Accelerated Diffusion Test on the Intact Rock Mass

2007 ◽  
Vol 35 (2) ◽  
pp. 100184 ◽  
Author(s):  
B Hanumantha Rao ◽  
A Dalinaidu ◽  
DN Singh
Keyword(s):  
Rock Mass ◽  
Intact Rock ◽  
Diffusion Test ◽  
Intact Rock Mass

Determination of Diffusion Characteristics of Intact Rock Mass: A Critical Evaluation

2008 ◽  
Vol 31 (6) ◽  
pp. 101514
Author(s):  
L. D. Suits ◽  
T. C. Sheahan ◽  
B. Hanumantha Rao ◽  
D. N. Singh
Keyword(s):  
Rock Mass ◽  
Critical Evaluation ◽  
Intact Rock ◽  
Diffusion Characteristics ◽  
Intact Rock Mass

Experimental Study of Mechanical Properties of Rock Mass Containing Intermittent Joints of Prefabricated

2010 ◽  
Vol 168-170 ◽  
pp. 2468-2472 ◽  
Author(s):  
Rui Hong Wang ◽  
Jian Lin Li ◽  
Jing Guo ◽  
Yu Zhou Jiang ◽  
Li Dang
Keyword(s):  
Mechanical Properties ◽  
Rock Mass ◽  
Ultimate Strength ◽  
Deformation Modulus ◽  
Strain Curve ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Intact Rock ◽  
Rock Masses ◽  
Intact Rock Mass

Most of the engineering rock masses contain a variety of different levels of geological tectonic joints and weak planes, which can weaken the rock strength. The rock masses containing joints have completely different mechanical properties with the intact ones. Through loading failure tests on the rock masses containing two intermittent joints of prefabricated of different spacing, the differences between jointed rock mass and intact one were studied. The research shows that: 1. Comparing with the intact rock mass, the stress-strain curve of jointed one has a relatively large fluctuation near the peak, it isn’t smooth, and there's a reduction in the stage of plastic flow after yielding; ultimate strength decreases obviously, joint depth has a great impact on strength, and there's no necessary link between ultimate strength of rock mass and joints spacing. 2. When the loading is failure, the elastic and deformation modulus of rock mass decrease obviously comparing with those of the intact rock mass, which tend small generally with the increment of joints spacing, however, they have a relatively complex relation and it isn't linear. 3. The failure characteristics of jointed rock mass are different from those of the intact rock mass, failure planes are relatively complex and no longer single shear or complementary shear ones, which presents that shear failures occur along the end of prefabricated joints with few extensional cracks; the spacing of prefabricated joints have a great impact on the failure pattern of rock mass. The research results can provide certain references for the mechanical parameters selection of jointed rock mass of engineering design and numerical analysis.

In situ observation of spalling process of intact rock mass at large cavern excavation

2017 ◽  
Vol 226 ◽  
pp. 52-69 ◽  
Author(s):  
Guofeng Liu ◽  
Xia-Ting Feng ◽  
Quan Jiang ◽  
Zhibin Yao ◽  
Shaojun Li
Keyword(s):  
Rock Mass ◽  
Intact Rock ◽  
In Situ Observation ◽  
Intact Rock Mass

Static and Dynamic Elastic Modulus of Jointed Rock Mass

2010 ◽  
Vol 1 (2) ◽  
pp. 89-112
Author(s):  
T. G. Sitharam ◽  
M. Ramulu ◽  
V. B. Maji
Keyword(s):  
Rock Mass ◽  
Elastic Modulus ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Intact Rock ◽  
Rock Properties ◽  
Dynamic Elastic Modulus ◽  
Joint Factor ◽  
Joint Frequency ◽  
Joint Inclination

In this paper the compressive strength/elastic modulus of the jointed rock mass was estimated as a function of intact rock strength/modulus and joint factor. The joint factor reflects the combined effect of joint frequency, joint inclination and joint strength. Therefore, having known the intact rock properties and the joint factor, jointed rock properties can be estimated. The test results indicated that the rock mass strength decreases with an increase in the joint frequency and a sharp transition was observed from brittle to ductile behaviour with an increase in the number of joints. It was also found that the rocks with planar anisotropy exhibit the highest strength in the direction perpendicular to the anisotropy and the lowest at an inclination of 30o-45o in jointed samples. The anisotropy of the specimen influences the dynamic elastic modulus more than the static elastic modulus. The results were also compared well with the published works of different authors for different type of rocks.

Quasi-site-specific prediction for deformation modulus of rock mass

2020 ◽  
Author(s):  
Jianye Ching ◽  
Kok-Kwang Phoon ◽  
Yuan-Hsun Ho ◽  
Meng-Chia Weng
Keyword(s):  
Rock Mass ◽  
Bayesian Model ◽  
Deformation Modulus ◽  
Intact Rock ◽  
Transformation Model ◽  
Geological Strength Index ◽  
Hierarchical Bayesian ◽  
Hierarchical Bayesian Model ◽  
Rock Mass Rating ◽  
Site Specific

A generic rock mass database consisting of 9 parameters is compiled from 225 studies. The 9 parameters include the deformation modulus, elastic modulus, dynamic modulus, rock quality designation, rock mass rating, Q-system, geological strength index of a rock mass as well as intact-rock Young’s modulus and intact-rock uniaxial compressive strength. This generic database, labeled as ROCKMass/9/5876, consists of 5876 rock mass cases. The goal of this paper is to examine how an existing transformation model such as deformation modulus versus rock mass rating can be made more unbiased and more precise for a specific site by combining sparse site data with ROCKMass/9/5876 in a manner sensitive to site-specific differences. The outcome is a quasi-site-specific transformation model. Four methods are studied to construct a quasi-site-specific transformation model for the deformation modulus of a rock mass: probabilistic multiple regression (current state of practice), hybridization method, hierarchical Bayesian model, and similarity method. The results from two case studies in Turkey show that the hierarchical Bayesian model is the most effective.

scholarly journals A Preliminary Investigation on the Role of Brittle Fracture in the Kinematics of the 2014 San Leo Landslide

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 256 ◽  
Author(s):  
Davide Donati ◽  
Doug Stead ◽  
Davide Elmo ◽  
Lisa Borgatti
Keyword(s):  
Rock Mass ◽  
Laser Scanning ◽  
Preliminary Investigation ◽  
Intact Rock ◽  
Slope Instability ◽  
Numerical Analyses ◽  
Rock Fracturing ◽  
Bedding Planes ◽  
Synthetic Rock

The stability of high rock slopes is largely controlled by the location and orientation of geological features, such as faults, folds, joints, and bedding planes, which can induce structurally controlled slope instability. Under certain conditions, slope kinematics may vary with time, as propagation of existing fractures due to brittle failure may allow development of fully persistent release surfaces. In this paper, the progressive accumulation of brittle damage that occurred prior to and during the 2014 San Leo landslide (northern Italy) is investigated using a synthetic rock mass (SRM) approach. Mapping of brittle fractures, rock bridge failures, and major structures is undertaken using terrestrial laser scanning, photogrammetry, and high-resolution photography. Numerical analyses are conducted to investigate the role of intact rock fracturing on the evolution of kinematic freedom using the two-dimensional Finite-discrete element method (FDEM) code Elfen, and the three-dimensional lattice-spring scheme code Slope Model. Numerical analyses show that the gradual erosion of clay-rich material below the base of the plateau drives the brittle propagation of fractures within the rock mass, until a fully persistent, subvertical rupture surface form, causing toppling of fault-bounded rock columns. This study clearly highlights the potential role of intact rock fracturing on the slope kinematics, and the interaction between intact rock strength, structural geology, and slope morphology.

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