Abstract: Numerical studies on seismic responses of a long-span bridge pier-pile-soil system relate with the following several aspects: the reasonability and convenience of the finite element model for a long-span bridge pier-pile-soil system, the validity of approach for multi-point earthquake motions at underground locations, the wave force and effect of hydrodynamic pressures-induced added mass; and multi-source visco-elastic artificial boundary conditions. Firstly, the essential difference between the long-span bridge pier-pile-soil system with and without artificial boundary conditions is expounded and pointed out. Then, a feasible and effect path for the inversion of earthquake motions is given and proposed, accounting for spatial variability, at under-ground location from ground surface, and the corresponding visible program called MEMS_c (Multiple Earthquake Motions Simulation_c) is further developed successfully. Further, a visual program named WFS (Wave Force Simulation) is developed and illustrated based on the wave force and its spectral characteristics for small-scale structures. At last, in order to improve the efficiency and flexibility of preprocessor, a quick workflow for establishing numerical modeling is presented and the visual modeling tool Foundation 2013.6 is developed. The content involves theory and practicability. It can be directly applied to the follow-up engineering.