Numerical simulation of a direct shear test on a rock joint using a bonded-particle model

Park, Jung-Wook; Song, Jae-Joon

doi:10.1016/j.ijrmms.2009.03.007

Cited by 263 publications

(93 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A key issue related to shear dilation for performance assessment of a deep geological repository is whether such significant shear dilation is expected at the moderate normal stress of up to 20 MPa [27]. Barton and Choubey presented an empirical model that predicts the dilation angle under given joint compressive strength (JCS), joint roughness coefficient (JRC), and confining stress [29]. The dilation angle is calculated to be around 51, which can be large enough to cause a significant increase in permeability with a normal stress of 20 MPa, a JRC value of 6-8, and a JCS of 100 MPa.…”

Section: Discussionmentioning

confidence: 99%

“…The dilation angle is calculated to be around 51, which can be large enough to cause a significant increase in permeability with a normal stress of 20 MPa, a JRC value of 6-8, and a JCS of 100 MPa. A numerical study using the discrete element method conducted by Park and Song [30] showed that the empirical equation by Barton and Choubey [29] actually underestimated the dilation angle, and the magnitude of shear dilation is substantial under moderate normal stress of up to 17 MPa. Furthermore, since there was an abrupt change of permeability even with a slight change of stress, a discrete element method is required to capture the elastoplastic behavior of the fracture.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Implications of thermally-induced fracture slip and permeability change on the long-term performance of a deep geological repository

Min

Lee

Stephansson

2013

International Journal of Rock Mechanics and Mining Sciences

View full text Add to dashboard Cite

This paper addresses thermally-induced shear slip, i.e., thermoshearing, and changes in permeability of a deep geological repository in large scale. We present a systematic examination of the thermal stress expected to be generated in the far-field around the repository. The main mechanisms for generation of thermal stress that can affect permeability are; comparatively high horizontal compressive thermal stress at the repository level, vertical tensile thermal stress right above the repository and horizontal tensile stress near the surface, and shear stress at the corners of the repository. Based on thermal loading history, probabilistic shear slip analysis was conducted to investigate the possibility of thermoshearing. Higher probability of shear slip is expected with higher differential thermal stress, and this was highly affected by fracture orientations. Stress paths obtained from the thermo-mechanical analysis were used as stress boundary conditions for Discrete Fracture Network-Discrete Element Method (DFN-DEM) Analysis to investigate the effect of stress changes on permeability. In four out of the six DFN models, normal deformation dominated the closure and opening of fractures, with shear dilation being the dominant factor in the other two models. Changes in permeability caused by shear dilation were not reversed after the repository cooled, which is explained by the irreversible fracture shear deformation after shear slip. This study was conducted on data from the Forsmark site in Sweden, and this analysis has implications for sites that have comparatively large horizontal in-situ stresses and relatively few fractures.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Implications of thermally-induced fracture slip and permeability change on the long-term performance of a deep geological repository

Min

Lee

Stephansson

2013

International Journal of Rock Mechanics and Mining Sciences

View full text Add to dashboard Cite

show abstract

“…PFC characterizes the joint element by reducing the particle strength [20]. To analyse the influence of joint angle, number, and spacing on the strength and AE characteristics of rock mass, three groups of jointed rock mass were established based on the abovementioned parameters.…”

Section: Uniaxial Compression Model Of Jointed Rock Massmentioning

confidence: 99%

Simulation analysis on the strength and acoustic emission characteristics of jointed rock mass

Wen

Wang

et al. 2016

Teh. vjesn.

View full text Add to dashboard Cite

Original scientific paper To analyse the influence of joint angle, number and spacing on the strength and acoustic emission (AE) characteristics of rock mass, the uniaxial compression model of rock specimens was established using the micro particle flow PFC2D software platform. The intact rock parameters were determined via trial and error, joints with different angles, numbers and spacing were prefabricated in the model, and a compression test was performed using the displacement control method. The compressive strength, elastic modulus, and AE time characteristics of the rock specimens increased, decreased, and then increased again along with increasing joint angle. The AE characteristics at joint angles 0°, 15°, 30° and 90° were consistent with those of the intact rock specimens, while the 45° ÷ 75° joint angle showed relatively discrete AE characteristics. A larger number of joints corresponded to lower uniaxial compressive strength, elastic modulus, and AE intensity. However, the time and strain range of the obvious AE were not significant. The compressive strength and AE signal intensity of the rock specimens increased along with joint spacing, but the AE triggering time did not show obvious changes. Uniaxial compression tests were performed via numerical simulation to avoid the non-homogeneous and discrete effects from the indoor test and to reflect accurately the influence of joint angle, number, and spacing on the strength and AE characteristics of rock mass. The results can help in generating reliable criteria for predicting the instability of engineering rock mass. Keywords: acoustic emission; intensity; joint angle; joint number; joint spacing; jointed rock mass Simulacijska analiza čvrstoće i karakteristika akustičke emisije raspucale stijenske maseIzvorni znanstveni članak Kako bi se analizirao utjecaj kuta, broja i raspona raspukline na čvrstoću i karakteristike akustičke emisije (AE) stijenske mase, postavljen je jednoosni kompresijski model uzoraka stijene uz primjenu PFC2D računalne platforme za protok mikro čestica. Metodom pokusa i pogreške određeni su originalni parametri stijene, u modelu su unaprijed izvedene raspukline različitih kutova, brojeva i razmaka, te je provedeno ispitivanje na pritisak metodom praćenja pomaka. Tlačna čvrstoća, modul elastičnosti i vremenske karakteristike AE uzoraka stijene su se povećali, smanjili te ponovo povećali kako se povećavao kut raspukline. Karakteristike AE kod raspukline kutova 0°, 15°, 30° i 90° bile su u skladu s onima kod originalnih uzoraka stijene, dok su se kod kuta raspukline od 45° ÷ 75° pojavile relativno diskretne karakteristike AE. Veći broj raspuklina podudarao se u nižoj jednoosnoj tlačnoj čvrstoći, modulu elastičnosti i intenzitetu AE. Međutim, nije došlo do značajne promjene u vremenu i veličini deformacije. Tlačna čvrstoća i intenzitet signala AE uzoraka stijene porasli su s povećanjem razmaka raspukline, ali se to nije pokazalo na pokazivaču vremena AE. Jednoosna ispitivanja kompresije provedena su numeričkom simulacijom kako bi se i...

show abstract

“…Discrete element method (DEM) is proved to be a very effective method in modelling rock-like materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The discontinuous nature of DEM makes DEM very suitable for dealing with the initiation and propagation of micro cracks in rock-like materials.…”

Section: Introductionmentioning

confidence: 99%

“…The discontinuous nature of DEM makes DEM very suitable for dealing with the initiation and propagation of micro cracks in rock-like materials. Within DEMs, the bonded-particle model (BPM) is widely used to simulate the deformation and fracture of rock-like materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Since the BPM was first proposed [1], it has been rapidly developed.…”

Section: Introductionmentioning

confidence: 99%

Bonded-Particle Model with Nonlinear Elastic Tensile Stiffness for Rock-Like Materials

Ouyang

Chen

2017

Applied Sciences

View full text Add to dashboard Cite

Abstract:The bonded-particle model (BPM) is a very efficient numerical method in dealing with initiation and propagation of cracks in rocks and can model the fracture processes and most of macro parameters of rocks well. However, typical discrete element method (DEM) underestimates the ratio of the uniaxial compressive strength to the tensile strength (UCS/TS). In this paper, a new DEM method with a nonlinear elastic tensile model embedded in BPM is proposed, which is named as nonlinear elastic tensile bonded particle model (NET-BPM). The relationships between micro parameters in NET-BPM and macro parameters of specimens are investigated by simulating uniaxial compression tests and direct tension tests. The results show that both the shape coefficient of the nonlinear elastic model and the bond width coefficient are important in predicting the value of UCS/TS, whose value ranging from 5 to 45 was obtained in our simulations. It is shown that the NET-BPM model is able to reproduce the nonlinear behavior of hard rocks such as Lac du Bonnet (LDB) granite and the quartzite under tension and the ratio of compressive Young's modulus to tensile Young's modulus higher than 1.0. Furthermore, the stress-strain curves in the simulations of LDB granite and the quartzite with NET-BPM model are in good agreement with the experimental results. NET-BPM is proved to be a very suitable method for modelling the deformation and fracture of rock-like materials.

show abstract

Numerical simulation of a direct shear test on a rock joint using a bonded-particle model

Cited by 263 publications

References 22 publications

Implications of thermally-induced fracture slip and permeability change on the long-term performance of a deep geological repository

Implications of thermally-induced fracture slip and permeability change on the long-term performance of a deep geological repository

Simulation analysis on the strength and acoustic emission characteristics of jointed rock mass

Bonded-Particle Model with Nonlinear Elastic Tensile Stiffness for Rock-Like Materials

Contact Info

Product

Resources

About