大型深基坑桩撑支护结构施工监测与数值分析

Construction monitoring and numerical analysis of pile-strut supporting structure of large deep foundation pit

针对深基坑桩撑支护结构的设计与造价问题,以某大型深基坑工程为背景,结合深基坑桩撑支护结构的设计、施工情况与监测,详细阐述了深基坑在开挖过程中的桩顶垂直位移、桩身水平位移、支撑轴力、基坑一定范围内的地表沉降、基坑附近建筑结构的沉降以及地下水位6个方面。结果表明:桩身最大水平位移与最大轴力的实际监测值分别为3.31 mm与2650 kN,数值均低于预警值与控制值,证明了该深基坑的设计安全系数较高,可以进行设计与优化操作。

In view of the design and cost of pile-supported retaining structure in deep foundation pit,taking a large-scale deep foundation pit project as the background,combined with the design,construction and monitoring of pile-supported retaining structure in deep foundation pit,the six aspects during excavation on vertical displacement of pile top,horizontal displacement of pile body,axial force of support,surface settlement in a certain range of foundation pit,settlement of building structures near foundation pit and groundwater level are expounded in detail in this paper.The results show that the actual monitoring values of the maximum horizontal displacement and the maximum axial force of the pile are 3.31mm and 2650 kN,which are respectively lower than the early warning value and the control value.Therefore it proves that the higher design safety factor of the deep foundation pit can be designed and optimized.