基于增量动力分析方法的砌体结构地震易损性分析

Seismic fragility analysis of masonry structures based on incremental dynamic analysis

砌体结构是一种脆性结构,变形能力和承载力均较低,因取材方便、施工简单和造价低等优势在中国被广泛应用。为了评估砌体结构的抗震性能,本文基于增量动力分析(Incremental Dynamic Analysis,IDA)方法研究了多层砌体结构的地震易损性,分析了影响砌体结构地震易损性的主要因素以及群体多层砌体结构地震易损性。研究结果表明:在相同场地条件情况下,砌体结构的房屋层数、砌筑砂浆强度、设防烈度和墙体面积率对结构的地震易损性影响较明显;当结构层高在2.8~3.3 m之间时,层高对结构地震易损性的影响不大。抗震设防砌体结构抗震能力比不设防结构有明显提高,说明构造柱和圈梁等构造措施能显著提高砌体结构的抗倒塌能力,这与目前的基本认识相同,也证明了增量动力分析方法的有效性。

Masonry structure is a brittle structure with poor performance in deformation and load-bearing.Becauseof its easy access,simple construction and low cost,masonry structure is widely used in China.Inorderto evaluate the seismic performance of masonry structure,this paper uses the incremental dynamic analysis(IDA)method to analyze the factors influencing seismic fragility of masonry structures and the seismic fragility of multi-story masonry structure.The corresponding results show that under the same site conditions,factors of mortar strength,floor and the seismic fortification intensity have obvious effect on the seismic fragility of masonry structures.When the structural height is between 2.8m and 3.3m,the seismic fragility value of masonry structures varies a little.The anti-seismic ability of fortified masonry structures is much higher than that of the unfortified structure,indicating that the construction measures like structural concrete columns and ring beams play a significant role in improving the anti-collapse ability of masonry structures.