DYNAMIC BEHAVIOR ANALYSIS OF A PLAIN CONCRETE PIER DURING SHAKING TABLE TEST BY USING REFINED DEM

Abstract

 The typical damage pattern of plain concrete piers during earthquakes is horizontal gap at the cold joint of a pier and falling down of concrete pieces from the pier under the cold joint. It is necessary to develop a numerical analysis method suitable for plain concrete piers to evaluate their seismic safety against the future earthquakes. With this background, this study investigated the applicability of the refined DEM for the dynamic analysis of plain concrete piers. First, it was found that the original refined DEM has a problem of overestimating friction properties. Therefore, the method was proposed to accurately simulate the friction properties by just modifying the arrangement of springs. Next, a shaking table test of a plain concrete pier was simulated, and the analytical and experimental results were compared. In the analysis, five acceleration histories with different peak acceleration values were input. In the case of smaller accelerations where the specimen suffered slight failure, it was found that the horizontal dislocation and failure occurrence situation was simulated with good accuracy. On the contrary, in the case of larger accelerations where the specimen suffered severe damage, it was found that the failure occurrence situation was barely simulated. It was also found that the refined DEM underestimates the rotational angle for all cases.