Macro-response of rock mechanics behavior affected by its micro-parameters

摘要

Micro-parameters of rock and soil material are hard to determine with present technology. But their unique physical & mechanics characteristics and failure mechanism are controlled by them, heterogeneity and micro-structure. So, virtual uniaxial compression tests of rock are done by means of inner fish language in particle flow code. Four different kinds of computing scheme such as friction coefficient, contact radius multiplier, elastic modulus and micro-strength between material particles based on these numerical models are designed. And each kind of computing scheme contains three calculating conditions of great, medium and less, total conditions being twelve, aiming to study relation between micro-mechanics-parameters and macro-mechanics-response of the rock and soil material. Found that the former three parameters can result in enhancement of material's modulus and strength, but micro-strength only increases macrostrength, that friction dominates post-peak strength of material, this friction effect is done after the micro-crack produced by micro-cohesion being overcome and under slipping condition. So the micro-cohesion only results in macro-strength change, but microfriction-coefficient can cause changes in strength and deformation feature. Contact radius multiplier determines cohesion strength and contact area of particles and elastic modulus dominates slipping strain of particles, so these two micro-factors can cause changes in strength and deformation. All these illustrate the relation is the one between part and whole. Features of assembly are large than particles, whose relation is not simply summation.