二元结构土层分布区工程降水诱发地面沉降变形研究

叶为民^{1, 2}，赵少阳^{1, 2}，陈永贵^{1, 2}, 谢雄耀^{1, 2}，黄钟晖³

(1. 同济大学 岩土及地下工程教育部重点实验室，上海，200092；
2. 同济大学 地下建筑与工程系，上海，200092；
3. 南宁市轨道交通有限责任公司，广西 南宁，530021)

摘 要：基于南宁市地铁1号线广西大学站上部为透水性较差的黏性土层，下部为透水性好的砂砾石土层，在分析基坑降水诱发地面沉降机理的基础上，探讨二元结构土层中附加应力和压缩土层分层厚度的确定方法，最后通过分层总和法计算得到因降水引起的地面沉降。研究结果表明：计算得到的地面沉降与实测沉降基本吻合，表明所提出的沉降参数确定方法合理、可靠，对类似工程具有借鉴作用。

关键词：地铁车站；深基坑降水；地面沉降；二元结构土层；分层总和法

Dewatering-induced land subsidence in binary-structure soil

YE Wei-min^{1, 2}, ZHAO Shao-yang^{1, 2}, CHEN Yong-gui^{1, 2}, XIE Xiong-yao^{1, 2}, HUANG Zhong-hui³

(1. Key Laboratory of Geotechnical and Underground Engineering, Ministry of Education, Tongji University,
Shanghai 200092, China;
2. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China;
3. Nanning Subway Transportation Co. Ltd., Nanning 530021, China)

Abstract:Based on the fact that for the first station of the first subway line in Nanning city, the binary-structure soil is very typical, where the cohesive soil with poor permeability is at the top, and the sand gravel soil with strong permeability is at the bottom, the mechanism of the dewatering-induced land subsidence around the pit in binary-structure soil was analyzed, the determination of the additional load was discussed, and the thickness of the compressed soil layers in binary-structure soil was delivered, and the settlement method was proposed. The dewatering-induced land subsidence around the pit was obtained by the delamination summation-method. The results show that the calculated land subsidences agree well with those monitored, which shows that the proposed settlement method is reasonable and reliable to determine the calculation parameters.

Key words:subway station; dewatering of deep pit; land subsidence; binary-structure soil; delamination summation- method