胶合木-混凝土组合梁斜向螺钉连接件受剪性能研究  

Shear performance of inclined screws in glulam-concrete composite beams

作　　者：杜浩[1] 胡夏闽[1] 王汉成 张婧 孙志翔 DU Hao;HU Xiamin;WANG Hanchen;ZHANG Jing;SUN Zhixiang(College of Civil Engineering,Nanjing Tech University,Nanjing 211800,China)

机构地区：[1]南京工业大学土木工程学院,江苏南京211800

出　　处：《建筑结构学报》2020年第7期191-200,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51678295,51478220)。

摘　　要：为研究斜向螺钉连接件在胶合木-混凝土组合梁中的受剪性能,对8组24个采用斜向螺钉连接件的胶合木-混凝土组合试件进行了推出试验,分析了嵌入方式和嵌入角度对螺钉连接件的破坏模式、荷载-滑移特性和受剪性能的影响。研究结果表明:沿剪力方向单向倾斜螺钉连接件的破坏模式主要为螺钉单铰弯曲破坏和螺钉双铰弯曲破坏;斜交螺钉连接件的破坏模式主要为受压剪作用螺钉的周围混凝土锥体破坏和受拉剪作用螺钉拔出破坏;随着斜向螺钉连接件与界面夹角逐渐增大,螺钉连接件的受剪承载力和抗剪刚度逐渐减小;沿剪力方向45°单向倾斜螺钉连接件的受剪承载力和抗剪刚度较垂直嵌入木梁的螺钉连接件的受剪承载力和抗剪刚度分别提高了21. 8%和51. 6%;±45°斜交螺钉连接件的受剪承载力与垂直嵌入木梁的螺钉连接件的受剪承载力相差不大,但其抗剪刚度较垂直嵌入木梁的螺钉连接件的抗剪刚度提高了76. 6%。在试验研究的基础上,提出了胶合木-混凝土组合梁斜向螺钉连接件受剪承载力的计算方法,该公式的计算结果与试验结果吻合较好,并验证了现有抗剪刚度计算公式的适用性。Eight groups of inclined screws,a total of twenty-four push-out tests were conducted to investigate the shear behavior of inclined screws for glulam-concrete composite beams. Based on push-out test results,the influences of screw inclination angle and screw embedding method on failure modes,the load-slip curves and the shear behavior were analyzed comprehensively. The test results show that the failure mode of the single inclined screw is the single or double plastic hinges occurring in the screw. The failure mode of inclined cross screws is the cone expulsion of concrete ahead of shear-compression damage of screw or the pull-out of shear-tensile screw from timber. The shear bearing capacity and stiffness are reduced with the increasing of the angle between inclined screw and shear plane. The shear bearing capacity and stiffness of the single inclined screw with an angle of 45° increase 21. 8% and 51. 6%,respectively,over those of the vertically inserted screw. The shear bearing capacity of inclined cross screws with the angle of 45° has little difference with that of the screw inserted vertically. However,the shear stiffness of inclined cross screws with the angle of 45° increases 76. 6% over that of the screw inserted vertically. The analytical methods for shear bearing capacity of inclined screws were proposed based on experimental results,and the calculation results were in good agreement with the experimental results. Besides,the applicability of the existing calculation method for the shear stiffness was verified.

关 键 词：胶合木-混凝土组合梁 斜向螺钉连接件 推出试验 受剪承载力 抗剪刚度 

分 类 号：TU398.903[建筑科学—结构工程]