后张预应力加固无筋砖砌墙体抗震性能试验研究  

Quasi-static test of unreinforced brick walls retrofitted with post-tensioning tendons

作　　者：刘航[1,2] 班力壬 兰春光[2,3] 杨学中[2] 

机构地区：[1]北京市建筑节能减排协同创新中心,北京100044 [2]北京市建筑工程研究院有限责任公司,北京100039 [3]北京交通大学土木建筑工程学院,北京100044

出　　处：《建筑结构学报》2015年第8期142-149,共8页Journal of Building Structures

基　　金：北京市科技计划重大项目(D131100003713003);中国博士后科学基金(2014M550020)

摘　　要：针对砖砌体结构抗震性能差的问题,提出了采用竖向后张预应力对砖砌体结构进行抗震加固的方法,即沿被加固墙体均匀布置预应力筋并施加竖向预应力,使墙体均匀受压,从而改善砌体墙体在地震作用下的破坏形态,提高其受剪承载力和抗震耗能能力。为验证该项方法的加固效果,对加固无筋砖墙体及其对比墙体进行了拟静力试验,试件中有5片为整截面墙体,4片为开洞墙体,研究对比分析了未加固墙体与后张预应力加固墙体的破坏形态和受力特点。结果表明,后张预应力加固可以显著提高墙体的受剪承载力和变形能力,抗震耗能能力显著增强。其中整截面墙体加固后,其承载力和延性的提高幅度较开洞墙体更为显著。但预应力施加不宜过大,当预应力与竖向荷载的组合作用轴压比超过临界点时,延性会有一定程度下降。同时,后张预应力加固还可以降低无筋砖砌墙体的刚度退化速率,提高无筋砌体墙的开裂后刚度,这对改善墙体在强震作用下的受力性能有重要作用。该加固方法基本不改变墙体的弹性抗侧刚度,加固后墙体的质量也基本没有增加,是一种行之有效的抗震加固方法。The seismic retrofitting method of clay brick masonry structure using vertical post-tensioning tendons is developed to improve the poor seismic performance of the structure. By arranging the post-tensioning tendons uniformly along the wall and applying vertical prestressing,the brick wall is under uniform compression,thus the failure pattern of the masonry walls is improved and the shear capacity and the energy dissipating ability are also improved. The effectiveness of this method was investigated experimentally through quasi-static test of nine unreinforced masonry walls,including five walls without opening and four walls with opening. The failure pattern and the mechanical behavior of the unretrofitted walls and the retrofitted walls were analyzed and compared. The results show that posttensioning can increase the shear capacity and the deformability substantially,and the seismic energy dissipating ability is also significantly increased. And the improvement of the shear capacity and the ductility of the walls without opening is more significant than that of the walls with opening. However,the axial force due to the addition of prestressing force and vertical load shouldn＇t exceed a certain limit,otherwise the ductility will decrease in some degree. Moreover,the lateral stiffness degradation speed of the wall retrofitted with post-tensioning tendons can be slowed down and after cracking stiffness can be improved,which may be very helpful to the mechanical behavior of the wall under a severe earthquake. In addition,the elastic stiffness and the weight of the brick wall are hardly changed due to the retrofitting method,which shows that the retrofitting method using vertical post-tensioning tendons is an effective and reliable strengthening alternative for unreinforced masonry structures.

关 键 词：无筋砌体墙 开洞墙体 后张预应力 抗震加固 拟静力试验 受剪承载力 延性 

分 类 号：TU362.02[建筑科学—结构工程]