The application of destressing method can change the distribution patterns of the stress field in the weak rock surrounding openings. locate the openings in the zone of low stress level, thus improve their loading and...The application of destressing method can change the distribution patterns of the stress field in the weak rock surrounding openings. locate the openings in the zone of low stress level, thus improve their loading and maintaining conditions. Such method is considered as a new way of opening maintenance in weak rock and has caused extensive interests in mining industry both at home and abroad. The results of theoretic research and lab experiments of utilizing top-destressing trough to maintain the opening affected by mining activities in weak rock, as well as its practical application in a coal mine are introduced in this paper. The research results indicate that the deformation and floor heaving of the opening in weak rock can be effectively controlled, and long-term stability of the opening can be realized by applying destressing method as long as the destressing plan and concerned parameters are carefully determined.展开更多
A mode II crack in single-crystal silicon was investigated experimentally using high-resolution transmission electron microscopy.Geometric phase analysis and numerical moiré method were employed to map the deform...A mode II crack in single-crystal silicon was investigated experimentally using high-resolution transmission electron microscopy.Geometric phase analysis and numerical moiré method were employed to map the deformation fields of the crack-tip area.The normal strain field maps of the crack-tip area indeed showed the deformation occurs primarily in the vicinity of the dislocations and the normal strains are near zero in the crack-tip area.The shear strain field map shows that the relatively large shear strain is in the crack-tip area.The experimental results were compared with the predictions of linear elastic fracture mechanics.The comparison shows that measured strain distribution ahead of the crack-tip agrees with the predictions of linear elastic fracture mechanics up to 1 nm from the crack-tip.展开更多
文摘The application of destressing method can change the distribution patterns of the stress field in the weak rock surrounding openings. locate the openings in the zone of low stress level, thus improve their loading and maintaining conditions. Such method is considered as a new way of opening maintenance in weak rock and has caused extensive interests in mining industry both at home and abroad. The results of theoretic research and lab experiments of utilizing top-destressing trough to maintain the opening affected by mining activities in weak rock, as well as its practical application in a coal mine are introduced in this paper. The research results indicate that the deformation and floor heaving of the opening in weak rock can be effectively controlled, and long-term stability of the opening can be realized by applying destressing method as long as the destressing plan and concerned parameters are carefully determined.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10862002 and 11062008)the Program for New Century Excellent Talents in University (Grant No. NCET-10-0909)the Natural Science Foundation of Inner Mongolia (Grant No. 2010BS0106)
文摘A mode II crack in single-crystal silicon was investigated experimentally using high-resolution transmission electron microscopy.Geometric phase analysis and numerical moiré method were employed to map the deformation fields of the crack-tip area.The normal strain field maps of the crack-tip area indeed showed the deformation occurs primarily in the vicinity of the dislocations and the normal strains are near zero in the crack-tip area.The shear strain field map shows that the relatively large shear strain is in the crack-tip area.The experimental results were compared with the predictions of linear elastic fracture mechanics.The comparison shows that measured strain distribution ahead of the crack-tip agrees with the predictions of linear elastic fracture mechanics up to 1 nm from the crack-tip.
