岩石细观破裂的实验观测研究及其对认识地震活动性的启示
|
摘要
对合一条预制中心割缝的大理岩六边形试件进行了对边均匀加压实验，在扫描电镜下实时观测了细观裂纹的起裂、扩展过程，研究了它们与外载大小和方向之间的关系．用实验过程中拍摄的显微照片测量与计算了裂端距（割缝周围次级裂纹开裂点至割缝端点的距离）与外载方向之间的关系，并分析了当加载方向变化时裂纹扩展的特征及变化规律．最后将实验结果与滇西北洱源－鹤庆断裂尾端张性盆地的发育过程做了对比，发现两者在受力方向改变时，次级断层的发育过程具有相似之处．
Uniaxial compression tests of marble plates cut as regular hexagon specimens containing a central slot were conducted under direct SEM observation. The initiation,propagation, opening and closure of cracks accompanying the increase of stress level and the change of loading direction throughout the whole test process were monitored.From the photographs taken at different stages of fracture development and for different directions of loading,the relationships between the crack to slotend distance and the direction of loading and between the crack length and stress level are analysed. A better understanding of the fracture characteristics of rock materials has been achieved. Finally,a prelimenary comparison between the rest results and the development of Eryuan-Heqing tensail basin in Northwestern Yunnan are conducted.
Uniaxial compression tests of marble plates cut as regular hexagon specimens containing a central slot were conducted under direct SEM observation. The initiation,propagation, opening and closure of cracks accompanying the increase of stress level and the change of loading direction throughout the whole test process were monitored.From the photographs taken at different stages of fracture development and for different directions of loading,the relationships between the crack to slotend distance and the direction of loading and between the crack length and stress level are analysed. A better understanding of the fracture characteristics of rock materials has been achieved. Finally,a prelimenary comparison between the rest results and the development of Eryuan-Heqing tensail basin in Northwestern Yunnan are conducted.
引文
［1］Brady，B．T，AninvestigationofthescaleinvariantPropertiesoffailure，Int．J．RockMech．Min．Sit．＆Geomech．Abstr．，14，121－126，1977．［2］Allegre，C．J，LeMouel，J．L，Provost．A，Scalingrulesinrockfractureandpossibleimplicationsforearthquakeprediction，Nature，297，47－49，1982．［3］King，G．，Theaccommodationoflargestrainsintheupperlithosphereoftheearthandothersolidsbyself－similarfaultsystems：thegeometricaloriginofb－value，PureAppl．Geophys．，121，76－815，1983．［4］Scholz，C．H．，Mandelbrot，B．B．eds，SpecialIssue，Fractalsingeophysics，PAGEOPH，131（1／2），316，1989．［5］洪时中、洪时明，地学领域中的分维研究：水系、地震及其它，大自然探索，7（2），33－40，1988．［6］Hirata，T．，Omori＇s power lawaftershock sequenceofmicrofracturingintherockfractureexPeriment，J．Geophys．REs．，92，6215－6221，1987．［7］zhaoYonghong，HuangJiefan，WangRen，Thefractalcharacteristiceofmeso－fractureincompressedrockspecimens，Int．J．RockMech．Min．Sci．＆．Geomech．Abstr．，30（7），877－882，1993a．［8］赵永红、黄杰藩、王仁，岩石微破裂发育的扫描电镜即时研究，岩石力学与工程学报，11（3），284－294，1992．［9］赵永红、黄杰藩、王仁，岩性和粒度对裂隙发育的影响之SEM实验研究，见：岩石圈地质科学，北京：地震出版社，153－159，1993．［10］W
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心