| Mining, drilling, construction, water conservancy and geology and other projects have occupied a very important position in the national production, but its foundation is rock mechanics. After One or two centuries of scientific research, rock mechanics has formed its own system, but for universality and precision of rock mechanics, we generally are skeptical, "the high reputation and low credibility" is a critical appraisal currently in rock mechanics field. The main problem in this paper includes the following aspects.First, the basic parameters of rock mechanics are difficult to determine. Many mechanics textbooks just provides the scope of the basic parameters for certain types of rock, but no exact values, such as elastic modulus and Poisson's ratio. Second, the universality rock mechanics is limited. A variety of strength criterion and constitutive equations is widespread, but it only applies to certain types of rock or some forms of rock. Third, Third, differences in parameter selection leads to inaccurate numerical results. The evaluation of numeral calculations in the rock mechanics academia is "Least bit of difference, huge mistakes". That is, if the input parameters and the selection of constitutive equations are not accurate, the results are no meaning even if the results of Computer calculation accurate to fifty of six decimal. In summary, the research of the basic parameters and constitutive equations is common ground on these issues.The research based on some major issues existing in rock mechanics. Based on triaxial confining pressure and instantaneous porosity measurements under "axle load-confining pressure" test, Objective analysis of the experimental data, expanded research of the basic parameters, redefines some new concepts, introduces a damage constitutive model and verified, also proposed a new damage constitutive model, this paper is expanding in order to find the better model, Details are as follows:(1) Based on triaxial confining pressure test, extended research for Poisson's ratio "?" and modulus of elasticity "E" of Nan chong and Wu sheng sandstone is done. Law in its full triaxial compression were analyzed, Proposed function of Poisson's ratio ?* and function of the elastic modulus E* (considered them as variable), fitting the basic equations and studied its own variation in the confining pressure.(2) The experimental device has been improved, for the first time measured instantaneous porosity under "confining pressure-axle load" effect. Deeply research for porosity (?), proposed "porosity-large strain" theory, and analyzed the correctness of the theory.studied the relation of porosity and the initial porosity, volume strain and axial strain, the rock of different nature and confining pressure.(3) For the first time, introduced the function of Poisson's ratio ?* and the function of elastic modulus E* to damage constitutive model based on Drucker-Prager criterion and the Correction parameters. The experimental results and theoretical results are verified, Degree of agreement is more than 99%.(4) Based on the "porosity-large strain theory" in this paper, First proposed "skeleton-pore" model and the basic theory of rock. Proposed the damage constitutive theory based on Skeleton-pore model. And solved its parameters, Compare experimental results and theoretical results, proved the results are fit better.(5) In the process of research of Skeleton-pore model, the rock strength will increase in certain stage, decrease in other certain stage, and first proposed the conception of negative and positive damage theory and introduced the details. |
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