Statistical Properties of Shear Deformation of Granular Media and Analogies with Natural Seismic Processes

Mykulyak, S.V.; Polyakovskyi, V.V.; Skurativskyi, Sergii

doi:10.1007/s00024-019-02209-0

Cited by 4 publications

(4 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Performing a quantitative categorization of AEs during grain crushing is a future prospect. We may identify qualitative similarity in the processes of self-organization of both natural and laboratory frictional faults (Mykulyak et al, 2019).…”

Section: Discussionmentioning

confidence: 99%

Acoustic Emission Reveals Multiple Slip Modes on a Frictional Fault

et al. 2021

View full text Add to dashboard Cite

The spectrum of fault slip modes spans a continuum from fast ruptures to slow slip events. The nucleation of a certain slip mode is governed by the frictional heterogeneity of fault interface and the rheological fault stiffness. There is a mounting evidence that a single fault can host multiple slip modes. In laboratory experiments we study acoustic emission (AE) initiated by a sliding frictional fault and focus our attention on gouge-filled faults hosting multiple slip modes. Deformation experiments were performed on a slider model setup with a precise control of mechanical parameters and monitoring the acoustic signal in the frequency range of 20–80 kHz. We have shown that the cumulative AE energy linearly depends on block displacement. Besides that, there is a high inverse correlation (-0.94) between fault friction and b-value of frequency-amplitude distribution of AE in the performed experiments. Provided that velocity weakening is specific for the fault interface, the self-organization of a gouge-filled fault at the micro scale is the key parameter that controls the frictional behavior of fault hosting multiple slip modes. Resting on a quantitative categorization of AE waveforms, two AE subpopulations have been distinguished. One of them manifests as AEs with harsh onsets. The second one exhibits a gradual amplitude rise and tremor-like waveforms. A longer duration of the intergrain rupture is specific for the second AE subpopulation. During a laboratory seismic cycle, the first AE subpopulation retains parameters, while the second one exhibits a pronounced cyclic recurrence of b-value. The b-value of the second subpopulation gradually decreases before slip events and recovers after them. Two AE subpopulations, probably, point to the coexistence of two dynamic subsystems. The revealed precursory changes of AE subpopulations are common for the entire spectrum of slip modes. We speculate on the unity of underlying mechanisms of different slip modes.

show abstract

Section: Discussionmentioning

confidence: 99%

Acoustic Emission Reveals Multiple Slip Modes on a Frictional Fault

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In particular, the deformation of granular media occurs intermittently and it is accompanied by the generation of acoustic perturbations. These stochastic perturbations obey the same statistical laws as earthquakes: Gutenberg-Richter law, Omori's law, the universal low for distribution of intervent times between avalanches [Geller et al, 2015;Lherminier et al, 2019;Mykulyak et al, 2019bMykulyak et al, , 2021Kumar et al, 2020].…”

mentioning

confidence: 95%

On the similarity of shear deformation of a granular massif and a fragmented medium in the seismically active area

Mykulyak

Kulich

Skurativskyi

2021

GZh

Self Cite

View full text Add to dashboard Cite

In recent research, the dynamics of the medium located in the seismic region at the boundary of tectonic plates is considered as the behavior of a complex open system that is in a state of self-organized criticality. Such an approach results from the very laws of earthquake generation and the complex structure of these areas. The network of faults and cracks makes seismic zones significantly heterogeneous and fragmented. Therefore, discrete models are increasingly used to model the dynamics of these media. The basis for comparing the model and the full-scale object serves the statistical regularities of their dynamic deformation. Relying on this concept, in the paper it is modeled the shear dynamics of a granular massif composed of identical cubic granules and is compared system’s statistical characteristics with the similar characteristics obtained for the earthquake generation zone. Shear deformation is carried out by means of the box consisting of two parts — movable and immovable ones. The movable part possesses the cover which receives kinetic energy from the granular massif in the process of shear deformation. For numerical simulations of the shear dynamics, the discrete element method is applied. The numerical calculations result in the distribution of cover’s kinetic energy jumps simulating the perturbations transmitted from the granular system to an external medium. It turned out that the distribution for these perturbations is the power dependence with an exponent that is inherent in earthquakes (Gutenberg-Richter law). Before and after large perturbations it is observed the swarms of smaller perturbations which are the analogues of foreshocks and aftershocks. The distributions of element’s velocity fluctuations and the correlation of velocity fluctuations are calculated as well. It is revealed the similarity of distributions for velocity fluctuations in the model massif and in the seismically active region of California, which includes the San Andreas fault. Moreover, the similarity of corresponding correlation functions is shown. They both are the functions of the stretched exponent. The obtained result indicates that shear processes in granular massifs and natural seismic processes in the San Andreas Fault are statistically similar.

show abstract

“…In a number of works it was found that the shear deformation of such discrete media as granular ones is statistically similar to seismic processes in natural media. In particular, the DOI: https://doi.org/10.24028/gzh.v43i2.230197 experiments [Behringer et al, 1999;Howell et al, 1999;Hayman et al, 2011;Geller et al, 2015;Mykulyak et al, 2019b] and the simulations [Zhao et al, 2006;Indraratna et al , 2014;Mykulyak et al, 2019 a] have shown that the displacement of granular media occurs intermittently and is accompanied by the radiation of stochastic acoustic disturbances. It turned out, these disturbances obey the statistical laws inherent in earthquakes, namely Gutenberg Richter's law, Omori's law and also the universal law for distribution of interevent times between avalanches [Geller et al, 2015;Lherminier et al, 2019;Mykulyak et al, 2019b;Kumar et al, 2020].…”

mentioning

confidence: 99%

“…Continuing the research [Mykulyak et al, 2019b], we investigate the influence of grain shape and size on the statistical properties of the shear process. Here we consider two types of grains: cubic grains and grains formed by crushed stone with an irregular but ribbed shape.…”

mentioning

confidence: 99%

Experimental study of shear deformation of the medium formed by the massif of ribbed grains

Mykulyak

Polyakovskyi

Skurativskyi

2021

GZh

View full text Add to dashboard Cite

The approach to the study of the seismically active zone as an open system that is in a state of self-organized criticality is becoming increasingly used in modern research. The models used in this approach should reflect the most characteristic features of such media: discreteness, nonequilibrium, nonlinear and nonlocal nature of interactions. In this paper, the medium is modeled by a granular massif with ribbed grains. Three different massifs are used in the research. Within one massif, all grains are identical, while grains from different massifs differ in shape (cubic or irregular ribbed) and characteristic size. A number of experiments of shear deformation of such granular massifs were carried out in order to study the influence of the shape and size of grains on the statistical charac-teristics of the process. The influence of the stress state on the deformation properties of these media was also studied. The experiments proved the qualitative similarity of the behavior of different granular media. Obtained experimentally force jumps, represen-ting the reaction of the granular medium to shear deformation, obey the distributions in the form of power dependencies. However, the magnitudes of the forces arising in the massifs depend on the grain shape and size as well as the stress state in the massifs. The experiments with shear deformation of the granular media under the external action of small impulse stresses have shown that such action causes a smoother, devoid of sharp jumps, deformation. External perturbations shift the distribution of the force jumps towards smaller values, leaving their exponents unchanged. The analysis of experimental results using nonadditive statistical mechanics confirmed the presence of long-range correlations in the massif of ribbed granules during its shear deformation.

show abstract

Statistical Properties of Shear Deformation of Granular Media and Analogies with Natural Seismic Processes

Cited by 4 publications

References 60 publications

Acoustic Emission Reveals Multiple Slip Modes on a Frictional Fault

Acoustic Emission Reveals Multiple Slip Modes on a Frictional Fault

On the similarity of shear deformation of a granular massif and a fragmented medium in the seismically active area

Experimental study of shear deformation of the medium formed by the massif of ribbed grains

Contact Info

Product

Resources

About