考虑连续梁桥布置方案的横向地震反应规律研究

Seismic Response Analysis for Continuous Beam Bridges in Transverse Direction Considering the Bridge Layout Scheme

考虑桥跨布置方案、梁墩线刚度比等因素,进行连续梁桥横向地震反应规律研究。以3跨连续梁桥为例,将其简化为弹性支承的连续梁模型,推导其横向地震反应规律的简化理论计算方法,并结合有限元通用程序分析等墩高条件下梁墩线刚度比变化、边跨对称和非对称条件下墩高比变化对桥梁横向地震反应规律的影响。理论计算分析和数值模拟的结果表明:给出的理论计算方法有效;桥墩横向地震剪力和弯矩分配系数不仅与桥墩的抗推刚度有关,还与桥跨布置方案、梁墩线刚度比有关;桥墩的抗推刚度越大、梁墩线刚度比越小,桥墩横向地震内力的分配系数越大。根据分析结果,提出了连续梁横向抗震优化设计的一般步骤。

Considering the bridge layout scheme and the linear rigidity ratios of beams to piers, the law of the transverse seismic response of continuous beam bridges was studied. Based on a three-span continuous beam bridge, a simplified theoretical calculation method for the law of its transverse seismic response was deduced through simplifying the bridge as an elastic support continuous beam model. The influence of the following different situations to the transverse seismic response was analyzed combining with the Finite Element Method （FEM） ： changing the linear rigidity ratio of beam to piers under the condition of equal pier height, changing the height ratio of piers under the condition of symmetrical and asymmetrical side-span. The theoretical analysis and the numerical simulation show that the simplified theoretical calculation method is effective. And the horizontal earthquake shear and moment partition coefficients of each pier are not only related to the anti-push rigidity of the pier, but also related to the bridge layout scheme and the linear rigidity ratios of the beams to piers. The internal force partition coefficient of a pier will increase when the anti-push rigidity of the pier is increased or the linear rigidity ratio of the beam to pier is decreased. According to the above analysis results, a reference method to optimization the seismic design of the continuous beam bridges in transverse direction is given.