Experimental study on coal samples creep in different water content states

By the immersion device of maintaining the structural integrity, X-ray diffractometer, and electro-hydraulic servo loading coal-rock triaxial creep seepage experimental platform, the water saturation curve, the change of microscopic component and creep characteristics under different water content states of the coal sample in Shangwan Coal Mine were obtained.The results show that the relationship between moisture content of the coal sample and the immersion time is satisfying the negative exponential function, and the moisture content change can be divided into three stages, including accelerated growth, decelerated growth and stabilizing.In the primary saturation process, with the water content increases, the quartz content of the coal sample remains almost unchanged, while the content of clay minerals such as kaolinite decreases greatly during this process.During the wetting-drying cycle, the attenuation of the quartz content of the coal sample is proportional to the number of cycles.With the moisture content and the number of wetting-drying cycles increase, the steady-state creep and accelerated creep axial load of the coal sample decreases.