Physical simulation experiment of factors affecting temperature field of heat adjustment circle in rock surrounding mine roadway

With the development of deep mining, the problem of heat damage is becoming more and more serious. The deep mine has a longer ventilation route, which will cause the tunnel exposed area is very large, and the surrounding rock with a high ground temperature could heat the ventilation air. Therefore, in this study, a facility to conduct a series of physical similarity simulation experiments for studying the heat conduction and transfer in mine roadway's surrounding rock is designed. The facility is applied to analyze, systematically and quantitatively, the effect of physical parameters on temperature field of the surrounding rock as well as its dynamic changes. The experimental results show that: the airflow velocity is strongly related to the temperature distribution of the surrounding rock when the temperature field is becoming stable. The maximum of the influence thickness can be up to 7 meters; the rock thermal diffusion coefficient of the rock also has a great effect on the curve of the rock's temperature when the curve is becoming stable but has a slight effect on the curve's shape; the rock's moisture content has a great effect on the range of the temperature field. But the effect does not last long; The roadway with the structure of thermal resistance circle that is a sign of the increasing of the medium's total thermal resistance has a large effect on heat transfer, which prolongs the period for the rock to reach a new thermal equilibrium state.