摘要
现阶段,基坑降水设计多通过理论计算结合数值模拟进行,然而,在保证安全的前提下,总抽水量仍具有优化空间。基于此,以江阴靖江长江隧道江北明挖基坑第二承压含水层降水施工为例,采用线性规划与数值模拟相结合的方法,在利用抽水试验反演渗透系数的基础上,通过数值模拟获取了构建线性规划模型的主要参数,求解了总抽水量最小时需开启的井点及对应抽水量,并与实际施工进行了对比。结果表明,在构建线性规划模型时,考虑的井数越多,管井位置越合理,得到的总抽水量和降深通常越小;对于开挖深度渐变的明挖隧道基坑,在挖深大区段抽水效率最高,此时挖深较浅区段的降水需求可能自然得到满足;降水优化可大幅降低开启井数、总抽水量和环境影响。
Currently,dewatering scheme is typically designed using the method of theoretical calculation and numerical simulation.The designed scheme,however,is far from the optimum,since the total pumping rate can be further optimized with engineering safety ensured.Based on the dewatering in the 2nd confined aquifer of a cut and cover tunnel belonging to the north part of Jiangyin-Jingjiang Yangtze River tunnel project,dewatering optimization is conducted combining the methods of linear programming(LP)and numerical simulation.In advance,the hydraulic conductivity is adjusted by simulating the pumping test.Then,the parameters required in the LP model are obtained with numerical simulation.The pumping wells with optimal locations and the corresponding pumping rates are further determined,and the results are compared with the ones in actual construction.It is found that more number of pumping wells and more rational well location usually result in lower total pumping rate and drawdown.For the cut and cover tunnel with gradually changing excavation depths along the tunnel,dewatering in the deepest excavation zone shows the highest efficiency,since the dewatering requirements of the subsequent zones with lower excavation depths may be met simultaneously.The dewatering optimization can significantly reduce the number of activated pumping wells,total pumping rate and environmental effect.
作者
孙彦晓
刘松玉
童立元
王峻
崔佳
李世龙
李敏
SUN Yan-xiao;LIU Song-yu;TONG Li-yuan;WANG Jun;CUI Jia;LI Shi-long;LI Min(Institute of Geotechnical Engineering,Southeast University,Nanjing,Jiangsu 211189,China;Jiangsu Provincial Transportation Construction Bureau,Nanjing,Jiangsu 210004,China;China Railway 14th Bureau Group Co.,Ltd.,Jinan,Shandong 250101,China;China Railway 14th Bureau Group Mega Shield Construction Engineering Co.,Ltd.,Nanjing,Jiangsu 211800,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2023年第6期1800-1810,共11页
Rock and Soil Mechanics
基金
国家自然科学基金(No.41972269,No.52178384)
江苏省交建局项目(No.2021QD05)。
关键词
承压水
降水优化
明挖隧道
线性规划
数值模拟
confined water
dewatering optimization
cut and cover tunnel
linear programming
numerical simulation
