钢腹杆-劲性骨架混凝土弦杆组合拱节点受力性能试验

发布时间：2018-01-10 02:17

本文关键词：钢腹杆-劲性骨架混凝土弦杆组合拱节点受力性能试验　出处：《中国公路学报》2017年02期 　论文类型：期刊论文

【摘要】：为进一步增大拱桥的跨越能力,结合劲性骨架钢筋混凝土拱桥的结构和施工特点,提出钢腹杆-劲性骨架混凝土(SRC)弦杆组合桁式拱圈结构,利用钢腹杆替代混凝土腹板,省去混凝土腹板的浇筑工作,并减轻拱圈自重以达到增大拱桥跨径的目的。为了解这种组合拱连接节点的受力特点,在钢腹杆-SRC弦杆组合拱桥试设计研究基础上,以弦杆外包混凝土厚度为主要参数,进行了3个组合拱节点及1个对比钢管混凝土节点的试验研究,并探讨了节点的失效机理。结果表明:组合拱节点首先发生弦杆外包混凝土开裂,最终发生钢管混凝土节点破坏;外包混凝土对受拉和受压腹杆的受力影响很小;相比钢管混凝土节点而言,组合拱节点受拉腹杆的接头刚度较大;弦杆外包混凝土的厚度只影响外包混凝土的开裂荷载,外包混凝土越厚,开裂荷载越大,但不影响组合拱节点的极限承载力;结合钢管混凝土劲性骨架混凝土柱的研究成果,建议组合拱节点的混凝土外包系数取0.50左右,其承载力可按照受拉节点发生冲剪失效模式和受压节点发生有效宽度失效模式进行计算,但其计算结果偏于安全。研究成果可为钢腹杆-SRC弦杆组合拱桥的设计提供依据,也可为类似连接节点的设计提供参考。
[Abstract]:In order to further increase the span capacity of arch bridge, combined with the structure and construction characteristics of reinforced concrete arch bridge with stiffened skeleton, the steel web and stiffened frame concrete reinforced concrete composite truss arch ring structure is proposed. The steel web bar is used to replace the concrete web to save the pouring work of the concrete web and to reduce the weight of the arch ring so as to increase the span of the arch bridge. Based on the experimental design of steel web SRC chord composite arch bridge, three composite arch joints and one Concrete-filled steel tubular joint were tested and studied with the chord concrete thickness as the main parameter. The failure mechanism of the joints is also discussed. The results show that the composite arch joints are first cracked by the chord and finally destroyed by the concrete-filled steel tube (CFST) joints. The external concrete has little effect on the tension and compression of web rod. Compared with the concrete-filled steel tubular joints, the joint stiffness of the tension webs of the composite arch joints is larger. The thickness of the chord concrete only affects the cracking load of the concrete. The thicker the concrete, the greater the cracking load, but not the ultimate bearing capacity of the composite arch joints. Combined with the research results of concrete-filled steel tubular reinforced concrete columns, it is suggested that the enclosing coefficient of composite arch joints should be about 0.50. The bearing capacity can be calculated according to the failure mode of the tensile joint and the effective width failure mode. The results of the study can be used as a reference for the design of steel web SRC chord composite arch bridge as well as for the design of similar joints.
【作者单位】：福州大学土木工程学院;青岛路桥建设集团有限公司;
【基金】：国家自然科学基金项目(51178119)
【分类号】：U446.1
【正文快照】： 0引言如何增大拱桥的跨越能力是桥梁工程的一个重要研究方向,拱结构以受压为主,从材料方面考虑,混凝土拱桥向超大跨径方向发展是最值得研究的方向。目前,超大跨径混凝土拱桥主要采用劲性骨架法施工,拱圈为劲性骨架混凝土结构,劲性骨架一般为钢管混凝土,施工过程为先架设、合龙

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