Numerical Manifold Realization And Stability Analysis Of Crack Propagation In Jointed Rock Mass

With the continuous exploration of geotechnical field,how to deal with continuum to discontinuity of medium has become the focus of scholars.The numerical manifold method has unique advantages in the analysis of such problems because it unifies the continuous and discontinuous deformation and mechanics problems into complete expressions.However,the numerical manifold method still has a lot of optimization in the coverage method,and there is no comprehensive qualitative and quantitative analysis and research on the accuracy.Therefore,the following research is conducted in this paper.Firstly,the cover displacement function of physical cover in numerical manifold calculation is optimized.Traditionally use the three-node triangular unit,covered by three weight function and displacement function to form the overall displacement function,when the six node triangle unit,three cover displacement function directly,and up to six displacement function and weight function jointly determine the displacement of point,increasing the precision of displacement of the manifold.At the same time,the problem of weight function construction is solved by using the area coordinates of points.In terms of accuracy,the influence of the order of overlaying displacement function and meshing on the result is also studied,and the error is evaluated qualitatively and quantitatively.After solving the above problems,this paper studies the application of numerical manifold method in static crack propagation.Analysis with unilateral horizontal crack tablet,center horizontal tablet of crack and oblique crack plate under tensile loads,manifold element changes,the crack propagation path,the stress intensity factor,good reproduce the damage process of material,at the same time reflects the numerical manifold method in calculation of continuous to the superiority of discontinuous problems.Finally,taking xinglong tunnel section of hechang expressway in chongqing as the engineering background,the inclination probability distribution model,inclination probability distribution model,trace length probability distribution model and spacing probability distribution model of the structure surface are fitted by using the structural surface information collected on site.By Monte Carlo stochastic simulation of uncertain structural plane,based on the theory of joint rock mass equivalent,through joint shown in process modeling,joint rock mass of equivalent continuum model for not well versed in,in order for grouping joint modeling and form a network model of engineering rock mass,with six node triangle cell coverage system on the subdivision,crack crack criterion to choose Moore coulomb criterion,extending the principles of maximum ring choose to tensile stress criterion,the stability of the evaluation of engineering rock mass and support advice is given.