By field observation and simulating test in shallow seam longwall mining, the asymmetry breaking of main roof is discovered during the first weighting. Based on simulating model test and theoretical analysis, the mech...By field observation and simulating test in shallow seam longwall mining, the asymmetry breaking of main roof is discovered during the first weighting. Based on simulating model test and theoretical analysis, the mechanism of main roof first breaking is revealed, and the asymmetry breaking parameter is determined at all.展开更多
As a case study of the Panji No.1 Coal Mine in Anhui Province, based on thesite measured and statistical data, summarized the lithologic associations, characteristicsand distribution laws of interlayer-gliding structu...As a case study of the Panji No.1 Coal Mine in Anhui Province, based on thesite measured and statistical data, summarized the lithologic associations, characteristicsand distribution laws of interlayer-gliding structures and tectonic coal in the No.11-2 coalseams.The results show that 9 modes of lithologic association can form interlayer-glidingstructures.It is more easy for rock slip to occur when the lithologic associations are mainroof + coal seam + immediate floor type, compound roof+immediate roof + coal seam +immediate floor type and immediate roof + coal seam + immediate floor type.Lithologicassociations of roof and floor are the precondition to the formation of interlayer-glidingstructures.展开更多
Collisional orogens form when tectonic forces amalgamte fragments of Earth’s continental lithosphere.The sutures between individual fragments,or terranes,are potential sites of weakness that facilitate subsequent con...Collisional orogens form when tectonic forces amalgamte fragments of Earth’s continental lithosphere.The sutures between individual fragments,or terranes,are potential sites of weakness that facilitate subsequent continental breakup.Therefore,the lithospheric architecture of collisional orogens provides key information for evaluating the long-term evolution of the continental interior:for example,the South China Block(SCB),where the tectonic history is severely obscured by extensive surface deformation,magmatism,and metamorphism.Using new passive-source seismic models,we show a contrasting seismic architecture across the SCB,with three prominent crustal dipping structures across the Jiangnan Orogen.Combined with constraints from multi-disciplinary regional geophysical datasets,these pronounced dipping patterns are interpreted as relict wedge-like lithospheric deformation zones initiated in the fossil collisions that assembled the Yangtze Block and the SCB.The overall trend of these tectonic wedges implies successive crustal growth along paleo-continental margins and is indicative of northward subduction and docking of accretional terranes.In contrast,no such dipping structures are preserved in the Cathaysia Block,indicating a weak and reorganized lithosphere.The variations in the deformation responses across the SCB reflect the long-term modifications of the lithosphere caused by prolonged collision and extension events throughout the tectonic history of the SCB.Our results demonstrate the critical roles that suture zones played in the successive growth and evolution of the continental lithosphere.展开更多
文摘By field observation and simulating test in shallow seam longwall mining, the asymmetry breaking of main roof is discovered during the first weighting. Based on simulating model test and theoretical analysis, the mechanism of main roof first breaking is revealed, and the asymmetry breaking parameter is determined at all.
基金Supported by the National Natural Science Foundation of China(40772092)
文摘As a case study of the Panji No.1 Coal Mine in Anhui Province, based on thesite measured and statistical data, summarized the lithologic associations, characteristicsand distribution laws of interlayer-gliding structures and tectonic coal in the No.11-2 coalseams.The results show that 9 modes of lithologic association can form interlayer-glidingstructures.It is more easy for rock slip to occur when the lithologic associations are mainroof + coal seam + immediate floor type, compound roof+immediate roof + coal seam +immediate floor type and immediate roof + coal seam + immediate floor type.Lithologicassociations of roof and floor are the precondition to the formation of interlayer-glidingstructures.
基金partially supported by the National Natural Science Foundation of China(91955210,41625016,and 41888101)。
文摘Collisional orogens form when tectonic forces amalgamte fragments of Earth’s continental lithosphere.The sutures between individual fragments,or terranes,are potential sites of weakness that facilitate subsequent continental breakup.Therefore,the lithospheric architecture of collisional orogens provides key information for evaluating the long-term evolution of the continental interior:for example,the South China Block(SCB),where the tectonic history is severely obscured by extensive surface deformation,magmatism,and metamorphism.Using new passive-source seismic models,we show a contrasting seismic architecture across the SCB,with three prominent crustal dipping structures across the Jiangnan Orogen.Combined with constraints from multi-disciplinary regional geophysical datasets,these pronounced dipping patterns are interpreted as relict wedge-like lithospheric deformation zones initiated in the fossil collisions that assembled the Yangtze Block and the SCB.The overall trend of these tectonic wedges implies successive crustal growth along paleo-continental margins and is indicative of northward subduction and docking of accretional terranes.In contrast,no such dipping structures are preserved in the Cathaysia Block,indicating a weak and reorganized lithosphere.The variations in the deformation responses across the SCB reflect the long-term modifications of the lithosphere caused by prolonged collision and extension events throughout the tectonic history of the SCB.Our results demonstrate the critical roles that suture zones played in the successive growth and evolution of the continental lithosphere.
