TY - JOUR

T1 - Challenges of Tunnelling in Volcanic Rock Masses

AU - Villeneuve, Marlene

PY - 2021/11/30

Y1 - 2021/11/30

N2 - Volcanic rock masses exhibit temporal and spatialvariability, even at the scale and duration of engineeringprojects. Volcanic processes are dynamic, resultingin rock masses ranging from high-porosity, clay-rich, fractured,and soil-like to low-porosity, high-strength, brittle,and massive. Based on a number of studies in a varietyof geological settings, such as active and fossil geothermalsystems, on the surface of active volcanoes and up to3000mbelow the surface, the work presented in this articleshows the relationship between geological characteristicsand mechanical parameters of volcanic rocks. These arethen linked to the resultant challenges to tunnelling associatedwith themechanical behaviour of volcanic rocks androck masses, ranging from ductile failure such as squeezingand swelling to dynamic failure such as spalling androckburst.This article highlights some of the key parameters thatshould be incorporated in site and laboratory investigationsto build representative ground models in volcanicrocks and rock masses. Rock mass characterisation needsto address the highly variable and anisotropic nature of volcanicrocks, ranging from millimetre to decametre scale.Ground models must include not only the mechanicalproperties, such as strength and stiffness, of typical labinvestigations, but also petrophysical properties, such asporosity, and geological conditions, such as alteration.Geomechanical characterisation of these rock masses requiresan understanding of geological processes to selectappropriate field, lab and design tools. In volcanic rocks,perhaps more than any other rock types, the geology iscritical to characterising and understanding the behaviourin response to tunnelling.

AB - Volcanic rock masses exhibit temporal and spatialvariability, even at the scale and duration of engineeringprojects. Volcanic processes are dynamic, resultingin rock masses ranging from high-porosity, clay-rich, fractured,and soil-like to low-porosity, high-strength, brittle,and massive. Based on a number of studies in a varietyof geological settings, such as active and fossil geothermalsystems, on the surface of active volcanoes and up to3000mbelow the surface, the work presented in this articleshows the relationship between geological characteristicsand mechanical parameters of volcanic rocks. These arethen linked to the resultant challenges to tunnelling associatedwith themechanical behaviour of volcanic rocks androck masses, ranging from ductile failure such as squeezingand swelling to dynamic failure such as spalling androckburst.This article highlights some of the key parameters thatshould be incorporated in site and laboratory investigationsto build representative ground models in volcanicrocks and rock masses. Rock mass characterisation needsto address the highly variable and anisotropic nature of volcanicrocks, ranging from millimetre to decametre scale.Ground models must include not only the mechanicalproperties, such as strength and stiffness, of typical labinvestigations, but also petrophysical properties, such asporosity, and geological conditions, such as alteration.Geomechanical characterisation of these rock masses requiresan understanding of geological processes to selectappropriate field, lab and design tools. In volcanic rocks,perhaps more than any other rock types, the geology iscritical to characterising and understanding the behaviourin response to tunnelling.

KW - Rock mechanics

KW - Characterisation

KW - porosity

KW - Deformation

KW - Lab testing

U2 - https://doi.org/10.1007/s00501-021-01175-2

DO - https://doi.org/10.1007/s00501-021-01175-2

M3 - Article

VL - 166.2021

SP - 612

EP - 617

JO - Berg- und hüttenmännische Monatshefte : BHM

JF - Berg- und hüttenmännische Monatshefte : BHM

SN - 0005-8912

IS - 12

ER -