钢桁结合梁整体节点及细节构造设计与研究

Study and Design of Integral Joints and Detailed Structures of Steel Truss Girder

研究目的:(1)研究确定腹杆与节点板间合理的连接方式,使腹杆与节点板间传力简捷明确,腹杆端部应力分布均匀,提高腹杆抗疲劳性能;(2)研究确定横梁与弦杆间合理的连接方式,使横梁上翼缘接头构造满足结构疲劳性能要求,避免与之连接的下弦杆竖板发生层状撕裂破坏;(3)研究确定钢桁结合梁桥整体节点细节构造,使受力复杂的整体节点传力简捷明确,避免应力集中,改善结构疲劳性能。研究结论:(1)腹杆与节点板间采用全截面拼接,腹杆应力分布均匀,节点刚度大,杆件抗疲劳性能好。(2)横梁上翼缘接头板与弦杆间采用大弧过渡及熔透焊缝,焊缝质量等级要求为Ⅰ级,焊缝端部要求打磨锤击处理,可满足此处焊接疲劳性能要求。弦杆与横梁相交处,弦杆竖板突出30 mm并采用Q370qE-Z25钢材,可避免此处弦杆竖板发生层状撕裂。(3)在整体节点及其它钢结构设计细节中,贯彻大弧、缓坡、打磨、锤击等防裂、防断措施。可有效提高整体节点和其它细节构造的疲劳性能,满足结构抗疲劳性能要求。

Research purposes： （1） The research is done on the reasonable connection between web member and gusset to make the dowel pattern simple and clear, make the stress distribution in the end of web member uniform, and improve the anti - fatigue performance of web member. （2） The research is done on the reasonable connection between cross beam and chord to make the joint structure of cross beam flange completely satisfying the requirement of fatigue performance of structure and get rid of the tearing failure between the cross beam and bottom chord. （3） The research is done on the reasonable design of the integral joints and detailed structures of steel truss girder to make the dowel pattern of integral joints simple and clear under complicated mechanical states, get rid of the stress concentration, and improve the anti -fatigue performance. Research conclusions： （ 1 ） The full cross - section splice is adopted between web member and gusset, obtaining the uniform stress in the web member, strong joint stiffness and perfect anti -fatigue performance of member bar. （2） The major arc transition and penetration weld are adopted between the joints plate of cross beam flange and chord with the I weld quality, and the weld edge must be hammered to satisfy the requirement of anti - fatigue performance of weld. At the intersection of chord and cross beam, the chord riser extrudes 30 mm with Q370qE - Z25 roiled steel to get rid of the tearing failure of chord riser. （3） In the design of integral joints and detailed structures of other steel structures, the measures for crack and rupture controls should be taken such as major are,gentle slope,grinding and hammering,to improve the anti - fatigue performances of integral joints and other detailed structures and satisfy the requirement of anti- fatigue performance of structures.