复杂地质条件下超深基坑渗流特性研究  

RESEARCH ON THE SEEPAGE CHARACTERISTICS OF SUPER-DEEP FOUNDATION PIT UNDER COMPLEX GEOLOGICAL CONDITIONS

作　　者：段凯 石广 DUAN Kai;SHI Guang(Changjiang Survey,Planning,Design and Research Co.,Ltd.,430010,Wuhan,China)

机构地区：[1]长江勘测规划设计研究有限责任公司,武汉430010

出　　处：《建筑技术》2023年第13期1591-1595,共5页Architecture Technology

摘　　要：以汉口长江Ⅰ级阶地某基坑为例,建立典型的二元结构渗流计算模型,对多种组合降水方案进行数值模拟,分析降水井底部高程、地下连续墙埋深深度及强透水层渗透系数对超深基坑渗流特性的影响。结果表明:在同一降水量条件下,降水井底部高程越高,坑内降深越大,降水效果越好,而坑外降深基本保持不变;地下连续墙底与相对隔水层的间距对抽水量存在明显的影响,大致呈线性正比关系。岩土层中的下部强透水地层是渗流的主要通道,设计时应根据透水层的渗透性系数采取合适的降水方案,实现工期和成本最优化。Taking one foundation pit in the level I terrace of the yangtze river in Hankou as an example,a typical binary seepage calculation model has been established,numerical simulations were conducted on various combinations of dewatering schemes,and the impact of the bottom elevations of dewatering wells,embedded depths of diaphragm walls and permeability coefficients of strong permeable layers on the seepage characteristics of the super-deep foundation pit were analyzed.Results show that,under the same precipitation conditions,the higher the bottom elevation of a dewatering well the greater the dewatering depth inside the foundation pit,and the better the dewatering effect,but the dewatering depth outside the foundation pit largely remains unchanged;and the spacing between the bottom of a diaphragm wall and the relative confining bed has a significant impact on the pumping capacity,which is approximately linearly proportional.The lower strongly permeable layer in the rock and soil layer is the main channel for seepage,so an appropriate dewatering scheme should be implemented based on the permeability coefficient of the permeable layer,in order to minimize the construction period and construction costs.

关 键 词：二元结构地层 超深基坑 渗流 地下连续墙 渗透系数 

分 类 号：TU463[建筑科学—结构工程]