Experimental investigation on mechanical properties and failure mechanism of rock-like specimens containing an arc-shaped ice-filled flaw under uniaxial compression

Abstract

The study of rock mass properties under low-temperature conditions is an important basis to ensure the stability of engineering in alpine regions and the safety of engineering construction using low-temperature technology. In order to investigate mechanical properties and failure mechanism of water-saturated fractured rocks at low temperature, indoor tests of rock-like specimens with an arc-shaped ice-filled flaw (Type-I) under uniaxial compression were performed in this paper, and the results were compared with those of flawed specimens Type-II (at 25 ℃ and without filled ice in the flaw). The results indicated that low temperature, flaw morphology and the presence of ice-filled flaw have significant effects on the mechanical properties. The overall peak stresses of Type-I specimens were larger than those of Type-II specimens, and the plasticity of the former one was significantly higher compared with that of the latter one. Meanwhile, the existence of filled ice resulted in significant differences in the failure characteristics between two types of specimens. The failure forms of Type-I specimens were dominated by tensile-splitting failure, while the failure forms of Type-II exhibited a tendency of varying with the flaw morphology. Combined with the macroscopic test phenomena, a water migration mechanism of water-saturated Type-I specimens was proposed, and the failure mechanism with the effect of frost heaving force under uniaxial compression was further analyzed in this paper.