经历平面内损伤的阻尼填充墙框架平面外受力性能试验研究

Experimental study on out-of-plane mechanical performance of damped infill wall frame with in-plane damage

为研究双向地震作用下阻尼填充墙(damped infill wall,DIW)的平面外受力性能,对3片经历了平面内拟静力加载试验的DIW进行平面外静力加载试验,研究DIW平面外的受力性能、变形模式和破坏特征。结果表明:DIW的平面外受力阶段分为弹性、弹塑性、塑性和破坏4个阶段,各阶段的DIW平面外位移沿墙体高度分布均呈"三折线"形态;DIW具有一定的平面外抗侧刚度,与以低强度砂浆作为阻尼层的DIW相比,以SBS改性沥青卷材作为阻尼层的DIW平面外初始刚度明显较大,可更好地控制墙体的平面外变形。DIW通过砌体单元间以及砌体单元与框架梁间的相互作用形成拱承载机制,具备抵御9度罕遇地震作用下平面外承载能力;DIW的拉结筋主要在墙体平面外位移较大时发挥作用,具有第二道防线的作用。拉结筋拉断标志着DIW的最终破坏,拉断前DIW未发生失稳倒塌现象。

In order to research the out-of-plane （OOP） mechanical performance of damped infill wall （DIW） under bidirectional earthquake motion, three DIWs with in-plane damage were tested through OOP monotonic loading test, and the OOP mechanical performance, deformation patterns and failure modes of DIW were studied. The results show that, OOP loading process of DIW can be divided into four stages, including elastic stage, elasto-plastic stage, plastic stage and failure stage. In each stage, the distribution of the OOP lateral deformation along the height of DIW presents trilinear shape. DIW possesses certain OOP stiffness. Compared with the DIW with low strength mortar damping layer, the DIW with SBS modified asphalt damping layer possesses higher initial stiffness, which is able to control the OOP deformation of DIW. Arching mechanism of DIW is developed by the interaction between RC beam and masonry unit as well as adjacent masonry units, which possess the OOP bearing capacity to resist the 9 degree rare earthquake. Tie bars of DIW which can provide the second line of defense play an important role when the OOP displacement of DIW is large. No collapse of DIW is observed before the snap of tie bars which indicates the failure of DIW.