Influence of High-Temperature Treatment on Strength and Failure Behaviors of a Quartz-Rich Sandstone under True Triaxial Condition

In this paper, the effect of high temperature on the mechanical properties of quartz-rich sandstone was studied by true triaxial pressure experiment. The density, P-wave velocity, elastic modulus, peak stress, peak strain, and failure mode of quartz-rich sandstone before and after heat treatment were analyzed and compared. It was found that the color of quartz-rich sandstone changes greatly when heated to 500 degrees C. In detail, the brittleness of quartz-rich sandstone gradually decreased and the ductility increased at high temperature. Although the density, P-wave velocity, and elastic modulus fluctuate, they showed a decreasing trend as a whole. In addition, the peak stress and peak strain showed an overall upward trend with the increase of temperature, and 500 degrees C was the high-temperature failure threshold of quartz-rich sandstone. The failure mode of quartz-rich sandstone at high temperature changes from shear failure to shear-tension combined failure, and the number of cracks increases. Therefore, these research results can provide a certain reference for high-temperature underground operation.

Automated summary

This paper studied the effect of high temperature on the mechanical properties of quartz-rich sandstone through true triaxial pressure experiments. It was found that the properties of the sandstone, including color, brittleness, and ductility, significantly changed when heated to 500 degrees Celsius. The density, P-wave velocity, and elastic modulus showed a decreasing trend, while the peak stress and peak strain exhibited an overall upward trend with the increase in temperature.