DIGITAL REPRESENTATION OF MESO-GEOMATERIAL SPATIAL DISTRIBUTION AND ASSOCIATED NUMERICAL ANALYSIS OF GEOMECHANICS:METHODS,APPLICATIONS AND DEVELOPMENTS
Abstract:This paper presents the author¢s efforts over the past decade for the establishment of a workable approach for geomechanics by taking into account the actual spatial distribution of different minerals,particulars and components in geomaterials at the meso-scale range. The primary goal of the approach is to provide a possible solution to solve the two intrinsic problems associated with the current main-stream methods for geomechanics. The problems are:(1) the constitutive models and parameters for soils and rocks cannot be given accurately in geomechanical prediction;and (2) there are numerous constitutive models for soils and rocks in the literature. The problems are possibly caused by the homogenization or averaging method in analyzing laboratory test results for establishing the constitutive models and parameters. The averaging method employs an assumption that the test samples can be represented by a homogeneous medium. Such averaging method ignores the fact that the geomaterial samples are also composed of a number of materials and components whose properties may have significant differences. In the proposed approach,digital image processing methods are used as a measurement tool to construct a digital representation for the actual spatial distribution of the different materials and components in geomaterial samples. The digital data are further proceeded to automatically generate meshes or grids for numerical analysis. These meshes or grids can be easily incorporated into existing numerical software packages for further mechanical analysis and failure prediction of the geomaterials under external loadings. The paper presents case studies to illustrate the proposed approach. Further discussions are also made on how to use the proposed approach to develop the geomechanics by taking into account the geomaterial behavior at micro-scale,meso-scale and macro-scale levels. A literature review of the related developments is given by examining the Science Citation Index(SCI) papers in the database of Science Citation Index Expanded. The results of this review have shown that the proposed approach is one of the latest research and developments in geomechanics where actual spatial distribution and properties of materials and component at the meso-level are taken into account.