轴向受力胶合竹螺栓拼接节点的耐火性能试验研究  

Experimental study on fire resistance performance of bolted glued laminated bamboo spliced connections subjected to axial loading

作　　者：王明谦 戴璐 许清风 韩重庆[2,3] 陈玲珠 冷予冰 WANG Mingqian;DAI Lu;XU Qingfeng;HAN Chongqing;CHEN Lingzhu;LENG Yubing(Shanghai Key Laboratory of Engineering Structure Safety,SRIBS,Shanghai 200032,China;School of Civil Engineering,Southeast University,Nanjing 210096,China;Architects&Engineers Co.,Ltd,Southeast University,Nanjing 210096,China)

机构地区：[1]上海市建筑科学研究院有限公司上海市工程结构安全重点实验室,上海200032 [2]东南大学土木工程学院,江苏南京210096 [3]东南大学建筑设计研究院有限公司,江苏南京210096

出　　处：《建筑结构学报》2024年第12期181-188,共8页Journal of Building Structures

基　　金：国家自然科学基金面上项目(52378522);上海市自然科学基金项目(21ZR1428200);上海市青年科技启明星项目(23QB1404400)。

摘　　要：为研究轴向受力胶合竹螺栓拼接节点的耐火极限,设计并制作了9个轴向受力胶合竹螺栓节点试件,分别进行常温下加载试验和耐火极限试验。试验参数包括节点类型、螺栓端距和荷载比。根据试验结果确定胶合竹螺栓节点的耐火极限。结果表明:螺栓端距对常温加载试件的破坏模式具有显著影响;临近破坏时,受火胶合竹组件出现了横纹劈裂破坏和顺纹剪切破坏;较高的荷载比会使得受火试件的螺栓产生更为明显的弯曲变形;荷载比会显著影响节点的耐火极限,当荷载比从0.3增加到0.5时,螺栓端距为7倍螺栓直径、10倍螺栓直径的内嵌钢板节点和螺栓端距为7倍螺栓直径的钢夹板节点的耐火极限分别降低了27.6%、32.9%和37.2%;螺栓端距对内嵌钢板节点的耐火极限具有显著影响,当螺栓端距从7倍螺栓直径增加到10倍螺栓直径后,荷载比为0.3和0.5的节点耐火极限分别提高了25.1%和15.9%。轴向受力胶合竹螺栓节点的耐火极限能满足现行木结构设计标准针对同类型螺栓节点的要求。随着受火时间增加,胶合竹构件的炭化速率有所降低,其平均炭化速率与T/CECS 1101—2022《工程竹结构设计标准》中规定的名义线性炭化速率(0.90 mm/min)接近。In this paper,nine axially loaded bolted glued laminated bamboo connection specimens were designed and tested at normal temperature and in fire to investigate the fire endurance of spliced connections subjected to axial loading.The test parameters included connection type,bolt end distance and load ratio.The fire endurance was determined based on the test results.The results indicate that the bolt end distance has an important influence on the failure modes of the specimens tested at normal temperature.Splitting failure perpendicular to the bamboo grain direction and longitudinal shear failure occurr in the glued laminated bamboo components when the specimens in fire are close to ultimate failure.A higher load ratio can lead to more notably bending deformation in the bolts of the specimens in fire.The load ratio plays an important role in the fire endurance of the connections.When the load ratio increases from 0.3 to 0.5,the fire endurance of the connections with slotted-in steel plates and a bolt end distance of 7 and 10 times the bolt diameter,and the connections encased with steel plates with a bolt end distance of 7 times the bolt diameter,decreases by 27.6%,32.9%and 37.2%,respectively.The bolt end distance has a significant impact on the fire endurance of the slotted-in steel plate connections.When the bolt end distance increases from 7d(d is the bolt diameter)to 10d,the connection fire endurance with load ratios of 0.3 and 0.5 increases by 25.1%and 15.9%,respectively.The fire endurance of the bolted glued laminated bamboo connections subjected to axial loading meets the requirements of current timber structure design standards for similar types of bolted connections.The charring rate of the glued laminated bamboo decreases with the extension of fire exposure time.The average charring rate of the glued laminated bamboo is close to the nominal linear charring rate(0.90 mm/min)prescribed by T/CECS 1101—2022‘Standard for design of engineered bamboo structures’.

关 键 词：胶合竹 螺栓节点 轴向受力 荷载比 受火试验 耐火极限 

分 类 号：TU366.3[建筑科学—结构工程]