多跨连续梁桥横桥向抗震的概念设计

连续梁桥是具有较好抗震性能的桥型之一.针对某桥梁工程进行抗震分析,利用连续梁桥等效模型的简化分析,并结合反应谱理论探讨桥墩刚度的分布对横桥向抗震性能的影响.提出对于坚实的地基,应采取在独柱墩上设置纵向竖缝的方案调整刚度分布;而针对软土地基则应采取改变制动墩或伸缩缝的位置,并在关键点将独柱墩分解为双柱墩的方案,以改善受力.2种方案的目的都是要尽量减小转动位移,从而提高横桥向抗震性能.并利用SAP2000进行了横桥向反应谱分析与验证.研究结果可应用于地震区连续梁桥的概念设计中.

Conceptual Design of Earthquake-resistance for Multi-span Continuous Bridges in Transverse Direction

Continuous bridge is one of good styles with better earthquake-resistance performance. Based on a true bridge construction and the theory of response spectrum, the equivalent model of a continuous bridge is used to analyse the regulation which indicates how the distribution of the piers' stiffness could influence the performance of earthquake-resistance in the transverse direction. The result is divided into two aspects:on firm stratum longitudinal perpends should be set on the single-pier shaft; however, on the soft stratum the position of expansion joints or brake piers should be reset, and certain single-piers would be taken apart into a double-piers in key points if necessary. The aim of both methods is to reduce the rotational displacement as much as possible, so as to improve the earthquake-resistance performance in the transverse direction. And the professional software SAP2000 is used to analyse and certify in this paper. The result could be adopted in conceptual design of continuous bridges in some seismic area.