Redevelopment Of The Common Soil Constitutive Model Based On ANSYS-UPFs And Its Application In Earth-Rock Dam Calculation

Material constitutive model is mathematical expression that describes its mechanical properties,and general in the form of relationship of stress-strain-time-intensity.As a kind of natural geological material,soil presents highly anisotropy,noncontinuity and randomness in composition and construction,which results in complex stress-strain relation.On the numerical calculation and analysis of geotechnical engineering,it is necessary to determine a soil constitutive model that its form is simple and its parameters are easy to obtain.Besides,it is also necessary to make use of a software platform with excellent pre-processing and post-processing function,efficient solution algorithm and powerful redevelopment capability.By summarizing the research achievements and practical experience,this paper establishes a general framework with theoretical basis of Duncan-chang model and equivalent linear model and the platform support of ANSYS software,and has carried out following works according to this framework:The first part of this paper makes some improvement on the method to obtain related physical parameters,so that it's able to consider the influence of soil tensile strength and reflect actual soil unload-reloading curve's characteristics.Then,by combining the elastic increment constitutive relation and the improved Duncan-chang model,this section designs the framework of subroutine and explaines some important details in the programming.The second part of this paper establishs the finite element model and analytical framework based on the conventional triaxial compression test,and designs various conditions to simulate the load-unload-reloading process and reflect the influence of variation of confining pressure,which purpose is to verify the reliability of the redeveloped Duncan-chang model subroutine.In addition this section also designs a condition calculated by Mohr-Coulomb strength criterion to make a further comparison and explains differences between them in detail.The third part of this paper redevelops the equivalent linear model,based on the characteristics of the dynamic stress-strain relationship of soil and the theory of viscoelastic linear dynamic model.In this section,the basic form of equivalent linear model,the dtermination of equivalent parameters G and D,the derivation of incremental constitutive relation,the programming idea of subroutine and some important details are introduced.The fourth part oft this paper establishs the finite element model and analytical framework,based on the cyclic simple shear tests,and respectively designs conditions under the action of simple harmonic tangential stress and simple harmonic tangential displacement,which purpose is to reflect nonlinearity and hysteresis of soil's deformation under cyclic-loading and to verify the reliability of the redeveloped equivalent linear model subroutine.Based on the previous verification,the fifth part of this paper applies redeveloped subroutines to the static and dynamic calculation of earth-rock dam,including the construction process simulation,the impoundment condition analysis and the seismic time-history analysis,which purpose is to demonstrate the applicability of the redeveloped subroutines in the actual calculation of earth-rock dam...