Abstract
In order to establish a proper finite element model of prototype RC girder with sand element for impact response analysis, dynamic response analysis of RC girders with sand cushion subjected to impact force due to falling weight was performed to improve the state of the art of protective design for real scale rock-sheds using LS-DYNA code. Here, in order to establish a modification method for material properties of concrete so as to rationally analyze the prototype RC girder with sand cushion using coarse mesh, an equivalent fracture energy concept for concrete elements was proposed and the applicability was investigated comparing numerical analysis results with experimental results. From this study, it is confirmed that even though coarse mesh was used for prototype RC girder with sand cushion, similar results with those obtained using fine mesh can be assured.