Risk Analysis of the Bridge Hit by the Mainshock-aftershock Sequence Considering Fault Distance
To improve the accuracy and rationality of the seismic damage prediction and estimation of the post-earthquake structural performance,a mainshock-aftershock construction method considering the fault distance attenuation is proposed,and 50 sets of the ground motion are constructed using this method.A three-span,continuous beam bridge is selected as the sample.Nonlinear dynamic analysis is carried out using OpenSees software,and an im-proved Park-Ang damage index is used to establish the vulnerability curve.The influence of the fault distance on the damage index and failure probability of the continuous beam bridge at different fortification levels when hit by the mainshock-aftershock sequence is analyzed.A post-earthquake risk analysis method is proposed,and the impact of the mainshock-aftershock sequence on the seismic risk of bridge structures considering fault distance is compared and analyzed.The results show that the probability of structural damage increases tenfold with the occurrence of af-tershocks.The risk of moderate or higher damage to structures within a fault distance of 10 km is relatively high.Increasing the aseismic fortification level can effectively prevent structures from serious or total collapse under the action of the main aftershock.The fault distance plays an important role in preventing the secondary damage in the post-earthquake rescue and reconstruction.
万方数据
维普
