Impact Effect On Superstructure Of Skew Bridge Under The Earthquake Action

According to the investigation of earthquake damage of skew bridge, the main forms of collision damage include rotation of the upper beam, failure of the deck and concrete cracking. At present, most of the studies mainly concentrated the rotation and the pier column internal force caused by the collision of the abutment and bridge deck, the collision force and upper beam deformation and stress should be studied, deep study on the effect of the collision of abutment and bridge deck is still needed. Therefore in this paper, influence on bridge deck caused by the collision was studied.In this paper, firstly, we review the present research situation of skew bridge collision, finite element analysis model is established considering the collision of deck and abutment, the impact of deck and abutment was studied under single moment and single collision, including bridge deck deformation and stress, impact force and impact duration. Finally, the seismic response of the upper beam is analyzed, including the acceleration, displacement and the impact force. The main conclusions are as follows:1. For a certain impact moment, there are three kinds of collisions, entire side collision, acute angle collision and obtuse angle collision. When the entire side collision happens, the deck will be no rotation, for the acute angle collision, the deck rotates in the direction of decreasing the tilt direction angle, for the obtuse angle collision, the deck rotates in the direction of increasing the tilt direction angle, The direction of rotation torque generated by the impact force is determined by the skew angle, the length and width of the bridge panel.2. Entire side collision may cause cracking of the beam; acute angle collision may lead to the destruction of the beam, intensify the collision between the transverse block and beam; obtuse angle collision caused very little deformation in the collide side, hence, less stress, the obtuse angle collision will exacerbate impact of the transverse block and deck. Three kinds of impact may lead bearing sliding even to bad.3. For single collision, skew bridge collision between the deck and abutment is divided into three kinds of collision model, entire side collision model, acute angle collision model and obtuse angle collision model, based on the range and position of beam collision. For any of collision model, deck corner will have larger impact force and long duration of strike.4. Through statistical analysis of earthquake response under eight seismic waves, results show that impact force suffered by the obtuse angle is greater than that of the acute angle, the acute angle is more likely to fall. With the increasing of the skew angle, the greater rotation displacement of the deck will be.