重复荷载下栓钉拉拔承载力与变形研究

Study on the pull-lifting capacity and deformation performance of studs under repeated loading

研究栓钉在重复荷载下的拉拔承载力和变形性能,进行4个试件的拉拔试验,得到重复荷载下的荷载-位移曲线,分析了栓钉直径及埋深对位移及拉拔承载力的影响.研究结果表明:栓钉直径由19 mm增加至22 mm,承载力增加10.8%~24.7%,栓钉埋深由120 mm增加至170 mm,承载力提升5.0%~41.3%,试件在极限荷载下的变形能力随栓钉深径比的增加而增大.荷载级别大于等于8时,混凝土出现裂缝,栓钉出现较大变形.栓钉埋深120 mm时,栓钉在90 kN左右产生明显的变形;埋深170 mm时,栓钉的变形出现在120 kN左右;试件残余位移在加载中后期成指数增长.

In order to study the pull-lifting capacity and deformation performance of the studs under repeated load,the drawing tests of four specimens were carried out with the diameter of stud and its depth buried as parameters under repeated load.The load-displacement curves were obtained,and the influence of the diameter of the stud and its depth on the displacement and the bearing capacity of the stud was analyzed.The results show that when the diameter of the pin increased from 19 mm to 22 mm,the carrying capacity increased by 10.8%~24.7%,the depth of the pin buried increased from 120 mm to 170 mm,and the capacity increased by 5.0%~41.3%.The deformation capacity of the specimen under the limit load increases with the increase of the ratio of depth to diameter of the pin.When load level is equal to or greater than 8 under the repeated loads,the concrete cracks and pin deformation begins to occur.When the bolt was buried at a depth of 120 mm,the bolt has significant deformation at a level of 90 kN.At a depth of 170 mm,the bolt displacement occurred relatively late,at about 120 kN.The residue deformations of specimens increase exponentially in the middle and later stage of the repeated load.