机械固定式单层卷材屋面系统关键连接节点抗拔性能试验研究OA

To study the pull-out performance of key connection joints in mechanically fixed single-ply membrane roofing systems which are prone to damage under the action of wind uplift,Q235 profiled steel plates with four thicknesses of 0.8,0.9,1.0,and 1.1 mm were combined with two types of long screws respectively,and static pull-out tests were carried out on twenty-four specimens in eight groups.The failure mechanism of long screw-profiled steel plate connections,the influencing factors of pull-out bearing capacity,and the applicability of the calculation formula of screw pull-out bearing capacity in Chinese and international codes were analyzed,Finally,the wind-uplift safety of a natatorium roof under different wind force levels was evaluated.The results show that when the thread width is the same,the pull-out bearing capacity of the long screw-profiled steel plate connection increases nonlinearly with the increase of the plate thickness.The increase in thread width has a more significant effect on the pull-out bearing capacity of thin plate specimens than on that of thick plate specimens.The calculation results of European standards are too conservative.For deep-thread long screw-profiled steel plate connections,the Australian standard calculation values are closest to the test values.For shallow-thread long screw-profiled steel plate connections,the calculated values of Chinese code are closest to the experimental value,while the calculation according to the Australian standard is unsafe.The natatorium roof will not suffer wind-uplift failure under wind forces of grades 0～14.When the wind force exceeds grade 14,the long screws will be pulled out,and wind-uplift failure will occur in the roofing system.