桥梁施工中钢抱箍滑移原因与防滑措施研究  

Research on Causes of Slip of Steel Hoops During Bridge Construction and Anti-Slip Measures

作　　者：顾颖 彭勇军[2] 陈永 王强 古松[1] GU Ying;PENG Yongjun;CHEN Yong;WANG Qiang;GU Song(School of Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang 621010,China;China Railway 18th Bureau Group Corporation Limited,Tianjin 300222,China;China Railway Construction Group Co.,Ltd.,Beijing 100040,China)

机构地区：[1]西南科技大学土木工程与建筑学院,四川绵阳621010 [2]中铁十八局集团有限公司,天津300222 [3]中铁建设集团有限公司,北京100040

出　　处：《世界桥梁》2024年第2期107-113,共7页World Bridges

基　　金：国家自然科学基金项目(52108385);四川省科技计划项目(2022ZYDF083)。

摘　　要：为研究桥梁施工中钢抱箍滑移原因并提出针对性的应对措施,对钢抱箍受力进行理论分析。针对钢-混界面进水及螺栓施拧不足造成的滑移,进行钢-混界面摩擦系数和螺栓拧紧力矩系数测试及定量分析,根据测试结果并结合现场经验提出钢抱箍防滑措施。结果表明:实测干燥状态下钢-混界面的静摩擦系数为0.62,大于常用设计值(0.3~0.4),钢抱箍偏安全;界面润湿后,静摩擦系数有所降低,但仍高于常用设计值,说明钢-混界面进水会降低钢抱箍承载能力,但降低程度还不足以导致钢抱箍滑移。螺栓拧紧力矩系数取值不当是钢抱箍滑移的主要原因,拧紧力矩系数常用设计值仅为测试值的1/1.7~1/3.6,偏不安全;拧紧力矩系数取值跟螺栓轴线与承压板法线间的夹角有关,建议现场对其进行实测,以保证螺栓预紧力与设计相符。钢抱箍设计时,摩擦系数可偏安全地取0.45,螺栓拧紧力矩系数可在参考范围内取大值,并结合1.5~2.0的安全系数确定螺栓数量,以避免钢抱箍滑移。This paper theoretically analyzes the mechanical properties of steel hoops and proposes the measures to prevent slip of steel hoops during bridge construction.To address the slip caused by water ingress in steel-concrete interface as well as insufficient bolt tightening torque,the steel-concrete interface friction factors and the nut factors were tested and quantitatively analyzed.In accordance with the test results and field experience,the steel hoop anti-slip measures were proposed.It is shown that the static friction factor of the dry steel-concrete interface is 0.62,greater than the common design value of 0.3 to 0.4,indicating sound load bearing condition of the steel hoops.When the steel-concrete interface is wetted,the static friction factor is decreased,but still higher than the common design value,meaning that water ingress indeed undermines the load bearing capacity of steel hoops,but does not reach the degree to induce slip of steel hoops.The improper value of nut factor is considered the main cause of the slip of steel hoops,as the common design value of which is only 1/1.7 to 1/3.6 of the tested value,indicating potential safety risk.The angle between the bolt axis and normal of load bearing plate is a key consideration in determining the nut factor,it is suggested to get a field-measured value to ensure the agreement of the bolt pre-tension with the design value.In the design of steel hoop,the friction factor can be set at 0.45,and the nut factor set at the maximum of the allowable range.The number of bolts should be determined with a safety coefficient of 1.5 to 2.0,to effectively prevent the slip of steel hoops.

关 键 词：桥梁工程 钢抱箍 滑移 钢-混界面 螺栓预紧力 摩擦系数 螺栓拧紧力矩系数 

分 类 号：U445[建筑科学—桥梁与隧道工程]