正交斜放竹条覆面桁架搁栅承载力试验研究

EXPERIMENTAL RESEARCH ON BEARING CAPACITY OF JOIST CONSISTING OF ORTHOGONAL OBLIQUE PLACEMENT BAMBOO STRIPS AND A WOODEN FRAME

正交斜放竹条覆面桁架搁栅的构造特征是把两层正交斜放的竹条钉接在矩形木骨架的两个侧面,形成一种新型竹木复合搁栅。通过对2组不同木骨架形式共计4根竹木复合搁栅进行受弯承载力试验,观察搁栅的变形和破坏特征,得到每根搁栅的荷载-变形曲线。试验表明:随着荷载不断增加,竹木复合搁栅表层竹条破坏前有明显征兆,从初步损伤到产生破坏的过程一般较长,变形较大,且具有良好的变形恢复能力。试验数据分析表明:新型竹木复合搁栅满足轻型木结构楼面搁栅以及低层冷弯薄壁型钢房屋楼面搁栅在楼面荷载作用下的强度和变形要求,在允许挠度范围内不会发生强度破坏。正交斜放竹条覆面桁架搁栅承载力试验研究证明了此类构件的工程应用价值,为后续技术优化和理论分析提供了有益参考。

A new type of bamboo-wood composite joist consisting of a rectangular timber frame and two layers of orthogonal oblique placement bamboo strips connected on both sides was proposed.In order to investigate the flexural capacity of the joists,a total of 4 bamboo-wood composite joists in 2 groups of different timber frame forms were tested respectively,the deformation and failure characteristics of the joists were observed.The load-deflection curves of the specimens were obtained.During the test,the split of bamboo strips showed the sign of joist wreck.The joists performed very good ductility because large deflection occurred from the initial wreck to final failure accompanied with the increasing of load.The results showed that the new type of bamboo-wood composite joists could meet the strength and deformation requirements of floor joists for light wooden structures and low-rise cold-formed thin-walled steel buildings under floor load,and strength failure should not occur within the allowable deflection range.The study could prove the engineering application value of such components,and provide a reference for further technical optimization and theoretical analysis.