Abstract It is of significance to research the thermo-hydro-mechanical characteristics of rock mass under the condition of low temperature and freeze-thaw cycles for engineering construction in cold regions. The four aspects:physico-mechanical properties of rock,temperatures,seepage characteristics and thermo-hydro- mechanical coupling characteristics under the condition of low temperature and freeze-thaw cycles were reviewed;and combining with the characteristics of tunnel in cold regions,a new idea to research the frost heave of surrounding rock and its insulation measure were put forward;firstly,based on field monitoring,a large number of freeze-thaw tests,uniaxial compression tests and triaxial compression tests,the thermo-hydro-mechanical parameters,such as coefficient of thermal conductivity should be obtained exactly;and then a proper coupled thermo-hydraulic model for low temperature rock including phase change should be established;after this,a damage factor is proposed to consider the freeze-thaw effect in rock and the thermo-hydro-mechano-damage coupled model considering the effect of volumetric strain on temperature and seepage field of surrounding rock and the effect of temperature gradient,seepage pressure and frost heave pressure on mechanical field for tunnel in cold region can be established to study the frost heave of surrounding rock;meanwhile,a high-performance foamed concrete is designed as an insulation material used in tunnel,which has the characteristics of lightweight,insulation,cold-proof,crack resistance and aseismic.
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Received: 30 March 2011
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