‘Strengthening by Assessment’ Using Finite Element Approaches – Case Studies of Rail Bridges

This paper presents the ‘strengthening by assessment’ of bridges achieved by the implementation of finite element techniques. The use of more accurate analysis methods and the implementation of non-linear modelling and functions to better understand buckling modes and the structural behaviour of historic construction details are outlined. Three case studies are presented, demonstrating the effectiveness of the sophisticated Level 2 Assessment methodology using finite element analysis against conservative hand calculation approaches. One rail overbridge and two rail underbridges that did not achieve the required load rating by means of a Level 1 Assessment are examined and the increase in assessed capacities given by the Level 2 Assessment is outlined.