Study on the Dynamic Splitting Mechanical Properties of Annular Sandstone Specimens with Temperature–Water Coupling in a Coal Mine

Abstract

With the gradual deepening of mine excavation depth, the strong disturbance of deep strata becomes more and more obvious. Rock’s failure under blasting mainly depends on its dynamic tensile strength. The changes in rock’s dynamic properties are obviously affected by temperature and water. In order to study the dynamic tensile properties of annular sandstone specimens under the influence of temperature and water, deep sandstone was drilled, followed by water bath tests at eight temperatures (25~95°C). It can be seen from the analysis of test results that the mass and volume growth rates of the annular and the intact sandstone specimens first increased and then decreased, while the density growth rate first decreased and then increased. The mass and volume growth rates of the annular sandstone specimens were smaller, but the density growth rate was larger. Because of the increase in water temperature, the dynamic compressive strength first increased and then decreased. The dynamic tensile strength of the annular sandstone specimen was lower. The average strain rate and peak strain also showed a quadratic function relationship of first decreasing and then increasing with the increase in water temperature. The average strain rate of the annular sandstone specimen was smaller, but the peak value changed greatly. The Brazilian disc validity condition is applicable to two failure conditions of sandstone specimens. Through XRD and SEM analysis, we found that the changes in the dynamic properties of sandstone specimens were not due to their own material composition, but to the damage to their structure caused by the temperature–water coupling effect.

Special Issue on Experimental Investigation and Numerical Modeling of Rock Brittle Failure Behavior under High Stress Conditions

“…It first decreased, and then increased with the increase in the ice-filled crack angle. The dynamic tensile properties of annular sandstone specimens under the influence of temperature and water were studied by Ping et al [6]. The variation in the mass, volume growth rates, density growth rate, dynamic compressive strength, average strain rate, and peak strain with water temperature was evaluated.…”

Influence of dynamic load and water on energy accumulation and dissipation in sandstone

“…Furthermore, a functional relationship was established between water temperature and the peak strain observed. The utilization of XRD and SEM tests provided conclusive evidence demonstrating that alterations in water temperature have the ability to modify the internal structure of sandstone, consequently affecting its dynamic properties 38 . Zhang tested various impact speeds on sandstone, and the findings suggested that the impact velocity had a major influence on the rock's mechanical characteristics, in addition to proposing some new mechanical coefficients 39 .…”

Experimental Study on Dynamic and Static Combined Dynamics of Temperature–Water-Coupled Sandstone and Energy Consumption Analysis

“…Therefore, to prevent the occurrence of disasters and ensure the safe operation of underground space projects, it is necessary to carry out experimental research on the dynamic mechanics of temperature-water-coupled sandstone under dynamic and static combined loading. The sandstone used in this paper was obtained from the roadway of the Pan Er Coal Mine in Huainan City, Anhui Province, China, based on previous kinetic tests of local sandstone by Ping et al It was found that the kinetic properties of sandstone change at 45 • C and that the strength of sandstone is weakest at 45 • C [31]. The dynamic and static combined SHPB device was used to carry out impact compression tests on sandstone with temperature-water-coupled effects at 45 • C under eight types of axial pressure (0.5~4.0 MPa) loading and without axial pressure loading.…”