(上海勘测设计研究院  200434)
［提要］  为保证基坑施工安全及了解基坑开挖时围护结构和支撑体系的受力、变形特点，对某人防工程深基坑进行了安全监测，共设置了水平位移、沉降、测斜、支撑轴力、钢筋应力和地下水位等监测项目。根据现场测试数据发现，基坑围护体系及周边环境的受力、变形在土方开挖期间变化较为显著，而在非开挖期间则相对稳定，钢筋混凝土支撑一般截面面积较大，控制地下连续墙侧向位移的效果比钢支撑好。现场监测是保证深基坑施工安全、验证设计理论的有效手段。
［关键词］  深基坑  安全监测  地下连续墙  支撑  土方开挖
Safety Monitoring and Analysis of Foundation Pit of an Antiaircraft Project/Tao Mingxing, Cao Guofu, He Zailiang (Shanghai Investigation Design & Research Institute, Shanghai 200434, China)
Abstract:A monitoring system including the survey of horizontal displacement, vertical displacement, incline of retaining wall, steel stress and level of underground water, is setup to find out the mechanical character of the retaining and supporting system in company with insuring of the safety of a deep foundation pit. By studying and analyzing the observed value, it is found that the stress and deformation of the retaining and supporting system changed evidently during earth excavation, and it is relatively steady in the other time. Reinforced concrete supporting system can bring better effect to control the displacement of underground diaphragm wall than steel supporting system because of the bigger section. Insite monitoring is an effective way to insure the safety of deep foundation pit and verify the design theory of deep foundation pit.
Keywords:deep foundation pit； safety monitoring； underground diaphragm wall； support structure； earth excavation