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
A four-node quadrilateral shell element with smoothed membrane-bending based on Mindlin-Reissner theory is proposed. The element is a combination of a plate bending and membrane element. It is based on mixed interpola...A four-node quadrilateral shell element with smoothed membrane-bending based on Mindlin-Reissner theory is proposed. The element is a combination of a plate bending and membrane element. It is based on mixed interpolation where the bending and membrane stiffness matrices are calculated on the boundaries of the smoothing cells while the shear terms are approximated by independent interpolation functions in natural coordinates. The proposed element is robust, computationally inexpensive and free of locking. Since the integration is done on the element boundaries for the bending and membrane terms, the element is more accurate than the MITC4 element for distorted meshes. This will be demonstrated for several numerical examples.展开更多
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.
文摘A four-node quadrilateral shell element with smoothed membrane-bending based on Mindlin-Reissner theory is proposed. The element is a combination of a plate bending and membrane element. It is based on mixed interpolation where the bending and membrane stiffness matrices are calculated on the boundaries of the smoothing cells while the shear terms are approximated by independent interpolation functions in natural coordinates. The proposed element is robust, computationally inexpensive and free of locking. Since the integration is done on the element boundaries for the bending and membrane terms, the element is more accurate than the MITC4 element for distorted meshes. This will be demonstrated for several numerical examples.
