多维多点平稳虚拟激励下高墩桥梁碰撞动力可靠度分析

Collision dynamic reliability study of high pier bridge structure under multi-dimensional and multi-point stationary pseudo excitation

动力可靠度研究是动力分析的一个重要发展方向。我国西南部山区地质地貌变化较大,地震频发,桥梁结构为其重要的生命线工程。适应于山区山高谷深的高墩大跨桥梁在强震作用下主梁的碰撞问题是一个重要的研究课题。结合西南部山区高墩大跨桥梁,运用高效准确的虚拟激励法来研究此类桥梁在各谱值地震动下的主梁碰撞动力可靠度,研究结果表明:当地震动加速度谱值小于0. 5g时,结构不碰撞;当加速度谱值大于0. 5g时,结构碰撞动力可靠度下降明显,即在强震作用下,桥梁结构发生碰撞,为了保证桥梁安全,需要做好减隔震措施。

Dynamic reliability research is an important development direction of dynamic analysis. Because of complex terrain and frequent earthquakes,the bridge structure is the important lifeline engineering in the western mountainou areas. The collision problem of high pier and large span bridge in high mountains and deep valleys under strong earthquake is an important research topic. Combining with the high pier and long-span bridge in western mountainou area,seismic reliability of this kind of bridge in the spectrum dynamic was studied by using the efficient and accurate pseudo dynamic method. The results show that,local vibration acceleration spectrum value less than 0. 5g will not contribute to the collision of structure;the structural impact dynamic reliability decreases obviously with the acceleration spectrum value greater than the 0. 5g,which means the collision is occurred under strong earthquakes. In order to ensure the structural safety,a good job of isolation measures should be done.