Study On Rock Mass Stability And Its Spatial Morphological Characterization

With the expansion of geotechnical engineering scale,the engineering surrounding rock conditions and the surrounding environment of the engineering is becoming more and more complex.This result in many geotechnical engineering design and construction cannot be safe controlled according to the corresponding specification and it is difficult to evaluate the stability of engineering rock mass.The stability evaluation of geotechnical engineering runs through the whole process of geotechnical engineering that has playing an important role in engineering construction.In particular,the safety evaluation in the construction process,such as excavation and support plan formulation,has important influence on the design planning and construction of the project.The stability evaluation of geotechnical engineering can be divided into two parts: the whole level and the local level.The internal stability of the overall engineering structure of rock and soil,namely the spatial distribution of internal damage of geotechnical engineering structure,can't be directly reflected in these two aspects.In this paper,based on the concept of yield approach index,the geotechnical engineering stability evaluation method is established.In addition,the corresponding analysis procedure is prepared by using the numerical software of geotechnical engineering.This rationality is verified according to the actual engineering example.According to the Matlab's graphic processing principle,the band diagrams of the rock mass security coefficient is recognized and extracted to realize the 3D space representation.The main research results of this paper are as follows:(1)Through theoretical analysis,the yield approach index based on the Griffith strength criterion is deduced.Theoretical deduction and model simulation results show that the yield approach index not only give the plastic yield zone,but also indicate the area outside the plastic zone is close to the degree of plastic yield.It intuitively shows the overall safety of surrounding rock and predicts the development of the plastic zone of surrounding rock,which provides reference for stability evaluation in engineering construction.(2)In this paper,the Weibull distribution function is used as the probability density function of the rock and soil mechanics parameters.Based on the FALC3 D built-in fish language,the rock and soil mechanics parameters are randomly distributed according to the probability density function.The influence of the rockand soil mechanics parameters heterogeneity on the internal damage of rock and soil structure is studied.(3)According to the mapping principle of bitmap,image color threshold is identified and extracted by Matlab image processing tool to realize the identification and extraction of the band diagram of the yield approach index of rock and soil.Then,through the successive identification and extraction of the color characteristics of the pixel points in the damaged area as well as the superposition of color characteristics in order to space,the 3D reconstruction of the safety factor of the rock mass model is realized.The study on the spatial distribution of the rock mass safety factor is helpful to analyze the expansion and evolution of the damaged area in the rock mass and its influence on the stability of geotechnical engineering.It can not only deepen the further understanding of the instability evolution of rock mass,but also deeply understand the relationship between local and generalized geotechnical failure problems.