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This paper aims to evaluate the impact interaction between the abutment and the girder subjected to nonuniform seismic excitation. An impact model based on tests is presented by taking material properties of the backfill of the abutment into consideration. The conditional simulation is performed to investigate the spatial variation of earthquake ground motions. A two-span continuous steel box girder bridge is taken as the example to analyze and assess the pounding interaction between the abutment and the girder. The detailed nonlinear finite element (FE) model is established and the steel girder and the reinforced concrete piers are modeled by nonlinear fiber elements. The pounding element of the abutment is simulated by using a trilinear compression gap element. The elastic-perfectly plastic element is used to model the nonlinear rubber bearings. The comparisons of the pounding forces, the shear forces of the nonlinear bearings, the moments of reinforced concrete piers, and the axial pounding stresses of the steel girder are studied. The made observations indicate that the nonuniform excitation for multisupport bridge is imperative in the analysis and evaluation of the pounding effects of the bridges. [ABSTRACT FROM AUTHOR]

• Blast performances of the SCS, CSC and RC slabs are experimentally and numerically studied. • Damage mode and maximum deflections of SCS, CSC and RC panels are summarized. • Two types of failure modes in the SCS, CSC and RC panels are defined. • Empirical formulas are proposed to predict the midspan deflection of the SCS and CSC panels. As a lateral resisting element, the steel–concrete composite structure has been gradually employed in the anti-seismic and the anti-explosion design of structures due to the favorable capacity of energy dissipation and impact resistance. The blast capacities of steel–concrete-steel (SCS) sandwich, concrete-steel–concrete (CSC), and reinforced concrete (RC) slabs were investigated by experiment and numerical simulation. The effects of the explosive charge, concrete grade, steel plate thickness, and length of shear studs on the blast behaviors of the composite slabs were studied by parametric analysis. The failure modes and dynamic responses of the specimens were investigated and compared. Simultaneously, the empirical formulas for mid-span deflection of the SCS and CSC slabs were proposed by using a multiple nonlinear regression analysis method. The results indicated that the three specimens exhibit different failure modes, in terms of local damage, spallation of concrete, and punching failure. And the steel plate takes a dominant role against the blast loads, which can provide a robust protective capacity to prevent the slab from damage due to the high tensile strength of steel. The SCS sandwich slab has the smallest damaged area on the front steel plate with a smaller mid-span displacement, maintains the integrity, and owns bearing capacity after the blast test compared with the CSC and RC members. The proposed empirical formula can well fit the relation among the deflection of the composite slabs, explosive charge, and thickness of steel plate, which can reasonably predict the midspan displacements of the composite slabs. [ABSTRACT FROM AUTHOR]