[Purposes]With the increasing proportion of the traffic network in the earthquake zone,it is necessary to study the influence of freeze-thaw cycle and ground motion on the tunnel entrance section in the cold region.[Methods]The freeze-heaving load in the freeze-thawing ring behind the lining was obtained through the coupled heat-moisture-stress control equation,and the initial ground stress was ap-proximated with the dead weight stress.The seismic load was equivalent to the physical strength of each particle,and the influence of the freeze-thaw cycle on the strength of soil in the freeze-thawing ring and the mechanical parameters of the lining was considered.The quasi-static method is used to investigate the seismic response rule of the entrance section of shallow buried tunnel in cold area.[Findings]No matter frozen or not,the foot of the wall that is not easy to detect is the most easy to enter the plasticity.The invert exhibits the stress characteristics of inner pulling and outer pressing,and the top arch ring and side curved wall have uniform and small forces.The earthquake effect on lining shows that the possi-bility of damage increases with freezing and thawing time(times),especially in the inner compressive stress area of wall foot.Constrained by the statistical method,the seismic response of the lining in the first 10 years of freeze-thaw is weak,and the seismic stability of the lining in the hole section has deterio-rated significantly since the 15th year of freeze-thaw.[Conclusions]Compared with the winter period,the stability of tunnel structure is worse during the earthquake during the melting period.Under the his-torical background of climate warming,it is more necessary to study the seismic response rule of the tun-nel entrance during the melting period in the cold area.
freeze-thaw cyclestunnel entrance in cold areabroken freeze-thaw circleearthquake
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