西北地区某大型深基坑群优化设计与施工分析

Optimization design and construction of large deep foundation pit groups in northwestern areas of China

西北地区深大复杂基坑日益增多,关于基坑群的优化设计与施工可查文献空白。西宁火车站综合改造项目涵盖了当前城市开发遇到的高层建筑的多层地下室、地下商场、地下车库、地下隧道与地铁换乘站等基坑工程。基于该特大型基坑群工程,综合考虑其特点、开发进度、工期及造价等方面的因素,确定了基坑群整体支护设计原则,结合各地块具体差异,给出了典型支护剖面优化设计和降水方案,通过施工监测说明了该方案的合理性。最后,根据内力试验和施工跟踪,分析了深基坑施工过程中质量控制要点。可为西北地区类似特大型深基坑群工程的支护方案设计和施工质量控制提供借鉴和参考。

There are more and more deep foundation pits in the northwestern areas of China, while the available references about the optimization design and construction of foundation groups are short. The comprehensive renovation project of Xining Railway Station covers excavations such as multi-layer basement, underground shopping mall, underground garage,underground tunnel and subway transfer station of high-rise buildings during the development of the current cities. Based on the large foundation pit groups, considering their characteristics, development progress, schedule and cost, the design principles of supports for the foundation pit groups are determined. According to the specific differences around the block, the optimization design of typical cross section of the supports and the dewatering scheme are proposed. The rationality of this scheme is validated by construction monitoring. Finally, according to the experiments on internal forces and construction tracking, the key points to control the construction quality of deep foundation pit groups are analyzed. It may provide reference for the design and control of similar support projects in the northwestern areas of China.