Research On Influence Of The Filling Height On Settlement Of Soil-rock Filling Body

Earth rock fill projects are rapidly increasing with the large-scale construction of infrastructure,height of which is also getting higher and higher.Among these projects,the high rock fill dam develops fastly.Deformation control is a key factor to ensure the safety of filling body,so deformation calculation is essential in design.However,with the increase of fill height,it is much more difficult to get accurate deformation calculation.The main purpose of this paper is to analyze the main error sources of the settlement calculation of the filling body,select the reasonable constitutive model and apply it to the finite element calculation of the rockfill dam,and then use the finite element method to analyze the influence of the height of the filling body on settlement.The main contents are as follows:(1)After summarizing main error sources in finite element settlement calculation,influences of constitutive model,material parameters and geometric model on the calculation results are analyzed.Discussion about shortcomings of the common constitutive model reveals the effect of unreasonable constitutive models on settlement calculation results.The calculation errors,which may be caused by material parameters,are discussed after comparing the difference between experimental materials and the actual filling materials.In addition,the impact of the simulation method of filling process on the calculation results is analyzed.(2)Based on the characteristics of CSUH model,the applicability of the model to clay,sand and coarse aggregate is demonstrated.The CSUH model is applied to predict the indoor test results under different confining pressures and stress paths,and the results from which proved that this model can describe mechanical properties of soil materials quite well.In order to apply the model to finite element analysis,the elastic-plastic matrix of CSUH model under transformation stress space is deduced.With the secondary development platform of finite element software,the user subroutine of the model is compiled by FORTRAN language and then verified through conventional tri-axial test,the correctness of the UMAT subroutine is illustrated.(3)The settlements of Shuibuya Dam and Zipingpu Dam during filling are calculated using ABAQUS.The predicted results are in good agreement with the measured values,which can validate the selected constitutive model,the way of choosing material parameters and the simulation of filling process.Besides,an equation reflecting the relationship between the filling height and the maximum construction settlement is proposed,and the result of the model prediction is compared with the measured data.