1. Hot

    THE GEOLOGICAL STRENGTH INDEX (GSI): A …

    The Geological Strength Index (GSI) is a system of rock mass characterization that has been developed in engineering rock mechanics to meet the need for reliable input data related to rock mass properties required as input for numerical analysis or closed-form solutions for design-ing tunnels, slopes, or foundations in rocks. The geological

  2. Hot

    Site investigation and rock mass characterization ...

    Site investigation and rock mass characterization. From QueensMineDesignWiki. Jump to: navigation, search. ... The empirical calculation of shear strength is shown in Equation 8 where "JRC", ... it may then be classified to help generalize and understand its behaviour and relationship to other rock masses .

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    Effects of Spatial and Temporal Variations of Rock-Mass ...

    The relationship between rock-mass quality and the distribution of potentially unstable areas observed in the model raises a concern. Because parameter values for both rock-mass stiffness and strength are estimated from rock-mass quality using empirical equations, it is possible that the observed relationships are mainly

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    Rock Engineering Practice & Design

    Rock Mass Classification & Empirical Design 1 of 40 Erik Eberhardt – UBC Geological Engineering ISRM Edition ... The Mohr-Coulomb failure criterion expresses the relationship between the shear stress and the normal stress at failure along a shear surface. s on (1997) s on & Harri ... Rock mass strength …

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    STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1 ...

    STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1. INTRODUCTION 2. TESTING OF INTACT ROCK FOR STRENGTH 2.1 Uniaxial Compression 2.2 Point Load Testing ... Rock mass strength is scale dependent and varies with the volume of rock under consideration. The modes of failure of intact rock are multiple. Rock can fail in tension, compression or shear.

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    Lecture 9 – Introduction to Rock Strength David Hart ...

    Lecture 9 – Introduction to Rock Strength David Hart University of Wisconsin ecow.engr.wisc.edu/cgi- ... • The compressive strength of rock is a function of the confining pressure. ... EMPIRICAL …

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    USING THE POINT LOAD TEST TO DETERMINE THE …

    category. This allows for intact rock strength data to be made available through point load testing for numerical geotechnical analysis and empirical rock mass classification systems such as the Coal Mine Roof Rating (CMRR). INTRODUCTION The point load test (PLT) is an accepted rock mechanics testing procedure used for the calculation of a rock ...

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    Relation of rock mass characterization and damage

    ABSTRACT: There are several empirical relations between the rock mass mechanical parameters (unconfined compressive strength, deformation modulus) and of the rock mass classification systems. These uniformly show increasing deformation modulus and compressive strength with the increasing quality of the rock mass.

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    Grouting of Rock Masses - Lombardi

    The RQD (Rock Quality Designation) ( 1968) was a first quite original and useful attempt to quantify the properties of the fissured rock masses, which depend on said discontinuities. The empirical relationship between deformability and RQD is shown in Figure 1. Figure 1: Relationship between RQD and a deformability factor defined

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    STUDY OF COMPRESSIVE STRENGTH OF JOINTED …

    STUDY OF COMPRESSIVE STRENGTH OF JOINTED ... The uniaxial compressive strength of rock mass is represented in a non-dimensional form as the ratio ... Based on the statistical analysis of the data, empirical relationship for the uniaxial compressive strength ratio as a function of a joint factor (Jf) ...

  11. Hot

    Estimating Hoek-Brown Rock Mass Strength Parameters from ...

    Parameters related to the geology and mineralogy of the rock mass, the degree to which the rock mass is broken, and the intact material strength should therefore be considered in deriving a relationship between rock mass strength and a clas­ sification. Hoek and Brown (9) showed a …

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    Empirical Estimation of Rock Mass Modulus

    Empirical estimation of rock mass modulus E. Hoek and M.S. Diederichs Based on an analysis of an extensive data set from China and Taiwan the authors have proposed two new equations for empirical estimates of the deformation modulus of rock masses. These estimates are based on the Geological Strength Index (GSI), the

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    Active and Passive Pressures for Bedrock - Foundation ...

    Mar 28, 2006· If it's still an issue, try to find "Rock Slope Engineering" by Evert Hoek and John W. Bray, Institution of Mining and Metallurgy, 3rd edition, 1981, pp. 107 - 110. There is an empirical relationship for rock-mass strength based on jointing, weathering, rock type, confining stress, etc.

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    EMPIRICAL STRENGTH CRITERION FOR ROCK MASSES

    EMPIRICAL STRENGTH CRITERION FOR ROCK MASSES. An empirical strength criterion for rocks and rock masses is proposed. The nonlinear criterion includes the uniaxial compressive strength of the intact rock material and introduces two dimensionless parameters, m and s.

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    Rock Mass Strength Gibson Rev 2 - SRK

    Rock Mass Strength derived from Rock Mass Characterization Gibson, W H, SRK Consulting, Perth, Western Australia, Australia Updated version of the paper published in the Journal of Australian Geomechanics Vol 41 No March 2006 ABSTRACT: The assessment of rock mass strength is a key element for the analysis of many rock excavations, both open

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    Review: GSI and Hoek Brown Procedure

    ñ can be calculated from the empirical relationship (Hoek et al. 2002): / Ø Ì ã ò Î Ø ò L 0.47 @ Î Ø ò Á A. (9) where is the unit weight of the rock mass, H is the depth of the tunnel below surface, and ê Ö à ñ is the "global" rock mass strength for the stress range ê ç O ê 7 ñ

  17. Hot

    Empirical Strength Criterion for Rock Masses

    Empirical Strength Criterion for Rock Masses. An empirical strength criterion for rocks and rock masses is proposed. The nonlinear criterion includes the uniaxial compressive strength of the intact rock material and introduces two dimensionless parameters, m and s. The parameter m varies with rock type, the angle of interblock or interparticle friction and the degree of block or …

  18. Hot

    Establishing Relationships between Some Engineering ...

    Establishing Relationships between Some Engineering Properties ... strength characteristics, granitic rock, relationship, regression analysis _____ INTRODUCTION Intact rock strength is a major rock property of rock material and governs the behaviour of a rock mass to the force field of its physical environment. Standard determination of rock ...

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    Determination and applications of rock quality designation ...

    Since in many cases rock quality designation (RQD) is the only rock mass classification index available, this paper outlines the key aspects on determination of RQD and evaluates the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses.

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    Volume 4, Issue 9, March 2015 A geological classification ...

    Volume 4, Issue 9, March 2015 52 ... to be between 40 and 60 and rock mass strength is about 10MPa. Blasting was the only effective excavation method when GSI is greater than 60 and rock mass strength is more than 15MPa. C. Blastability index and Rock Mass Classification

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    Estimating the Strength of Jointed Rock Masses

    for determining the rock mass strength'' (Edelbro et al. 2006). In this article, the existing empirical methods for esti- ... the best empirical relationship between r cm/r c and J

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    Empirical relations between rock strength and physical ...

    well (for example, some strength–porosity relationships for sandstone and shale), rock strength variations with individual physical property measurements scatter considerably, indicating that most of the empirical equations are not sufficiently generic to fit all the data published on rock strength and physical properties.

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    Estimating Rock Mass Strength - BM 1997 02

    ESTIMATING ROCK MASS STRENGTH USING ... Back-analysis of observed failures can provide representative values for large scale rock mass strength, but obviously, this is only possible for cases in which rock mass failure has ... The Hoek-Brown failure criterion is an empirical criterion developed through curve-fitting of

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    1 Rock mass classification - Rocscience

    At the other end of the spectrum, one or more rock mass classification schemes can be used to build up a picture of the composition and characteristics of a rock mass to provide initial estimates of support requirements, and to provide estimates of the strength and deformation properties of the rock mass.

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    NUMERICAL MODELING OF BRITTLE ROCK FAILURE UNDER …

    the empirical relationship for estimating depth of failure under dynamic loading. ... boundary, is brittle, which means that there is a sudden reduction of rock mass strength from peak to residual once failure occurs (Golchinfar & Cai, 2012). In a recent study, Golchinfar and Cai (2012) demonstrated that brittle ...

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    Estimation of rock mass permeability using ... - SpringerLink

    Abstract. Determining permeability of fractured rocks is a focal point in engineering projects. Many methods have been developed for direct in situ determination of the hydraulic parameter; nevertheless, especially in the preliminary stages of rock mass characterization, empirical correlations are used to estimate the rock permeability.

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    A Rock Mass Approach to Assess Hydro-Mechanical ...

    A Rock Mass Approach to Assess Hydro-Mechanical Deformation in Tight Rock Reservoirs ... 1997). This classification scheme is simple and aims to identify poor or good strength rock ... The empirical relationship is then tested through numerical simulation under a …

  28. Hot

    Tunneling in Squeezing Ground

    uniaxial compressive strength of rock mass can then be estimated as CJ = 2ccosq>/(l-sin cf>) em The deformation modulus of rock mass was estimated by using an empirical relationship compiled by Chern et at (1997), instead of using the formula suggested by Serafim and Pereira ( 1983) which is more suitable for very hard rocks.

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    A new general empirical approach for the ... - ScienceDirect

    Most of the empirical equations given in Table 1 consider just RMR, GSI or the joint parameter (JP) as an input parameter.But these characterization schemes may not explicitly include the strength and deformability of intact rock material, which may play an important role on the strength behavior of rock masses, particularly for softer ones.

  30. Hot

    (PDF) Effects of the Rock Mass Parameters on Dragline ...

    In order to analyze the impacts of the change in rock mass properties on the excavation performance, GSI representing the rock mass classification, modified by [46], was used. The main objective of the study is to investigate: (i) the impact of rock strength on the excavation and (ii) the impact of rock mass properties on the bucket filling ...

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