Abstract: In order to investigate the spatial and temporal evolution laws of pile lateral displacement and surface subsidence during the excavation of deep foundation pits in the metro stations in Xian area, a certain deep foundation pit of a metro station in Xian area was taken as the engineering background, meanwhile the measured data of 20 narrow and long foundation pits on Line 2, 3, and 4 in the above region were collected and statistically analyzed. The results show that the maximum lateral displacement δhm of the subway foundation pit enclosure structure is 0.04%H~0.10%H (H is the excavation depth), the average value is 0.06%H, and the maximum lateral displacement position depth is 0.7H. The maximum surface subsidence value δvm is within the range of 0.036%H~0.116%H, and the main influence area is within the range of 1.4H. Gaussian function model can predict the surface subsidence in Xian area, whose influence range is 3.5H. Within a specific range, increasing the stiffness and insertion ratio of the supporting pile can effectively control the foundation pit deformation. The research results can provide reference for the design and construction of foundation pit support structures for other subway stations in Xian.

Key words: geotechnical engineering; railway engineering; deep foundation pit of subway station; pile deformation; foundation pit deformation; settlement prediction; statistical analysis

摘要： 为了探究西安地铁车站深基坑开挖过程中桩体侧移、地表沉降等时空演变规律，以西安地区某地铁车站深基坑为工程背景，同时收集了该地区2#、3#、4# 线20个狭长基坑的实测数据，并对其进行统计分析。结果表明：地铁基坑围护结构最大侧移δhm=0.04%H~0.10%H（H为开挖深度），平均值为0.06%H，最大侧移位置深度为0.7H；地表最大沉降值δvm=0.036%H~0.116%H，主要影响区在1.4H范围以内；高斯函数模型可以预测西安地区的地表沉降，其影响范围为3.5H；在特定范围内，提高支护桩的刚度和插入比可以有效控制基坑变形。研究结果可为西安市其他地铁车站基坑支护结构的设计与施工提供借鉴。

关键词: 岩土工程；铁道工程；地铁车站深基坑；桩体变形；基坑变形；沉降预测；统计分析