Rock Mass Strength Estimation Using Structural Factor Based on Statistical Strength Theory

2018 ◽  
Vol 277 ◽  
pp. 111-122 ◽  
Author(s):  
Dmytro Babets
Keyword(s):  
Rock Mass ◽  
Scale Effect ◽  
Structural Factor ◽  
Statistical Approach ◽  
Quantitative Estimation ◽  
Discontinuity Surface ◽  
Strength Theory ◽  
Support Design ◽  
Statistical Strength ◽  
Rock Mass Strength

Quantitative estimation of scale effect is a complex problem which contained many uncertainties and should be solved using probability calculus and statistical approach. This paper aims to derive the structural factor according statistical strength theory involving discontinuity surface conditions account to estimate the design rock mass strength. A short review of scale effect estimation techniques based on statistical strength theory is given. A new method of structural factor evaluation is proposed. This technique allows accounting discontinuity conditions by changing the variation of tested specimen random sample. A function that describes the decreasing of strength due to poor discontinuity surface quality is introduced to correct the initial and central statistical moments of strength random distribution. The evaluation of the joints condition function based on analysis of the results of uniaxial compressive strength tests and petrographic structure of specimens is shown. Improving the statistical approach of structural factor evaluating increase the accuracy of the rock mass strength assessment and allow avoiding costly modifications of the mining excavation support design. A case of rock mass strength estimation under conditions of coal mine “Komsomolets Donbassa” according to proposed statistical method is studied.

Scale effect on rock mass strength and stability

2020 ◽  
pp. 101-110 ◽  
Author(s):  
G.E. Exadaktylos ◽  
C.E. Tsoutrelis
Keyword(s):  
Rock Mass ◽  
Scale Effect ◽  
Rock Mass Strength

Unification of Hoek-Brown Criterion on the Basis of United Strength Theory

2014 ◽  
Vol 501-504 ◽  
pp. 415-418
Author(s):  
Yuan Li ◽  
Qi Liang Liu ◽  
Qing Chi Cai
Keyword(s):  
Rock Mass ◽  
Rock Strength ◽  
Hard Rock ◽  
Strength Criterion ◽  
Strength Reduction ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Rock Mass Strength ◽  
Decomposition Formula ◽  
Theory Formula

Based on twin failure mechanism of fracture and shear , the bilinear transitional strength decomposition formula reflecting the nonlinear strength of rock material is proposed,.The decomposed brittle shear formula is integrated and finally the unified strength theory formula characterized by nonlinearity of Hoek-Brown criterion is established. It makes the unified strength theory characterized by nonlinearity of empirical strength criterion, rock mass strength reduction, etc. Besides, it contributes to promote the accuracy and applicability of unified strength theory in rock strength and rock mass strength,especially for the hard rock failure analysis.

ROCK MASS STRENGTH IN RELATION TO LANDSLIDE PROGRESSION

2018 ◽  
Author(s):  
Brooke M. Hornney ◽  
◽  
Marlene C. Villeneuve ◽  
Jonathan Davidson
Keyword(s):  
Rock Mass ◽  
Rock Mass Strength

Rock Mass Strength Assessment for Bedrock Landsliding

1996 ◽  
Vol II (3) ◽  
pp. 325-338 ◽  
Author(s):  
K. M. SCHMIDT ◽  
D. R. MONTGOMERY
Keyword(s):  
Rock Mass ◽  
Strength Assessment ◽  
Rock Mass Strength

Estimation of rockburst wall-rock velocity invoked by slab flexure sources in deep tunnels

2014 ◽  
Vol 51 (5) ◽  
pp. 520-539 ◽  
Author(s):  
Shili Qiu ◽  
Xiating Feng ◽  
Chuanqing Zhang ◽  
Tianbing Xiang
Keyword(s):  
Rock Mass ◽  
Seismic Source ◽  
Friction Angle ◽  
Wall Rock ◽  
Assessment Method ◽  
Source Mechanism ◽  
Uniaxial Tensile ◽  
Roughness Coefficient ◽  
Support Design ◽  
True Triaxial

For rock support in burst-prone ground, the wall-rock velocity adjacent to the surface of underground openings is a vital support design parameter, and depends on the seismic source mechanism inducing rockburst damage. In this study, to estimate the wall-rock velocity evoked only by rock slab buckling (an important rockburst source mechanism), a comprehensive velocity assessment method is proposed, using an excellent slab column buckling model with a small eccentricity, which relies on a novel compressive or tensile buckling failure criterion of rock slab. The true-triaxial loading–unloading tests and rockburst case analyses reveal that rock mass slabbing induced by high rock stress has major impacts on the evolution and formation of buckling rockburst in deep tunnels. Using a method based on the energy balance principle, the slabbing thickness of intact rock mass is also calculated by an analytical method, which indicates that the slabbing thickness parameter has a nonlinear relation to the following six parameters: uniaxial tensile strength (UTS), uniaxial compressive strength (UCS), normal stress (σn), length of joint (L), friction angle ([Formula: see text]), and joint roughness coefficient (JRC). These proposed models and methods have been quite successfully applied to rockburst and slabbing cases occurring in deep tunnels. These applications show that slab flexure is an important source mechanism invoking high wall-rock velocities and leading to severe rockburst damages in the area surrounding deep tunnels.

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