Fracture Mechanics Behavior of Jointed Granite Exposed to High Temperatures

Abstract

Based on the research background of the damage of high-temperature jointed rock masses, this paper studies the mechanical properties of jointed granite under high-temperature conditions and analyzes the failure law of jointed rock masses with increasing temperature, decreasing temperature and types of joints. The results have important scientific and engineering value. The main research results are as follows: (1) high-temperature conditions change the mechanical properties of granite, especially when the temperature is higher than 400 °C, and the peak stress of granite decreases sharply; the change rate of the mechanical parameters of granite under the condition of water cooling is higher than that under the condition of natural cooling. (2) The uniaxial compressive strength of jointed granite increases with increasing angle α between the joint and the maximum principal plane, and the peak strength of intact granite is higher than that of jointed granite with either conjugate or echelon joints (referred to as conjugate or echelon jointed granite here). (3) The conjugate jointed granite exhibits three failure modes, in which the fractures are all tensile fractures; the echelon jointed granite exhibits three failure modes, most of which include tensile and shear fracturing.