Distribution Of Temperature Field And Analysis Of Coupled Problem With Stress Field In The Seasonally Frozen Soil Tunnel

In high latitude or high elevation cold region, especially means of many years frozen earth region, freeze injure always happens in tunnel when ground water grows. Thus is proved by a lot of practice of construction and transportservice of railway and highway tunnel overseas and interiorly. Freeze injure endangers the safety of tunnel structure and transport service directly, causes serious economic loss.Aimed the shaziya tunnel in Hubei Province as an example and on base of study on large quantity phenomena and principle of tunnel freeze injure, that frost force is main reason of tunnel freeze injure is temperature, water, surrounding rock, engineering measure are main factors of tunnel freeze injure. This paper connects tightly with the real engineering. Using the research method combined the theoretical computational analysis with the field observation; the researches on the theoretical computational analysis of the seasonally frozen soil tunnel, the technology of constructing and preventing the damage of the seasonally frozen soil tunnel have been investigated. The research results can provide the theoretical help and reference for the constructing and the damage of the seasonally frozen soil tunnel. The following research work has been done in detail.According to the essential theories of geocryology and heat transfer, taking the coupled effects of the moisture field and the temperature field into account, two-dimensional governing differential equations of the couple problem are presented, the finite element formulae of this problem are obtained by Galerkin's method, and the computer program of the finite element is compiled. Using ANSYS software, two-dimensional nonlinear analysis for the coupled problem of the moisture field and the temperature field in Shaziya tunnel are worked out.On the one the hand, the results show that the effect of the moisture field on temperature field in the tunnel in the seasonally frozen soil tunnel is very great, and that the moisture field should be taken into account during the design. On the other hand, the results show, if the insulation material, whose conduction coefficientλis 0.03 W ( m ?°C ) and width d is 8.0 cm, is fitted with tunnel, the rock surrounding the entrance of tunnel will occur litter part frozen earth.According to the essential theories of heat transfer and finite element, considering the coupled effects of the stress field and temperature field, two-dimensional computational model of the coupled problem are given, the finite element formulae of this problem are obtained by Galerkin's method. The results show that the effect of the temperature filed on the stress field in the seasonally frozen soil tunnel is very great, and the stress field should be taken into account during the design.