强透水层中竖井基坑悬挂式止水帷幕渗透稳定及降水影响分析
Analysis of Seepage Stability and Dewatering Effect on the Suspended Impervious Curtain in the Deep Excavation for a Vertical Shaft in a Highly Permeable Stratum
何伟 1海涵 1詹源 2陈孝湘 3龚建伍 4李羿江1
作者信息
- 1. 陕西省电力有限公司建设分公司,西安 710065
- 2. 中国能源建设集团陕西省电力设计院有限公司,西安 710054
- 3. 武汉科技大学城市建设学院,武汉 430081;中国电建集团福建省电力勘测设计院有限公司,福州 350003
- 4. 武汉科技大学城市建设学院,武汉 430081
- 折叠
摘要
基于西安某DN3500电力工程顶管始发工作井的明挖顺作基坑,首先通过理论计算并分析在砂土等强透水层中,悬挂式止水帷幕对渗透稳定性的影响;其次分析了坑内集水明排、坑内井点降水和坑外管井降水等不同的地下水控制方案对基坑围护桩和坑外土体变形的影响规律,结果显示:采用坑外降水的方案可以合理减小支护桩的土侧压力,提高基坑的安全性,但相比于坑内降水,采用坑外降水会显著增大井外地表的沉降量;最后结合止水帷幕和降水施工的工艺特点,提出"按需降水"等相关的风险控制措施,为该工程的建设提供依据,也为相关工程的建设提供参考.
Abstract
This paper presents a case history of a cut-and-cover deep excavation for a DN3500 power project in Xi'an where the pipe jacking initiation working shaft.Through theoretical analysis,the influence of the suspended impervious curtain on the seepage stability in the sandy soil and other highly permeable strata is evaluated.And then,the influence of different groundw-ater control options,such as,water collection and open drainage,dewatering of pipe well points in the pit and dewatering of tube wells outside,on the deformation of the soldier pile in the deep excavation and the soil outside the excavation area are stud-ied.The lateral earth pressure of the soldier pile can improve the safety of the excavation,but compared with the dewatering in-side the excavated area,the use of the dewatering outside the pit will significantly increase the settlement of the surface outside the well.Risk control measures related to"requiring dewatering"provide a basis for the pipe jacking project's construction and a reference for the construction of related projects.
关键词
强透水层/竖井基坑/悬挂式止水帷幕/渗透稳定/地层沉降Key words
Highly Permeable Stratum/Deep Excavation for Vertical Shaft/Suspended Impervious Curtain/Osmotic Stability/Ground Settlement引用本文复制引用
出版年
2024
NETL
NSTL
万方数据