Analyzing the role of tensile and hybrid fractures on the max-imum relief topography

TL;DR

This study compares fracture criteria in slope stability analysis, showing that the Griffith criterion with variable traction offers different and potentially more accurate maximum relief estimates than the traditional Mohr-Coulomb law.

Contribution

It introduces the use of the Griffith criterion with variable traction for large-scale relief stability analysis, contrasting it with the traditional Mohr-Coulomb law.

Findings

Griffith criterion predicts lower maximum relief than Mohr-Coulomb law.

Differences in relief estimates are comparable to geological phenomena impacts.

Results validated using Carrara marbles case study.

Abstract

Slope stability description through mechanical laws has important implication for Earth morphology understanding and risk assessment. Previous researches have showed that shear, tensile, and hybrid fractures can be observed experimentally and in the field, but their descriptions by a single equation is still an open debate. Fracture envelope able to describe contemporaneously these three fracture modes differ signif-icantly from the Mohr-Coulomb law. Despite the need to apply such a law at all scales, from the laboratory to the mountain range, the fracture criterion that characterizes all types of fractures is rarely used in geotechnical engineering and geological investiga-tions. In order to analyze the stability thresholds of large-scale relief, the current work examines the effects of considering the Griffith criterion with a variable rock traction instead of the Mohr-Coulomb law using a modelling approach. The difference esti-mated on maximum relief using these two different rupture criterions could be of the same order than the one caused by geological phenomena, such as with or without seismic activity, or from the one caused by the destabilization processes (tilting vs. landslide). When compared to the modified Griffith criterion, the Mohr-Coulomb law tends to overestimate the maximum escarpment height. The results are examined in relation to the Carrara marbles, which serve as a case study for the theoretical frame-work.