基于图像数字化技术的裂隙岩石多场耦合分析

COUPLED MULTIPHYSICS ANALYSIS IN FRACTURED ROCK MASSES BASED ON DIGITAL IMAGE PROCESSING TECHNIQUE

引入图像数字化技术来客观地反映裂隙化岩石的非均质性结构分布,并将其转化成物理参数(渗透系数、弹性模量等)的分布图,然后将它和数值方法相结合,应用于裂隙化岩石流固热多场耦合分析中。首先需要获得高清晰度的裂隙岩石数字图像,岩石中不同的结构对应不同的归一化特征值I值(图像像素颜色的特征值),通过I值与材料参数之间的一一对应关系就可以得到岩石中不同结构材料物理参数的真实分布。将物理参数分布输入到我们开发的基于MATLAB和FEMLAB的岩石多场耦合分析程序中,就可以得到真实地反映裂隙岩石的多场耦合作用过程。数值分析结果表明:图像数字化技术与数值方法相结合是可行且有效的,其结果更能反映真实的物理现象。

A digital image-based （DIB） numerical method is used in two-dimensional coupled multiphysics analysis of fractured rock masses by actually taking into account the heterogeneous spatial distribution of rock structures-main fractures, minor fractures and intact rock. The digital image processing technique is developed to identify and classify these structures in the fractured rock masses and to translate spatial distribution of rock structures to spatial distributions of material parameters （permeability, Young＇s modulus, heat conductivity, etc.）. Then the characterized material parameters of rock masses are directly imported into our newly developed multiphysics simulator, a MATLAB and FEMLAB based Simulator of Coupled Multiphysics in Rock, to evaluate the effect of heterogeneity on the coupled multiphysics process in fractured rock masses. The DIB numerical results of coupled multiphysics process show that DIB technique is capable of characterizing the heterogeneity and fracture structures of fractured rock masses and that the DIB numerical method may be a new approach to predict more realistic numerical results.