带抗拔不抗剪栓钉的钢-混组合梁桥面连续构造理论研究

Theoretical Study on Link Slabs of Steel-concrete Composite Beam Bridges with Uplift-restricted and Slip-permitted Studs

随着钢-混组合梁桥的快速发展,组合梁桥面连续构造开裂已成为一个亟需解决的问题。目前,现有的桥面连续抗裂措施大多针对混凝土桥,且实际工程中的配筋缺乏计算分析。因此,研究提出了将抗拔不抗剪连接新技术应用于钢-混组合梁桥面连续构造的抗裂设计。根据该技术的作用机理,推导出梁端变形作用下桥面连续构造内力及顶部受拉钢筋应力的计算公式,并分析了各类荷载工况下考虑桥面连续影响的梁端变形值。为验证理论方法的准确性,以广州市某座两跨装配式钢-混组合梁桥为依托,将桥面连续顶部受拉钢筋应力的理论计算值与实测值及有限元计算值进行了对比,结果吻合良好。最后,以该理论分析方法为基础对抗拔不抗剪栓钉的布置范围及桥面连续配筋率作了参数分析,其结论可为带抗拔不抗剪栓钉的钢-混组合梁桥面连续构造的设计提供一定的指导。

With the rapid development of steel-concrete composite beam bridges,cracking of link slabs has become an urgent problem.Most of the existing anti-cracking measures for link slabs are for concrete bridges.Futhermore,lack of calculation and analysis of reinforcement exists in practical engineering.Therefore,this study proposes that the uplift-restricted and slip-permitted(URSP)connection technique is applied to the crack resistance deisgn of link slabs of steel-concrete composite beam bridges.According to the mechanism of this technique,the calculation formulas for the internal force of link slabs and the stress of the top tension bar are derived.Moreover,the girder end deformation considering the effect of link slabs under various load conditions is also analyzed.To verify the accuracy of proposed theoretical method,a two-span precast steel-concrete composite beam bridge in Guangzhou is analyzed.The theoretical results of the stress of the top tension bar is compared with the test data and the finite element results,which shows good matches.Finally,on the basis of the proposed theoretical method,a parametric study is carried out to investigate the layout range of the URSP connectors and the reinforcement ratio of link slabs.The corresponding conclusions can be used to provide certain guidance for the design of link slabs of steel-concrete composite bridges with uplift-restricted and slip-permitted studs.