Effect of high temperature and confining pressure on the mechanical behavior of granite from Batang fault zone

Abstract

The mechanical behavior of rocks under high temperature and confining pressure contributes to the design and stability analysis of deep-buried tunnels. In this study, a series of triaxial compression tests with high temperature and confining pressure was conducted on granite samples through a self-developed high temperature true triaxial test system. The granite samples were collected from the Batang fault zone located at the eastern of the Qinghai-Tibet Plateau. Based on the actual geological conditions, three temperatures (room temperature/70°C/110°C) and the confining pressure of 30 MPa were used. The stress–strain output, peak stress, and peak strain were summarized, and the relationship between the peak stress and temperature was obtained based on the experimental data. The results of the test show that high temperatures can weaken the mechanical properties of granite. The peak stress of the granite is decreased with the increase in temperature. A linear function can describe the strength behavior of the granite being studies at different temperatures. The experimental data obtained in this study can be used as basic parameters for the construction and stability evaluation of the deep-buried tunnels near the Batang fault zone.