Research On Seismic Response Reduction And Anti-collision For Simply Supported Bridge Based On Cable Restrainer

Abstract:Under intense earthquake, the bearings of simply supported bridge are easy to be damaged, resulting in poundings between the adjacent beams and even girder falling. A strong collision will directly lead to the traffic interruption, and the transport capacity of the bridge can not be restored within a short time, which not only causes direct economic losses, but also leads to tremendous inconvenience for the subsequent disaster relief. Therefore, the appropriate control measures are needed for seismic response reduction and Anti-collision. Since the cable restrainer has good characteristics with clear principle, convenient arrangements and simple form, it has been used abroad. But the research based on cable restrainers is relatively fewer in China. In this paper, the cable restrainer is set up between the adjacent beams, as well as between the beam and the abutment for the research on anti-collision effect of the simply supported bridge under earthquake excitations. The main contents and results are as follows:(1) A four-span simply supported highway bridge finite element model is established by using ANSYS software, and the Kelvin model is selected to simulate the pounding and the nonlinear restoring force model is used to simulate the bearings.(2) The collision effect of the simply supported beam bridge is analyzed under earthquake excitations including the EL-Centro wave, the Taft wave, the Takochi-oki wave and the Tianjian wave, whose amplitude peak acceleration are adjusted to0.15g,0.30g,0.60g respectively. The results show that the seismic response was related with the dynamic characteristic of the bridge and the seismic wave spectrum. With the increase of peak acceleration, the seismic responses will be intensified.(3) Parametric analysis of collision effect are investigated by changing the ratio of adjacent pier height, the distance of adjacent beam, and the damping of pounding element etc, then the influence pattern of collision effect with the change of different parameters are obtained. The results indicate that the greater displacement response occurs in the higher pier and the collision force and collision number will decrease with the increase of adjacent beam’s distance.(4) The study on seismic response reduction and Anti-collision for the simply supported beam bridge is investigated, based on cable restrainers. Cable restrainers are set up between two adjacent beams, as well as between the beam and the abutment. Seismic responses with different number of cable restrainers under different seismic waves are analyzed. The results indicate that cable restrainers can effectively reduce the displacement of the beam and avoid collisions between two adjacent beams as well as between beam and abutment, also reduce the probability of girder falling. The effect of anti-collision will be better with the number of cable restrainer increasing.