Research And Application Of Constitutive Model Of Cement Sand And Gravel Dam

As a new type of dam building material,cement sand and gravel has the advantages of green,environmental protection,economy and simple construction.At present,the cement sand and gravel l material has been widely used abroad,but the dam building material in China is in the promotion stage.Scholars at home and abroad have done a lot of research work on the durability and mechanical properties of cemented sand gravel material,but there is less research on its stress-strain relationship.In order to carry out the section design of the cement sand and gravel dam and the finite element analysis of stress and deformation,the analysis of the stress and deformation of the cemented sand gravel material has practical significance.Therefore,it is particularly important to construct a constitutive model of cement sand and gravel,whether it is the cross-section design study of multi-gelled sand gravel or the finite element analysis.This paper summarizes the indoor and outdoor experimental data of cement sand and gravel,compares the advantages and disadvantages of each constitutive model and applicability,proposes a constitutive model suitable for cement sand and gravel material,and applies this model to the cement sand and gravel dam.The finite element analysis aims to provide important theoretical basis and application value for the design and application research of gelled sand gravel dams.The specific research is as follows:(1)This paper collects the indoor and outdoor experimental data and constitutive models of cement sand and gravel material at home and abroad,compares and analyzes them,and studies the applicability of the cement sand and gravel material constitutive models.It is found through research that the cement sand and gravel material constitutive model considers the influence of confining pressure and age on its stress-strain relationship,but does not consider the effect of the amount of cementing material on it.The amount of cementitious material is the most important factor that affects the mechanical properties of cement sand and gravel material.Therefore,the cement sand and gravel material model has a poor degree of fit to the experimental data under different mix ratios,which is not convenient for the application of engineering examples.(2)Based on the K-G constitutive model of rockfill,a constitutive model suitable for cement sand and gravel material is proposed.The model considers the influence of different confining pressures and the amount of different cementing materials on its stress-strain relationship,and can better fit the stress-strain relationship under different confining pressures when the amount of cementing material is between 40 kg / m3-80 kg / m3.And the relationship between body strain and axial strain.(3)Based on the study of the engineering example of the Shoukoubao cement sand and gravel dam,the nonlinear and constitutive model constructed in this paper is used as the basis and combined with the actual local temperature conditions,the temperature and stress fields of the Shoukoubao Dam are numerically simulated.It is verified through calculation that the non-linear constitutive model proposed in this paper is suitable for finite element analysis,can accurately describe the constitutive behavior of cement sand and gravel material,and has good applicability in engineering applications.