后张预应力加固无筋砖砌墙体抗震性能试验研究

发布时间：2018-06-29 12:00

本文选题：无筋砌体墙 + 开洞墙体　；参考：《建筑结构学报》2015年08期

【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。
[Abstract]:Aiming at the problem of poor seismic behavior of brick masonry structure, a method of seismic reinforcement of brick masonry structure by vertical backward prestress is put forward, that is, the prestressed bars are arranged uniformly along the strengthened wall and the vertical prestress is applied to make the wall under uniform compression. Thus, the failure mode of masonry wall under earthquake is improved, and its shear capacity and seismic energy dissipation capacity are improved. In order to verify the reinforcement effect of this method, the pseudo-static test was carried out on the unreinforced brick wall and its contrast wall. The failure patterns and mechanical characteristics of unreinforced wall and post-tensioned prestressed strengthened wall are compared and analyzed. The results show that the post-tensioned prestressing can significantly improve the shear capacity and deformation capacity of the wall, and the seismic energy dissipation capacity is significantly enhanced. The bearing capacity and ductility of the whole section wall strengthened are more obvious than that of the open wall. When the axial compression ratio of prestress and vertical load exceeds the critical point, the ductility will decrease to a certain extent. At the same time, the post-tensioned prestressing reinforcement can also reduce the stiffness degradation rate of the unreinforced brick wall and improve the post-cracking stiffness of the unreinforced masonry wall, which plays an important role in improving the mechanical performance of the wall under strong earthquake. The method does not change the elastic lateral stiffness of the wall, and the quality of the strengthened wall is not increased, so it is an effective seismic reinforcement method.
【作者单位】：北京市建筑节能减排协同创新中心;北京市建筑工程研究院有限责任公司;北京交通大学土木建筑工程学院;
【基金】：北京市科技计划重大项目(D131100003713003) 中国博士后科学基金(2014M550020)
【分类号】：TU364;TU352.11

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