关键词: 饱水花岗岩, 低温效应, 霍普金森压杆(SHPB), 动力学特性, 损伤

Abstract: In this paper, the variation rules of kinetic parameters, dynamic mechanical properties and failure form of saturated granite under low temperature from 25 ℃ to – 40 ℃ are investigated by means of split Hopkinson pressure bar(SHPB) dynamic impact experiment system. Experimental results show that, under high strain rate condition, the peak stress of saturated granite changes like a "乁" glyph with decreasing temperature. The peak strain decreases first, then increases, and the inflection point temperature is –10 ℃. The failure mode of specimen is significantly affected by temperature. Under the impact of high strain rate, the damage variable which is represented by energy dissipation can accurately reflect the macroscopic fracture characteristics of saturated granite in different low temperature conditions. The peak strain and damage variable change with temperature shows that when low temperature is within a certain range, the strength of the frozen granite is not only affected by the degradation of ice, instead, the strength of the saturated granite increases with the low temperature. The research results possess important reference value for the engineering planning, design and construction of similar rock mass blasting excavation in alpine region.

Key words: saturated granite, low temperature effects, split Hopkinson pressure bar(SHPB), dynamic characteristic, damage