Destructive testing and simulation for newly designed full-scale high-speed railway box girder

Abstract

Destructive testing and numerical simulation of a full-scale box girder were conducted to understand the mechanical behaviour of a newly designed pre-stressed concrete box girder for high-speed railways. In the destructive testing, load values close to 2.5 times the designed bending moment were applied to the investigated box girder in 26 steps. The global displacement behaviour, local strain variation, and crack development throughout the destructive process were measured. During the numerical simulation, this study proposes a concrete constitutive relation considering the reinforcement effect of steel bars on the elastic modulus and failure peak stress of concrete for high-speed railway box girders. A refined and simplified finite element model (FEM) were established, and the mechanical behaviour under entire loading process was simulated using ABAQUS software, which agreed well with the testing results to a certain extent. The testing and simulation results show that the newly designed pre-stressed concrete box girder did not collapse under 2.5 times the designed bending moment, verifying the safety margin and providing guidelines for the subsequent structural design optimisation of high-speed railway box girders.