Numerical Simulations And Avoidance Research Of Rolling Stone-Bridge Pier Collision

Located in the mountain areas with adverse geological conditions,Mountain Bridges are often affected by various geological disasters.Especially,Rolling Stones pose a serious threat to the safety of the bridge.In recent years,there have occurred many major bridge damage accidents due to the impact of strike.Thus,the problem of bridge pier against impact of Rolling Stones has caused people's attention.In order to increase the ability to resist the impact of Rolling Stones and ensure the security of the bridge during the operation,this paper takes a mountain hollow,thin-wall bridge pier as the study object, simulation analysed the dynamic process of Rolling Stones- pier collision and several major factors that affect it.Developed a pier prevention device against the rolling stones, and analysed the prevention function of the device.Through the large structural analysis program ANSYS/LS-DYNA, respectively, simulation analyzed the process about rolling stone-pier collision and the process about rolling stone-pier with prevention device collision. The major work in this thesis are listed as follows:1)Analysed the method of numerical simulation's application in bridge collisions, and listed several commonly used constitutive model of concrete in simulation analysis, finally comparative analysed the constitutive models of concrete.2)Establish a rolling stone and bridge pier finite element model,simulation analysed the dynamic process about rolling stone-pier collision.has gained the mechanics mechnaism,Time-history curves of collision force,Time-history curvesof pier stress and croud map of pier stress during the process of collision.3)Analysis of the main factors influnce the impact force to study their relationship with the collision force.4)Summarize the existing anti-impact device of the bridge pier resisting rolling stones colliding,analyze their advantages and disadvantages and applicationof occasions,and the last,have developed a safe,durable,and economical protection device of the bridge pier resisting rolling stones colliding.5)Establish a rolling stone,bridge pier and prevention device finite element model,simulation analysed the dynamic process about rolling stone-protection device collision.and gained the mechanics mechanism,Time-history curves of protection device engergy absorption, Time-history curves of rolling stone kinetic energy, and the Damage strain protection device.Finally argument the effectiveness of device developed.6)By changing the size of structure of the protection device,studied the changes in the size Influence on the prevention function of the device.