中文摘要：

为防止非规则梁桥在地震下的不确定破坏，需要对其进行基于位移的抗震设计。以一类常见的非规则梁桥横桥向作为研究对象，采用推倒分析探讨如何建立合理的能力谱，提出如何将此能力谱与非弹性需求谱组合来预计非规则梁桥的地震位移需求，最后，在此基础上提出一种非规则梁桥基于位移的简化抗震设计方法。结果表明：以反应谱分析的位移形状作为分布力模式推倒结构，以最先屈服墩墩顶节点作为位移参考点，得到的推倒曲线可作为能力谱，其弹性段、低屈服段和高屈服段对应的位移形状比例系数需要分别取值；此能力谱与非弹性需求谱的组合能够预计非规则梁桥的地震位移需求，相应的基于位移的简化抗震设计方法能够对非规则梁桥进行合理的抗震设计。

英文摘要：

Irregular continuous bridges need displacement-based seismic design to avoid uncertain damages. With one type of familiar irregular continuous bridges in the transverse direction as the object of study, pushover analysis is conducted for construction of the capacity spectrum, and a discussion is provided on how to obtain the displacement demand by combining the capacity spectrum with the inelastic demand spectrum. Based on the discussion, a simplified displacement-based seismic design approach for irregular continuous bridges is presented. Results show that, when the structural displacement shape from the response spectrum analysis is selected as the distribution pattern of pushover force and the first yielding pier top point is selected as the monitoring point of structure displacement, pushover analysis can obtain reasonable capacity spectrum. With the structural displacement the capacity spectrum, slightly damaged region and severely damaged shape factor corresponding to the elastib region of region should be different. The combination of the capacity spectrum and the inelastic demand spectrum can effectively estimate the displacement demand of irregular continuous bridges, and the corresponding simplified displacement-based seismic design approach can be applied.