北方某高铁客运站钢筋直螺纹套筒连接低温疲劳试验

Low Temperature Fatigue Tests of Reinforced Straight Thread Sleeve Connections of a High Speed Railway Station in Northern China

目的验证北方某高铁客运站轨道层结构中钢筋直螺纹套筒连接在动力荷载下的疲劳性能,以保证施工工期、质量和结构运营的安全可靠.方法进行了低温下钢筋接头的常幅疲劳试验.制备强度等级为HRB400、直径为28 mm和32 mm的钢筋直螺纹套筒连接接头共13个;疲劳试验加载由常应力幅100 MPa控制,采用专门设计的低温控制设备实现-10℃和-20℃的低温环境.结果 13个钢筋接头试样中,4个在200万次循环前发生疲劳断裂,其余9个均满足200万次循环的耐疲劳性能要求.结论根据《钢筋机械连接技术规程》(JGJ 107-2010),钢筋直螺纹套筒连接接头基本满足了工程所需的低温疲劳性能要求,为其在铁路站房轨道层等直接承受动载的结构构件中的应用提供了重要试验基础.

The low temperature constant amplitude fatigue tests of reinforced straight thread sleeve connections in rail floor structure of a high speed railway station in Northern China were carried out to verify their fatigue resistance under dynamic loadings,in order to control the construction period,and to ensure the quality,safety and reliability of the structure.A total of 13 connection specimens fabricated from HRB400 steel reinforced bars with diameters of 28 mm and 32 mm were prepared.The fatigue tests were controlled by constant stress range of 100 MPa and a low temperature controlling equipment was specially designed to achieve conditions with low temperatures of -10 ℃ and -20 ℃.Among the thirteen tested specimens,four failed due to fatigue before 2.0 million cycles and the remaining met the fatigue resistance requirement of enduring 2 million cycles.The test results indicate that the reinforced straight thread sleeve connections satisfy the fatigue performance at low temperatures required by the engineering project according to ＂Technical Specification for Mechanical Splicing of Steel Reinforcing Bars（JGJ 107-2010）＂.The present study provides an experimental basis for applications of reinforced straight thread sleeve connections in rail floor structures subjected to dynamic train loadings.