Seismic Analysis of the Reservoir-Earth Dam-Pore Fluid System Using an Integrated Numerical Approach

In this paper, an integrated numerical approach is proposed for analyzing the seismic response of the reservoir-earth dam-pore fluid system subjected to earthquake loading. The fluid-mechanical coupling approach is deployed to capture the fluid-solid matrix coupling effects automatically. A hysteretic damping constitutive law is adopted to follow the modulus reduction and damping ratio curves. The Finn-Byrne equation is used to represent the shear-induced volumetric strain behavior of liquefiable materials. The interaction between the reservoir water and the dam boundary is treated as a dynamically updated pressure boundary condition. The deconvolution is accomplished by the equivalent linear program SHAKE. An automatic remeshing algorithm is employed to replace the badly distorted mesh with a new regular mesh whenever needed during the system evolution process. The system integrating these elements is constructed in the explicit finite-difference program FLAC, and applied to analyze the responses of a reservoir dam under seismic loading in both horizontal and vertical directions; the potential liquefied regions, earthquake-induced settlement and lateral spreading predicted by the simulation are presented