Coupled thermo-mechanical constitutive damage model for sandstone

Underground rock dynamic disasters are becoming more severe due to the increasing depth of human operations underground. Underground temperature and pressure conditions contribute significantly to these disasters. Therefore, it is important to understand the coupled thermo-mechanical (TM) behaviour of rocks for the long-term safety and maintenance of underground tunnelling and mining. Moreover, investigation of the damage, strength and failure characteristics of rocks under triaxial stress conditions is important to avoid underground rock disasters. In this study, based on Weibull distribution and Lemaitre's strain equivalent principle, a statistical coupled TM constitutive model for sandstone was established under high temperature and pressure conditions. The triaxial test results of sandstone under different temperature and pressure conditions were used to validate the model. The proposed model was in good agreement with the experimental results up to 600 degrees C. The total TM damage was decreased with increasing temperature, while it was increased with increasing confining pressure. The model's parameters can be calculated using conventional laboratory test results. (C) 2022 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The severity of underground rock dynamic disasters is increasing due to the deepening of human operations underground. Understanding the thermo-mechanical behavior of rocks is important for the long-term safety and maintenance of underground tunnels and mining. This study proposed a statistical coupled thermo-mechanical constitutive model for sandstone under high temperature and pressure conditions, and validated the model using triaxial test results. The model showed good agreement with the experimental results up to 600 degrees C.