Based on the engineering background of No.8402 stope face in Silaogou Coal Mine of Datong Mineral Bureau and the theory of plate presented by researchers before, considering surrounding rock structure in the stope and...Based on the engineering background of No.8402 stope face in Silaogou Coal Mine of Datong Mineral Bureau and the theory of plate presented by researchers before, considering surrounding rock structure in the stope and according to mechanical property of rock bodies with various kinds of joint planes, presented an assumption that the key roof was divided into a series of elastic plate group by joint planes, then set up mechanical model of elastic plate group with pin joint. After compared the deflection and the stress in the mechanical model by numerical modeling with data from field engineering, the rule of rock plates’ break in turn and the difference in rock plates’ stress during the roof’s first and periodic weighting along the stope face were found.展开更多
Based on study of the influence of main roof fracture on ground pressure, this paper considered the immediate roof as a semi-infinite long beam on a Winkler elastic foundation. In the model the coal seam is the founda...Based on study of the influence of main roof fracture on ground pressure, this paper considered the immediate roof as a semi-infinite long beam on a Winkler elastic foundation. In the model the coal seam is the foundation and the pressure caused by mian roof deflection is the load. Having solved the model and analyzed relevant factors,the authors indicate that the disturbance caused by the breakage of the mian roof can be observed in both gates of longwall face and explain why it can be. The paper points out that the applicability of the method to obtain the disturbance information by measuring the loads on supports is wider than that by measuring the roof convergence rate. The results are useful for monitoring and predicting ground pressure.展开更多
Taking the Xinhe mine's structure, mine pressure, structural fissure, fault andfault displacement, the distance between fault and water inrush point, thickness of block,water pressure those geological factors whic...Taking the Xinhe mine's structure, mine pressure, structural fissure, fault andfault displacement, the distance between fault and water inrush point, thickness of block,water pressure those geological factors which influenced the water inrush as the independentvariable, based on these data of water inrush point and water uninrush point, usingthe method of quantification theory(Ⅰ,Ⅱ), it would quantitatively disposes the qualitativevariable, applied to calculation to evaluate the risk of Xinhe's water inrush.展开更多
Based on lab model experiments and through the limit analysis, the theoretical formula of calculation coal breaking pressure with compressed air was derived. The experimental result shows that blasting pressure must e...Based on lab model experiments and through the limit analysis, the theoretical formula of calculation coal breaking pressure with compressed air was derived. The experimental result shows that blasting pressure must exceed 84.0MPa to break coal with compressive strength of 13.2MPa. The research provides an important theoretical basis for the design of airshooting mining and industrial tests.展开更多
The wurtzite MnO has been obtained lately and is expected to have large potentiai in varies applications. Since elastic properties are the bases of various applications, we calculate these properties of wurtzite MnO b...The wurtzite MnO has been obtained lately and is expected to have large potentiai in varies applications. Since elastic properties are the bases of various applications, we calculate these properties of wurtzite MnO based on the density-functionai theory and compare it with other two phases of MnO （rocksalt and zinc-blende MnO）. The Young＇s modulus of wurtzite and zinc-blende MnO are 65.6 GPa and 73.4 GPa, respectively, which are much lower than those of rocksaJt MnO （177.6 GPa）. More importantly, both the Poisson ratio and the bulk modulus to shear modulus ratio indicate that wurtzite MnO should have much better ductile properties than rocksalt MnO. The calculated piezoelectric constants of wurtzite MnO are comparable to those of ZnO, This suggests wurtzite MnO is a good piezoelectric material. Furthermore, the slowness surfaces of acoustic waves of them are given from Christoffel equation.展开更多
基金Supported by the National Nature Science Foundation of China (10372111)
文摘Based on the engineering background of No.8402 stope face in Silaogou Coal Mine of Datong Mineral Bureau and the theory of plate presented by researchers before, considering surrounding rock structure in the stope and according to mechanical property of rock bodies with various kinds of joint planes, presented an assumption that the key roof was divided into a series of elastic plate group by joint planes, then set up mechanical model of elastic plate group with pin joint. After compared the deflection and the stress in the mechanical model by numerical modeling with data from field engineering, the rule of rock plates’ break in turn and the difference in rock plates’ stress during the roof’s first and periodic weighting along the stope face were found.
文摘Based on study of the influence of main roof fracture on ground pressure, this paper considered the immediate roof as a semi-infinite long beam on a Winkler elastic foundation. In the model the coal seam is the foundation and the pressure caused by mian roof deflection is the load. Having solved the model and analyzed relevant factors,the authors indicate that the disturbance caused by the breakage of the mian roof can be observed in both gates of longwall face and explain why it can be. The paper points out that the applicability of the method to obtain the disturbance information by measuring the loads on supports is wider than that by measuring the roof convergence rate. The results are useful for monitoring and predicting ground pressure.
文摘Taking the Xinhe mine's structure, mine pressure, structural fissure, fault andfault displacement, the distance between fault and water inrush point, thickness of block,water pressure those geological factors which influenced the water inrush as the independentvariable, based on these data of water inrush point and water uninrush point, usingthe method of quantification theory(Ⅰ,Ⅱ), it would quantitatively disposes the qualitativevariable, applied to calculation to evaluate the risk of Xinhe's water inrush.
文摘Based on lab model experiments and through the limit analysis, the theoretical formula of calculation coal breaking pressure with compressed air was derived. The experimental result shows that blasting pressure must exceed 84.0MPa to break coal with compressive strength of 13.2MPa. The research provides an important theoretical basis for the design of airshooting mining and industrial tests.
文摘The wurtzite MnO has been obtained lately and is expected to have large potentiai in varies applications. Since elastic properties are the bases of various applications, we calculate these properties of wurtzite MnO based on the density-functionai theory and compare it with other two phases of MnO （rocksalt and zinc-blende MnO）. The Young＇s modulus of wurtzite and zinc-blende MnO are 65.6 GPa and 73.4 GPa, respectively, which are much lower than those of rocksaJt MnO （177.6 GPa）. More importantly, both the Poisson ratio and the bulk modulus to shear modulus ratio indicate that wurtzite MnO should have much better ductile properties than rocksalt MnO. The calculated piezoelectric constants of wurtzite MnO are comparable to those of ZnO, This suggests wurtzite MnO is a good piezoelectric material. Furthermore, the slowness surfaces of acoustic waves of them are given from Christoffel equation.
