Analysis on rock fracture signals and exploration of infrared advance
prediction under true triaxial loading
Abstract
To predict the fractured rock failure under deep triaxial stress in
advance, the true triaxial tests were carried out using thermal infrared
monitoring and acoustic emission (AE). This paper proposes “infrared
temperature jumping rate (ITJR)” to reflect the “jumpiness” of the
temperature field matrix, and establishes an infrared advance prediction
method. The results show that the high temperature area will converge
and expand gradually, and cracks propagate along a certain direction. In
the sudden temperature reduction area, the rock stripping is easy to
occur. At the boundary between high-low temperature areas, it is easy to
produce breakage cracks and form rock spalling. In the short quiet
period, the rock gradually gathers strain energy, which will be released
in the fracture period. By comparing the time of AE sudden increase with
the time of ITJR mutation, it shows that the method has a good advance
prediction effect for rock fracture.