LAUSR

In western China, red sandstone is widely distributed. This type of rock is susceptible to generate cracks after being disturbed, and thus becomes a communication channel for groundwater, which poses a great hidden danger in Engineering, such as shaft and tunnel construction. To solve this problem, artificial freezing method is applied to underground engineering. This article focuses on the dynamic tensile strength of red sandstone (RS) at negative temperatures. According to the actual freezing temperature in the site, the temperature range was set to − 5, − 10, − 20 °C in the test, and the rock at normal temperature was set as a control group. The results show that the tensile strength of RS at temperatures below zero is significantly greater than the tensile strength of rock at normal temperature, and − 10 °C is a turning point of rock strength. In order to reveal the mechanism of this change, the scanning electron microscopic (SEM) technique was used to observe the rock fragments after the rock rupture. It is found that the rock fracture patterns are closely related to the rock cement property and its environmental temperature.