In vivo CT X-ray observations of porosity evolution during triaxial deformation of a calcarenite

Raynaud, Suzanne; Vasseur, G.; Soliva, Roger

doi:10.1016/j.ijrmms.2012.07.020

Cited by 13 publications

(5 citation statements)

References 19 publications

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“…In 2011, Cnudde et al [14] investigated the damage features generated during the sandstone compression with CT. In 2012, Raynaud et al [15] observed the evolution of internal porosity during limestone triaxial deformation with CT. In 2013, Sufian et al [16] used CT to identify the changes and the energy distribution in pores before and after damage was incurred in the Gosford sandstone bore.…”

Section: Methodsmentioning

confidence: 99%

Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

Sun

Hou

et al. 2016

Minerals

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Abstract:The integrated disposal of surface subsidence pits and surface solid waste can be realized by backfilling a surface subsidence area with a paste made from the solid wastes of mines, such as tailings and waste rock. The microstructures of these wastes determine the macroscopic properties of a paste backfill. This paper presents an experimental study on the internal structure evolution of pasty fluid mixed with different waste rock concentrations (10%, 30%, and 50%) and cement dosages (1% and 2%) under damage. To this end, a real-time computed tomography (CT) scan is conducted using medical CT and a small loading device. Results show that UCS (uniaxial compressive strength) increases when the amount of cement increases. Given a constant amount of cement, UCS increases first and then decreases as waste rock content increases. UCS is maximized at 551 kPa when the waste rock content is 30%. The paste body is a typical medium used to investigate initial damage, which mainly consists of microholes, pores, and microcracks. The initial damages also exhibit a high degree of random inhomogeneity. After loading, cracks are initiated and expand gradually from the original damage location until the overall damages are generated. The mesostructure evolution model of the paste body is divided into six categories, and this mesostructure is reasonable when the waste rock content is 30%.

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Section: Methodsmentioning

confidence: 99%

Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

Sun

Hou

et al. 2016

Minerals

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“…This was achieved by scanning samples at different loading levels prior to failure in order to link the pore structure evolution to the macroscopic energy dissipation. In situ µCT observations of porosity evolutions under triaxial tests were also investigated for calcarenite in [13]. The relationship between specific surface and porosity in ten different types of sandstone was scrutinized in [14] by µCT in order to build modified Carman-Kozeny equations for sandstones; and real time (in situ) µCT triaxial experiments were performed in sandstone to assess the effect of chemical corrosion in [15].…”

Section: Contextmentioning

confidence: 99%

Comparison of advanced discretization techniques for image-based modelling of heterogeneous porous rocks

et al. 2019

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This contribution presents an assessment of computational techniques enabling automated simulations of complex porous rocks microstructures based on 3D imaging techniques. A subset of a CT-scanned sandstone sample is used to compare the results obtained by two advanced discretization frameworks. Raw scan results are processed by a level set-based segmentation technique to produce smooth geometries prone to finite element discretizations. A recently developed technique is outlined for conforming mesh generation for complex porous geometries described implicitly by functions. This allows generating high quality tetrahedral meshes with selective refinement. Next to this, a technique that uses a kinematic enrichment by incompatible modes to represent the heterogeneous geometry is explained. Both techniques use the same implicit geometry as main input for the simulations. Mechanical simulations are conducted on a subset of a scanned sample of a sandstone under triaxial loading conditions for isotropic compressive loading and for loading conditions involving a stress deviator. The results are compared and discussed based on local stress distributions and on a Mohr-Coulomb criterion with tensile cut-off. The results show that both discretization strategies yield complementary tools and allow envisioning automated simulations based on raw CT scan data for porous rocks exhibiting complex pore space morphologies.

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“…However, it is still very difficult for real-time monitoring of laboratory experiments designed to quantitatively analyse the chemical corrosion process of rock while subjected to loading. To have a better understanding of crack initiation, propagation and coalescence processes during external rock compression, indirect techniques, such as acoustic emission (AE) [17][18][19], computerised tomography (CT) scan [20][21][22], microscopic observation (petrographical thin section, SEM/ESEM) and highspeed camera are sometimes used [23].…”

Section: Introductionmentioning

confidence: 99%

A parallel-bonded chemical corrosion model for discrete element modelling of chemically corroded limestone

Eshiet²,

Sheng

et al. 2018

Engineering Fracture Mechanics

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The mechanical behaviours of rock mass are influenced by the presence of cracks at the microscopic and macroscopic levels. When coupled with corrosion by chemical ions in ground water, these cracks can cause instabilities and fragmentation near the excavated surface of underground structures, such as shield tunnels, etc. This paper presents the development of a parallel-bonded chemical corrosion (PCC) model for modelling corroded rocks (limestone). The model extends the bonded-particle model (BPM) by adding a chemically induced damage law to the particle bond. The damage law of the PCC model is derived from Nuclear Magnetic Resonance (NMR) and triaxial compression tests. The PCC model is validated with experimental results and is capable of simulating the micro-damage evolution process as well as predicting the macro-mechanical degradation caused by the chemical corrosion. It is then applied to investigate chemical effects on crack initiation, propagation, coalescence, and the mechanical properties of the limestone containing preexisting flaws. Microscale correlations are derived linking the crack propagation process, flaw distribution and the effects of chemical corrosion.

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In vivo CT X-ray observations of porosity evolution during triaxial deformation of a calcarenite

Cited by 13 publications

References 19 publications

Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

Experimental Study on the Microstructure Evolution of Mixed Disposal Paste in Surface Subsidence Areas

Comparison of advanced discretization techniques for image-based modelling of heterogeneous porous rocks

A parallel-bonded chemical corrosion model for discrete element modelling of chemically corroded limestone

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