|
Abstract Characteristics of displacements evolution in aspects of time and space in instability process of fault rockburst are inspected and analyzed by using the digital speckle correlation method. The test material is a kind of Fangshan granodiorites and the specimens are loaded by a large-scale double-axis test machine；the specimen surface speckles images in instability process of fault rockburst are recorded by adopting high speed cameras. The analysis results show that：(1) Fault rockburst is associated with confining pressure. Fault rockburst needs to meet certain confining pressure conditions；and fault will slick steadily when the confining pressure is lesser. (2) Peak stress and stress drop increase in the process of fault rockburst when confining pressure increases. (3) There are interval sliding characteristics of displacement evolution in fault rockburst；and the time of interval sliding increases with the increasing of confining pressure. The sliding distance and velocity at the first sliding are both greater than that at the second sliding. (4) Fault displacement evolution displays space differences characteristics in instability process of rockburst；and sliding value will increase with the increasing of the distance between observation point and loading end.
|
|
Received: 17 December 2010
|
|
|
|
2011, Vol. 30 
