Consolidation Solution of Aquitard Induced by Dropping of Groundwater Table with Continuous Drainage Boundary
In order to investigate the influence of the drainage boundary,which can better reflect the actual permeability,on the land subsidence caused by over-exploitation of groundwater,firstly,a one-dimensional consolidation model of aquitard caused by the dropping of groundwater table in phreatic aquifer with continuous drainage boundary was established by introducing the continuous drainage boundary,where the pore pressure decayed exponentially with time.Secondly,the general analytical solutions of the model and the analytical solutions of two special dewatering models for the instantaneous dropping of the groundwater table and the single-stage and constant-rate dropping of the groundwater table were obtained by using the method of separate variables.Then,the correctness of the analytical theory in this paper was preliminarily verified by the degeneracy of the analytical solutions under certain conditions.Finally,the single-stage and constant-rate dropping of the groundwater table was taken as an example,and the consolidation curves of the aquitard under different interface parameters B were calculated based on the analytical solutions.In addition,the influence of interface parameter B on the consolidation behaviors was analyzed emphatically.The results show that the maximum error rate is 13%by comparing the theoretically calculated settlement curve with the experimental settlement curve,which further indicates that the continuous drainage boundary is closer to the actual permeable boundary.Furthermore,larger interface parameter B indicates(better water permeability of the drainage boundary)a faster pore pressure dissipation rate,faster consolidation rate,and shorter consolidation time,but the final consolidation state is not affected.
dropping of groundwater tablesoil mechanicscontinuous drainage boundaryinterface parameteranalytical solution
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