Influence of Bidirectional Impact Loading on Anomalously Low‐Friction Effect in Block Rock Media

Li, Liping; Li, Weijun; Tang, Jupeng; Lv, Jiaqing

doi:10.1155/2018/9156304

Cited by 3 publications

(3 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The weak structural plane and layered interface, which is easy to slide abruptly, are the most important factors leading to rockburst. li [5] deduced a new formula of normal force between blocks and a new formula of horizontal displacement of working blocks by establishing a theoretical model of ultra-low friction effect of block rock mass considering overburden pressure. The research shows that the decrease of normal force between blocks leads to the decrease of friction between blocks, and in the case of horizontal disturbance, it is easy to induce ultra-low friction rockburst.…”

Section: Introductionmentioning

confidence: 99%

Archives of Mining Sciences

Song,

Ren,

et al. 2021

View full text Add to dashboard Cite

ExpErimEntal Study on dEformation and damagE Evolution of a mining roadway with wEak layEr rock undEr comprESSion-ShEar loadThe structure and load characteristics of the roadway are simplified, and the experimental model of the roadway deformation and damage under compression-shear load is established. The experimental data acquisition system is built with a CCD camera. The digital speckle correlation method is used to calculate the image data of the experimental model. The correspondence between the evolution law of the deformation field, the interlayer displacement and deformation evolution are analysed, including the dynamic characteristic of the roadway surrounding the rock. Research results indicate: (1) The damage peak load of the weak layer structure shows a decreasing trend as the interlayer shear stress increases. As the initially applied shear stress increases, the value of interlayer sliding displacement increases, and the dynamic characteristics become more apparent. (2) in the sub-instability phase of the loading curve, when the surrounding rock slides along the layers under compression-shear load, the stress is re--distributed and transmitted to the deep part of the surrounding rock. Then the surrounding rock of the roadway forms the characteristic of alternating change, between tension to compression. (3) According to the state of dynamic and static mechanics, the deformation evolution of the roadway before the peak load belongs to the static process. Zonal fracturing is part of the transition phase from the static process to the slow dynamic process, and the rockburst damage is a high-speed dynamic process. (4) under the compression-shear load, due to the weak layer structure of the coal and rock mass, the local fracture, damage, instability and sliding of the surrounding rock of the roadway are the mechanical causes of rockburst. (5) Even if the coal and rock mass does not have the condition of impact tendency, under stress load of the horizontal direction, distribution of large shear stress is formed between layers, and the dynamic damage of the rockburst may occur.

show abstract

Section: Introductionmentioning

confidence: 99%

Archives of Mining Sciences

Song,

Ren,

et al. 2021

View full text Add to dashboard Cite

show abstract

“…When an external disturbance load is applied on rock masses, friction between adjacent rock blocks in the orthogonal direction to the disturbance load may be significantly reduced or even completely disappeared, which is known as an anomalously low friction phenomenon [1,2]. e phenomenon may lead to serious geological disasters, such as the large-scope tunnel deformations [3][4][5] and sliptype rock bursts [6][7][8] in the surrounding rock masses around tunnels.…”

Section: Introductionmentioning

confidence: 99%

“…A simple rock block model as shown in Figure 1 is taken to analyse the geological disasters induced by the anomalously low friction phenomena [2,17,18]. Kurlenya et al [19,20] studied the anomalously low friction phenomena in block media from various geomaterials and found that significant displacements of the working blocks occur at absolute values of plus actions, which are much smaller than the corresponding friction forces.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Anomalously Low Friction Phenomena in Blocky Rock Systems

Shi

Lü

Deng

et al. 2020

Advances in Civil Engineering

View full text Add to dashboard Cite

Rock masses can be regarded as a blocky rock system. After a disturbance load is applied, the anomalously low friction phenomenon may take place and cause geological disasters. A series of impact experiments on granite blocks were conducted to investigate the anomalously low friction phenomena. Vertical vibration, Fourier frequency spectrum, and horizontal motions were investigated. It can be found that the tensile phases of vertical vibration can reduce the maximum static friction force, namely, the shear strength. The quasi-resonance operating mode of the rock blocks was observed. During the stress wave propagation, the vibration in the loading direction tends to transfer from high frequency to low frequency and the modes of stress wave propagation do not depend on disturbance energies. The observed translational and rotational motions were due to the initial shear force, which is less than the friction force with no disturbance load. Stability of the blocky rock system is very sensitive to the initial stress state. In the subcritical state, friction force reduction can easily break the equilibrium of forces along the contact surface and even a slight disturbance may make the horizontal motions happen, which may lead to geological disasters with great energy release.

show abstract