Evaluating damage during shear tests of rock joints using acoustic emissions

Moradian, Zabihallah; Ballivy, G.; Rivard, Patrice; Gravel, C.; Rousseau, Baptiste

doi:10.1016/j.ijrmms.2010.01.004

Cited by 184 publications

(48 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cracks closure can also induce AE, but this has been shown to be limited compared to the crack shearing process (e.g. Moradian et al, 2010). We also examine the relationship between the signal amplitude and duration, considering that a higher attenuation should correspond to a shorter duration for a given amplitude.…”

Section: Discussionmentioning

confidence: 99%

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall

Amitrano

Gruber

Girard

2012

Earth and Planetary Science Letters

View full text Add to dashboard Cite

Ice formation within rock is known to be an important driver of near-surface frost weathering as well as of rock damage at the depth of several meters, which may play a crucial role for the slow preconditioning of rock fall in steep permafrost areas. This letter reports results from an experiment where acoustic emission monitoring was used to investigate rock damage in a high-alpine rock-wall induced by natural thermal cycling and freezing/thawing. The analysis of the large catalog of events obtained shows (i) robust power-law distributions in the time and energy domains, a footprint of rock micro-fracturing activity induced by stresses arising from thermal variations and associated freezing/ thawing of rock; (ii) an increase in AE activity under sub-zero rock-temperatures, suggesting the importance of freezing-induced stresses. AE activity further increases in locations of the rock-wall that are prone to receiving melt water. These results suggest that the framework of further modeling studies (theoretical and numerical) should include damage, elastic interaction and poro-mechanics in order to describe freezing-related stresses. Keywords: frost-cracking acoustic emission mechanical weathering scaling properties a b s t r a c t Ice formation within rock is known to be an important driver of near-surface frost weathering as well as of rock damage at the depth of several meters, which may play a crucial role for the slow preconditioning of rock fall in steep permafrost areas. This letter reports results from an experiment where acoustic emission monitoring was used to investigate rock damage in a high-alpine rock-wall induced by natural thermal cycling and freezing/thawing. The analysis of the large catalog of events obtained shows (i) robust power-law distributions in the time and energy domains, a footprint of rock micro-fracturing activity induced by stresses arising from thermal variations and associated freezing/ thawing of rock; (ii) an increase in AE activity under sub-zero rock-temperatures, suggesting the importance of freezing-induced stresses. AE activity further increases in locations of the rock-wall that are prone to receiving melt water. These results suggest that the framework of further modeling studies (theoretical and numerical) should include damage, elastic interaction and poro-mechanics in order to describe freezing-related stresses.

show abstract

Section: Discussionmentioning

confidence: 99%

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall

Amitrano

Gruber

Girard

2012

Earth and Planetary Science Letters

View full text Add to dashboard Cite

show abstract

“…The lack of ability to continuously measure the contact area during the test is another problem in using these methods. Methods such as the X-ray computer tomography (Re and Scavia 1999) and acoustic emission (AE) (Moradian et al 2010(Moradian et al , 2012) that measure the contact area indirectly. The main drawback of these methods is that they require special equipment and present only qualitative results.…”

Section: Description Of the New Methods For Joint Surface Characterizamentioning

confidence: 99%

Geometric Effect of Asperities on Shear Mechanism of Rock Joints

et al. 2015

View full text Add to dashboard Cite

Three-dimensional tracking of changes of asperities is one of the most important ways to illustrate shear mechanism of rock joints during testing. In this paper, the changes of the role of asperities during different stages of shearing are described by using a new methodology for the characterization of the asperities. The basis of the proposed method is the examination of the three-dimensional roughness of joint surfaces scanned before and after shear testing. By defining a concept named 'tiny window', the geometric model of the joint surfaces is reconstructed. Tiny windows are expressed as a function of the x and y coordinates, the height (z coordinate), and the angle of a small area of the surface. Constant normal load (CNL) direct shear tests were conducted on replica joints and, by using the proposed method, the distribution and size of contact and damaged areas were identified. Image analysis of the surfaces was used to verify the results of the proposed method. The results indicated that the proposed method is suitable for determining the size and distribution of the contact and damaged areas at any shearing stage. The geometric properties of the tiny windows in the pre-peak, peak, post-peak softening, and residual shearing stages were investigated based on their angle and height. It was found that tiny windows that face the shear direction, especially the steepest ones, have a primary role in shearing. However, due to degradation of asperities at higher normal stresses and shear displacements, some of the tiny windows that do not initially face the shear direction also come in contact. It was also observed that tiny windows with different heights participate in the shearing process, not just the highest ones. Total contact area of the joint surfaces was considered as summation of just-in-contact areas and damaged areas. The results of the proposed method indicated that considering differences between just-in-contact areas and damaged areas provide useful insights into understanding the shear mechanism of rock joints.

show abstract

“…As an effective non-destructive method that has dynamic monitoring coverage, high sensitivity and other superiorities, acoustic emission (AE) is widely used in geotechnical engineering field [2][3]. But there lack a distinguishing method for rock moisture content that can tightly combine moisture content and AE characteristics.…”

Section: Introductionmentioning

confidence: 99%

Rock Moisture Recognition by Combining AE with Musical-staff-inspired Model

Jiang¹,

Zheng²,

Tao³

2017

Proceedings of the 2016 International Conference on Modern Management, Education Technology, and Social Science (MMETSS 2016)

View full text Add to dashboard Cite

Abstract. Mechanical properties of rocks change under hydrous condition, which easily causes instability and failure of rock, and triggers a disaster. Questions about determining the effect of moisture on the acoustic emission characteristics of rocks, and establishing an automatic identification model loom large at present. In this study, a large number of acoustic emission data were collected during the rupture of rocks with different moisture contents, and the data were turned into data that are composed of musical parameters by a musical-staff-inspired model which reflect AE characteristics of water-filled rocks. Through training these data with a curves similarity determination method, the measured rock could be classified into the corresponding moisture group. Results of experiments indicate success of recognition of rock moisture.

show abstract

Evaluating damage during shear tests of rock joints using acoustic emissions

Cited by 184 publications

References 19 publications

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall

Evidence of frost-cracking inferred from acoustic emissions in a high-alpine rock-wall

Geometric Effect of Asperities on Shear Mechanism of Rock Joints

Rock Moisture Recognition by Combining AE with Musical-staff-inspired Model

Contact Info

Product

Resources

About