TY - JOUR

T1 - Calculating the cohesion and internal friction angle of volcanic rocks and rock masses

AU - Villeneuve, Marlene

AU - Heap, M. J.

N1 - Publisher Copyright: © 2021 Volcanica. All rights reserved.

PY - 2021/11/23

Y1 - 2021/11/23

N2 - Rock failure criteria are key input parameters for models designed to better understand the stability of volcanic rock masses. Cohesion and friction angle are the two defining material variables for the Mohr-Coulomb failure criterion. Although these can be determined from laboratory deformation experiments, they are rarely reported. Tabulated data for volcanic rocks, calculated using published triaxial results, show that cohesion and friction angle decrease with increasing porosity. If porosity is known, these empirical fits can provide laboratory-scale cohesion and friction angle estimations. We present a method to upscale these parameters using the generalised Hoek-Brown failure criterion, discuss the considerations and assumptions associated with the upscaling, and provide recommendations for potential end-users. A spreadsheet is provided so that modellers can (1) estimate cohesion and friction angle and (2) upscale these values for use in large-scale volcano modelling. Better constrained input parameters will increase the accuracy of large-scale volcano stability models.

AB - Rock failure criteria are key input parameters for models designed to better understand the stability of volcanic rock masses. Cohesion and friction angle are the two defining material variables for the Mohr-Coulomb failure criterion. Although these can be determined from laboratory deformation experiments, they are rarely reported. Tabulated data for volcanic rocks, calculated using published triaxial results, show that cohesion and friction angle decrease with increasing porosity. If porosity is known, these empirical fits can provide laboratory-scale cohesion and friction angle estimations. We present a method to upscale these parameters using the generalised Hoek-Brown failure criterion, discuss the considerations and assumptions associated with the upscaling, and provide recommendations for potential end-users. A spreadsheet is provided so that modellers can (1) estimate cohesion and friction angle and (2) upscale these values for use in large-scale volcano modelling. Better constrained input parameters will increase the accuracy of large-scale volcano stability models.

KW - Mohr-Coulomb

KW - Hoek-Brown

KW - Strength Failure Criteria

KW - Porosity

KW - Failure Criteria

KW - Strength

UR - http://www.scopus.com/inward/record.url?scp=85120752287&partnerID=8YFLogxK

U2 - 10.30909/vol.04.02.279293

DO - 10.30909/vol.04.02.279293

M3 - Article

VL - 4

SP - 279

EP - 293

JO - Volcanica

JF - Volcanica

SN - 2610-3540

IS - 2

ER -