نتایج جستجو برای: rock mass modulus

تعداد نتایج: 535751  

2013
Chen Mian Wang Zheng Yuan Jianbo Liu Ming

A series of experiments were performed to determine rock mechanical parameters related to was studied. Experimental results show that the coal seam in the study areas has a relatively low elastic modulus, high Poisson’s ratio, high fragility and is easily broken and compressed. The coal seam is considered as a transversely isotropic medium, since the physical properties in the direction of bedd...

Journal: :journal of mining and environment 2013
reza rahmannejad a.i. sofianos

wall displacements and ground pressure acting on the lining of a tunnel increase with time. these time-dependent deformations are both due to face advance effect and to the time-dependent behavior of the rock mass.  viscoelastic materials exhibit both viscous and elastic behaviors. thorough this study, the effect of different linear viscoelastic models including maxwell, kelvin and kelvin-voigt...

2010

Data on discontinuities are always necessary for design, characterization and analysis of rock structures. The time honored method of manual measurements with Brunton compass is both time consuming and often inconvenient given issues such as restricted access to measurement areas, introduction of erroneous data due to sampling difficulties and human bias, considerable safety risks since measure...

In order to analyze the slope stability in open-pit mines, the structural parameters of rock mass such as persistence and spatial orientation of discontinuities are characterized through field surveys, which involve spending high costs and times as well as posing high risks of rock toppling and rock fall. In the present work, a new application of terrestrial digital photogrammetry is introduced...

2009
S. Yagiz J. Rostami T. Kim L. Ozdemir

Intact rock properties together with rock mass characteristics should be well investigated for selection of proper tunnel boring machine (TBM) for tunneling in various ground conditions. This is due to the significant impact of rock mass characteristics on machine performance. TBMs are site specific and designed for optimal performance in given ground conditions. When selected and put to work a...

Journal: :Journal of Rock Mechanics and Geotechnical Engineering 2019

The purpose of this study was to develop a model for the estimation of rock mass classification of Sarvak limestone in the Bakhtiari dam site, south-west (SW) Iran. Q system had been used as the starting point for the rock mass classification. This method was modified for sedimentary rock mass which is known as Qsrm. Because Qsrm considers a wide range of rock mass propert...

Journal: :Physical chemistry chemical physics : PCCP 2015
Shuyin Yu Qingfeng Zeng Artem R Oganov Gilles Frapper Litong Zhang

We have performed first-principles evolutionary searches for stable Ti-N compounds and have found, in addition to the well-known rock-salt TiN, new ground states Ti3N2, Ti4N3, Ti6N5 at atmospheric pressure, and Ti2N and TiN2 at higher pressures. The latter nitrogen-rich structure contains encapsulated N2 dumbbells with a N-N distance of 1.348 Å at 60 GPa. TiN2 is predicted to be mechanically st...

Presence of joints and fractures in rocks strongly influences the behavior of the rock mass by dividing the media into smaller units. These structures intensify the potential instability besides the development of sliding and rotational movements. The assumption of discontinuum media changes the whole analysis conditions in relation to the continuum analysis. Acquisition of geometrical and stru...

Journal: :journal of nanostructures 2015
y. zeraatkish m. jafarian m. g. mahjani

electrochemical properties of various rock-shaped-cuo/graphite (g) composites and monoclinic structure cuo nanoparticles as the cathode versus a zinc plate as the anode in a 4m naoh electrolyte were elucidated by electrochemical impedance spectroscopy (eis) and chronopotentiometry (cp) in a two electrode configuration cell. various values of g 9, 16 and 28 wt% were prepared and studied as catho...

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