Research On Rock Damage Mechanism Based On Strain Hardening/Softening Model And Stability Analysis Of Surrounding Rock

In recent years,with the development of infrastructure in our country,geotechnical engineering such as underground space,tunnel construction,and mining has been increasing.In the process of engineering construction,engineering accidents caused by disturbance of surrounding rock due to disturbance are not uncommon.Therefore,it is of great significance to study the damage mechanism of rock and the stability analysis of surrounding rock.This article is based on the National Natural Science Foundation of China(No.51874112): “Evolution of rock mass mechanical behavior and three-dimensional dynamic fracture morphology characterization”.Based on the elastic-plastic theory,a strain hardening / softening constitutive model is established to describe The damage and destruction process gives the derivation process of the damage proximity that can qualitatively and quantitatively analyze the degree of rock damage,so as to analyze the stability of the surrounding rock,and use FLAC3D and MATLAB software to realize the three-dimensional reconstruction of the rock internal shape Finally,the above research is applied to the case,the main research results and conclusions are as follows:(1)By using the M-C model and strain hardening / softening model built in FLAC3D numerical software to perform uniaxial compression simulation on rock specimens,the effect of different dilatancy angles on the calculation results was analyzed,and it was found that: considering the strain hardening / softening model in the pre-peak hardening stage It can better describe the process of rock damage and destruction,and can be well applied to geotechnical materials;the value of the dilatancy angle has a great influence on the damage and damage form of the rock specimen.The specific value should be based on the rock properties and stress conditions make change.(2)Through the analysis of two cases of rock uniaxial compression numerical simulation test and roadway excavation,it is found that the damage proximity index derived on the basis of M-C yield criterion can qualitatively describe the damage and failure process of rock samples and surrounding rocks,And the damage degree zoning based on the damage proximity can provide reference for the stability analysis of surrounding rock and the selection of actual engineering construction and support scheme.(3)The data derived from FLAC3D is processed by MATLAB software to realizethree-dimensional reconstruction,and is applied in two cases.The process of sample damage and failure,as well as the distribution and development law of stress,displacement,damage and failure area in the surrounding rock of roadway are displayed in three-dimensional intuitionistic way,which has practical value.(4)In addition to verifying the applicability of strain hardening / softening models and failure criteria in geotechnical engineering,the effects of roadway excavation on the stress,displacement and damage of adjacent roadways were analyzed through numerical simulation.It is consistent with the law of damage and destruction,and provides a reference for the support design and monitoring point arrangement of relevant roadways in real projects,and reflects the practicality of the research content of this article.