混合结构对正交胶合木剪力墙抗侧性能的影响

为评价层板材料对正交胶合木(cross-laminated timber,CLT)剪力墙抗侧性能的影响,对普通结构(单一锯材材料)CLT剪力墙和混合结构(锯材与单板层积材混合材料)CLT剪力墙进行了单向和低周反复加载试验。结果表明:墙体在单向荷载作用下主要因一侧墙角锚栓和基底锚栓的严重变形而发生破坏,在低周反复加载作用下则为墙角锚栓连接件的变形及钉子的疲劳剪断破坏; CLT剪力墙耗能主要来自于连接件变形和自攻螺钉弯曲、拔出和剪断; 混合结构CLT墙体在单向和低周反复加载中的破坏位移、抗剪强度分别比普通结构CLT墙体低3.03%,24.75%和7.33%,3.31%; 抗侧刚度则高出8.70%,7.45%。混合结构对CLT剪力墙不同抗侧性能影响不同,应加强CLT剪力墙与基础的连接,充分发挥CLT墙体本身的抗侧性能。
Compared with other engineering wood products, such as laminated strand lumber(LSL), laminated veneer lumber(LVL)and structural plywood, cross-laminated timber(CLT)demonstrates a great potential in serving as crucial elements in the construction of buildings made entirely from timber. Hybrid CLT(HCLT)shear wall was fabricated by using lumber and/or LVL in this study. Two groups of CLT and HCLT shear walls were tested under monotonic and cyclic loads, respectively. Failure modes and load-displacement curves of CLT/HCLT shear walls were obtained and the yield load, ultimate load, elastic lateral stiffness and ductility of those shear walls were obtained through the calculation. The effects of different layer materials of CLT on the lateral load capacity were also analyzed. The results showed that the prime failure mode of CLT shear walls under the monotonic load was the failure of hold-down connection and bracket connection, however, the prime failure mode of CLT shear walls under cyclic loads was the failure of hold-down connection and nails connection failure. The dissipated energy of CLT shear walls were resulted from the deformations of hold-down and brackets connections and the deformations, pulling-out and fracture of nails under cyclic loads. Compared with normal CLT shear walls, the ultimate displacement and shear strength of HCLT shear walls under monotonic and cyclic loads were 3.03%, 24.75%, 7.33% and 3.31% lower than those of normal CLT shear walls, respectively. However, the elastic lateral stiffness of HCLT shear walls under monotonic and cyclic loads were 8.70% and 7.45% higher than those of normal CLT shear walls, respectively. It was concluded that the connection properties of hold-down and/or brackets between CLT walls and foundation need to be improved. The further research in this field is needed to improve the connection properties of CLT shear walls