To solve design and construction problems of Monglian tunnel under high geothermal, based on the change rules of thermal parameters of surrounding rock and lining during excavation period, this paper analyzed the temperature distribution, heat transfer in tunnel and interaction between lining and surrounding rock, then by using numerical simulation, the relationship between temperature field and mechanical characteristics of lining and surrounding rock was discussed. Finally, the methods of using blast furnace cement, utilizing wet spraying concrete construction technology, and making surrounding rock exposure time as short as possible to reduce damages high temperature caused was proposed. The result can provide experience in similar tunnel design and construction.

This paper introduces a method of three-dimensional simulation of geothermal field in the study area by using the finite element method after the geothermal geological modeling based on geophysical exploration. First of all, through geophysical exploration, the three-dimensional geological model of the study area is established, and the thermal conductivity of different strata and lithology of the geological model is assigned, then the three-dimensional geothermal geological model is established;Second, set initial conditions such as surface temperature and heat source for the geothermal geological model, and then use mesh adaptive technology to perform automatic mesh division; Finally, three-dimensional geothermal field was obtained by parallel calculation in three-dimensional simulation space. This method has been applied in geothermal research in Shuguang area of Liaohe Oilfield, and the simulation results are very well.