不同设计参数下刚构-连续组合曲线梁桥地震响应敏感性分析

The seismic response sensitivity analysis of rigid-frame continuous combined curve bridge with different design parameters

结合大跨、高墩、长联曲线铁路梁桥的工程实例,利用大型通用有限元软件ANSYS,采用反应谱的分析方法,给出了该桥在不同的曲线半径、桥墩墩高、墩梁约束方式下的自振频率和振型,分别按纵桥向和横桥向的激励方式,分析了中跨跨中位移,墩顶位移及墩底弯矩随设计参数变化的规律。结果表明:自振频率受桥墩墩高和墩梁连接方式的影响较大,受曲线半径的影响较小;曲线半径在一定范围内变化时,地震响应变化较小;在纵向反应谱的作用下,桥墩墩高的改变对地震响应的变化规律比较复杂,在横向反应谱的作用下,地震响应有一定的变化规律;墩梁约束方式为约束7的地震响应最小,但综合考虑温度、制动力学因素,应该是原设计约束5最优。

According to a long -span, high -pier and multi -span curve bridge, it is calculated the natural vi- bration frequencies and vibration modes in different curve radiuses, the height of pier and different pier - beam constraint ways were calculated by the finite element software of ANSYS. Using the method of response spec- trum, the rules varying along design parameters were obtained from the internal force of pier bottom, the dis- placement of pier top and girder in the middle span by longitudinal and transversal incentive ways respectively. The results show that the pier height and pier - beam constraint ways have a big influence on the natural vibration frequencies , but curve radiuses have lesser effect; curve radiuses changing in a certain range have a small influ- ence on the seismic response ; in the longitudinal response spectrum, the change rules of seismic response varying along the height of piers is complex, in the transversal response spectrum, the seismic response has certain chan- ges in law; the seismic response of the constraint 7 of pier - beam constraint ways is the lowest, but overall con- sideration of temperature and braking mechanics, the original design constraint 5 is optimal.