翼墙加固方法对框架结构抗震性能的影响分析

汶川地震震害表明,单跨体系不满足多道抗震防线的要求,在罕遇地震作用下极易破坏,甚至发生整体倒塌,造成极大的人员伤亡和财产损失。翼墙加固方法因布置灵活、施工方便、在地震作用下能起到二道防线作用而得到广泛应用。本文首先研究了翼墙框架柱结构体系动力特性,指出对该类结构宜采用等效截面长厚比不大于4的竖向构件。然后,设计了一栋典型单跨教学楼,并采用翼墙对其加固,通过有限元数值分析,研究了单向、双向翼墙加固方案及不同翼墙长度对框架结构的加固效果。结果表明,不宜采用单向翼墙加固方案,而应采用双向翼墙加固方案,并认为翼墙长度为500mm的双向加固方案为本文算例最合适的加固方案。本文研究为有效地提高多层单跨钢筋混凝土框架结构抗倒塌能力的加固方法奠定了基础。

Analysis of the influence on structural seismic capability by wing wall strengthening method

The Wenchuan earthquake damage survey shows that the single-span system are applied,which the requirements of installation with seismic multiple-defense lines are not satisfied.Under rarely earthquake this kind of structure is easily damaged,even the whole structure is collapsed with great casualty and property losses.For the construction procedure is convenient and the arrangement is flexible,and the second defense line is generated under earthquake,the wing wall strengthening method is widely applied.In this paper the dynamic characteristics of frame structure system strengthened by wing wall are studied,which is in the vertical components of frame structure the length-thickness ratio of equivalent section should not be more than 4.Then a typical teaching building is designed and strengthened by wing walls,and simulated by three dimensions using finite element softwares.The influence on frame structures of single direction and two directions strengthening schemes is studied with different wing wall lengths.The results show that,the single direction strengthening schemes should not be adopted,while the two directions strengthening schemes should be used;the two directions strengthening scheme of 500mm wing wall is the most appropriate scheme for the example in this paper.The study of this paper could provide a foundation for the study on enhancing collapsed ability of multi-story single-span reinforced concrete frame structure.