VEHICLE COLLISION WITH A BRIDGE PIER

Abstract

The work has been divided into 5 parts. The first part of the report contains provisions regarding the impact given in some of the international design codes. The second part contains an analytical approach that can be used to find the force which will be acting on any pier subjected to impact by any vehicle. The only information required is the force time history the collision of the vehicle against a rigid barrier. This data can be acquired by doing either live test or through simulation. The third part contains finite element simulation results wherein I have modelled the vehicle and the bridge and ran the simulation for the collision process. A medium weight 7 ton truck was made so as to compare results available for a 66 KN Ford truck. The vehicle was impacted against a pier of 1 meter diameter at various approach speeds. The main parameter that was looked for was the impact forces. The results were later compared with the current provisions to check their suitability. No experiments were conducted in the present work but a number of other things were done to develop credence in the outcome of the work. Some of them are comparing with previously done research, mesh refinement studies, conservation of energy, keeping the hour glass energy low during the process.It was found that the as a result of impact the pier was mainly failing in punching shear. Shear capacity of the pier in punching was found using the provisions given in American code. It was found to be unsafe. Similarly shear capacities were found for other piers by varying 3 important parameters, namely, the grade of concrete, the diameter of the pier, and the pitch of the spiral reinforcement. The results that have come through this research depicts that the demands created by the impact are much higher than the provisions given in any of the codes. This implies that the present provisions are unconservative for design. This is problematic is there are vehicles like tractor trailers plying on road which are much heavier than the vehicle studied