A composite truss bridge is an efficient structural type where the merits of both the steel member and the prestressed concrete member are combined. The design of a connection for the truss bridge is of particular interest due to complex details resulting from concentrated forces at the composite joint. In this paper, experimental investigations were conducted to evaluate the performance of the joint with bent studs welded on a gusset plate. Push-out tests for static and fatigue loadings on a group stud connection were conducted to evaluate the direct shear strength and fatigue endurance of the joint. Because the joints are subject to various loading conditions, flexure-shear tests were also performed to verify the design provisions for the joints under a combination of tension and shear. In order to enhance the structural behavior of the connection, a bent shaped stud was proposed to increase the pull-out strength of the concrete slab. Test results showed that it is adequate to use Eurocode-4 for the evaluation of a shear connection which satisfies the requirement of minimum stud spacing specified in Eurocode-4. Since the shear load is concentrated at the joint structure of composite truss bridges, additional confining reinforcements are needed to enhance the horizontal shear strength of the shear connection. The design provision on the interaction of tension and shear for the joint structure gave conservative results. When the pyramid failure surface was assumed, internal studs had little effect on the pull-out strength of the joint. Constructability of the joint can be enhanced by decreasing the number of connectors and by strengthening the concrete slab through simplified design checks assuming four failure modes and their interactions.

中文翻译：

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弯曲螺柱的复合节点的结构性能

复合桁架桥是一种有效的结构类型，其中钢构件和预应力混凝土构件两者的优点结合在一起。桁架桥的连接设计特别受关注，这是由于复合接头处集中的力导致的复杂细节。在本文中，进行了实验研究以评估在角撑板上焊接的弯曲螺柱的接头性能。进行了一组双头螺栓连接上的静载荷和疲劳载荷的推出试验，以评估接头的直接抗剪强度和疲劳强度。由于关节承受各种载荷条件，因此还进行了弯曲剪切试验，以验证在拉伸和剪切作用下关节的设计规定。为了增强连接的结构性能，提出了一种弯曲的螺柱以增加混凝土板的抗拉强度。测试结果表明，使用Eurocode-4评估剪力连接足以满足Eurocode-4中规定的最小螺柱间距的要求。由于剪切载荷集中在复合桁架桥的连接结构上，因此需要附加的围边加强件来增强剪切连接的水平剪切强度。关节结构中拉力和剪力相互作用的设计规定给出了保守的结果。当假定为金字塔破坏面时，内部螺柱对接头的拉拔强度影响很小。