邻近深埋地铁车站水-土阻隔效应及其对基坑抽水致沉的影响  

Barrier effect of adjacent deep-buried metro station and its influence on ground settlement induced by foundation pit dewatering

作　　者：薛秀丽[1,2] 谢伟睿 廖欢 曾超峰[1,2] 陈宏波 徐长节[3] 韩磊 XUE Xiu-li;XIE Wei-rui;LIAO Huan;ZENG Chao-feng;CHEN Hong-bo;XU Chang-jie;HAN Lei(Hunan Provincial Key Laboratory of Geotechnical Engineering for Stability Control and Health Monitoring,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;School of Civil Engineering,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China;State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang,Jiangxi 330013,China;China Construction Eighth Engineering Division Corp,Ltd.,Shanghai 200122,China)

机构地区：[1]湖南科技大学岩土工程稳定控制与健康监测湖南省重点实验室,湖南湘潭411201 [2]湖南科技大学土木工程学院,湖南湘潭411201 [3]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,江西南昌330013 [4]中国建筑第八工程局有限公司,上海200122

出　　处：《岩土力学》2024年第9期2786-2796,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金项目(No.51978261,No.52238009);湖南省自然科学基金项目(No.2022JJ20023);湖南省科技创新计划项目(No.2022RC1172);江西省自然科学基金项目(No.20223BBG71018)。

摘　　要：既有地下结构会阻隔地下水渗流(阻水效应)和其周边土体运动(阻土效应),使得该条件下的基坑抽水致沉规律与无邻近地下阻隔时不同。以实际基坑抽水试验为工程依托,以基坑外既有地铁车站结构的水−土阻隔效应为例,通过建立不同车站位置、车站埋深及基坑抽水强度的系列三维数值仿真模型来研究不同水−土阻隔效应条件下的基坑抽水致沉规律。研究表明:当基坑外存在车站结构时,基坑抽水沉陷被加剧或被限制,这取决于阻水和阻土效应孰强孰弱,而车站与基坑间距D的远近将决定阻水和阻土效应的相对强弱,进而决定基坑抽水沉陷是被加剧还是被限制;车站埋深H只会单一影响阻水或阻土效应的发挥强度,不会决定阻水和阻土效应谁起主导作用。工程中应针对基坑外邻近车站的具体位置和埋深考虑其水−土阻隔效应的影响,从而更准确地评估该条件下的抽水致沉规律。The existing underground structure blocks groundwater seepage(i.e.,water-blocking(WB)effect)and restricts surrounding soil movement(i.e.,soil-blocking(SB)effect).This leads to differences in the dewatering-induced behaviors of groundwater and strata compared to scenarios without nearby structures.In this study,a typical metro station was chosen as the nearby underground structure that impedes groundwater and soil flow.Three-dimensional hydro-mechanical numerical models were developed based on an actual foundation pit pumping test to analyze the dewatering-induced responses of groundwater and strata under different WB and SB effects.Factors such as the relative location of the metro station to the excavation,the buried depth of the station structure,and the dewatering depth in the model were considered.The results indicate that the presence of a metro station near the excavation site can either aggravate or restricte dewatering-induced ground settlement,depending on the strength of the SB and WB effects.The distance D between the excavation and the metro station determines the relatively strength of the SB and WB effects,thereby influencing whether the ground settlement is aggravated or restricted.On the other hand,the buried depth H of the station only singularly affects the intensity of the WB or SB effect and could not determine which barrier effect plays the dominant role.In practical engineering applications,it is essential to consider both WB and SB effects based on the proximity and buried depth of the adjacent station structure to effectively assess the dewatering-induced behaviors of groundwater and strata.

关 键 词：基坑抽水 阻隔效应 地下结构 基坑变形 抽水试验 数值模拟 

分 类 号：TU470[建筑科学—结构工程]