The superstructure behavior assessment of the railway bridge with truss element damage

Abstract

The analysis of railway bridge accidents shows that at the present stage, the number of accidents and mechanical superstructures damage is associated with vehicle impacts. Bridge design standards recommend to check bridge structures for survivability, operational control standards do not cover such issues. To superstructure behavior assessment of a single-track railway bridge with truss element damage, a numerical study of changes in the stress-strain state of bridge superstructure was carried out within the framework of the dissertation research «Assessment of the operational reliability of metal spans with damage and methods of their monitoring». The object of the research is a typical superstructure with an estimated length of 66 m in the condition of complete or partial failure of various truss elements due to mechanical damage. As a result of the research, the nature of the redistribution of the stress-strain state of the superstructure was revealed. It is determined that the spatial redistribution of the stress-strain state occurs along the path of increasing stresses in the lattice elements of the parallel truss and longitudinal links. According to the control of allowable stresses and deflections, the survivability of the superstructure is maintained while 70 % of the single truss element elimination is reached. The elements for which mechanical damage is most dangerous have been identified.