Research On The Size Effect Of Jointed Rock Mass Deformation Parameter And REV

This paper theme is Research on the size effect of jointed rock mass deformationparameter and REV. Based on the anisotropic elastic theory and theory of equivalentcontinuum, through the application of general distinct element software, the size effectand REV of equivalent elastic modulus of jointed rock mass are studied, the factorswhich may influence the result are analysed. The main work of this paper includes thefollowing contents:First, the research status of deformation parameters of jointed rock masses, researchstatus of size effect and REV of strength and deformation of jointed rock mass aresummarized;Second, the theory and method this paper applys are briefly introducd, whicn include:equivalent continuous model of jointed rock mass, joint statistics characteristics anddeformation and mechanical properties of jointed rock mass s, anisotropic elastic theory,the two-dimensional distinct element code;Third, a variety of regular Jointed rock mass model are establish, and their size effectand REV of equivalent elastic modulus are investigated. The use of anisotropic elastictheory is verified though the stress-strain curve relationship. The working conditiontypes include:(1) regular models with one set joints, two sets joints and four setsjoints(2) analysis of joint angle (3) analysis of joint spacing (4) joint shear stiffness andnormal stiffness ratio K value.Fourth, the measured parameters of joint in literature data are used to establish themodel of random jointed rock mass, the size effect ofequivalent elastic modulus isstudied and its REV value is solvedFifth, when the REV value of established model is solved, the influence of jointsparameters on the deformation properties of jointed rock are studied.Through the above study, we can draws the conclusion: for the regular jointed rockmass model:(1) joint angle has no effect on the size effect and REV of equivalentelastic modulus;(2) the REV of equivalent elastic modulus of regular jointed rock massmodel is about4times of the distance between joints;(3) the ratio of joint shearstiffness and the normal stiffnesst has no effect on the size effect and REV of equivalentelastic modulus;(4) the equivalent elastic modulus of jointed rock mass is inversely proportional to the joints density, inversely proportional to the joints spacing,proportional to joint shear stiffness and normal stiffness ratio K value, in the conditionsof different joints angle, equivalent elastic modulus of jointed rock masses showanisotropy. For the established random jointed rock mass model, the equivalent elasticmodulus shows obvious size effect, we can take4m as its model REV.