Failure monitoring of the collapsed group of RC piers of the hanshin expressway during the 1995 Hanshin Great Earthquake

During the 1995 Hanshin Great Earthquake in Kobe City and vicinity, about 600 m of the elevated part of Hanshin Expressway which had been constructed as a group of pirtz RC piers collapsed. The pier No. 126 of this group (the tallest one in the collapses group) is simulated for three cases based on the assumptions of weakness of material or amplification of ground acceleration as the main causes for collapse. in case one, the same material and acceleration from the site and near field are used in analysis while in case 2 it is assumed that the concrete strength is less than the strength of the case one. In case 3 it is assumed that the acceleration is amplified 7, times of the case one. The simulation results show that the pier collapsed due to the material weakness (case 2) and/or amplification of acceleration (case 3) while was only cracked in case cine. The well agreement between the collapsed mechanism in the site and the one from the simulation also approves the ability of the program for failure monitoring of the structures.