نتایج جستجو برای: rock mass structure

تعداد نتایج: 2005773  

Journal: :The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences 2019

2003
C. IRIGARAY J. CHACÓN

The geomechanical classification SMR (Slope Mass Rating) enables the preliminary assessment of the susceptibility of rock slopes to failure. The SMR index is obtained from Bieniawski’s basic RMR (Rock Mass Rating) through an “adjustment factor” and an “excavation factor”. Since its appearance in 1985, this classification has been used for appraisals and preliminary studies in many countries. Th...

2000
Norbert H. Maerz Paul Germain

The in situ block size of the rock mass may be the single most important parameter influencing the stability and strength of some underground openings. Rock masses can often reasonably be characterized by a simple size-strength classification. The actual block size distribution is the product of the interaction between the joint orientation, spacing and persistence of that rock mass. Despite th...

2005

Underground longwall mining of coal causes large scale disturbance of the surrounding rock mass. The disturbance can increase the rock mass permeability through a reduction on the stress as well as formation of new fractures in the rock. Methane gas contained in the disturbed rock mass can migrate towards the low pressure mine workings and present an explosion hazard. This paper describes the a...

1999
Donald W. Brown

Large volumes of naturally jointed Precambrian crystalline rock can be stably maintained at pressures considerably above the least principal earth stress in the surrounding rock mass. At Los Alamos National Laboratory’s Fenton Hill hot dry rock (HDR) geothermal test site, tests carried out for a cumulative period of 11 months in the deeper and larger of the two HDR reservoirs showed no evidence...

2000
Brian Asbury Jamal Rostami Levent Ozdemir

Over the last several decades mechanical mining machines have developed into highly productive, light weight, mobile machines which are able to economically mine many soft rock ore bodies. Due to the utilization of disc cutters Tunnel Boring Machines, with great mass and limited mobility, have developed the ability to cut the hardest rocks at high production rates. Technological advancements ha...

Journal: :journal of biomedical physics and engineering 0
z. mortazavinia s. arabi a. r. mehdizadeh

background: numerical study of angulation effects of renal arteries on blood flow has been of great interest for many researchers. objective: this paper aims at numerically determining the angulation effects of stenosed renal arteries on blood flow velocity and renal mass flow. method: an anatomically realistic model of abdominal aorta and renal arteries is reconstructed from ct-scan images and...

2015
Annina Sorg Andreas Kääb Andrea Roesch Christof Bigler Markus Stoffel

While the responses of Tien Shan glaciers--and glaciers elsewhere--to climatic changes are becoming increasingly well understood, this is less the case for permafrost in general and for rock glaciers in particular. We use a novel approach to describe the climate sensitivity of rock glaciers and to reconstruct periods of high and low rock glacier activity in the Tien Shan since 1895. Using more ...

2003
Yang Chung

RMR, Rock Mass Rating, is one of the famous rock classifications. However, RMR was proposed empirically and absolutely depends on the experience of engineer. Therefore, engineering verification is needed for RMR system itself. In this study, the factor analysis and the multiple regressions were performed in order to evaluate the validity of rating factor of RMR. Also numerical analysis was carr...

Journal: :Science 2006
Julian B Murton Rorik Peterson Jean-Claude Ozouf

The volumetric expansion of freezing pore water is widely assumed to be a major cause of rock fracture in cold humid regions. Data from experiments simulating natural freezing regimes indicate that bedrock fracture results instead from ice segregation. Fracture depth and timing are also numerically simulated by coupling heat and mass transfer with a fracture model. The depth and geometry of fra...

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