Lacunarity analysis of fracture networks: Evidence for scale-dependent clustering
Lacunarity analysis of fracture networks: Evidence for scale-dependent clustering
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DOI：
10.1016/j.jsg.2010.08.010
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发表时间：
2010-10
影响因子：
3.1
通讯作者：
A. Roy;E. Perfect;W. Dunne;N. Odling;Jung-Woo Kim
中科院分区：
文献类型：
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作者：
A. Roy;E. Perfect;W. Dunne;N. Odling;Jung-Woo Kim
以前对裂缝网络的研究表明，包含在不同力学单元（“层控”）内的裂缝是规则间隔的，而那些终止于岩体内的裂缝是聚集的（“非层控”）。孔隙度是一个可以量化岩石裂隙间距分布的参数。当考虑到裂缝丰度的差异进行归一化时，空隙度将空间的分布表征为裂缝网络中的聚类程度。归一化孔隙度曲线，L（r），使用滑动盒算法计算，并绘制为框大小的函数，r，构造天然裂缝模式从Telpyn点，威尔士和Hornelen盆地，挪威。对Telpyn Point断裂的分析结果表明，这种曲线对同一尺度下不同断裂组的聚类差异很敏感。对于从Hornelen盆地在不同尺度上绘制的裂缝网络，我们的分析表明，聚类随着空间尺度的减小而增加。这一趋势归因于从作为不同机械单元的沉积旋回（100- 200米）尺度的“层控”系统向厚度为10米的更精细层理尺度的“非层控”断裂系统几何形状的过渡。
Previous studies on fracture networks have shown that fractures contained within distinct mechanical units (“stratabound”) are regularly spaced while those that terminate within the rock mass are clustered (“non-stratabound”). Lacunarity is a parameter which can quantify the distribution of spaces between rock fractures. When normalized to account for differences in fracture abundance, lacunarity characterizes the distribution of spaces as the degree of clustering in the fracture network. Normalized lacunarity curves, L∗(r), computed using the gliding-box algorithm and plotted as a function of box-size, r, were constructed for natural fracture patterns from Telpyn Point, Wales and the Hornelen basin, Norway. The results from analysis of the Telpyn Point fractures indicate that such curves are sensitive to differences in the clustering of different fracture sets at the same scale. For fracture networks mapped at different scales from the Hornelen basin, our analysis shows that clustering increases with decreasing spatial scale. This trend is attributed to the transition from a “stratabound” system at the scale of sedimentary cycles (100–200m) that act as distinct mechanical units to a “non-stratabound” fracture system geometry at the finer 10’s of meters thick bedding scale.