A Note on the Relation of Rock Fracture and Fjord Direction

The article presents the studies into the secondary stress field formed in surrounding rock mass around underground excavations of different cross-sections and the variants of principal stresses at a mining depth greater than 1 km. The stress-strain analysis of surrounding rock mass around development headings was performed in Map3D environment. The obtained results of the quantitative analysis are currently used in adjustment of the model over the whole period of heading and support of operating mine openings. The estimates of the assumed parameters of excavations, as well as the calculations of micro-strains in surrounding rock mass by three scenarios are given. During heading in the test area in granite, dense fracturing and formation of tensile strain zone proceeds from the boundary of e ≥ 350me and is used to determine rough distances from the roof ( H roof) and sidewalls ( H side) of an underground excavation to the 3 boundary e = 350me (probable rock fracture zone). The modeling has determined the structure of secondary stress and strain fields in the conditions of heading operations at great depths.

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Grouting effect on rock fracture using shear and seepage assessment

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.118131 ◽

2020 ◽

Vol 242 ◽

pp. 118131 ◽

Cited By ~ 16

Author(s):

Zhen Li ◽

Huoxing Liu ◽

Zhilin Dun ◽

Lianwei Ren ◽

Jinjin Fang

Keyword(s):

Rock Fracture

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Modeling the Approach of Non-mated Rock Fracture Surfaces Under Quasi-static Normal Load Cycles

Rock Mechanics and Rock Engineering ◽

10.1007/s00603-020-02349-z ◽

2021 ◽

Author(s):

S. M. Rezaei Niya ◽

A. P. S. Selvadurai

Keyword(s):

Normal Load ◽

Rock Fracture ◽

Fracture Surfaces

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Effects of depth on rock fracture

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(91)92279-8 ◽

1991 ◽

Vol 28 (2-3) ◽

pp. A76

Keyword(s):

Rock Fracture

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Investigation of Microcrack Propagation and Energy Evolution in Brittle Rocks Based on the Voronoi Model

Materials ◽

10.3390/ma14092108 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2108

Author(s):

Guanlin Liu ◽

Youliang Chen ◽

Xi Du ◽

Peng Xiao ◽

Shaoming Liao ◽

...

Keyword(s):

Uniaxial Compression ◽

Damage Evolution ◽

Rock Sample ◽

Rock Fracture ◽

Damage Threshold ◽

Crack Development ◽

Energy Evolution ◽

Shear Cracks ◽

Compression Tests ◽

Microcrack Propagation

The cracking of rock mass under compression is the main factor causing structural failure. Therefore, it is very crucial to establish a rock damage evolution model to investigate the crack development process and reveal the failure and instability mechanism of rock under load. In this study, four different strength types of rock samples from hard to weak were selected, and the Voronoi method was used to perform and analyze uniaxial compression tests and the fracture process. The change characteristics of the number, angle, and length of cracks in the process of rock failure and instability were obtained. Three laws of crack development, damage evolution, and energy evolution were analyzed. The main conclusions are as follows. (1) The rock’s initial damage is mainly caused by tensile cracks, and the rapid growth of shear cracks after exceeding the damage threshold indicates that the rock is about to be a failure. The development of micro-cracks is mainly concentrated on the diagonal of the rock sample and gradually expands to the middle along the two ends of the diagonal. (2) The identification point of failure precursor information in Acoustic Emission (AE) can effectively provide a safety warning for the development of rock fracture. (3) The uniaxial compression damage constitutive equation of the rock sample with the crack length as the parameter is established, which can better reflect the damage evolution characteristics of the rock sample. (4) Tensile crack requires low energy consumption and energy dispersion is not concentrated. The damage is not apparent. Shear cracks are concentrated and consume a large amount of energy, resulting in strong damage and making it easy to form macro-cracks.

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