二元结构地层中“天窗”在基坑降水中的环境效应  

Environmental Effects of"Windows"in Dual Structural Stratum during Foundation Pit Dewatering

作　　者：孙啟钊 阎长虹[1] 李慧 徐源 祁磊磊 刘刚 SUN Qizhao;YAN Changhong;LI Hui;XU Yuan;QI Leilei;LIU Gang(School of Earth Science and Engineering,Nanjing University,Nanjing Jiangsu 210023 China;Nanjing Metro Construction Co.,Ltd.,Nanjing Jiangsu 210046 China;Beijing Urban Construction Zhongnan Civil Engineering Group Co.,Ltd.,Beijing 100012 China;The First Geological Brigade of the Geological Bureau of Jiangsu Province,Nanjing Jiangsu 210041 China)

机构地区：[1]南京大学地球科学与工程学院,江苏南京210023 [2]南京地铁建设有限责任公司,江苏南京210046 [3]北京城建中南土木工程集团有限公司,北京100012 [4]江苏省地质局第一地质大队,江苏南京210041

出　　处：《江苏建筑》2025年第1期81-85,106,共6页Jiangsu Construction

基　　金：国家自然科学基金项目(编号:42077232);南京大学与南京地铁建设有限责任公司和江苏南京地质工程勘察院校企合作项目(编号:S-D.S08.S-XY03-00-2211-0333);江苏省地质工程环境智能监控工程研究中心开放基金项目(编号:2021-ZNJKJJ-11)。

摘　　要：长江下游漫滩区广泛分布二元结构地层,呈现出典型“上细下粗”的地层岩性特征。在天然状态下,上部淤泥质土层或黏性土层中常夹有透水性较好的囊状或透镜状粉细砂天然“天窗”;在工程建设中也会遗留一些具有一定透水性的孔洞和缝隙的人工“天窗”。这些“天窗”在基坑降水过程中容易引起突涌、渗流及大范围地面沉降等不良环境岩土工程效应。文章通过理论分析和数值计算,探讨“天窗”构造的成因及其空间位置因素诱发的不良环境岩土工程效应。结果表明,各类不良环境岩土工程效应与“天窗”构造关系密切,并且是非线性关系。这一研究成果对于二元结构地层分布区基坑支护结构设计及施工具有重要的指导作用。Dual structure stratum is widely distributed along the lower reaches of the Yangtze River floodplain,showing the typical"upper fine and lower coarse"stratigraphic features.The upper silty soil layer or clay soil layer is often sandwiched with natural"windows"of capsule or lens-like fine sand with good permeability.There will also be some artificial"windows"with permeability,such as holes and crevices in the construction.These"windows"are prone to cause gushing,seepage,large-scale ground settlement,and other adverse environmental geotechnical effects during dewatering.We discuss the causes of the"windows"and its adverse effects through theoretical analysis and numerical calculation,focusing on the hazardous response of the"windows"spatial location factors.The results show that all kinds of adverse environmental geotechnical effects are closely related to the"windows"structure,and the relationship is nonlinear.This result is an important guide for the design and construction of foundation pit support structures in area with dual structure stratum distribution.

关 键 词：长江下游 二元结构地层 “天窗”构造 深大基坑 不良环境岩土工程效应 

分 类 号：TU463[建筑科学—结构工程]