finite element software to numerically simulate the entire excavation process of the foundation pit effectively reflects the deformation trend of the support during the overall excavation process of the foundation pit.The results show that:①the concrete strength of the support structure,the number and spacing of steel bars in the support beam and crown beam,and the density of the soil outside the support pile all meet the design and standard requirements;②The displacement deformation,overall stability calculation,and anti overturning calculation of each section of the foundation pit support plan meet the engineering design requirements;③The numerical simulation results indicate that the displacement and deformation values of the support pile and support beam at each stage are within the deformation control range of the foundation pit,meeting the requirements for safe use of the foundation pit.