Energy analysis and criteria for structural failure of rocks

TLDR

Energy dissipation and strain‑energy release govern rock deformation and abrupt failure, with strain‑energy release causing catastrophic breakdown. The study proposes criteria linking energy dissipation to rock strength deterioration and energy release to abrupt structural failure. These criteria are derived from quantifying energy dissipation and strain‑energy release in rocks. Using the criteria, critical stresses at failure can be predicted and were applied to analyze the failure conditions of tunnel surrounding rock.

Abstract

The intrinsic relationships between energy dissipation, energy release, strength and abrupt structural failure are key to understanding the evolution of deformational processes in rocks. Theoretical and experimental studies confirm that energy plays an important role in rock deformation and failure. Dissipated energy from external forces produces damage and irreversible deformation within rock and decreases rock strength over time. Structural failure of rocks is caused by an abrupt release of strain energy that manifests as a catastrophic breakdown of the rock under certain conditions. The strain energy released in the rock volume plays a pivotal role in generating this abrupt structural failure in the rocks. In this paper, we propose criteria governing (1) the deterioration of rock strength based on energy dissipation and (2) the abrupt structural failure of rocks based on energy release. The critical stresses at the time of abrupt structural failure under various stress states can be determined by these criteria. As an example, the criteria have been used to analyze the failure conditions of surrounding rock of a circular tunnel.