（1 南通开放大学建筑工程学院， 南通 226000； 2 南通大学交通与土木工程学院， 南通 226018；3 上海申元岩土工程有限公司， 上海 200011）

［摘要］以上海某医院基坑工程为例，对“两墙合一”地下连续墙基坑的支护结构变形、内力以及周边建筑物沉降的现场实测数据进行全面系统的分析，研究不同施工工况下支护结构内力、变形变化规律，以及基坑开挖对坑外建筑沉降的影响。结果表明，基坑开挖时地下连续墙侧向位移呈抛物线形状，最大侧向位移出现在开挖面下方1～2m处，随着开挖深度的增大，地下连续墙侧向位移逐渐增大； 支撑内力的发展呈迅速增大、趋于稳定两个阶段； 基坑开挖对建筑物的沉降有较大的影响，基坑北侧建筑物沉降的发展经历四个阶段：基本稳定、开始增大\|缓慢回弹、加速增大、趋于稳定； 由于坑外邻近建筑的存在，2倍基坑开挖深度范围以外坑外地表沉降实测值与经验预估值基本保持一致，而在2倍基坑开挖深度范围以内坑外地表沉降实测值与经验预估值有较大偏差。

［关键词］基坑开挖； “两墙合一”地下连续墙； 沉降； 现场监测

中图分类号：TU476+.3, TU753文献标识码：A文章编号：1002-848X(2020)20-0128-05

Analysis on deformation influence and field monitoring of adjacent building induced by foundation pit excavation using “one wall acted as two” for underground diaphragm wall

ZHANG Kefeng1, WU Changjiang2, YI Li3

(1 School of Architecture Engineering, Nantong Open University, Nantong 226000, China；2 School of Transportation and Civil Engineering, Nantong University, Nantong 226019, China； 3 Shanghai Shenyuan Geotechnical Engineering Co., Ltd., Shanghai 200011, China)

Abstract:A hospital foundation pit engineering in Shanghai was taken as an example, a comprehensive systematic analysis on field measured data was conducted on the supporting structure deformation and internal force of foundation pit excavation using “one wall acted as two” for underground diaphragm wall and surrounding buildings settlement, and the internal force and deformation laws of the supporting structure under different construction conditions were studied as well as the influence of foundation pit excavation on the settlement of buildings outside the pit. The results show that the lateral displacement of the underground diaphragm wall is parabolic, and the maximum lateral displacement occurs at 1～2m below the excavation surface. With the increase of the excavation depth, the lateral displacement of the underground diaphragm wall increases gradually. The development of the supporting internal force is two stages which  rapidly increases and tends to be stable. The excavation of the foundation pit has a greater impact on the settlement of the building, and the development of the settlement of the building on the north side of the foundation pit has gone through four stages: basically stable, beginning to increase and rebounding slowly, acceleration increase, and tending to be stable; due to the existence of adjacent buildings outside the pit, the measured value of the surface settlement outside the pit is basically consistent with the empirical estimate outside the range of 2 times the excavation depth of the foundation pit, while the measured value of the surface settlement outside the pit within the range of 2 times the excavation depth of the pit has a large deviation from the empirical estimate value.

Keywords:foundation pit excavation; “one wall acted as two” for underground diaphragm wall; settlement; site monitoring

*江苏省高校自然科学基金研究面上项目（17KJD560002），江苏省自然科学基金青年项目（BK20180954）。

作者简介：张珂峰，硕士，副教授，Email：zhangkefeng2210@163.com； 通信作者：吴昌将，博士，高级工程师，Email：15921360161@163.com。