| The distribution of temperature field in dry rock mass is studied experimentally.The main conclusions are as follows:(1)The distribution of temperature field in dry surrounding rock is concentric circle.(2)With the increase of ventilation time,the temperature of surrounding rock decreases with the increase of ventilation time.The equation of dimensionless temperature with Fo in surrounding rock accords with BiDoseResp equation.(3)The temperature of surrounding rock body decreases in different stages with different wind flow velocity.Different airflow velocity,surrounding rock temperature to reach the stable state of the time different,the larger the wind flow velocity,the surrounding rock temperature to reach the stable state of the time the shorter,conversely,the smaller the wind flow velocity,The longer it takes for the temperature of surrounding rock to reach a stable state.The transient variation of temperature field in rock mass around a single fissure with different parameters is studied.The main conclusions are as follows:(1)The higher the temperature of the original rock is,the longer the temperature begins to decrease,and after a period of water flowing,the temperature of the rock mass around the fissure suddenly drops.(2)The higher the temperature of the original rock,the higher the final temperature of the surrounding rock mass.(3)The temperature of fissured water affects the temperature of steady state at the measuring point.The lower the temperature of fissured water is,the lower the temperature of steady state is.The law of temperature field in water-bearing rock mass is studied,and the following laws are obtained:(1)The variation of temperature field with ventilation time in water-bearing rock mass can be divided into three stages:rapid descending stage,levelling stage and slow descending stage.The decreasing rate of the first stage decreases with the increase of the temperature of the original rock and the temperature of the flat stage increases with the increase of the temperature of the original rock.The decreasing rate of the third stage increases with the increase of the temperature of the original rock.(2)The thermal equilibrium of rock mass and water in the temperature field of porous water-bearing rock mass is closely related to the original rock temperature and ventilation time.The higher the temperature of the original rock is,the faster the temperature of each measuring point decreases,and the longer the ventilation time is,the lower the temperature is.(3)When the original rock temperature is 30℃,the drop of temperature at each measuring point is in order,and the closer the tunnel is,the shorter time it takes for the temperature of surrounding rock to be disturbed.When the temperature of the original rock increases,the disturbance of wind flow on the temperature field of surrounding rock is almost simultaneous.This is due to the increase of the temperature of the original rock and the increase of the temperature difference between the wind flow and the wall surface of the surrounding rock,which enhances the heat transfer effect and reduces the disturbance time. |
