The size of a fracture within a rock mass can be obtained using borehole sampling data or exposed surfaces. This paper aims at building a method to estimate the fracture size, without the presupposed size distribution, based on full three-dimensional geometric parameters (shape, orientation and position). In this study, the rock fracture was considered as an elliptical plane, and each set of fractures had the same aspect ratio. The statistical parameters of fracture size were derived, from sample (sub fracture group) to population (parent fracture group), based on multiple borehole samples. Parent fracture group simulations were realized using MATLAB, and the codes were designed by the authors. Moreover, in-situ time domain electromagnetic methods (TEM) and borehole induced polarization methods (BPM) were used to validate the Monte Carlo simulation. The results revealed that the statistical rules of Monte Carlo simulation of the parent fracture group are similar to those of the in-situ detection.

可以使用钻孔采样数据或裸露表面获得岩体内裂缝的大小。本文旨在建立一种基于全三维几何参数（形状、方向和位置）估计裂缝尺寸的方法，无需预先假定的尺寸分布。在本研究中，岩石裂缝被视为一个椭圆平面，每组裂缝具有相同的纵横比。基于多个钻孔样品，从样本（子裂缝组）到总体（母裂缝组）推导出裂缝尺寸的统计参数。母裂缝群的模拟使用MATLAB实现，代码由作者设计。而且，原位时域电磁法 (TEM) 和钻孔激发极化法 (BPM) 用于验证蒙特卡罗模拟。结果表明，母裂缝组蒙特卡罗模拟的统计规律与原位检测的统计规律相似。