RESEARCH ON TYPE OF TUNNEL-LANDSLIDE SYSTEM AND TUNNEL DEFORMATION MODE

While constructing tunnels of highway or railway in the mountainous area,the situation that tunnels pass through the landslide site often occurs.These tunnels usually suffers deformation and crack diseases because of landslide.Generally,tunnel excavation and landslide creep are considered separately,which can not well explain the interaction between them.The spatial position relationship of tunnel and landslide controls the nature and scale of the disease,and it is the main factor that decides the interaction model of tunnel-landslide system.It confirms the force mode of tunnel in the landslide,and the force that acts on tunnel is the fundamental reason of tunnel deformation.Therefore,the position relationship of tunnel and slip plane of the landslide determines the stress mechanism and deformation characteristics of the tunnel.According to the position relationship of the tunnel and the slip plane,tunnel-landslide system has been divided into three types,which are parallel,orthogonal and oblique systems.With typical engineering examples,different systems have been divided into more subtypes.Then the stress mode and deformation characteristics of each type have been analyzed,the interaction law of the tunnel-landslide system is got ultimately.The results show that,the stress and deformation of different systems have great differences generally,and the tunnel-landslide system interaction decreases with the increase of the distance between tunnel and landslide.