Study On Meso-structural Models Of Soil-rock Mixture And Adaptive Finite Element Analysis And Applications

As for soil rock mixture,which is a two-phase composite material,its mechanical properties depend on the mechanical properties of soil and rock block as well as the contact relationship between them.Establishing a meso model that conforms to the actual natural c onditions(the location,shape and size of rock block are random)is the premise and foundation for numerical simulation of soil rock mixture meso mechanics.Finite element method is one of the most effective methods for meso numerical simulation of soil rock mixture.After selecting the appropriate element type,it is necessary to set the mesh density according to the characteristics of the probl em and the calculation accuracy.In the meso elastic-plastic finite element analysis of soil rock mixture,there is stress concentration in the sharp corner area of block stone,and the phenomenon of stress concentration will also appear in the numerical simulation of soil mass.Therefore,it is necessary to adopt adaptive grid technology to avoid the blindness of grid encry ption.In order to better capture the large plastic strain in the plastic zone and improve the calculation accuracy of the plastic zone,adaptive mesh technology is also needed.This paper mainly focuses on the establishment of two-dimensional meso stochastic model of soil rock mixture,efficient adaptive finite element analysis and application.The main contents and conclusions are as follo ws:(1)The "Boolean intersection operation" in computer graphics is used to judge the intersection of block stones.It can not only avoid the complex mathematical operation of traditional methods in the intersection judgment of polygon block stones,but also solve the difficulty of the intersection judgment of irregular curved polygon block stones,and improve the content of block stones in the meso structure model.The implementation method is simple and efficient,which greatly improves the modeling efficien cy.Through the secondary development of ABAQUS by writing PYTHON script,a two-dimensional meso model of soil rock mixture in line with the actual natural conditions is established,in which the shape of block stone is random(2)The adaptive remeshing algorithm based on the a posteriori error estimation is used,and the corresponding elastic-plastic adaptive finite element PYTHON script is written in combination with the secondary development of ABAQUS to realize the whole process of adaptive solution of the fine view numerical simulation of soil-rock mixture,and the geometric model building method and the adaptive finite element method based on the remeshing algorithm are applied to several types of typica l soil-rock mixture numerical simulation.The reliabilit y of the stochastic model of soil-rock mixture and the effectiveness and adaptability of the adaptive finite element method are verified.(3)The above algorithm is used to generate the corresponding soil rock mixture slope,and the adaptive finite element alg orithm combined with the strength reduction method is used to analyze the stability of the soil rock mixture slope model.Through comparison,it is concluded that the adaptive finite element calculation is more accurate in the slope stability analysis,and can better obtain the shape and location of the sliding surface of the slope.