摘要：To study the effect of cyclic wetting and drying and water temperature in wetting process on energy dissipation characteristics of coalmine sandstone,dynamic compressive tests are carried out by modified SHPB apparatus for coalmine sandstone specimens suffered cyclic wetting and drying treatment.The number of wetting and drying cycle varies from 1 to 20 and water temperature in wetting process changes from 20 ℃ to 98 ℃.Reflected energy,transmitted energy,and total absorbed energy increase with the time of half-sine loading stress wave.Both energy consumption density and dissipated energy density increase with the dynamic strain,while releasable elastic strain energy density first increases then decreases.With the increase of wetting and drying cycles,transmitted energy,total absorbed energy,energy consumption density and peak releasable elastic strain energy density demonstrate a decrease trend,while reflected energy and energy dissipation ratio show an increase trend.Hence,energy dissipation characteristics of coalmine sandstone deteriorate with the number of wetting and drying cycles.After 15 wetting and drying cycles,energy dissipation characteristics of coalmine sandstone degrade in a fluctuating tendency with elevating water temperature in wetting process.Water temperature at 60 ℃ demonstrates a serious deterioration of energy dissipation characteristics.Therefore,a threshold value for the effect of water temperature on cyclic wetting and drying is found to be about 60 ℃.
关键词：Rock dynamics;SHPB;cyclic wetting and drying;energy;energy dissipation ratio
