Seismic Mitigation of Curved Continuous Girder Bridge Considering Collision Effect

Due to structural irregularity, curved bridgesaremore likely to cause non-uniform collisions and unseating between adjacent components when subjected to earthquakes. Based on the analysis of the collision response of curved bridges duringearthquakes, and according to the seismic characteristics of curved bridges, research was carried out on pounding mitigation and unseating prevention measures. A curved bridge with double column piers was taken as an engineering example, and a finite element model of curved bridges thatcould consider the non-uniform contact collision between adjacent components was built with ABAQUS software. Viscoelastic dampers, viscous dampers, and a lead rubber bearing were selected as the damping devices, and a steel wire rope-rubber mat was used as the pounding mitigation device to form the combinatorial seismic mitigation system. Based on the principle of energy dissipation combined with constraints, three kinds of combined seismic mitigation case were determined; a seismic response analysis was then performed. The results indicated that the three kinds of combined seismic case were effective atreducing the response topounding force, stress, damage, girder torsion and displacement, and achieved the goals of seismic mitigation and unseating prevention.

SEISMIC MITIGATION EFFICIENCY STUDY OF THE COUPLING BEAM DAMPER IN THE SHEAR WALL STRUCTURE

Coupling beam damper can be easily repaired in the post-earthquake, which can dissipate the seismic energy of the structure in the earthquake action. In this paper, the seismic mitigation efficiency of the coupling beam damper in the shear wall structure is analysed by using the fast nonlinear analysis method. Meanwhile, the effect of the layout location and number of the coupling beam dampers on the seismic mitigation efficiency of the structure are studied. Finally, the effect of the performance parameter of the coupling beam damper on the seismic mitigation efficiency is also analysed. The results indicate that: the story shear force and the drift angle of the shear wall structure can be effectively decreased because of the coupling beam damper, and the maximum decreased amplification of the story drift angle and base shear force can reach up to 16.7% and 8.8% respectively. Relating to the decreased amplification of the base shear force, the decreased amplification of the story drift angle of the structure with coupling beam damper is obvious. The coupling beam damper installed in the upper part of the structure is more economical, because the deformation of the structural coupling beam is mainly concentrated in the upper part of the structure. To ensure economic of the structure with damper, the reasonable coupling damper performance parameter should be determinate according to the dynamic response of the shear wall structure in the earthquake action. The above research work can provide guidance for the seismic design of the shear wall structure.