轻骨料混凝土桥梁地震易损性分析

为提高强震区桥梁的抗震性能,采用轻骨料混凝土替代普通混凝土以降低结构自重、提高墩柱变形能力,从而降低地震响应。以一座强震区典型中小跨径连续梁桥为研究对象,基于OpenSees建立轻骨料混凝土桥梁有限元分析模型,进行非线性时程分析,生成地震易损性曲线来评估桥梁的抗震性能。研究结果表明:与普通混凝土桥梁相比,仅上部结构或下部结构采用轻骨料混凝土对降低桥梁整体的损伤概率并不明显,而全桥均采用轻骨料混凝土的桥梁能够显著降低桥墩、桩基和支座的损伤概率以及桥梁整体的损伤概率。建议在强震区进行桥梁建设时,全桥均采用轻骨料混凝土来替代普通混凝土以提高桥梁抗震性能。

Analysis of seismic vulnerability of lightweight aggregate concrete bridges

In order to improve the seismic performance of bridges in strong earthquake areas, lightweight aggregate concrete can be used to replace normal concrete to reduce the structural weight and improve the deformation capacity of the pier and column. It reduces the seismic response. Taking a typical medium and small span continuous beam bridge in a strong earthquake area as the research object, the finite element analysis model of lightweight aggregate concrete bridge was established based on OpenSees. Nonlinear time history analysis was carried out, and the seismic vulnerability curve was generated to evaluate the seismic performance of the bridge. The results show that compared with normal concrete bridges, the use of lightweight aggregate concrete for the upper structure or the lower structure is not obvious for reducing the overall damage of the bridge. Lightweight aggregate concrete bridges in the whole bridge can significantly reduce the damage probability of bridge piers, pile foundations and supports, and the overall damage probability of bridges. It is recommended that when constructing bridges in strong earthquake areas, the whole bridges use lightweight aggregate concrete instead of normal concrete to improve the seismic performance of the bridge.