Dewatering-Induced Building Settlement around a Deep Excavation in Soft Deposit in Tianjin, China
Dewatering-Induced Building Settlement around a Deep Excavation in Soft Deposit in Tianjin, China
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中国天津软沉积物深基坑周围脱水引起的建筑物沉降
DOI：
10.1061/(asce)gt.1943-5606.0002045
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发表时间：
2019-05-01
影响因子：
3.9
通讯作者：
Shen, Shui-Long
中科院分区：
文献类型：
--
作者：
Wu, Yong-Xia;Lyu, Hai-Min;Shen, Shui-Long
本文介绍了天津某存款区深基坑降水引起的建筑物沉降研究。发掘地点位于天津市中心，周围有许多现存建筑。现场的地质条件涉及一个多含水层系统，其中一个潜水含水层位于三个承压含水层之上。为保持基坑底部的稳定，采用防渗墙阻挡地下水渗漏，并打大直径威尔斯井降低地下水位。在施工期间安装了现场仪器，以监测（1）抽取的地下水量，（2）地下水位，（3）周围建筑物的沉降。现场观测结果表明：（1）地下水的抽取会导致建筑物的大面积沉降和地面沉降;（2）降水引起的沉降大部分没有回弹;（3）防渗墙在降水过程中对减少建筑物沉降起到了重要作用;（4）开挖过程中应实施按需降水程序。(C)2019年美国土木工程师协会。
This case study presents an investigation on building settlement induced by dewatering for a deep excavation constructed in a deposit in Tianjin, China. The excavation site is located in the Tianjin urban center, around which there are many existing buildings. Geological conditions at the site involve a multiaquifer system with one phreatic aquifer over three confined aquifers. To maintain the stability of the bottom of the excavation, a cutoff wall was used to block groundwater seepage with large diameter wells to lower the groundwater level. Field instrumentation was installed during construction to monitor (1) the quantity of withdrawn groundwater, (2) the groundwater head, and (3) the settlement of surrounding buildings. The field observations yielded the following results and implications: (1) pumping of groundwater could lead to large building settlement and a large area of ground settlement; (2) most of the settlement caused by dewatering did not rebound; (3) the cutoff wall played a significant role in reducing the building settlement during dewatering; and (4) the dewatering-on-demand procedure should be implemented during excavation. (C) 2019 American Society of Civil Engineers.