A Constitutive Model of Opened Rock Joints in the Field
Mechanical properties of rock joints govern the strength and deformational behaviour of a rock mass. The responses of a rock joint to shear and normal loadings highly depend on its surface properties, block size and matching state. Rock joints can become mismatched or opened due to underground excav...
Main Author: | |
---|---|
Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
Published: |
UNSW, Sydney
2016
|
Subjects: | |
Online Access: | http://hdl.handle.net/1959.4/57069 https://unsworks.unsw.edu.au/bitstreams/805bdcce-3525-495a-b71e-0190c379a17a/download https://doi.org/10.26190/unsworks/19307 |
id |
ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/57069 |
---|---|
record_format |
openpolar |
spelling |
ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/57069 2023-05-15T17:08:23+02:00 A Constitutive Model of Opened Rock Joints in the Field Li, Yingchun 2016 application/pdf http://hdl.handle.net/1959.4/57069 https://unsworks.unsw.edu.au/bitstreams/805bdcce-3525-495a-b71e-0190c379a17a/download https://doi.org/10.26190/unsworks/19307 EN eng UNSW, Sydney http://hdl.handle.net/1959.4/57069 https://unsworks.unsw.edu.au/bitstreams/805bdcce-3525-495a-b71e-0190c379a17a/download https://doi.org/10.26190/unsworks/19307 open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read CC-BY-NC-ND Constitutive model Rock joints Opening effect Field scale doctoral thesis http://purl.org/coar/resource_type/c_db06 2016 ftunswworks https://doi.org/10.26190/unsworks/19307 2022-08-09T07:42:24Z Mechanical properties of rock joints govern the strength and deformational behaviour of a rock mass. The responses of a rock joint to shear and normal loadings highly depend on its surface properties, block size and matching state. Rock joints can become mismatched or opened due to underground excavation, earthquake vibration and nearby blasting. Previous studies indicate that the opening along joint walls significantly decreases the normal and shear stiffness of a joint, which undermines the stability of rock masses. Nevertheless, the opening effect has not been well considered before in developing constitutive models for the rock joint behaviour. The primary objective of this dissertation is to provide a comprehensive understanding of the mechanical behaviour of field-scale opened joints. A new constitutive model for rock joints with various degrees of opening under both normal and shear loadings is presented. The normal deformability is represented by a semi-empirical non-linear relationship that accounts for the stiffness reduction due to joint opening. A formulation of a joint shear model is developed based on the wear fundamentals. Roughness degradation depends on the relative normal stress and the geometry of the asperity involved in shear. Numerical investigation using UDEC with Voronoi tessellation quantifies how much these parameters affect the dilation behaviour during shear. Experimental curves from both triangular and JRC-shaped joint replicas agree well with the analytical predictions. Scale dependence of the joint roughness is investigated by postulating that a natural joint profile is a self-affine fractal. The proposed scaling laws show that both slopes of waviness and unevenness become gentler with increased sampling length, which has been validated by morphological examinations of several 400 mm long rock joints. The proposed constitutive law has been incorporated into UDEC via the built-in language, FISH. The deformation of three rock structures is assessed by numerical simulations in which ... Doctoral or Postdoctoral Thesis Long Rock UNSW Sydney (The University of New South Wales): UNSWorks Long Rock ENVELOPE(-61.198,-61.198,-62.689,-62.689) |
institution |
Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
English |
topic |
Constitutive model Rock joints Opening effect Field scale |
spellingShingle |
Constitutive model Rock joints Opening effect Field scale Li, Yingchun A Constitutive Model of Opened Rock Joints in the Field |
topic_facet |
Constitutive model Rock joints Opening effect Field scale |
description |
Mechanical properties of rock joints govern the strength and deformational behaviour of a rock mass. The responses of a rock joint to shear and normal loadings highly depend on its surface properties, block size and matching state. Rock joints can become mismatched or opened due to underground excavation, earthquake vibration and nearby blasting. Previous studies indicate that the opening along joint walls significantly decreases the normal and shear stiffness of a joint, which undermines the stability of rock masses. Nevertheless, the opening effect has not been well considered before in developing constitutive models for the rock joint behaviour. The primary objective of this dissertation is to provide a comprehensive understanding of the mechanical behaviour of field-scale opened joints. A new constitutive model for rock joints with various degrees of opening under both normal and shear loadings is presented. The normal deformability is represented by a semi-empirical non-linear relationship that accounts for the stiffness reduction due to joint opening. A formulation of a joint shear model is developed based on the wear fundamentals. Roughness degradation depends on the relative normal stress and the geometry of the asperity involved in shear. Numerical investigation using UDEC with Voronoi tessellation quantifies how much these parameters affect the dilation behaviour during shear. Experimental curves from both triangular and JRC-shaped joint replicas agree well with the analytical predictions. Scale dependence of the joint roughness is investigated by postulating that a natural joint profile is a self-affine fractal. The proposed scaling laws show that both slopes of waviness and unevenness become gentler with increased sampling length, which has been validated by morphological examinations of several 400 mm long rock joints. The proposed constitutive law has been incorporated into UDEC via the built-in language, FISH. The deformation of three rock structures is assessed by numerical simulations in which ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Li, Yingchun |
author_facet |
Li, Yingchun |
author_sort |
Li, Yingchun |
title |
A Constitutive Model of Opened Rock Joints in the Field |
title_short |
A Constitutive Model of Opened Rock Joints in the Field |
title_full |
A Constitutive Model of Opened Rock Joints in the Field |
title_fullStr |
A Constitutive Model of Opened Rock Joints in the Field |
title_full_unstemmed |
A Constitutive Model of Opened Rock Joints in the Field |
title_sort |
constitutive model of opened rock joints in the field |
publisher |
UNSW, Sydney |
publishDate |
2016 |
url |
http://hdl.handle.net/1959.4/57069 https://unsworks.unsw.edu.au/bitstreams/805bdcce-3525-495a-b71e-0190c379a17a/download https://doi.org/10.26190/unsworks/19307 |
long_lat |
ENVELOPE(-61.198,-61.198,-62.689,-62.689) |
geographic |
Long Rock |
geographic_facet |
Long Rock |
genre |
Long Rock |
genre_facet |
Long Rock |
op_relation |
http://hdl.handle.net/1959.4/57069 https://unsworks.unsw.edu.au/bitstreams/805bdcce-3525-495a-b71e-0190c379a17a/download https://doi.org/10.26190/unsworks/19307 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.26190/unsworks/19307 |
_version_ |
1766064122532724736 |