scholarly journals CASE HISTORY ROCK MECHANICS EXAMINATION OF THE JEFFERSON ISLAND SALT MINE: II. LABORATORY EVALUATION OF STRENGTH AND CREEP DEFORMATION CHARACTERISTICS OF DOME SALT UNDER CONFINING PRESSURE. TECHNICAL MEMORANDUM REPORT RSI-0057

1978 ◽  
Author(s):  
Not Given Author
Keyword(s):  
Rock Mechanics ◽  
Creep Deformation ◽  
Case History ◽  
Confining Pressure ◽  
Laboratory Evaluation ◽  
Deformation Characteristics ◽  
Salt Mine

scholarly journals Experimental Study on the Creep Characteristics of Coal Measures Sandstone under Seepage Action

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 110 ◽  
Author(s):  
Ziheng Sha ◽  
Hai Pu ◽  
Ming Li ◽  
Lili Cao ◽  
Ding Liu ◽  
...  
Keyword(s):  
Creep Deformation ◽  
Deformation Rate ◽  
Confining Pressure ◽  
Test System ◽  
Stability Control ◽  
Surrounding Rock ◽  
Natural State ◽  
Saturation State ◽  
Creep Characteristics ◽  
Coal Measures

The seepage action of underground water accelerates the deformation of roadway surrounding rock in deep mines. Therefore, the study of creep characteristics of surrounding rock under seepage action is the basis for the stability control of roadway surrounding rock in deep water-rich areas. In this paper, a seepage-creep coupling test system for complete rock samples was established. Combined with a scanning electron microscopy (SEM) test system, the seepage-creep law of coal measures sandstone and the damage mechanism were revealed. The study results showed that the maximum creep deformation of sandstone under natural and saturation state decreased gradually with the increase of confining pressure, and the maximum creep deformation under saturation state was greater than the corresponding value under natural state when the confining pressure was same. When the confining pressure was constant, the creep deformation, the constant creep deformation rate and the accelerated creep deformation rate of sandstone increased rapidly with the increase of infiltration pressure. With the change of time, the change of permeability parameters went through three cycles; each cycle was divided into two stages, slow change stage and rapid change stage, and the rate of variation increased with the increase of the seepage pressure. Based on the macroscopic and microscopic characteristics of sandstone rupture, the connection between macroscopic and microscopic mechanism on sandstone rupture was established. The results in this paper can provide a theoretical basis for stability control of roadway surrounding rock in water-rich areas.

Cyclic Creep Deformation Characteristics Of Single Crystal Of Nickle Basesuperalloy CMSX 3

1996 ◽  
pp. 663-668
Author(s):  
J. Zrník ◽  
Z. G. Wang ◽  
Y. Yu ◽  
J. A. Wang ◽  
M. Žitňanský ◽  
...  
Keyword(s):  
Single Crystal ◽  
Creep Deformation ◽  
Cyclic Creep ◽  
Deformation Characteristics

Experimental Research on Deformation Characteristics and Energy Change of Rock under Different Unloading Rates of Confining Pressures

2011 ◽  
Vol 243-249 ◽  
pp. 2885-2888
Author(s):  
Xian Min Han ◽  
Shou Ding Li
Keyword(s):  
Rock Mass ◽  
Energy Release ◽  
Rock Burst ◽  
Experimental Research ◽  
Volumetric Strain ◽  
Confining Pressure ◽  
Deformation Characteristics ◽  
Confining Pressures ◽  
Unloading Rate ◽  
Unloading Confining Pressure

Experiments of unloading confining pressure of rock were conducted to reveal deformation characteristics of rock mass under different excavation intension in thigh geostress condition. It were concluded from tests that volumetric strain of rock is inverse proportional to unloading rate. The smaller the unloading rate, the bigger the ductility of rock. Energy release are bigger under high unloading rate than that under low unloading rate. That means that tendency of rock burst turn smaller when unloading rates decrease.

Strain Hardening of a Porous Limestone

1967 ◽  
Vol 7 (03) ◽  
pp. 229-234 ◽  
Author(s):  
J.B. Cheatham
Keyword(s):  
Yield Strength ◽  
Mechanical Behavior ◽  
Strain Hardening ◽  
Rock Mechanics ◽  
Mathematical Theory ◽  
Confining Pressure ◽  
Plasticity Theory ◽  
Single Type ◽  
Microscopic Structure ◽  
Theory Of Plasticity

Abstract Applications of the mathematical theory of plasticity promises to lead to the solution of many drilling and rock mechanics problems. Because of mathematical considerations, the inelastic behavior of rock has frequently been represented by a perfectly plastic model in conjunction with a yield criteria of the Coulomb or Mohr type. The totality of all stress states for which a solid ceases to behave elastically can be represented as a limit surface in stress space. Probing of such limit surfaces indicates details of strain hardening which are not provided by the standard triaxial testing procedure. Probing tests of the limit surfaces have been performed on Cordova Cream limestone to provide data for extending plasticity theory to cover situations in which consolidation and strain hardening are present. Test results indicate that this highly porous limestone undergoes a permanent volume decrease when it is subjected to hydrostatic pressures in excess of 3,500 psi. A virgin sample tested under a confining pressure of 1,500 psi has a yield strength of 1,700 psi; however, if the sample is subjected to a consolidation pressure of 5,000 psi, before testing at 1,500 psi, the yield strength is raised to 2,300 psi. Thus, both consolidation and strain hardening are important considerations in describing the mechanical behavior of this limestone. Tests conducted with the axis of the core having different orientations indicate that this rock is also anisotropic. Portions of the initial and subsequent limit surfaces are determined for samples loaded either perpendicular or parallel to the bedding planes. INTRODUCTION Previous experimental work in rock mechanics indicates that no mathematically tractable constitutive theory is inclusive enough to describe the mechanical behavior exhibited by all types of rocks under all conditions of stress and temperature. Indeed, the type of deformation encountered in a single type of rock is known to depend upon the stress and temperature conditions in the rock during deformation.1-5 Certain rocks and minerals, notably those minerals composed of ionic salts, have been shown to exhibit plastic deformation when tested under conditions of high confining pressure.2 Since the mathematical theory of plasticity provides simplifications over the theory of elasticity in certain types of problems, such as those in which limit analysis can be applied, it is of interest to know under what conditions plasticity theory may be applied to rock mechanics problems. The following factors determine the nature of the deformation a particular specimen will undergo:the microscopic structure of the rock, i.e., the structure visible under an optical microscope, including number of phases, porosity, distribution of phases,the mineralogical structure of the solid phases,the conditions of stress and the rate of change of stress andthe temperature. Extensive experiments on Yule marble, Carthage marble, Solenhofen limestone and other calcerous rocks indicate that these relatively nonporous rocks deform plastically under certain conditions of loading, and creep under other conditions of loading.1-3 This study is concerned with the behavior of Cordova Cream limestone (Austin chalk) which is also composed almost entirely of calcite and thus has the same mineralogical composition but, because of a rather large porosity, it possesses a different microscopic structure. This investigation was undertaken to learn if Cordova Cream limestone deforms plastically despite the embrittling effect of the pore spaces, and to provide data which can be used to determine whether the mathematical theory of plasticity can describe the mechanical behavior of Cordova Cream limestone.

Investigation on Creep Damage of Natural Gas Storage in Salt Rock Layer

2006 ◽  
Vol 324-325 ◽  
pp. 451-454
Author(s):  
Feng Chen ◽  
Chun He Yang ◽  
Chao Zhang ◽  
Shi Wei Bai
Keyword(s):  
Natural Gas ◽  
Creep Damage ◽  
Confining Pressure ◽  
Gas Storage ◽  
Deviatoric Stress ◽  
Constitutive Law ◽  
Salt Mine ◽  
Salt Rock ◽  
Rock Layer ◽  
Natural Gas Storage

To research the creep behavior of salt rock, the uniaxial and triaxial creep experiments were carried out under different deviatoric stresses and same confining pressure or different confining pressures and same deviatoric stress. The experiment results showed that the analysis on the creep damage of salt rock should consider the influence of confining pressure and deviatoric stress. By introducing the damage variable to the Norton Power law of salt rock, a new constitutive law of salt rock was presented. The damage equivalent stress was the function of the confining pressure and the deviatoric stress in the new constitutive law. The constitutive law can embody the steady creep and accelerative creep of salt rock, in which the parameters are obtained by simulating the experimental data of salt rock in some salt mine. The theoretic results are in good agreement with the experimental results. The new constitutive law was embedded in the three dimension numerical codes. The natural gas storage in the salt mine was analyzed by the new constitutive law. The evolvement law of damage bound and the displacement law around the natural gas storage were studied under the minimal natural gas storage pressure. The continuous operating time of the natural gas storage was also analyzed under the pressure. The research conclusions are expected to be applied in the natural gas storage projects in salt rock layer.

scholarly journals A rock mechanics case history of Elliot Lake

1974 ◽  
Author(s):  
D F Coates ◽  
H U Bielenstein ◽  
D G F Hedley
Keyword(s):  
Rock Mechanics ◽  
Case History ◽  
History Of
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