Estimating the intensity of rock discontinuities
Estimating the intensity of rock discontinuities
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DOI：
10.1016/s1365-1609(00)00022-8
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发表时间：
2000-07
影响因子：
7.2
通讯作者：
Lianyang Zhang;H. Einstein
中科院分区：
文献类型：
--
作者：
Lianyang Zhang;H. Einstein
本文提出了一种估计不连续面强度的方法，并将强度和方向表示为断裂张量。具体地说，首先估计不连续面的大小分布和数目，然后从中导出断裂张量。利用真实迹线长度分布与假定圆形不连续点的不连续点直径分布之间的一般体视关系，从圆形窗口采样的迹线数据中推断出不连续点的尺寸分布。针对实测迹线长度存在偏置的问题，提出了一种估算圆窗采样迹线长度真实分布的方法。圆窗采样在估计真实迹线长度时具有自动消除方向偏差的优点。然后提出了一种方法，该方法可以通过在正常尺寸钻孔中观察到的不连续面数量和从岩石表面的圆窗采样中推断的不连续面直径来估计目标体积中的不连续面总数。根据导出的结构面大小分布和数目，可以计算出结构面强度，即单位体积的结构面总面积，并将其包含在裂缝张量的新定义中。应用该方法对模拟不连续面进行了分析，得到了满意的结果。
This paper presents an approach for estimating the intensity of discontinuities and formulating intensity and orientation as a fracture tensor. Specifically the size distribution and the number of discontinuities are estimated first, from which the fracture tensor is then derived. Discontinuity size distribution is inferred from the trace data sampled in circular windows by using a general stereological relationship between the true trace length distribution and the discontinuity diameter distribution assuming circular shaped discontinuities. Because the measured trace lengths are biased, a method is proposed to estimate the true trace length distribution for circular window sampling. Circular window sampling has the advantage of automatically eliminating the orientation bias when estimating the true trace lengths. A method is then presented with which the total number of discontinuities in an objective volume can be estimated from the number of discontinuities observed in normal-size boreholes and using the inferred discontinuity diameter from the circular window sampling on the rock surface. With the derived size distribution and number of discontinuities, the intensity of discontinuities, which is the total surface area of discontinuities per unit volume, can then be calculated and included in a new definition of a fracture tensor. An application of the approach to analyze simulated discontinuities produces satisfactory results.