Calculation methods for hydrogeological parameters of confined aquifers under the condition of drop waterproof curtain
The drop waterproof curtain is widely used in deep foundation pit engineering in Wuhan area with typical dual structure strata,and the existence of the drop waterproof curtain changes the seepage environ-ment of groundwater in the dual structure aquifer.Therefore,the analysis and numerical calculation method of hydrogeological parameters of confined aquifer under the condition of the drop waterproof curtain are proposed.The correctness and reliability of the method were verified by the test data of deep foundation pit pumping in Wuhan Garden Road subway station.The results are as follows:the permeability coefficient of confined aquifer is calculated from 17.47 to 25.55 m/d with an average value of 20.722 m/d by the newly established analytical formula considering the drop waterproof curtain.The horizontal permeability coeffi-cient of confined aquifer is obtained by three-dimensional numerical simulation inversion(21.6 m/d for the silty sand layer and 25.92 m/d for the fine sand layer)and the vertical permeability coefficient(2.592 m/d for the fine sand layer and 3.456 m/d for the fine sand layer)has obvious anisotropy.The newly proposed analytical method and numerical method can obtain reliable hydrogeological parameters of confined aquifer.It can provide a more direct scientific basis for the design of foundation pit dewatering under the condition of the drop waterproof curtain,and has a certain popularization and application value.
万方数据
维普
