Multi-scale Study On Parameters Of Cemented Sand And Gravel Constitutive Model

As a new type of dam-building material,cemented sand and gravel material is in line with the development and purpose of The Times.It has the advantages of low energy consumption,simple process,low cost and environmental protection,which meet the requirements of sustainable development.However,by referring to a large number of relevant literatures,it is found that there are few researches on the material properties of cemented sand and gravel.Most scholars believe that the properties of cemented sand and gravel and concrete can be summed up in one category.However,the research on constitutive model and related parameters of cemented sand and gravel is relatively lacking.According to the material properties of cemented sand and gravel,starting from the meso and macro parameters of the constitutive model,through the cemented sand and gravel,a finite element numerical simulation program combined with the improved genetic algorithm inversion theory is established.Parameter inversion analysis,on the basis of random aggregate models with different sand ratios,discussed the relationship between the microscopic parameters of cemented sand and gravel and the macroscopic mechanical behavior.Then the equivalence theory model of composite material is used to calculate the meso-parameters of cemented sand and gravel material and study the macroscopic parameter characteristics of cemented sand and gravel material,which provides an important theoretical basis for the application research of cemented sand and gravel dam and has application value.The specific research of this paper is as follows:(1)By referring to relevant literatures,a relatively simple linear elastic model was adopted to determine the constitutive model of cemented sand and gravel in the numerical simulation scheme.The sensitivity analysis of the meso-component parameters of the numerical model of cemented sand and gravel materials was carried out,and the meso-component parameters with higher sensitivity factors were screened out.Then,an inverse calculation combining the improved genetic algorithm and numerical simulation was proposed.According to the uniaxial compression results of indoor macro tests,the micro-parameters of highly sensitive factors were inverse calculated to determine the meso-component parameters of cemented sand and gravel.(2)In determining the cemented sand and gravel mesoscopic component parameters,on the basis of considering the macro more difficult for a numerical simulation test,set up under different sand ratio and adjustment for the random polygonal aggregate grading of aggregate model,and simulate the macroscopic damage experiment,to explore the cemented sand and gravel aggregate gradation and the relationship between the macroscopic mechanical properties(3)Based on the study of meso-component parameters,combined with the existing theoretical models of composite material equivalence,establish the quantitative relationship between the macroscopic properties of cemented sand and gravel composites and the meso-components under each equivalence model,And through theoretical analysis method to study the macro parameters of cemented sand and gravel,determine the parameters with higher adaptability,and explore the relationship between the macro parameters of cemented sand and gravel.