Assessment of concrete bridge performance under moderate seismic shock using concrete damage plasticity model

Abstract

In the paper the assessment of seismic performance of the reinforced concrete bridge to the moderate earthquake is presented. To represent the inelastic behaviour of the concrete material under dynamic loading the concrete damage plasticity model was assumed. The seismic input data were registered during the most recent natural seismic shock that occurred in Poland on 6th January 2012. A model of non-uniform kinematic excitation, typical for multiple-support structures, was introduced. The analysis proved that the first natural frequency of the bridge lied in the range of dominant frequencies of the shock that caused the amplification of the dynamic response. It turned out that the tensile damage (cracking) in some parts of the bridge appeared and the stiffness of the concrete material was degraded even under moderate seismic event. Hence, the seismic resilience of the bridge decreased after the shock. This is especially important not only in case of earthquake but in case of mining tremors as well. Considering their high repeatability the concrete material might be gradually degraded.