Forward Modeling Of Coupled Seepage And Current Fields Based On Element-free Galerkin Method

In earth dam seepage simulation,is only the saturated area of the seepage field and can not fully reflect the real underground seepage state of rockfill,accurate underground seepage model of earth-rock dam seepage detection plays an important role,so the study of saturated-unsaturated domain is very necessary,including zero pressure side position are key problems in the research of whole flow field.In addition,for earth-rock DAMS,the exploration of seepage channels in earth-rock DAMS from the hydrogeological level is mostly limited to the surface or limited borehole data to collect hydrological information.The number and distribution of Wells determine the accuracy of the distribution of hydrologic parameters in any intrusive hydrogeological test.It is difficult to obtain spatial continuous hydrological parameters through in-situ experiments.The forward analysis results of the seepage field and current field coupling model provide a solid theoretical basis for geophysical exploration of seepage channels.Therefore,this paper adopts element-free Galerkin method to calculate the coupling forward of seepage field and current field.In this paper,the solution of saturated-unsaturated infiltration watershed is studied by using the element-free Galerkin method.Firstly,the seepage equation and boundary conditions are derived from Darcy’s law,and the element-free Galerkin method is derived in detail.The essence of Galerkin method is to construct form function by sliding least square method,and calculate boundary conditions by penalty function.Then,the accuracy and effectiveness of the method are proved by comparing with the saturated-unsaturated seepage field and saturatedunsaturated seepage field calculated by Geostudio software.Finally,the distribution of zero pressure line,water head value,pore pressure and water content in the dam body is studied by different heterogeneous models.The element-free Galerkin method only needs nodes to achieve accurate approximation of the whole domain seepage field,which solves the dependence on grid cells.Compared with other numerical methods,its early processing data is simple and has the advantages of high precision,and it is more suitable for forward simulation of the complex situation of the saturated-unsaturated model of stable seepage field.Then the solution of line source current field using element-free Galerkin method is studied,and the potential field function of current field is derived in detail by imposing boundary conditions.The potential distribution and current density of a uniform underground half-space model with abnormal body are studied and analyzed,which verifies the feasibility of this method.Thirdly,the uncoupling relationship between seepage field and current field is established for the same dam under undulating terrain,that is,the permeability coefficient in seepage field and the conductivity in current field are given randomly.Through uncoupled control analysis,the potential distribution is basically consistent with the water head distribution,and the current density and seepage velocity are roughly similar in the case of abnormal body.By archie empirical formula is established,therefore,the coupling relationship between them,and homogeneous dam design obtained with saturated-unsaturated seepage abnormal body dam domain model,calculated the potential distribution,current density and the water head distribution and seepage velocity has the very good consistency,it also verifies the similar mathematical relationship between two field,the feasibility of the method presented in this paper,The coupling relationship between seepage field and current field in earth-rock dam is realized by using the same method and the same set of nodes.