铁路钢-混组合梁抗拔不抗剪栓钉设计研究

Study on Uplift Restricted-slip Free Studs Design of Railway Steel-concrete Composite Beam

为研究抗拔不抗剪栓钉在铁路钢-混组合连续梁桥中的适应性及存在问题,以4×40 m铁路钢-混组合连续梁为例,基于有限元分析软件Midas Civil,对常规栓钉的设计参数进行分析,对抗拔不抗剪栓钉及加密过渡区的设置范围进行比选,拟定铁路钢-混组合梁可行的抗拔不抗剪栓钉设计方案。研究表明:综合桥面板受力、过渡区栓钉受力、钢梁整体刚度等因素,推荐抗拔不抗剪设置范围取支点两侧0.15L(L为梁跨度);抗拔不抗剪连接区域滑移量较大,但其栓钉不受剪力;需要重点关注过渡区首排栓钉,确保其满足强度以及疲劳性能的要求,推荐加密过渡区设置范围取3 m;相较双工字形截面,双槽形截面与抗拔不抗剪需要设置的过渡区适应性较好,但用钢量增加约10%;相较常规栓钉方案,抗拔不抗剪栓钉方案桥面板钢筋减少17.7%,栓钉减少12.4%,梁部每延米造价降低2.8%。

In order to study the adaptability and existing problems of uplift restricted-slip free studs in railway steel-concrete composite continuous beam,a steel-concrete continuous composite beam with a span of 4×40m is taken as an example to analyze design parameters of studs based on finite element analysis software Midas Civil.Then the setting range of uplift restricted-slip free studs and transition region are compared and selected to determine the feasible design of uplift restricted-slip free studs.The study shows that:based on the factors of the stressed state of concrete deck,the force performance of studs in transition area,and the stiffness of steel-concrete composite beam,it is recommended to use uplift restricted-slip free studs at the range of 0.15L(L is the beam span)on both sides of the fulcrum.The slip in the uplift restricted-slip free area is large,but the studs are not stressed.The first row of studs in the transition region should be focused on to ensure that they meet the requirements of strength and fatigue performance.The recommended setting range of transition region is 3 m.Compared with I-shaped section,the grooved section has better adaptability to the transition region set up for uplift restricted-slip free studs,but the steel consumption increases by about 10 percent.Compared with shear studs,steel rebar,studs and per meter cost of construction using uplift restricted-slip free studs are decreased by 17.7 percent,12.4 percent and 2.8 percent respectively.