Research On The Temperature Field And The Frost Heaving Characteristics Of Operating Railway Tunnel In Cold Region

The construction of traffic system is being accelerate advanced in china,the railway construction is ushered in a new round of development opportunities,many of the new railway line has been gradually extended to cold regions of high altitude and high latitude,which includes a large number of built tunnel in cold regions.Experts have paid more attention to the engineering problems of tunnel in cold region caused by external environment and climate,and as an important research topic was mentioned on the agenda.This paper rely on the Shahukou Tunnel of Zhunchi railway,and based on the measured data of temperature,analysis of the variation law of inside and outside temperature of tunnel;by using the numerical simulation method,expansion research on the variation law of the transient temperature field of lining behind and surrounding rock in complete freeze-thaw cycle and the 0? isotherm in the tunnel.Using the water frost heave model,according to method of rock mechanics and structural mechanics respectively,numerical simulation analysis on the stress and deformation of lining caused by water frost heave.The main research work:(1)Study on distribution law of temperature field of operating railway tunnel in cold region.According to the layout principle,the temperature sensor were arranged at internal and external different positions of the tunnel,long-term monitoring the internal and external environment temperature of tunnel and temperature of behind lining and surrounding rock,after the analysis of measured data,to master the variation law of temperature of above measurement items during the monitoring period.(2)Expansion analysis on temperature field of surrounding rock of operating railway tunnel in cold region.Due to temperature measured data of behind lining and surrounding rock is not complete,the measured values of the environment temperature in the tunnel are used as boundary conditions,establish a temperature field model,FLAC3 D finite difference software was used for numerical simulation analysis;in order to verify the correctness of the model,the numerical results are compared with the measured results.On the basis of correct calculation of the model,after the calculation results are finished,the variation law of the transient temperature field and the change rule of the 0? isotherm in the external of tunnel are obtained.(3)Research on frost heaving characteristics of operating railway tunnel in cold region.Consulted the literature of the frost heave model and made comments the theory of the frost heave model,using the water frost heave model,according to method of rock mechanics and structural mechanics respectively,numerical simulation analysis on the stress and deformation of Shahukou Tunnel lining caused by water frost heave.The calculated results are compared with the values in the code,the stress ratio and safety factor were obtained,and as a reference to evaluated the lining structure.The research results of this paper provide technical support for the prevention and control of the freezing damage of tunnel in cold region,which has certain reference significance.