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为了研究山区高墩桥梁在地震动作用下的特殊抗震性能,基于随机振动理论,研究了场地效应、相干效应及行波效应对高墩桥梁在强地震多点激励下的随机响应规律,及墩高变化对高墩桥梁地震响应规律的影响。研究表明:场地效应对高墩桥梁地震响应影响明显,软场地墩的位移值约为硬场地的12倍,行波效应的影响次之,相干效应的影响最小。场地效应对桥梁的影响大小取决于场地卓越频率是否接近于桥梁自振频率;行波效应是不可忽略的一个重要因素,中场地时桥墩最小的位移值约为最大值的30%,软场地时最小值约为最大值的60%;与场地效应和行波效应相比,部分相干效应对桥墩顺桥向位移影响较小。对于山区高墩桥梁随机地震响应分析,考虑地震动空间效应的多点激励分析是必要的。应对有可能的桥型(不同墩高和墩高差)进行分析,以确定地震力最小的桥型并注意桥梁截面抗力的提升和附加减震措施。
In order to study the special anti-seismic performance of high-pier bridges in mountainous area under the action of earthquake, based on stochastic vibration theory, the random responses of high-pier bridges to multi-point strong earthquakes under field and coherent effects and traveling wave effects are studied, Influence of High Variations on Seismic Response of High Pier Bridge. The results show that the effect of site on the bridge seismic response is obvious. The displacement of soft ground piers is about 12 times that of the hard field, followed by the traveling wave effect, and the effect of the coherent effect is the least. The effect of site effect on the bridge depends on whether the site’s excellent frequency is close to the natural frequency of the bridge. Traveling wave effect is an important factor that can not be neglected. The minimum displacement of the bridge pier is about 30% of the maximum value at the mid- The minimum value is about 60% of the maximum value. Compared with the site effect and the traveling wave effect, the partial coherence effect has little effect on the displacement of abutment along the bridge. For the analysis of random seismic response of high pier in mountainous area, it is necessary to analyze multi-point excitation considering the spatial effect of earthquake. The possible bridge types (different pier height and pier height difference) should be analyzed to determine the bridge type with the lowest seismic force and pay attention to the improvement of bridge cross-section resistance and additional damping measures.