A Gradient Smoothing Technique-Based S-FEM for Simulating the Full Impacts of Anomalies on Seepage Solutions and its Application in Multi-Parameter Seepage Inversion

Searching for the precise solution of the free surface has remained the main bottleneck in analyzing the unconfined seepage problem for earth-rock dams. This paper proposes an approach to solve classic earth-rock dams using the smoothed finite element method (S-FEM). To overcome the problems of complex calculation and accuracy loss caused by integrating the area of intersecting elements in saturated seepage, this paper optimizes the shape function calculation by reducing the area integral to a line integral along the elements. To achieve a balance between efficiency and accuracy, we investigated the distinct effects of various smooth elements on computational efficiency, which included computation time and iteration times. Moreover, we first explored the extensive effect of seepage anomalies and their positional changes on hydrological state variables, including head, free surface, overflow point, seepage velocity, and fluid pressure. This exploration presented could provide a potential for developing multi-parameter seepage inversion and serve as constraints for hydro-geophysical inversion.