Circumstances controlling technology of high altitude tunnel during construction in permafrost regions

Fenghuoshan and Kunlunshan Tunnels lie in hinterland of Qinghai-Tibet Plateau, of which the altitude is about 5 000 m. The problems of the life and health of workers, the protection of permafrost and the quality of tunnel become very severity because of lack of oxygen, coldness and bad geological condition in permafrost regions. The governing differential equations of construction circumstances temperature field and the surrounding-rock temperature field are established. The simulation of temperature field, the development and application of the construction ventilation and heating unit, the system of making and supplying oxygen, and the system of monitoring and controlling made the general controlling of air temperature and air quality become realism; it can provide important technology guarantee and appropriate working condition.