Rearch On The Geomaterials Structure

Since the geological material is a kind of complex material having strong structural property, the structural property problem has been always a difficult and frontier problem in the field. The purpose of this paper is to study the structural property of this kind of complex geological material and to understand&master its description method as well as material’s property, feature and variation rule under environmental influence, especially the influence of this material’s structural property on its macroscopic properties.In this paper, the study on material granules which are the basic elements constituting materials is the starting point of research; the characteristics and properties of granular structure as well as the mechanical and geometrical characteristic of granular structure are analyzed in full consideration of geometrical shape of granules, surface characteristics of granules and properties of granular materials. The relation between mechanical properties&geometrical features of granular scale and macroscopic features&properties of this material is established through analysis of the structural properties of granules.Through the analysis method based on granular scale, this paper sets up the description method for this kind of geotechnical structural material, including granular shape, geotechnical material structure composed of granules, material structural properties associated with structure; preliminarily establishes the static analysis method for structural materials; sets up the strength theory of granular materials and corresponding force chain analysis method; puts forward the full state function theory including the elastic modulus of granular structural materials, structural critical strength and geometric variation characteristics, from which the constitutive relation of granular materials is deduced.The established key concepts include the following aspects:(1) The basic components of geological materials including geometric shape of granules, their surface features and physical properties have decisive influence on macroscopic properties;(2) The structure composed of granules is another important factor that affects the macroeconomic properties of materials. Granular structure can be divided into simple structure and complex structure:simple structure includes the connection structure of basic uniform effect, chain structure and mesh structure; complex structure is mainly the fractal structure;(3) The macroscopic elastic modulus of this material is determined by the static (or elastic) performance of material structure, and the yield strength of material is subject to the critical strength of material structure. That is to say, the structural static variation has nothing to do with the macroscopic elastic properties, and the changes of structural critical strength are related to the macroscopic plastic performance;(4) The three elements, namely, the static elastic modulus, critical strength of the structure and geometric conditions of material structure, constitute the structural material’s full state function, from which the corresponding material constitutive relation can be derived.The complexity of geological materials originates from its constitutive property. The research object of classical elastic-plastic theory is the material with continuous and structureless, which belongs to simple material. The theory used to study geological material is a complex material mechanics theory.