单跨无洞框支墙梁抗震受力性能研究

Research on Seismic Behaviors of Single-span Frame-supported Wall-beam

以单跨无洞框支墙梁为研究对象 ,通过两榀接近足尺的墙梁试件的试验研究 ,揭示了竖向荷载作用下 ,以及竖向荷载与水平荷载联合作用下框架支承墙梁的基本受力特征。研究表明 ,竖向荷载单独作用下 ,墙梁存在明显的组合作用 ,构造柱可帮助砌体承担相当比例的竖向荷载 ;在水平力作用下 ,作用在墙梁顶面的均匀分布竖向荷载在向下传递至托梁顶面的过程中 ,会偏移至倾覆弯矩受压一侧梁端 ,并可能使该侧墙角砌体压碎以及梁端明显的剪切破坏。

Through the experiments of two full scale single span holed frame supported wall beams, the seismic resistance mechanism, no matter whether the vertical load presents alone or when the vertical load is accompanied by seismic horizontal load, has been studied. Test results show that when only the vertical load exerted on top of the brick wall, both symmetrically holed and non symmetrically holed wall beams displayed an evident composite arch action. When the seismic horizontal load is introduced and if the shear strength of the brickwork is relatively high, for the coupled brick-walls, there would be no diagonal shear cracks but significant horizontal crack at the bottom observed. The supporting beam may suffer flexural failure around the holed span or splitting failure along the longitudinal bars between the hole edge and the nearest beam end. The lower corner aside the hole of coupled wall may experience compression crushing, the beam end may have shear failure and the brick coupling beam will be subjected to serious shear failure.