Uniaxial and triaxial single and multistage creep tests on coal-measure shale rocks

Mishra, Brijes; Verma, Priyesh

doi:10.1016/j.coal.2014.11.005

Cited by 121 publications

(34 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The multistage triaxial test is an information‐rich testing technique that utilizes a minimum number of specimens and can circumvent the consequences of the variability of specimens often observed from one single‐stage triaxial test to the other (Ho & Fredlund, ). Since its first practical application in the early 1950s (Taylor, ), multistage triaxial tests have been successfully used to characterize the strength of various rocks and soils (Goodman, ; Houston et al, ; Kovari & Tisa, ; Mishra & Verma, ; Parker et al, ; Youn & Tonon, ). To our best knowledge, only one study used this technique to study the strength of laboratory synthesized cementing hydrate‐bearing sands (Rees et al, ).…”

Section: Introductionmentioning

confidence: 99%

Multistage Triaxial Tests on Laboratory‐Formed Methane Hydrate‐Bearing Sediments

et al. 2018

View full text Add to dashboard Cite

A sound understanding of the geomechanical behavior of hydrate-bearing sediments (HBSs) is essential not only for assessing reservoir and wellbore stability during methane gas production but also for projecting the impact of global warming on the stability of geological settings that contain hydrates. This study experimentally investigated the geomechanical responses of laboratory-formed methane-HBS to triaxial shearing under drained conditions. The hydrate pore habit formed in the sediments is noncontact-cementing, which is different from contact-cementing or grain-coating hydrate pore habits formed when the excessive gas method is used. The multistage triaxial test method, which shears a single specimen under different confinements, was employed to examine its applicability in measuring geomechanical properties of the HBS. Conventional single-stage triaxial tests were also performed to serve as baselines. The results show that both the strength and stiffness of HBS increase with increased hydrate saturation and confining stress. Shear dilatancy increases with increased hydrate saturation and decreased confining stress. The peak strength and peak/postpeak shear dilation measured using the multistage tests are comparable to those using the single-stage tests. However, the stiffness measured in later stress stages in the multistage tests was enhanced by the stress-strain history of earlier stages. Therefore, the multistage test offers an efficient way of measuring the strength and volumetric response of the HBS with a much smaller number of specimens than the single-stage test. This benefits the geomechanical characterization of the HBS, as obtaining the pressure cores is extremely costly and preparing lab samples is usually sophisticated and time consuming. Key Points: • Multistage triaxial tests are conducted on noncontact-cementing, hydrate-bearing sediments under drained conditions • The strength, dilatancy, and stiffness of the hydrate-bearing sediments are measured • The multistage test can be a viable and efficient method to measure the strength and dilatancy of the hydrate-bearing sediments

show abstract

Section: Introductionmentioning

confidence: 99%

Multistage Triaxial Tests on Laboratory‐Formed Methane Hydrate‐Bearing Sediments

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Many laboratory and field tests have confirmed that rock with high strength and integrity exhibits lower rheological properties [14][15][16][17][18]. In accordance with this, the grouting technique as a reinforcement method was applied to improve the physical and mechanical properties of the rock mass.…”

Section: Introductionmentioning

confidence: 88%

Stability Control for the Rheological Roadway by a Novel High-Efficiency Jet Grouting Technique in Deep Underground Coal Mines

Sun

Zhang

et al. 2019

Sustainability

View full text Add to dashboard Cite

In maintaining the efficiency of coal mining, the stability of roadway plays a significant role, as it is closely related to the production of coal and the safety of personnel. In deep underground coal mines, the rheological deformation of roadway normally occurs, which affects its service life. To address this problem, in this paper, a novel high-efficiency Jet Grouting (JG) technique was presented, and its control effect on roadway stability was investigated. A creep test of a coal specimen in a laboratory scale was performed, and its creep behavior was revealed. The rheology of the coal mass surrounding the roadway was further analyzed according to the field-monitoring results of roadway deformation. A time-dependent numerical model with a Burger-creep visco-plastic model (CVISC) was established and validated by comparing the calculated displacement with in-situ measurement. The JG technique was tested in the field, and its applicability and practicability were confirmed. According to the validated model and field test results of JG, a numerical model with CVISC by JG support was established to analyze the effect of JG on the roadway. The results showed that the JG support can effectively reduce roadway deformation, optimize stress conditions, and reduce the extent of the plastic zone around the roadway. The rheological properties of the soft coal roadway were constrained and long-term stability was ensured. This pioneering work can guide the application of JG for the stability control of roadways and promote the sustainability of coal mining efficiently.

show abstract

“…In deep underground engineering, the creep deformations of rocks become more common due to the high stress (He et al, 2005). The time-dependent deformations of rocks negatively affect the mining safety (Li et al, 2017;Mishra and Verrna, 2015;Sainoki and Mitri, 2017;Zhou et al, 2019), backfill mining(Z. Guo et al, 2019;Q.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation on the nanoindentation viscoelastic constitutive model of quartz and kaolinite in mudstone

Sun

Li²,

Elgharib

et al. 2020

Preprint

View full text Add to dashboard Cite

The creep behaviors in deep underground engineering structures, especially in soft rocks, have a remarkable impact on the long-term stability of the excavations, which finally leads to the high risk and failure of it. Accordingly, it is essential to recognize the time-dependent deformation through the investigation of this phenomenon. In this study, the creep behaviors of soft rocks have been widely examined to help understand the underlying mechanism of the extended time-dependent deformation. Due to the limited results about the time-dependent properties of the constituents of the rock that reveal their heterogeneity, the targeting nanoindentation technique (TNIT), was adopted to investigate the viscoelastic characteristics of kaolinite and quartz in a two-constituent mudstone sample. The TNIT consists of identifications of mineralogical ingredients in mudstone with nanoindentation experiments on each identified constituent. After conducting experiments, the unloading stages of the typical indentation curves were analyzed to calculate the hardness and elastic modulus of both elements in mudstone. Additionally, the 180 s load-holding stages with the peak load of 50 mN were transformed into the typical creep strain-time curves for fitting analysis by using the Kelvin model, the standard viscoelastic model, and the extended viscoelastic model. Fitting results show that the standard viscoelastic model not only can perfectly express the nanoindentation creep behaviors of both kaolinite and quartz but also can produce suitable constants used to measure their creep parameters. Furthermore, the creep parameters of kaolinite are much smaller than that of quartz, which causes the considerable time-dependent deformation of the soft mudstone. Eventually, the standard viscoelastic model was also verified on the quartz in a sandstone sample.

show abstract

Uniaxial and triaxial single and multistage creep tests on coal-measure shale rocks

Cited by 121 publications

References 6 publications

Multistage Triaxial Tests on Laboratory‐Formed Methane Hydrate‐Bearing Sediments

Multistage Triaxial Tests on Laboratory‐Formed Methane Hydrate‐Bearing Sediments

Stability Control for the Rheological Roadway by a Novel High-Efficiency Jet Grouting Technique in Deep Underground Coal Mines

Experimental investigation on the nanoindentation viscoelastic constitutive model of quartz and kaolinite in mudstone

Contact Info

Product

Resources

About