深厚含水层悬挂式截水帷幕设计实践  

Design practice of suspended groundwater cut-off curtain in deep aquifer

作　　者：宋翔东 Song Xiangdong(Shanghai Changkai Geotechnical Engineering Co.,Ltd.,Shanghai 200093,China)

机构地区：[1]上海长凯岩土工程有限公司,上海200093

出　　处：《工程勘察》2024年第5期27-32,共6页Geotechnical Investigation & Surveying

摘　　要：在长江中下游地区,部分深基坑位于深厚含水层区域,截水帷幕无法隔断坑内外的水力联系,需要采用悬挂式截水帷幕。截水帷幕选择合适的嵌入深度有助于在保证工程安全的情况下节约工期、降低成本。本文结合上海某项目降水设计与施工,阐述在深厚含水层中如何利用其渗透系数各向异性的特征,确定经济合理的截水帷幕嵌入深度,首次引入截水帷幕等效绕流距离的概念,将截水帷幕嵌入深度、截水帷幕底端与降水井滤管底端的高差、水平渗透系数与垂向渗透系数比这三个影响水位降深因素统一用截水帷幕等效绕流距离表示,提出了截水帷幕嵌入深度设计快速判断方法,为类似项目提供了经验和参考。In the middle and lower reaches of the Yangtze River,some deep foundation pits are located in areas with deep aquifers,and the groundwater cut-off curtain cannot separate the hydraulic connection inside and outside of the pit.Therefore,a suspended cut-off curtain is required.An appropriate embedding depth for the cut-off curtain would help to save time and cost while to ensure pit safe.The dewatering design and construction of a project in Shanghai is combined to explain how to use the anisotropic characteristics of its permeability coefficient in deep aquifers to determine the economically reasonable embedding depth of the groundwater cut-off curtain in this article.For the first time,the concept of equivalent flow distance of the groundwater cut-off curtain is introduced.The embedding depth of the groundwater cut-off curtain,the height difference between the bottom of the curtain and the bottom of the precipitation well filter tube,and the ratio of horizontal permeability coefficient to vertical permeability coefficient,which affect the depth of water level drawdown,are uniformly represented by the equivalent flow distance of the water cut-off curtain.A quick judgment method for the embedding depth design of the groundwater cut-off curtain is proposed,providing experience and reference for the similar projects.

关 键 词：悬挂式截水帷幕 等效绕流距离 截水帷幕嵌入深度 降水工程 

分 类 号：TU753.6[建筑科学—建筑技术科学]