Study On Damage Mechanism Of Structure Of High-speed Railway Tunnel In Cold Area

With the sustained and rapid development of economy in our country, especially the development of the western region and revitalization of the northeast old industrial base strategy, the implementation of the construction of tunnels in cold area in our country will be more and more, these areas due to the temperature change is bigger itself, causing the tunnel itself under high temperature stress, combined with the surrounding rock around the frost heaving force caused by temperature change, will directly cause damage of the tunnel, causing the safety of the structure affected by a lot of. but also cause considerable economic losses. So how can accurately calculate the stress of the tunnel lining, and when the failure, able to timely take measures to repair work of the tunnel, avoid to cause collapse and so on.Using ANSYS parametric language and Monte Carlo method, we established with different initial void ratio of mesoscopic mechanics model of tunnel concrete lining in this paper. And according to this model in mesoscopic mechanics point of view, with the application of ANSYS transient analysis method, the structure of concrete lining in load and temperature variations caused by the mechanical properties of stress under the effect of coupling load at the same time, the change laws of tunnel in the process of using strain. Results show that the temperature difference between the larger area without any heat preservation measures, the temperature stress of tunnel lining caused by fatigue damage can be fatal.This paper based on the stiffness attenuation theory, under the action of the temperature stress of concrete lining of the expansion of the mesoscopic damage cracks, the fatigue damage fracture of railway tunnel lining structure development change rule. Research results show that in the early stages of the temperature stress, the strain growth of the tunnel is bigger, the middle belongs to the state of steady growth, the temperature stress in the later damage will on the tunnel is deadly.