Based on the stress distribution characteristics of rock burst multiple sites,the criterion of horizontal stress inducing layer dislocation rock burst was established.Accordingly,the influencing factors were analyzed....Based on the stress distribution characteristics of rock burst multiple sites,the criterion of horizontal stress inducing layer dislocation rock burst was established.Accordingly,the influencing factors were analyzed.The analysis results indicate that the stress condition,edge of elastic zone depth,supporting strength,and the friction angle and cohesion among coal stratum,roof and floor are sensitive factors.By introducing double-couple model,the layer dislocation rock burst was explained and the energy radiation characteristics were analyzed.The SOS micro-seismic monitoring system was applied to observe the rock burst hazards about a mining face.The results show that P-and S-wave energy radiations produced by rock burst have directional characteristics.The energy radiation characteristics of the 22 rock bursts occurring on 79Z6 long-wall face are basically the same as theoretical results,that is,the ratio of S-wave energy of sensor 4 to 6 is about 1.5 and that of P-wave is smaller than 0.5.The consistency of the monitored characteristics of the energy radiation theoretically increases with the total energy increasing.展开更多
Language serves for the expression of mind.By analyzing the conversations in the short story The Rocking-Horse Winner from the perspective of Grice’s cooperative principle,the paper draws a conclusion about the disti...Language serves for the expression of mind.By analyzing the conversations in the short story The Rocking-Horse Winner from the perspective of Grice’s cooperative principle,the paper draws a conclusion about the distinct personalities of the protago nists in the novel.According to the findings,the conversational implicature of the protagonists actually reflects their different char acters which are or aren’t the results of the industrial background,hypocritical or pure,greedy or diligent.In this way,the study hopes to provide readers an access to a deep understanding of the story and drive them to care more about the ever important yet complex parents-child,especially mother-child relation.展开更多
Size and quantity of fractured zone and non-fractured zone are controlled by cracks contained in deep rock masses. Zonal disintegration mechanism is strongly dependent on the interaction among cracks. The strong inter...Size and quantity of fractured zone and non-fractured zone are controlled by cracks contained in deep rock masses. Zonal disintegration mechanism is strongly dependent on the interaction among cracks. The strong interaction among cracks is investigated using stress superposition principle and the Chebyshev polynomials expansion of the pseudo-traction. It is found from numerical results that crack nucleation, growth and coalescence lead to failure of deep crack- weakened rock masses. The stress redistribution around the surrounding rock mass induced by unloading excavation is studied. The effect of the excavation time on nucleation, growth, interaction and coalescence of cracks was analyzed. Moreover, the influence of the excavation time on the size and quantity of fractured zone and non-fractured zone was given. When the excavation time is short, zonal disintegration phenomenon may occur in deep rock masses. It is shown from numerical results that the size and quantity of fractured zone increase with decreasing excavation time, and the size and quantity of fractured zone increase with the increasing value of in-situ geostress.展开更多
Compositions, proportions, and equilibrium temperature of coexisting two-feldspar in crystalline rocks are of great importance to classification in petrography and interpretation of petrogenesis. Crystalline rocks are...Compositions, proportions, and equilibrium temperature of coexisting two-feldspar in crystalline rocks are of great importance to classification in petrography and interpretation of petrogenesis. Crystalline rocks are usually composed of 4-6 minerals （phases）, depending on their independent chemical components and the equilibrium temperature of crystallizations. In general, number of mineral phases can be determined by the ＂Phase Rule＂. According to the mass balance principle, bulk composition of coexisting two-feldspar could be evaluated from the bulk chemistry of a rock, provided that the compositions of the coexisting mafic mineral phases containing calcium, sodium, and potassium oxides are determined, e.g., by microprobe analysis. The compositions, proportions, and temperature of two-feldspar in equilibrium can thus be simultaneously resolved numerically from bulk composition of the rock, by incorporating the activity/composition relations of the ternary feldspars with the mass balance constraints. Upon the numerical approximation method presented in this paper, better-quality, internally consistent data on feldspar group could usually be obtained, which would be expected more realistic and accurate in consideration of thermodynamic equilibria in the system of crystalline rocks, as well as bulk chemistry of a rock and the composing minerals.展开更多
In order to study the mechanism of bearing behavior at the tip of a pile embedded in rock,the generalized nonlinear unified strength criterion and slip line principle for resolving the differential equation systems wh...In order to study the mechanism of bearing behavior at the tip of a pile embedded in rock,the generalized nonlinear unified strength criterion and slip line principle for resolving the differential equation systems which govern the stress field were applied to derive the ultimate end bearing capacity based on some reasonable hypothesis and failure plane model.Both numerical simulation and test results were compared with the theoretic solution.The results show good consistency with each other and verify the validity of the present approach.The depth effect with respective to embedment ratio and other influence factors like geological strength index,intermediate principal stress,overburden factor,and damage on end bearing capacity were discussed in the analytical solution.The results show that the proposed yield criterion can be much better for investigating the ultimate end bearing performance of rock-socketed pile.The end bearing capacity increases with embedment ratio and the increasing degree is influenced intensely by the above parameters.Furthermore,ignoring intermediate stress effect would underestimate the strength properties of the rock material and lead to a very conservative estimation value.展开更多
The giant perilous rock at Wangxia (named Wangxia perilous rock) is representative in Three Gorges of the Yangtze River, China, has threatened badly the navigation of the Yangtze River channel for a long period. The g...The giant perilous rock at Wangxia (named Wangxia perilous rock) is representative in Three Gorges of the Yangtze River, China, has threatened badly the navigation of the Yangtze River channel for a long period. The giant perilous rock is composed of siliceous limestone and argillaceous limestone, and includes two elements marking by W1 and W2, respectively. The W1 is an isolated pillar while the W2 is in clintheriform. The linking segment of dominant fissure in the W2 is composed by moniliform solution funnels at its back, and the locked segment of the dominant fissure at the base of the W2 is composed by two parts. For the locked part of the dominant fissure of the W2, the upper segment shows the same lithology with the perilous rock and it can be simplified as an elastic medium, for the lower segment composed by argillaceous shale and mudstone can be simplified as a strain-softening medium. Introducing the water-softened function, the constitutive curves with two kinds of medium materials for the locked segment in the dominant fissure of the W2 have been proposed. Based on energy principle, the cusp catastrophe model for perilous rock rupture is built and formulas for the transient elastic and impulsive acceleration and the elastic-impulsive velocity of perilous rock catastrophe rupture have been established. By the calculation, the elastic-impulsive acceleration for the catastrophe rupture of the W2 is 531.4 m/s2, while the average elastic-impulsive velocity is 2.608 m/s. Further, it is deduced that the elastic-impulsive velocity at the base of the W2 is about 5.2 m/s. For the transient ruture of the W2, there is a greater speed difference between the top and the base of the W2, which impels the giant perilous rock to be retroverted sliding rupture, coinciding with the fact. Undoubtedly, studies in this paper must play an important role to analyze the catastrophe rupture mechanism of giant perilous rocks at both banks in Three Gorges of the Yangtze River, China.展开更多
Based on the fundamental principle of rock mechanics, the stresses of single joint rock mass under three-dimensional compression were analyzed. The effect of the in-termediate principle stress on the strength of singl...Based on the fundamental principle of rock mechanics, the stresses of single joint rock mass under three-dimensional compression were analyzed. The effect of the in-termediate principle stress on the strength of single joint rock mass were discussed in par-ticular. It is found that the strength of single joint rock are affected by the intermediate principal stress, which may be the main factor in some conditions.展开更多
基金Project(2012LWB63) supported by the Fundamental Research Funds for the Central Universities, ChinaProject(SZBF2011-6-B35) supported by the Priority Acadamic Program Development of Jiangsu Higher Education Institutions (PAPD),China
文摘Based on the stress distribution characteristics of rock burst multiple sites,the criterion of horizontal stress inducing layer dislocation rock burst was established.Accordingly,the influencing factors were analyzed.The analysis results indicate that the stress condition,edge of elastic zone depth,supporting strength,and the friction angle and cohesion among coal stratum,roof and floor are sensitive factors.By introducing double-couple model,the layer dislocation rock burst was explained and the energy radiation characteristics were analyzed.The SOS micro-seismic monitoring system was applied to observe the rock burst hazards about a mining face.The results show that P-and S-wave energy radiations produced by rock burst have directional characteristics.The energy radiation characteristics of the 22 rock bursts occurring on 79Z6 long-wall face are basically the same as theoretical results,that is,the ratio of S-wave energy of sensor 4 to 6 is about 1.5 and that of P-wave is smaller than 0.5.The consistency of the monitored characteristics of the energy radiation theoretically increases with the total energy increasing.
文摘Language serves for the expression of mind.By analyzing the conversations in the short story The Rocking-Horse Winner from the perspective of Grice’s cooperative principle,the paper draws a conclusion about the distinct personalities of the protago nists in the novel.According to the findings,the conversational implicature of the protagonists actually reflects their different char acters which are or aren’t the results of the industrial background,hypocritical or pure,greedy or diligent.In this way,the study hopes to provide readers an access to a deep understanding of the story and drive them to care more about the ever important yet complex parents-child,especially mother-child relation.
基金supported by the National Natural Science Foundation of China(Nos.50490275 and 50778184)
文摘Size and quantity of fractured zone and non-fractured zone are controlled by cracks contained in deep rock masses. Zonal disintegration mechanism is strongly dependent on the interaction among cracks. The strong interaction among cracks is investigated using stress superposition principle and the Chebyshev polynomials expansion of the pseudo-traction. It is found from numerical results that crack nucleation, growth and coalescence lead to failure of deep crack- weakened rock masses. The stress redistribution around the surrounding rock mass induced by unloading excavation is studied. The effect of the excavation time on nucleation, growth, interaction and coalescence of cracks was analyzed. Moreover, the influence of the excavation time on the size and quantity of fractured zone and non-fractured zone was given. When the excavation time is short, zonal disintegration phenomenon may occur in deep rock masses. It is shown from numerical results that the size and quantity of fractured zone increase with decreasing excavation time, and the size and quantity of fractured zone increase with the increasing value of in-situ geostress.
基金granted by the National Eleventh Five-year Supporting Plan for Science and Technology (2006BAD10B04)China Geological Survey Project (12120113087700)
文摘Compositions, proportions, and equilibrium temperature of coexisting two-feldspar in crystalline rocks are of great importance to classification in petrography and interpretation of petrogenesis. Crystalline rocks are usually composed of 4-6 minerals （phases）, depending on their independent chemical components and the equilibrium temperature of crystallizations. In general, number of mineral phases can be determined by the ＂Phase Rule＂. According to the mass balance principle, bulk composition of coexisting two-feldspar could be evaluated from the bulk chemistry of a rock, provided that the compositions of the coexisting mafic mineral phases containing calcium, sodium, and potassium oxides are determined, e.g., by microprobe analysis. The compositions, proportions, and temperature of two-feldspar in equilibrium can thus be simultaneously resolved numerically from bulk composition of the rock, by incorporating the activity/composition relations of the ternary feldspars with the mass balance constraints. Upon the numerical approximation method presented in this paper, better-quality, internally consistent data on feldspar group could usually be obtained, which would be expected more realistic and accurate in consideration of thermodynamic equilibria in the system of crystalline rocks, as well as bulk chemistry of a rock and the composing minerals.
基金Project(2007AA11Z134) supported by the National High-tech Research and Development Program of ChinaProject(10JJ4035) supported by Hunan Provincial Natural Science Foundation of ChinaProject(04SK2008) supported by Hunan Provincial Science and Technology Department,China
文摘In order to study the mechanism of bearing behavior at the tip of a pile embedded in rock,the generalized nonlinear unified strength criterion and slip line principle for resolving the differential equation systems which govern the stress field were applied to derive the ultimate end bearing capacity based on some reasonable hypothesis and failure plane model.Both numerical simulation and test results were compared with the theoretic solution.The results show good consistency with each other and verify the validity of the present approach.The depth effect with respective to embedment ratio and other influence factors like geological strength index,intermediate principal stress,overburden factor,and damage on end bearing capacity were discussed in the analytical solution.The results show that the proposed yield criterion can be much better for investigating the ultimate end bearing performance of rock-socketed pile.The end bearing capacity increases with embedment ratio and the increasing degree is influenced intensely by the above parameters.Furthermore,ignoring intermediate stress effect would underestimate the strength properties of the rock material and lead to a very conservative estimation value.
文摘The giant perilous rock at Wangxia (named Wangxia perilous rock) is representative in Three Gorges of the Yangtze River, China, has threatened badly the navigation of the Yangtze River channel for a long period. The giant perilous rock is composed of siliceous limestone and argillaceous limestone, and includes two elements marking by W1 and W2, respectively. The W1 is an isolated pillar while the W2 is in clintheriform. The linking segment of dominant fissure in the W2 is composed by moniliform solution funnels at its back, and the locked segment of the dominant fissure at the base of the W2 is composed by two parts. For the locked part of the dominant fissure of the W2, the upper segment shows the same lithology with the perilous rock and it can be simplified as an elastic medium, for the lower segment composed by argillaceous shale and mudstone can be simplified as a strain-softening medium. Introducing the water-softened function, the constitutive curves with two kinds of medium materials for the locked segment in the dominant fissure of the W2 have been proposed. Based on energy principle, the cusp catastrophe model for perilous rock rupture is built and formulas for the transient elastic and impulsive acceleration and the elastic-impulsive velocity of perilous rock catastrophe rupture have been established. By the calculation, the elastic-impulsive acceleration for the catastrophe rupture of the W2 is 531.4 m/s2, while the average elastic-impulsive velocity is 2.608 m/s. Further, it is deduced that the elastic-impulsive velocity at the base of the W2 is about 5.2 m/s. For the transient ruture of the W2, there is a greater speed difference between the top and the base of the W2, which impels the giant perilous rock to be retroverted sliding rupture, coinciding with the fact. Undoubtedly, studies in this paper must play an important role to analyze the catastrophe rupture mechanism of giant perilous rocks at both banks in Three Gorges of the Yangtze River, China.
基金Supported by National Nature Science Foundation of China (50104013)Scientific Research Startup Foundation for Returnee Who Studied Abroad [Ministry of Education (2002) 247]
文摘Based on the fundamental principle of rock mechanics, the stresses of single joint rock mass under three-dimensional compression were analyzed. The effect of the in-termediate principle stress on the strength of single joint rock mass were discussed in par-ticular. It is found that the strength of single joint rock are affected by the intermediate principal stress, which may be the main factor in some conditions.
