328 / 2018-05-04 19:01:54

Experimental study on the mechanical properties of coal and rock mass under thermo-mechanical coupling

Keywords: Uniaxial compression, Full stress-strain, Peak stress, Peak strain, Elastic modulus

矿山职业健康与环境安全 > 防火

Abstract: For investigating the properties of coal and rock mass in the coalfield fire area, the samples could be deformed and produce cracks impact by the thermo-mechanical coupling, which would form the interconnected channels that supported through air. The combustion center developed along the coal seam to promote further prolongation. The MTS880/25T electro-hydraulic servo material test system was employed to conduct the experimental tests. The variations of peak stress, peak strain and elastic modulus of samples were achieved as different temperatures. The results indicated that the temperature had a significant effect on rock strength. From room temperature to 300C, the peak stress of the rock sample increased with the elevation of temperature. While the temperature exceeded 300C, the peak stress rose rapidly to reach the maximum, and then gradually decreased. The peak strain of rock samples represented obviously stage characteristics with the temperature augmentation. Before 200C, the peak strain of rock samples was linear with temperature, the elastic modulus first increased and then became slowly mild. From 200C to 400C, the peak strain of rock samples gradually increased with raising temperature, the elastic modulus was linear with temperature. The peak strain and elastic modulus of rock samples gradually lessened after 400C. Furthermore, the peak stress, peak strain and elastic modulus of coal samples inverted “M”.