Abstract：Steel-concrete composite truss is a new type of railway bridge structure. Performance of joints in bottom chord of steel-concrete composite trusses is complicated. 3 joint models with PBL connectors were tested under horizontal loading to study the mechanical performance, failure modes and load-bearing capacity. Influences of mechanical characteristics, failure models, and the ultimate bearing capacity are investigated. A 3D finite element model is developed to further analyse the horizontally loaded behaviour of the steel-concrete composite truss and the numerical results agree well with the experimental data. The results show that the joints have good mechanical behaviour and the PBL shear connectors transfer force well. The web members are weak links, whose yield strength and ultimate bearing capacity can be obviously improved by increasing the thickness of the steel web member. Based on modeling analysis, a ventral pole asymmetry design rule is proposed, which gives more conservative data than the experimental results. The proposed method can meet the requirements of domestic bridge design and provide reference for the practical engineering application.
