Analysis of surface settlement caused by group wells dewatering in suspended waterproof curtain for deep foundation pit under confined aquifer conditions

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Dec.2023, Vol.46 No.12: 1679-1684

DOI: 10.3969/j.issn.1003-5060.2023.12.014

Authors

SUN Dapeng $ ^{1} $, WU Yuntao $ ^{2} $, WANG Pengcheng $ ^{2} $

(1. China Railway Construction Group Co., Ltd., Beijing 100040, China; 2. School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China)

Abstract and Keywords

Abstract: When the thickness of the aquifer is large, the suspended waterproof curtain is usually used for economic consideration. Based on the construction of the wall-well seepage system of deep foundation pit, the force caused by dewatering is equivalent to the additional force exerted on the interface of overlying soil layer and confined aquifer, and the Mindlin displacement solution is introduced to put forward the calculation formula of the surface settlement caused by the deep foundation pit group wells dewatering under the condition of suspended waterproof curtain. It is suitable for the situation where the curtain insertion ratio is greater than 0.6 and the pumping well insertion depth is relatively shallow. The influence of curtain insertion ratio, the depth of water head in foundation pit, the ratio of foundation pit radius to the thickness of confined aquifer on the surface settlement value is investigated. The research results have been well applied in the dewatering problem of deep foundation pit with confined aquifer in the station building project of a high-speed railway station in Hefei City, and provide reference for the optimization of dewatering schemes in other similar projects.

Keywords: confined aquifer; waterproof curtain; group wells dewatering; Mindlin displacement solution; surface settlement

作者信息

孙大朋 $ ^{1} $，吴云涛 $ ^{2} $，汪鹏程 $ ^{2} $

(1. 中铁建设集团有限公司, 北京 100040; 2. 合肥工业大学土木与水利工程学院, 安徽合肥 230009)

摘要和关键词

摘要: 在含水层厚度较大时,从经济性考虑通常采用悬挂式止水帷幕降水。文章基于构建深基坑墙-井渗流系统,将降水引起的作用力等效为施加在上覆土层和承压含水层交界面处的附加力,引入Mindlin位移解,提出悬挂式止水帷幕条件下深基坑群井降水引起的地表沉降计算公式,适用于止水帷幕插入比大于0.6且抽水井插入深度相对较短的情形,探究了止水帷幕插入比、基坑内水头降深、基坑半径与承压含水层厚度之比对地表沉降值的影响。研究结果在合肥某高铁站站房工程承压水地层深基坑降水问题中得到较好的实际应用,为其他类似工程降水方案优化提供了参考。

关键词: 承压水；止水帷幕；群井降水；Mindlin位移解；地表沉降

Funding

国家自然科学基金资助项目（51979068）

合肥工业大学学报(自然科学版)

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