高烈度地区连续刚构桥地震响应分析

为探究高烈度地区连续刚构桥地震响应规律,首先以贵州某高烈度地区大跨度连续刚构桥为研究背景,基于Midas Civil 2019建立三维空间有限元模型,并探究了该桥的结构自振特性;其次基于该桥场地条件,结合相关规范给出了目标反应谱和人工合成地震波;最后给出了反应谱和时程分析计算结果,并做了详细对比分析。研究表明:在保障强度和稳定性前提下,位于高烈度地区的大跨度连续刚构桥在纵向和横向上要有一定的约束释放,有助于结构变形吸收地震能量,进而减小地震破坏;反应谱计算工况下纵向位移和横向位移最大值分别为0.304 m和0.381 m,且与地震激励方向有关,竖向位移约为0.05 m,与地震激励方向关系不大;对比分析反应谱和时程分析计算结果可知,时程分析计算结果整体上要大于反应谱计算结果,符合相关规范要求。

Analysis on Seismic Response of Continuous Rigid-frame Bridges in High Intensity Areas

In order to explore the seismic response law of continuous rigid-frame bridges in high-intensity areas, firstly, taking a long-span continuous rigid-frame bridge in a high-intensity area in Guizhou as the research background, a three-dimensional spatial finite element model is established according to MIDAS Civil 2019, and the structural natural vibration characteristics of the bridge are explored. Secondly, based on the site conditions of the bridge, combined with the relevant specifications, the target response spectrum and artificial seismic wave are given. Finally, the results of response spectrum and time history analysis are given, and a detailed comparative analysis is made. The research shows that under the premise of ensuring the strength and stability, the long-span continuous rigid-frame bridge located in high intensity areas should have certain restraint release in the longitudinal and transverse directions, which is conducive to the structural deformation to absorb the seismic energy, and then reduce the seismic damage. Under the working condition of response spectrum calculation, the maximum longitudinal displacement and transverse displacement are 0.304 m and 0.381 m respectively, which are related to the direction of seismic excitation. The vertical displacement is about 0.05 m, which has little relationship with the direction of seismic excitation. By comparing and analyzing the calculation results of response spectrum and time history analysis, it can be seen that the calculation results of time history analysis are larger than the calculation results of response spectrum on the whole, which also meets the requirements of relevant specifications.