Research On The Mutual Conversion For Hard-working And Soft-working Properties Of Rock With Statistical Damage Theory And Method

The simulation of the deformation process of rock in hard-working status or in soft-working status, that is, study on rock constitutive model, is the foundational content of rock mechanics, then the condition of mutual conversion for hard-working and soft-working properties of rock, and the strength rule are two of the most important parts of rock constitutive model, on which study still underway and far from enough, the existing product can only describe the effect of rock stress status in influencing hard-working and soft-working properties of rock, but can't take into accout either the stress status or physical and mechanical characteristic. For these, study was developed in this paper to solve the problem, which is of great thoeratical and practical significant.On the basis of research on the statistic damage constitutive model which can describe hard-working status as well as soft-working status, through discussing strain hard-working and soft working mechanism and variational law of stress-strain curve, the means to study the conversion condition of hard-working stauts and soft-working status was developed to get the quantificational expression of the conversion condition, which can describe not only the effect of rock stress status but also the effect of physical and mechanical characteristic itself, then the understanding on the conversion mechanicm was also deepen; Then, via discuss on the variational rule of curvature on the damage point or yield point in the stress-strain curve, the means to get the rock strength rule was deeply studied by getting extremum of multifunction, then primarily established the new type of rock strength rule, which can describe effects of multi-factor, and more accordance to the characteristic of failure envelopes.The analysis result on the engineering example indicates that, the quantificational conversion condition of rock strain hard-working status and soft-working status, and the new type of strength rule can almost exactly describe the measured result, so the research in this paper can enrich and perfect the product of rock constitutive model.