This study mainly investigates the mechanical mechanism of overlying strata breaking and the development of fractured zones during close-distance coal seam group mining in the Gaojialiang coal mine.First,a mechanical ...This study mainly investigates the mechanical mechanism of overlying strata breaking and the development of fractured zones during close-distance coal seam group mining in the Gaojialiang coal mine.First,a mechanical model for the second"activation"of broken overlying strata is established,and the related mechanical"activation"conditions are obtained.A recursive formula for calculating the separation distance of overlying strata is deduced.Second,a height determining method for predicting the height of fractured zones during close-distance coal seam group mining is proposed based on two values,namely,the separation distance and ultimate subsidence value of overlying strata.This method is applied to calculate the fractured zone heights in nos.20107 and 20307 mining faces.The calculated results are almost equal to the field observation results.Third,a modified formula for calculating the height of a waterflowing fractured zone is proposed.A comparison of the calculated and observed results shows that the errors are small.The height determining method and modified formula not only build a theoretical foundation for water conservation mining at the Gaojialiang coal mine,but also provide a reference for estimating the height of water-flowing fractured zones in other coal mines with similar conditions.展开更多
The widely spread Carboniferous-Permian coal seam group in southern China has great potential for coalbed methane resources,but the extensively developed tectonically deformed coal seriously restricts its development....The widely spread Carboniferous-Permian coal seam group in southern China has great potential for coalbed methane resources,but the extensively developed tectonically deformed coal seriously restricts its development.Taking the Dahebian block in western Guizhou as the study area,the geological model of coalbed methane reservoirs in the tectonically deformed coal seam group was established,and the spatial distribution pattern of model parameters was clarified by clustering algorithms and factor analysis.The facies model suggests that the main coal body structures in Nos.1,4,and 7 coal seams are cataclastic coal and granulated coal,whereas the No.11 coal seam is dominated by granulated coal,which has larger thicknesses and spreads more continuously.The in situ permeability of primary undeformed coal,cataclastic coal,granulated coal,and mylonitized coal reservoirs are 0.333 mD,0.931 mD,0.146 mD,and 0.099 mD,respectively,according to the production performance analysis method.The property model constructed by facies-controlled modeling reveals that Nos.1,4,and 7 coal seams have a wider high-permeability area,but the gas content is lower;the high-permeability area in the No.11 coal seam is more limited,but the gas content is higher.The results of the self-organizing map neural network and K-means clustering indicate that the geological model can be divided into 6 clusters,the model parameter characteristics of the 6 clusters are summarized by data analysis in combination with 6 factors extracted by factor analysis,and the application of data analysis results in multi-layer coalbed methane co-development is presented.This study provides ideas for the geological modeling in the tectonically deformed coal seam group and its data analysis.展开更多
Steeply dipping seam group, which has complex occurrence conditions, belongs to the steeply dipping seam. The research on the strata movement around the coal face not only improves safe production technology in practi...Steeply dipping seam group, which has complex occurrence conditions, belongs to the steeply dipping seam. The research on the strata movement around the coal face not only improves safe production technology in practice, but also develops the mining theory. By using physical simulation experiments, numerical simulation and site test, the deformation, failure and movement of surrounding rock in Iongwall working face were analyzed. According to the analysis, characteristics of the seam group were formed which is different from the single seam. Asymmetry mechanics, sequential changes and imbalance of strata movement along the tendency working face were summarized. Furthermore the features of upper and lower seams were different. The mining of the lower seam induced more complex strata movement along the strike. Multi-section mining disturbed surrounding rocks in larger areas than the single section mining did, which had an impact on and dynamic loading function to the support when mining the lower seam, and produced a great influence on the stability of support-rock system.展开更多
According to the influence of the combination of short-distance coal seam group on mining roadway, using numerical simulation software FLAG2D to draw the abutment pressure distribution ahead the working face and the a...According to the influence of the combination of short-distance coal seam group on mining roadway, using numerical simulation software FLAG2D to draw the abutment pressure distribution ahead the working face and the area of influence in fully-mechanized mining conditions, the variation rules of surrounding rock supporting pressure of floor roadway and the deformation rules were summarized. GYS-300 anchor dynamometer was used to measure the roadway surface displacement, and the conclusions of numerical simulation were verified.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51474137,and 51574154)Shandong Province Natural Science Fund(No.ZR201709180101)+1 种基金Tai’shan Scholar Engineering Construction Fund of Shandong Province of ChinaPostgraduate Technology Innovation Project of Shandong University of Science and Technology(No.SDKDYC 180103).
文摘This study mainly investigates the mechanical mechanism of overlying strata breaking and the development of fractured zones during close-distance coal seam group mining in the Gaojialiang coal mine.First,a mechanical model for the second"activation"of broken overlying strata is established,and the related mechanical"activation"conditions are obtained.A recursive formula for calculating the separation distance of overlying strata is deduced.Second,a height determining method for predicting the height of fractured zones during close-distance coal seam group mining is proposed based on two values,namely,the separation distance and ultimate subsidence value of overlying strata.This method is applied to calculate the fractured zone heights in nos.20107 and 20307 mining faces.The calculated results are almost equal to the field observation results.Third,a modified formula for calculating the height of a waterflowing fractured zone is proposed.A comparison of the calculated and observed results shows that the errors are small.The height determining method and modified formula not only build a theoretical foundation for water conservation mining at the Gaojialiang coal mine,but also provide a reference for estimating the height of water-flowing fractured zones in other coal mines with similar conditions.
基金supported by the National Natural Science Foundation of China(Grant No.41727801)the Geological Exploration Foundation of Guizhou Province(No.208-9912-JBN-UTSO)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘The widely spread Carboniferous-Permian coal seam group in southern China has great potential for coalbed methane resources,but the extensively developed tectonically deformed coal seriously restricts its development.Taking the Dahebian block in western Guizhou as the study area,the geological model of coalbed methane reservoirs in the tectonically deformed coal seam group was established,and the spatial distribution pattern of model parameters was clarified by clustering algorithms and factor analysis.The facies model suggests that the main coal body structures in Nos.1,4,and 7 coal seams are cataclastic coal and granulated coal,whereas the No.11 coal seam is dominated by granulated coal,which has larger thicknesses and spreads more continuously.The in situ permeability of primary undeformed coal,cataclastic coal,granulated coal,and mylonitized coal reservoirs are 0.333 mD,0.931 mD,0.146 mD,and 0.099 mD,respectively,according to the production performance analysis method.The property model constructed by facies-controlled modeling reveals that Nos.1,4,and 7 coal seams have a wider high-permeability area,but the gas content is lower;the high-permeability area in the No.11 coal seam is more limited,but the gas content is higher.The results of the self-organizing map neural network and K-means clustering indicate that the geological model can be divided into 6 clusters,the model parameter characteristics of the 6 clusters are summarized by data analysis in combination with 6 factors extracted by factor analysis,and the application of data analysis results in multi-layer coalbed methane co-development is presented.This study provides ideas for the geological modeling in the tectonically deformed coal seam group and its data analysis.
基金the New Century Excellent Talents in University of China(NCET-04-972)
文摘Steeply dipping seam group, which has complex occurrence conditions, belongs to the steeply dipping seam. The research on the strata movement around the coal face not only improves safe production technology in practice, but also develops the mining theory. By using physical simulation experiments, numerical simulation and site test, the deformation, failure and movement of surrounding rock in Iongwall working face were analyzed. According to the analysis, characteristics of the seam group were formed which is different from the single seam. Asymmetry mechanics, sequential changes and imbalance of strata movement along the tendency working face were summarized. Furthermore the features of upper and lower seams were different. The mining of the lower seam induced more complex strata movement along the strike. Multi-section mining disturbed surrounding rocks in larger areas than the single section mining did, which had an impact on and dynamic loading function to the support when mining the lower seam, and produced a great influence on the stability of support-rock system.
文摘According to the influence of the combination of short-distance coal seam group on mining roadway, using numerical simulation software FLAG2D to draw the abutment pressure distribution ahead the working face and the area of influence in fully-mechanized mining conditions, the variation rules of surrounding rock supporting pressure of floor roadway and the deformation rules were summarized. GYS-300 anchor dynamometer was used to measure the roadway surface displacement, and the conclusions of numerical simulation were verified.
