土工基础

土工基础 ›› 2024, Vol. 38 ›› Issue (2): 181-185.

• 工程实录 • 上一篇    下一篇

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

何 伟1，海 涵1，詹 源2，陈孝湘3,4，龚建伍3，李羿江1   

  1. （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；4．中国电建集团福建省电力勘测设计院有限公司，福州 350003）
  • 收稿日期:2022-08-05 修回日期:2022-08-19 出版日期:2024-02-29 发布日期:2024-12-22
  • 作者简介:何伟（1966-），男，高级工程师，研究方向为电网公司建设管理与研究。
  • 基金资助:
    国网陕西省电力有限公司科技项目

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

HE Wei1, HAI Han1, ZHAN Yuan2, CHEN Xiaoxiang3,4, GONG Jianwu3， LI Yijiang1   

  1. (1.Construction Division, State Grid Shaanxi Electric Power Co. Ltd., Xi’an 710065；
    2.CEEC Shaanxi Electric Power Design Institute Co. Ltd., Xi’an 710054；
    3.School of Urban Construction, Wuhan University of Science and Technology, Wuhan 430081；
    4.POWERCHINA Fujian Electric Power Survey & Design Institute Co. Ltd., Fuzhou 350003)
  • Received:2022-08-05 Revised:2022-08-19 Online:2024-02-29 Published:2024-12-22

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。

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

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 groundwater 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 studied. The lateral earth pressure of the soldier pile can improve the safety of the excavation, but compared with the dewatering inside 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.

Key words: Highly Permeable Stratum, Deep Excavation for Vertical Shaft, Suspended Impervious Curtain, Osmotic Stability, Ground Settlement

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