摘要
用盒维数方法估计了受压岩石表面断裂带的分维值，研究了分维值随载荷、结构（平板伏试件合圆孔或与加载方向成不同角度的割缝）、岩性（大理岩、灰岩、砂岩）和粒度的变化特征，分析了统计自相似性成立的范围与岩性和粒度的关系。研究结果表明。在微裂纹发育未连通为宏观断裂带阶段，分维值随载荷上升而上升，当宏观断裂带形成之后，分维值保持为常数，且随岩性不同而不同。对于所测三种岩石，自相似性成立的尺度范围的上限为颗粒尺寸的Ｚｙｌｊｌｏ倍。最后，结合岩石破裂过程的能量耗散机理，讨论了岩石分维断裂的物理意义。
he fractal dimension of geometric pattern of cracks on the sUrface of plate specimens of three rocks, namely, marble, sandstone and limestone, was calculated. The variation of the fractal dimension D with the stress level in each structured specimens (specimen containing a central circular hole or a central slot which makes different angles with the loading direction) as well as the variation of self-similarity range with lithology and grain size were analysed. The results show that the D-value increases during the process of microcracks initiation and their coalescence into the main fracture but remained unchanged as the macrofracture developed further. The upper scale limit of self similarity range is about two to ten times the grain size for the three rocks tested. Finally, the physical meanning of fractal distribution of crack pattern is discussed according to the energy dissipation mechanism in rock.
出处
《地质科学》
CAS
CSCD
北大核心
1994年第2期137-143,共7页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
地震科学联合基金
国家自然科学基金
关键词
岩石
破裂带
分维变化
自相似范围
Rock fracture, fractal characteristics, self-similarity range
