摘要
为避免常规轻木剪力墙中易出现的板边撕裂、钉帽穿透、钉子拔出等不利破坏,选取竹胶板和自攻螺钉分别作为墙体的覆面板和连接件,并通过4组单调和低周往复加载墙体试验,分析其破坏模式、抗剪强度、弹性剪切模量、延性系数、墙角锚固(hold-down)节点承载力,并与常规轻木剪力墙进行对比。试验结果表明,自攻螺钉连接的竹胶板覆面剪力墙能有效避免上述不利破坏,其抗剪强度较常规轻木剪力墙提升了79.6%~159.6%,是GB 50005—2017《木结构设计标准》中轻木剪力墙抗剪强度设计值的2.4~3.8倍;屈服位移、极限位移分别是常规轻木剪力墙的9.3倍、1.4倍,满足GB/T 51226—2017《多高层木结构建筑技术标准》中的弹性和弹塑性层间位移角要求,且在h/25的层间位移水平下仍能承受80%P_(peak)以上的侧向荷载。墙体在往复加载过程中频繁出现螺钉弯曲疲劳剪断,导致其抗剪强度比单调试验结果低。减小螺钉间距会显著提升墙体的弹性剪切模量,但受限于端部墙骨柱和底梁板的脆性劈裂破坏,对墙体抗剪强度的提升较小。建议选用直径小、数量多的螺栓群来连接端部墙骨柱与hold-down锚固件,以避免端部墙骨柱过早发生劈裂破坏,并使hold-down节点趋向于发生螺栓弯曲延性变形。
Sheathing edge-tear,nail head pull-through and nail withdrawal failures are commonly observed in typical wood-frame shear walls when subjected to lateral loads.To prevent such undesired failures,this research proposed using plybamboo panels and self-tapping screws(STS)as the sheathing panel and sheathing fastener,respectively,in place of traditional wood-based sheathing panels and common nails.Four groups of plybamboo-sheathed wood-frame shear(PSWFS)walls with STSs were tested under monotonic and cyclic loadings.The shear strength,elastic shear modulus,ductility ratio of the walls and the load-bearing capacity of their hold-down joints were evaluated and compared with those of common wood-frame shear walls.Test results showed that the above-mentioned failures were well avoided in the PSWFS walls with STSs.Their shear strengths were 79.6%-159.6%higher than those of conventional wood-frame shear walls,and 2.4-3.8 times the design shear strength values for wood-frame shear walls specified in GB 50005-2017“Standard for design of timber structures”.The yield and ultimate displacement of the PSWFS walls with STSs were 9.4 times and 1.4 times those of conventional wood-frame shear walls,respectively,and meet the requirements for the elastic and elastic-plastic inter-story drift ratio of wood-frame construction as stipulated in GB/T 51226-2017“Technical standard for multi-story and high-rise timber buildings”.Moreover,the PSWFS walls with STSs could hold lateral loads over 80%of their maximum load capacity even at displacements over 1/25 drift level.The shear strength of the PSWFS walls with STSs in the cyclic test was slightly lower than that in the monotone test due to the frequent screw bending fatigue failure.Reducing the screw spacing resulted in a remarkable enhancement of the elastic shear modulus,yet only a slight improvement in shear strength,primarily due to the brittle splitting failures occurring at the end studs and bottom plates.Regarding the connection between the hold-down connector and the end stud,it is more suitable to adopt bolts with small diameter and large quantity rather than bolts with large diameter and small quantity.This approach increases the likelihood of the hold-down joints failing through ductile bending of the bolts,rather than the brittle splitting of end stud.
作者
张百皓
董利
郑维
王志强
张玲云
王小炜
ZHANG Baihao;DONG Li;ZHENG Wei;WANG Zhiqiang;ZHANG Lingyun;WANG Xiaowei(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;A-Zenith Home Furnishings Co.Ltd.,Nantong 226402,China;Nantong Jiazhu Construction Technology Co.Ltd.,Nantong 226532,China)
出处
《林业工程学报》
北大核心
2025年第3期163-170,共8页
Journal of Forestry Engineering
基金
湖北省2024科技计划重点研发专项(2024BCB071)
国家重点研发计划(2021YFD2200605)
国家自然科学基金(51808547)。
关键词
轻木剪力墙
竹胶板
自攻螺钉
抗侧力性能
破坏模式
wood-frame shear wall
plybamboo panel
self-tapping screw
lateral performance
failure mode
