双肢薄壁墩参数对连续刚构桥抗震影响分析

Effect of the parameters of two-limb thin-walled piers on the seismic performance of continuous rigid frame bridges

为了研究地震响应下双肢薄壁墩参数对高墩连续刚构桥抗震性能的影响,本文以某高墩连续刚构桥为研究对象,采用时程分析方法。以桥墩纵横向的薄壁厚度、双肢间距以及桥墩截面形式结合系梁为主要参数,从桥梁的振型频率、桥墩的位移以及内力变化三个方面对其抗震性能进行评价。结果表明:双肢薄壁厚度与双肢间距对桥梁高阶振型频率的影响较大;双肢薄壁墩的厚度与桥墩的抗弯刚度以及抗推刚度成正比关系;纵桥向抗弯刚度随双肢间距的增大而逐渐增大;设置纵向横系梁会增大桥梁的纵向刚度和减少墩顶的内力及位移;空心截面桥墩的抗震性能要优于实心截面桥墩的抗震性能。

In order to study the influence of the parameters about the thin-walled piers on the seismic behavior of the high-pier continuous rigid frame bridge under seismic response,a high-rise continuous rigid frame bridge is taken as the research object and the time-history analysis method is adopted.The thickness of the thin,vertical wall of the pier,the two-limb spacing and the cross-section form of the pier are the main parameters.The seismic performance is evaluated in three aspects:the vibration mode frequency of the bridge,the displacement of the pier,and the internal force variation.The analysis results show that:the thickness of the two limbs and the distance between the two limbs have a great influence on the high-order mode frequency of the bridge;the thin wall thickness of both limbs is proportional to the bending stiffness and the thrust stiffness of the pier;the bending stiffness of the longitudinal bridge gradually increases with the increase of the distance between the two limbs;the provision of longitudinal transverse beam will increase the longitudinal stiffness of the bridge and reduce the internal forces and displacements of the pier top;the seismic performance of the hollow section pier is better than that of the solid section pier.