Abstract
Faulting of rocks is a dominant earth process that governs small-scale fracturing, formation of tectonic plate boundaries, and earthquakes occurrence. Since the 18th century, the mechanics of rock faulting was commonly analyzed with the Coulomb criterion that offers empirical, useful tools for scientific and engineering applications. Here we revisit the processes of rock faulting by an alternative approach that incorporates elastic energy, strain-state, and three-dimensional deformation; these mechanical fundamentals are missing in Coulomb criterion. We propose that a stressed rock-body fails as two conditions are met: (A) The elastic energy generated by the loading system equals or exceeds a critical energy intensity that is required for the faulting process; (B) To maintain physical continuity, the internal strain of the stressed rock-body due to slip and dilation along the developing faults equals the strain-state created by the loading system. Our simulations reveal that meeting these energy and strain conditions requires an orthorhombic, polymodal fault geometry that is comparable to natural and experimental fault systems. The application of our formulation to hundreds of rock-mechanics experiments provides a new, comprehensive benchmark for rock-faulting.
Original language | English |
---|---|
Article number | 117818 |
Journal | Earth and Planetary Science Letters |
Volume | 597 |
DOIs | |
State | Published - 1 Nov 2022 |
Bibliographical note
Publisher Copyright:© 2022 Elsevier B.V.
Keywords
- energy-based
- experimental rock-mechanics
- faulting-theory
- rock-engineering
- simulation of fault patterns
- three-dimensional strain