Influence of water content on coal mechanical properties under triaxial loading
Water content has an important influence on the mechanical properties of coal.To further explore the mechanism of water content under triaxial loading conditions,representative coal samples in Pingdingshan mining area were selected and experimental groups with different water contents were set up.Uniaxial compression tests of coal samples with different water contents and triaxial compression tests of coal samples with different confining pressures were carried out,and comprehensive performance tests of stress-strain relationship and compressive strength of coal samples with different water contents were carried out.The results show that under different confining pressure conditions,the stress-strain curve of water-bearing coal shows the same trend.Under triaxial loading,the stress-strain curve in the axial direction of water-bearing coal body is the same as that under uniaxial loading.In the condition of same water content,the axial strain of the test coal samples with different confining pressures is slightly different at the stress peak.Generally,the larger the confining pressure has,the smaller the axial strain is at the stress peak.During the whole loading process,the axial strain of the test coal sample is always positive,that is,the axial compression deformation of the coal body occurs in the axial direction,and at the same time,the radial expansion deformation of the test coal sample occurs.In uniaxial/triaxial loading conditions,with the increase of water contents,the peak strength typically decreases,and water content and peak strength are connected in a quadratic function.The research result provides a scientific basis for coal resource development and utilization in Pingdingshan mine area.
万方数据
维普
