A STUDY ON EVALUATION METHOD OF GEOTECHNICAL ENGINEERING ZONE SAFETY DEGREE BASED ON STRAIN SOFTENING

In view of the fact that the problems encountered in the stage of tensile failure, yield and failure stage are not considered in most existing local safety evaluation methods of geotechnical engineering, the local safety evaluation method of surrounding rock has been improved accordingly. The new evaluation method and new definition of geotechnical engineering zone safety degree were established based on strain softening model and Mohr-Coulomb yield criterion. It is defined by a uniform variable ZSD (Zone Safety Degree)synthetically considering shear and tension pattern, describing the safety degree of geotechnical body element from elastic stage, yield stage to failure stage, realizing the local safety quantitative evaluation with complex stress state and progressive failure progress. The ZSD expression formulas at different stages are derived, and the program by FISH language based on FLAC^3D platform is compiled. The corresponding examples and engineering are calculated, and the accuracy and efficiency of the ZSD method are verified. This method is simple in parameter expression and easy to be implemented in the program. It can judge the state of the zone in the range of ZSD and directly reveal the progressive failure process of rock and soil mass. This method provides an effective means for the analysis and prediction of the evolution of hazardous areas in geotechnical engineering and the description of the progressive failure process.