| With the development of China’s “One Belt and One Road” concept,more and more highways and railways are being constructed in mountainous regions in the central and western regions.With the increasing scale and number of tunnels,the entrance and exit sections of tunnels often have “tunnel-slope” interactions,making it a disaster-prone area.The excavation of the tunnel destroys the stress balance of the slope and greatly reduces the stability of the slope.In case of rainfall,it will aggravate the slope instability.On the other hand,the landslide thrust acts on the tunnel lining,causing the tunnel lining to be damaged by shear,cracking and deforming in the light,and collapse and breaking in the heavy.We all know that in the tunnel construction process,there is always a saying that “difficult to enter the tunnel,difficult to exit the tunnel.” Therefore,this article uses the Daping slope group Sunjiaya tunnel as the engineering background to carry out the study of the tunnel-slope interaction laws:1.The multi-functional tunnel model test system under the action of rainfall and groundwater seepage is independently developed.The system is a comprehensive test platform,which is composed of artificial rainfall simulation device,groundwater seepage simulation device,tunnel excavation simulation device,intelligent control device,data collection system,etc.it can carry out the research on rainwater infiltration mode and “tunnel-slope” interaction mechanism in different rainfall processes.2.Taking the typical slope of sunjiaya tunnel in daping slope group as the engineering background,a large-scale model test of the interaction between the tunnel and the slope system under three sets of rainfall conditions were carried out,and the moisture content,soil pressure,seepage pressure,displacement of the slope during the rainfall were obtained.The change law reveals the influence of slope instability on the deformation and failure of the tunnel lining,and a failure mode of the tunnel-slope system with or without support is proposed.3.By carrying out a large-scale model test of the tunnel-slope system interaction under three sets of rainfall conditions,the failure modes of the tunnel-slope system interaction during construction and operation periods were obtained,revealing both tunnel excavation and slope instability.The law of interaction affects the mechanism of slope instability caused by rainfall infiltration.4.Through numerical simulation,the change laws of seepage field,displacement field and stress field of tunnel-slope system in the process of rainfall are revealed,the influence laws of slope instability on tunnel lining under rainfall conditions are discussed,the evolution mechanism of tunnel-slope system stability in the process of rainfall is revealed,and the reliability and accuracy of model test results are further verified.There are 89 figures,4 tables and 138 references in this paper. |
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