Experimental study on infrared photographs of deformation and failure of surrounding rock of tunnels procession induced by excavation

The equivalent material simulating experiments and thermal infrared imager equipments are employed to study the rules of deformation and failure of surrounding rock induced by rock burst. By using three-axial restraint and uniaxial loads, three-dimensional initial stress state is simulated. The deformation and failure of the surrounding rock are analysed using infrared photographs in the way of“loading before excavation”. The rules of temperature change are studied when the deformation and failure of surrounding rock of deep tunnels induced by rock burst consider some factors such as excavation speed and support pattern. The experimental results show that the faster the excavation, the greater the change of model surface temperature; and the more intense the accumulation of elastic energy of surrounding rock of tunnels, the higher the tendency of rock burst. The increase of the supporting strength plays a role in lowering the tendency of rock burst of surrounding rock of deep tunnels. The rapid increase of surface thermal radiation temperature of the surrounding rock caused by the infrared anomaly can be regarded as early signs of rock burst. This study reveals the relationship between the deformation and failure of the surrounding rock of tunnels and the change of temperature fields, and it will provide a basis for reasonable excavation and safe support of deep tunnels.