基坑降水时长江Ⅰ级阶地互层土中地下水运移规律  

Study on Groundwater Movement in Interbedded Soil of Grade Ⅰ Terrace of Yangtze River during Dewatering of Foundation Pit

作　　者：张红章 李腾龙[1] 范卫琴 熊宗海 程华强[3] ZHANG Hong-zhang;LI Teng-long;FAN Wei-qin;XIONG Zong-hai;CHENG Hua-qiang(Wuhan Fengda Geological Engineering Ltd,Wuhan 430074,China;College of Civil Engineering,Sanming University,Sanming365004,China;Wuhan Bridge Engineering Co.,Ltd.Wuhan 430074,China)

机构地区：[1]武汉丰达地质工程有限公司,湖北武汉430074 [2]三明学院建筑工程学院,福建三明365004 [3]武汉市桥梁工程有限公司,湖北武汉430074

出　　处：《三明学院学报》2020年第2期58-63,共6页Journal of Sanming University

基　　金：福建省中青年教育科研项目(JAT170538);武汉市市政建设集团有限公司科研项目(wszky201821)。

摘　　要：在长江Ⅰ级阶地某深基坑进行现场群井抽水试验,观测了抽水过程中各含水层水位变化,发现互层土中地下水水位在降水过程中呈稳定下降趋势,但相对其下砂层承压水,互层土水位下降存在明显的滞后。在此结论的基础上,将互层土层视为由粘土层和砂层交互层叠而成,并假定这两类组成单元的渗透系数分别一致,推导了降水过程中互层土地下水水头随降水时间变化的公式。公式显示:互层土水头下降时间与其中粘土层厚度占总厚度的比例、土体体积压缩系数、土体孔隙度、互层土厚度的平方成正比,与粘土层的渗透系数成反比。Field group well pumping tests were carried out in a deep foundation pit on grade I terrace of the Yangtze River. The water level changes of each aquifer during pumping were observed. It was found that the groundwater level in the interbedded soil decreased steadily in the process of dewatering, but the water level of the interbedded soil decreased obviously lagged behind the confined water in the lower sand layer. On the basis of this conclusion, the interbedded soil layer is considered to be formed by the interaction of clay layer and sand layer. Assuming that the permeability coefficients of the two components are identical, the formula of the variation of groundwater head with precipitation time in the process of precipitation is deduced. The formula shows that the head drop time of interbedded soil is proportional to the proportion of the thickness of clay layer to the total thickness, the volume compression coefficient of soil, the porosity of soil and the square of the thickness of interbedded soil, and inversely proportional to the permeability coefficient of clay layer.

关 键 词：地下水 互层土 基坑降水 水头下降 

分 类 号：TU753.66[建筑科学—建筑技术科学]