Abstract The frost heave of surrounding rock in cold regions tunnel involves the complicated interaction of temperature field,seepage field,stress field and freeze-thaw damage. Starting with the thermo-hydro-mechnical- damage(THMD) coupling mechanism analysis,based on the continuum mechanics,thermodynamics,the percolation mechanics,damage mechanics and points of segregation potential theory,a THMD coupled model under the condition of freeze-thaw cycles was established. The model not only considered the influence of volumetric strain on temperature field and seepage field,temperature gradient and seepage pressure on rock mass stress,but also,according to actual engineering,considered the influence of frost heave pressure and freeze-thaw cycles on the damage of rock mass. This model was applied to simulate the temperature and deformation of a pipeline engineering in cold region. By comparing with the in-situ monitoring data,it is found that the proposed model can reflect the frost heave phenomenon exactly. After that,a forecast about frost heave pressure of Galongla tunnel under extreme weather conditions was given,and the stress and deformation law after freeze-thaw cycles are obtained. From the calculation results,it is concluded that the maximum frost heave pressure can reach up to 1.6 MPa and the stress is increased greatly after freeze-thaw cycles.
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Received: 13 July 2012
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