Influence of boundary conditions and size effect on the drift capacity of URM walls
Influence of boundary conditions and size effect on the drift capacity of URM walls
复制标题
边界条件和尺寸效应对URM墙体漂移能力的影响
DOI：
10.1016/j.engstruct.2014.01.048
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发表时间：
2014
影响因子：
5.5
通讯作者：
K. Beyer
中科院分区：
文献类型：
--
作者：
S. Petry;K. Beyer
在规范中，无筋砌体墙的抗侧移承载力通常是根据破坏模式和高宽比来估算的。经验关系是基于单URM墙，这是测试模拟固定或悬臂边界条件的准静态循环试验的结果。在真实的结构中，板和拱肩的刚度和强度确定了墙的边界条件，因此确定了地震时作用在墙上的力矩、剪力和轴力。根据墙、板和拱肩的具体形状，边界条件可以有很大的变化，为了研究这些边界条件对URM墙的力-变形性能的影响，进行了6次准静态循环试验。通过改变轴压比和墙顶弯矩与墙底弯矩的比值，模拟了不同的边界条件。本文介绍了试验结果，并讨论了边界条件对墙体破坏机理和抗侧移能力的影响。此外，对64个不同高度和砌体类型的URM墙的拟静力试验结果进行了评价。这些试验证实了边界条件对漂移能力的影响。此外，他们表明，存在一个强大的尺寸效应，导致较小的漂移能力，随着壁高的增加。为此，提出了一个经验漂移能力方程，该方程考虑了弯矩剖面、轴向荷载比和尺寸效应。
In codes the drift capacity of unreinforced masonry (URM) walls is often estimated as a function of the failure mode and the aspect ratio. The empirical relationships are based on results from quasi-static cyclic tests on single URM walls, which were tested simulating either fixed-fixed or cantilever boundary conditions. In real structures, the stiffness and strength of slabs and spandrels define the boundary conditions of the walls and therefore the moment, shear force and axial force imposed on a wall during an earthquake. Depending on the exact configuration of wall, slab and spandrel, the boundary conditions can vary significantly.In order to investigate the influence of these boundary conditions on the force-deformation behaviour of URM walls, six quasi-static cyclic tests were performed. Different boundary conditions were simulated by varying the axial load ratio and the ratio of top and bottom moment applied to the wall. This article presents the test results and discusses the influence of the boundary conditions on the failure mechanism and the drift capacity of the walls. In addition, the results from 64 quasi-static tests on URM walls of different heights and masonry types are evaluated. These tests confirm the influence of the boundary conditions on the drift capacity. Moreover, they show that a strong size effect is present which leads to smaller drift capacities with increasing wall height. For this reason, an empirical drift capacity equation is proposed which accounts for the moment profile, the axial load ratio and the size effect.