Numerical Simulation on Mesoscopic Damage Evolution Mechanism of High-speed Railway Tunnel Lining Concrete

For the high-speed railway tunnel concrete lining, there have been some such initial damages as initial pores or cracks, therefore the initial damages will be expanded gradually under aerodynamic fatigue loads resulting from the high-speed train passing by tunnel, elastic module attenuation laws of concrete was adopted to reflect the effects of fatigue loads on the tunnel lining mesoscopic concrete, taking the second stage of the elastic module attenuation as the main research stage, the mesoscopic damage mechanism and fatigue damage cracks developing-and-changing laws of high-speed railway lining concrete were simulated under the repetitive aerodynamic loads. Study indicates: for the concrete lining with initial damages, under the repeated aerodynamic fatigue loads, the mechanical properties of the tunnel lining concrete will gradually deteriorate to the whole damage of the concrete structure, which will cause serious inference on the durability of the tunnel especially during the middle and later periods of the high-speed railway tunnel serving.