地下结构对含水层挡水作用的室内试验研究

Laboratory Investigation on Cutoff Effect of Underground Structure to Groundwater Seepage of Aquifer

随着沿海地区大规模的地下基础设施的建设,越来越多的地下连续墙和桩基础等地下结构物被建造在深层的土体中。由于这些地下构筑物的存在,对地下水渗流产生阻挡作用,原有的地下水渗流场受到影响。本文通过室内试验研究,观察对比了有构筑物阻挡和没有构筑物两种情况下地下水渗流情况的变化。研究表明地下构筑物的存在改变了水位的分布状况,并延长了地下水位稳定的时间。构筑物埋深与水力梯度变化之间的关系可采用指数曲线进行拟合,随着构筑物埋深的增加,上下游水力梯度初期增加缓慢,后期呈现快速增长。如果构筑物插入土中的深度与土层厚度之比能控制在70%以内,则地下构筑物挡水作用的影响程度可以控制较小的范围。

With the development of urbanization,more and more underground structures are constructed in the soft deposit along coastal region.These underground structures will cut off the flow of groundwater and obstruct the replenishment of groundwater.In order to investigate the cutoff behavior of underground structure to groundwater flow through impervious wall,a series of laboratory tests was conducted.Test results show that the wall changes the distribution of groundwater level and delays the steady period of groundwater seepage.The relationship between the buried depth of the wall and the increment of hydraulic gradient can be represented by exponential curve.The optimal insertion depth ratio of the wall（ratio of the buried depth over the thickness of soil layer） for reduction of cutoff effect is about 70%.