复杂巨厚第四纪松散沉积层地区深基坑降水三维渗流场数值模拟——以上海地铁4#线董家渡段隧道修复基坑降水为例  

THREE-DIMENSIONAL SEEPAGE NUMERICAL SIMULATION OF DEEP FOUNDATION PIT DEWATERING IN COMPLICATED QUATERNARY LOOSE SEDIMENTS WITH GREAT THICKNESS——A CASE STUDY OF DEWATERING RECONSTRUCTED FOUNDATION PIT AT DONGJIADU SUBWAY OF THE 4TH LINE IN SHANGHAI

作　　者：骆祖江[1] 张月萍[1] 刘金宝[1] 

机构地区：[1]河海大学土木工程学院,南京210098

出　　处：《岩石力学与工程学报》2007年第A01期2927-2934,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：上海市重大科研项目基金资助(04dz12003)

摘　　要：针对长江三角洲地区分布有复杂巨厚第四纪松散沉积层,且具有较高的承压水位,其深基坑降水的模拟、预测难度大。以上海地铁4#线董家渡段隧道修复基坑降水为例,建立基坑降水三维渗流模型,并采用有限差分数值模拟方法,模拟在多层含水层复合存在、含水层最深底板埋深达150 m、基坑周围挡水连续墙埋深达65 m、抽水井埋深达59 m、抽水井过滤器埋深为44～59 m及30口抽水井联合降水情况下,基坑中心下伏第2承压含水层中部降压段水位降至埋深43.35 m时的地下水复杂流动状态。经后续工程验证,该结果正确、可靠,该理论用于模拟预测此类地区深基坑降水引起的地下水流场变化具有较高的可信度。The Quaternary loose sediment with great thickness and complex character in the Yangtze River delta is found,and the water table of the confined aquifer is so high that it is difficult to predict dewatering of deep foundation pit.A three-dimensional seepage model was established and three-dimensional finite difference numerical simulation method was adopted in foundation pit dewatering at Dongjiadu subway of the 4th line in Shanghai.The complicated flow state of groundwater was simulated under these conditions as follows：（1） the aquifers deposited layer by layer;（2） the bottom of the aquifers with thickness 150 m;（3） the horizontal flow barrier with thickness 65 m（;4） the pumping wells being penetrated to depth of 59 m（;5） the filters of the pumping wells being located between 44 m and 59 m;（6） thirty pumping wells being operated at the same time;and（7） the water level of the middle part of confined aquifer II under the center of foundation pit decreases to 43.35 m under ground surface.The result was proven to be correct and reliable by succedent project.It is concluded that it is very reliable to use the theories to simulate and predict the state change of groundwater flow in deep foundation pit dewatering in such areas.

关 键 词：数值模拟 第四纪松散沉积层 深基坑降水 三维渗流场 

分 类 号：O241[理学—计算数学] TV139.16[理学—数学]