This paper introduces the calculation of the deformation of the surroundings of roadways and the division of surroundings into 5 levels by means of fuzzy integral assess matrix, which serves as the scientific basis fo...This paper introduces the calculation of the deformation of the surroundings of roadways and the division of surroundings into 5 levels by means of fuzzy integral assess matrix, which serves as the scientific basis for selecting supporting pattern of roadways and determining the parameters of support.展开更多
High temperature affects rocks in a way that changes the physical and mechanical properties of them. The temperature field in rock overlying a high temperature zone has been estimated using experimental research on th...High temperature affects rocks in a way that changes the physical and mechanical properties of them. The temperature field in rock overlying a high temperature zone has been estimated using experimental research on thermal conductivity of the overlying strata. Numerical analysis software was used to esti- mate rock thermal conductivity at different temperatures. These estimates were then used with COMSOL Multiphysics to perform a numerical analysis with the heat conduction model. The results show that rock thermal conductivity decreases as the temperature increases and that various lithologies show similar behavior. The thermal conductivity of each rock type differs from the others at a given temperature. Exact values for the temperature distribution in the overlying strata during the process of underground coal gasification are obtained from the numerical simulation. The temperature in the rock changes with the height and direction from the gasifier. Temperature gradients vary for different types of rock. This result provides an important reference for further study of the strength of overlying strata subject to the process of underground coal gasification.展开更多
In the present study an attempt has been made to carry out the detailed petrographic characterization of the Karharbari coals of Talcher coalfield and to reconstruct the paleoenvironment conditions of coal formation u...In the present study an attempt has been made to carry out the detailed petrographic characterization of the Karharbari coals of Talcher coalfield and to reconstruct the paleoenvironment conditions of coal formation using macerals and microlithtotypes as a tool. For these purposes a large number of samples were collected following the pillar sampling method and were subjected to detailed petrographic study. The petrographic observation shows that these coals are vitrinite rich followed by the liptinite and inertinite group of macerals. On microlithotype scale, these coals shows the dominance of the vitrite followed by clarite, vitrinertite and inertite. The concentration of liptite, clarodurite, duroclarite and vitriner- toliptite are insignificant. The vitrinite reflectance ranks the Karharbari coal as high volatile bituminous ＇C＇ to high volatile ＇B＇ bituminous. Coal petrography based depositional models suggest peat accumulation in forested telmatic swamp. Moreover, during the time of their evolution, there were alternate phases of oxic and anoxic moor conditions with good tissue preservation.展开更多
文摘This paper introduces the calculation of the deformation of the surroundings of roadways and the division of surroundings into 5 levels by means of fuzzy integral assess matrix, which serves as the scientific basis for selecting supporting pattern of roadways and determining the parameters of support.
基金support from the State Key Basic Research Program of China (No. 2010CB226805)the National Natural Science Foundation of China (No. 50874103)+3 种基金the Natural Science Foundation of Jiangsu Province (No. BK2008135)the StateKey Laboratory Program (No. SKLGDUEK0905)the Natural Science Fundsof the Education Department of Anhui Province (No.KJ2009B096Z)the Brain Gain Funds Program of Anhui University of Scienceand Technology (No. 2008yb011)
文摘High temperature affects rocks in a way that changes the physical and mechanical properties of them. The temperature field in rock overlying a high temperature zone has been estimated using experimental research on thermal conductivity of the overlying strata. Numerical analysis software was used to esti- mate rock thermal conductivity at different temperatures. These estimates were then used with COMSOL Multiphysics to perform a numerical analysis with the heat conduction model. The results show that rock thermal conductivity decreases as the temperature increases and that various lithologies show similar behavior. The thermal conductivity of each rock type differs from the others at a given temperature. Exact values for the temperature distribution in the overlying strata during the process of underground coal gasification are obtained from the numerical simulation. The temperature in the rock changes with the height and direction from the gasifier. Temperature gradients vary for different types of rock. This result provides an important reference for further study of the strength of overlying strata subject to the process of underground coal gasification.
文摘In the present study an attempt has been made to carry out the detailed petrographic characterization of the Karharbari coals of Talcher coalfield and to reconstruct the paleoenvironment conditions of coal formation using macerals and microlithtotypes as a tool. For these purposes a large number of samples were collected following the pillar sampling method and were subjected to detailed petrographic study. The petrographic observation shows that these coals are vitrinite rich followed by the liptinite and inertinite group of macerals. On microlithotype scale, these coals shows the dominance of the vitrite followed by clarite, vitrinertite and inertite. The concentration of liptite, clarodurite, duroclarite and vitriner- toliptite are insignificant. The vitrinite reflectance ranks the Karharbari coal as high volatile bituminous ＇C＇ to high volatile ＇B＇ bituminous. Coal petrography based depositional models suggest peat accumulation in forested telmatic swamp. Moreover, during the time of their evolution, there were alternate phases of oxic and anoxic moor conditions with good tissue preservation.
