Experimental Study on the Creep Behavior of Red Sandstone under Low Temperatures

Abstract

In cold regions, the deformation characteristics and long-term mechanical properties of rocks under low-temperature conditions are considerably different from those in other regions. To study the deformation characteristics and long-term mechanical properties of rocks in a low-temperature environment and the effect of different temperatures, we perform a multilevel loadingunloading uniaxial creep test on red sandstone samples and obtain the creep curves at different temperatures (20°C, − 10°C, and − 20°C). e results demonstrate that the total strain at each temperature can be divided into instantaneous and creep strains; the instantaneous strain includes instantaneous elastic and plastic strains, and the creep strain includes viscoelastic and viscoplastic strains. Temperature has a significant effect on the deformation properties of red sandstone. A decrease in temperature reduces the instantaneous and creep deformations of the rocks at all levels of stress. In addition, a decrease in temperature exponentially attenuates the total creep and viscoplastic strains of the rocks. 0°C is a critical point for the reduction of the total creep and viscoplastic strains of the rocks. When the temperature is greater than 0°C, the total creep and viscoplastic strains of the rocks decrease rapidly and linearly with decrease in temperature; however, when the temperature is less than 0°C, the decrease in the total creep and viscoplastic strains of the rocks is slow. e steady-state creep rate of the rock samples decreases with decrease in temperature, whereas the creep duration increases with decrease in temperature, especially in the case of the accelerated creep stage. e accelerated creep durations of the rock samples S4 (20°C) and S7 (-10°C) are 0.07 h and 0.23 h, respectively.

Analysis of Mechanical Properties and Slope Stability of Red Bed Soft Rock: A Case Study in Xinjiang Irrigation Diversion Channel

“…Yu et al [19] carried out a series of uniaxial compressive strength tests and multistage creep tests on red sandstone samples to study the creep characteristics of red sandstone under diferent immersion conditions. In recent decades, based on various slopes, dams, and road projects, a large number of experiments have been carried out to study the rheological phenomena of soft rocks, and many rheological models have been put forward and established, including empirical formula model, unit model, and some new combined models formed by introducing damage mechanics and fracture theory [20][21][22][23]. Terefore, the creep characteristics of sandstone is of great signifcance for reasonably explaining the time-dependent mechanical behavior of slope engineering, and evaluating the long-term stability and safe operation of the project.…”

Mechanical Properties of a Typical Jurassic Shaximiao Sandstone Under Subzero and Deep in situ Temperature Conditions

“…While a temperature decrease increased the uniaxial compressive strength of each rock, the highest rate of increase in the uniaxial compressive strength was observed in the granite. Other researchers (Tang et al, 2010;Pang et al, 2015;Song et al, 2019) have examined the low-temperature mechanical properties of rocks and confirmed that physical and mechanical properties at low temperatures differ notably from those at normal and high temperatures.…”

Triaxial Creep Behavior of Red Sandstone in Freeze-Thaw Environments

“…Based on the data processing method of the multilevel loading and unloading creep tests, the instantaneous strains of the rock at various stress levels comprised the instantaneous elastic strain and instantaneous plastic strain, considering the 8 Geofluids loading history [37,38]. Figure 12 shows the instantaneous elastic and plastic strains versus the number of freeze-thaw cycles at various stress levels under 2 MPa of confining pressure.…”