Abstract:In order to investigate the effects of freeze-thaw action on physical and mechanical properties and internal fracture damage of sandstone, freeze-thaw cycle tests were carried out on sandstone at different temperature range, and acoustic emission tests were carried out on freeze-thaw damaged rocks under uniaxial loading, so as to study the influence of freeze-thaw temperature range on physical and mechanical parameters and acoustic emission characteristics of rock. The results show that the temperature range increases with the freeze-thaw cycle, the mass loss rate and the change rate of p-wave velocity on the whole show a trend of first steep and then slowly rising, declining peak intensity and peak strain of the sandstone gradually increase, the uniaxial compressive strength and elastic modulus decreases, and the same freezing and thawing temperature range of the influence of elastic modulus under uniaxial compressive strength is more significant, and Poisson"s ratio shows a trend of gradual increase. With the increase of freeze-thaw temperature range, the acoustic emission ringing count showed a gradual increasing trend, the cumulative ringing count gradually steepened, the silence period became smaller, the acoustic emission distribution time range gradually decreased, and the peak frequency showed a trend of low frequency development. The research results provide experimental basis for predicting engineering stability of rock mass in cold area.