The Numerical Simulation Analysis On Coupling Of Temperature Field And Stress Field For Fu-dang Tunnel

With the rapid development of railway market and the increasement of high speed railway,designers focus on bridges and tunnels to make lines more smoothly. Tunnels, as a common structure, has been widely applied in recent years, and even the length of tunnels has been increased continuously. When long tunnels bring more convenience to the location of railway route selection, tunnel diseases turn more obviously, even takes more bad effects to the structure during the period of construction and operation. For instance, In consequence of the length amplified, the depth of the tunnel increased, high rock temperature do more harms to the safety of the structure of tunnel lining. The influence of geothermal appears.In this paper, according to the research of the combination of the heat transfer theory and the measurement in the FU-DANG tunnel, which located in high altitude and high rock temperature area, the author has conducted the numerical simulation by using ANSYS finite element software, comparing stress and safety index of the lining structure by gravity independently and by the gravity coupling the affect of geothermal, decide to use insulation materials to reduce the temperature of the tunnel. According to the actual situations, select the fittest material and thickness of the material, then reduce the thermal in the tunnel by ventilation, guarantee the lining structure safe during the period of construction and operation.(1) Using ANSYS finite element software, calculate the stress and safety index of FU-DANG tunnel on the lining structure by gravity independently and by the gravity coupling affect of geothermal. The result illustrates that the stress increased under the condition of coupling action, and the safety index drops.(2)Compare the thermal of the tunnel lining structure with the insulation materials and without it. The result reveal temperature in the lining climb up more slowly, and in lower temperature conditions during calculating period when insulation materials was installed.(3)Select the fittest cooling measures — —10cm compound silicate materials —— after comparing the result of different material and varies thickness of the materials.(4)The air in the tunnel and outside cross-ventilation not so efficient in construction period.In order to ensure security of the workers and maintain construction equipment running all right, we use mechanical ventilation to reduce the temperature in the tunnel. Result shows that temperature in the range of 110 m back from digging work pace can reduce beneath 28℃ only in the condition of the air at 15℃ in the wind pipe blowing over the speed of 20m/s.(5)It could be assume that air in the tunnel cross-ventilate fully enough with the air outside during period of operation. The statistics elaborates stress in the lining structure reduced and the safety proved after we take measures to cool down temperatures in the tunnel.