【摘要】 结合某大型深基坑工程实例,借助大型岩土类有限元分析软件Midas-GTS,对基坑在土方跃层开挖施工过程中地下连续墙与临界基坑地表的变形进行动态的数值模拟;同时,通过地下连续墙的水平变形监测,获得地下连续墙典型测点随基坑开挖深度变化的曲线。通过对数值模拟成果和现场实测结果的综合分析与对比,获得该深基坑土方跃层开挖过程中地下连续墙及周边土体的变形响应特征。结果表明:土方跃层开挖将对地下连续墙及周边环境产生不利影响,其产生的地下连续墙最大水平位移值约20 mm,但仍在合理值范围内;适当的采取施工措施,如在基坑四周尽可能预留较多反压土,可有效减小土方跃层开挖对地下连续墙产生的不利影响。研究成果对指导类似深基坑的设计和施工具有重要的参考价值。更多还原

【Abstract】 With a large and deep foundation pit engineering examples,using the large-scale geotechnical finite element analysis software Midas-GTS,we simulate the change state of the deformation of foundation pit earthwork in the thermocline in the process of excavation of underground continuous wall and the critical excavation surface. At the same time,through monitoring the deformation of underground continuous wall,obtain the typical measuring points curve of underground continuous wall with excavation depth changes. Through the comprehensive analysis and comparison of numerical simulation results and field measurement results,the deformation response characteristics of underground continuous wall and surrounding soil during the excavation process of deep foundation pit are obtained. The results show that the earthwork thermocline excavation has adverse effect on underground continuous wall and the surrounding environment,the maximum horizontal displacement of underground continuous wall is about 20 mm,but still in a reasonable range. We suggest taking proper construction measures,such asset aside more anti-pressure soil around the pit,can effectively reduce the adverse effects of earthwork thermocline the excavation of the underground continuous wall. The research results have important reference for guiding the design and construction of similar deep foundation pit.更多还原