Research Of Mechanics Behavior For LNG Technology Of Tunnel Under Disasters

LNG technology of tunnel may be affected by the leakage and fire disaster During operation because of its own structure and operating characteristic of requirement. The design of the lining structure is one of them. In this paper, ShenZhen LNG technology of tunnel as an example, refer to the high and low temperature experiment of concrete at home and abroad, adopts the method of finite element, the LNG leakage and fire temperature field inside the tunnel, lining structure temperature field, stress field was simulated, analyzed the damage law of lining structure in low temperature and high temperature. Adopt the method of the theoretical analysis, the structure under the disaster reconstruction model is put forward, and calculating the carrying capacity of the lining structure after the disaster. Disaster prevention measures related to are put forward.The specific work includes:(1) Using FLUENT fluid calculation software, tunnel temperature field and the methane concentration under different leakage mouth diameter and air inlet conditions is analyzed; According to the concentration of methane under different working condition of leakage analyzed the fire temperature field in tunnel.(2) According to the temperature field in the tunnel which was obtained, using the finite element software ANSYS, analyses the change of tunnel lining structure temperature field in the affected and normal temperature, and fitting formula of temperature field in lining was obtained by means of fitting.(3)Analyses the compressive stress and shear stress change trend in the five largest stress position of tunnel lining structure by indirect Temperature-stress coupling method. Analyzes structural damage rule caused by the temperature stress, and gets the relationship formula between damage depth and affected length by the method of fitting.(4) According to the cross section of the tunnel lining structure and material performance reduction method under proposed in disasters, rebuilt the structure calculation model. Use The load-structure method to check the structure safety coefficient and the quantity of calculation of reinforcement after a disaster. Combining with the results in this paper and the LNG technology tunnel characteristics, the disaster prevention measures are put forward.