考虑土体水平变形下的基坑降水诱发的地面沉降简化计算  

Simplified Calculation of Ground Settlement Induced by Foundation Excavation Dewatering Under Horizontal Deformation of Soil

作　　者：王晓华 杨光[1] 贾文彪[1] 林成 张凤鸣 WANG Xiaohua;YANG Guang;JIA Wenbiao;LIN Cheng;ZHANG Fengming(China Railway First Bureau Construction and Installation Engineering Co.,Ltd.,Xi'an,Shaanxi 710054,China;College of Civil Engineering,Xi’an University of Architecture and Technology,Xi'an,Shaanxi 710055,China)

机构地区：[1]中铁一局建筑安装工程有限公司,陕西西安710054 [2]西安建筑科技大学土木工程学院,陕西西安710055

出　　处：《施工技术（中英文）》2022年第10期65-71,共7页Construction Technology

基　　金：国家自然科学基金(51408463);陕西省教育厅专项科研计划(17JK0424)。

摘　　要：以西安地铁6号线钟楼站基坑工程为例,分析坑内、外含水层未完全隔离,存在水力联系时,基坑内潜水不完整井抽降水导致的地面沉降变化规律。基于Dupuit假设,以弹性半无限体理论和渗流力学为理论基础,简化浸润曲线,从二维平面和三维空间上定量推导出能计算饱和区内任意一点附加应力的计算公式,同时考虑绕渗区内渗流力在水平向的分量,修正推导出的降水引起坑外地表沉降计算方法,最终将理论计算值与工程案例监测值进行对比分析。结果表明,相较于规范算法,该方法可更精准地预测不同深度处由抽降水引起的坑外不同距离处地面沉降量,且能综合考虑浸润曲线形状和水位下降深度等影响因素。Taking the foundation excavation engineering of Zhonglou Station of Xi’an metro line 6 as an example,the ground surface settlement law caused by incomplete dewatering in the foundation excavation is studied under the condition that the aquifer inside and outside the foundation excavation is not completely separated,and there is a hydraulic connection.Based on the Dupuit hypothesis and the theory of elastic semi-infinite body and seepage mechanics,the calculation formula for calculating the additional stress at any point in the saturated region is derived quantitatively from the two-dimensional plane and three-dimensional space by simplifying the infiltration curve.Considered the horizontal upward component of seepage force in the seepage zone,the calculation method of surface subsidence caused by preciexcavationation is modified.Finally,the theoretical calculation value is compared with the monitoring value of the engineering case.The results show that,compared with the standard algorithm,this method can more accurately predict the land subsidence at different distances outside the foundation excavation caused by drainage at different depths,and can comprehensively consider the influencing factors such as the shape of the infiltration curve and the depth of water level decline.

关 键 词：基坑 降水 沉降 附加应力 侧向变形 

分 类 号：TU473[建筑科学—结构工程]