Static-Dynamic Nonlinear FEM Analysis For Steady Of Earth-Rockfill Dam Structure

In this thesis, based on collecting and arranging the interrelated information, by the application of secondary development and the flexible use of general software, a series of research and analysis had been deployed on the matter of deformation and stability for earth-rockfill dam. First of all, the Duncan-Chang hyperbola constitutive model and the Hardin-Drnevich constitutive model were implemented by using User Subroutine in ABAQUS software. The results of the validate computation shows that: this development of the subroutine is reasonable, it could be used for the static and dynamic stress- strain analysis.Secondly, the slope stability of an earth-rockfill dam was analyzed by shear strength reduction finite element method associated with seepage finite element analysis. With considering the effect of seepage, the position of the exit point and the phreatic surface, as well as the total head was calculated through iteration at first. The seepage forces were also determined according to the hydraulic gradient. In the consequent stability analysis, seepage forces, buoyancy, self-weight, and the earthquake inertia forces were loaded on the dam. The critical limit state and the factor of safety of the dam is calculated using temperature-driven strength reduction finite element method. The analysis results demonstrated that this method was reasonable and efficient for slope stability analysis.Finally, taking Kizil Clay-core Dam as an example, static and dynamical response had been calculated, the slope stability has been analyzed, and the stress deformation and safety factor had been educed under each case. The comparison between the calculated results and measured results shows that, the secondary development of the subroutine is efficient with high precision, in addition, we think that Kizil Clay-core Dam stress and strain distribution is reasonable, no tensile stress generated within the dam and could not result in hydraulic fracturing. In the slope stability analysis, the comparison with the limit equilibrium method and analysis of temperature-driven strength reduction FEM shows that temperature-driven strength reduction FEM is rational and applicable in practical project, and the Kizil clay core dam slope design is stable. Through the analysis of dam system base frequency and the maximum acceleration response, the results shows that the dynamic response is coincides with the general laws of the dam body and seismic design is reasonable. Above results show that the establishment of static and dynamic constitutive model subroutine, iterative method to calculate the free surface seepage and the use of temperature-driven strength reduction FEM for the dam slope stability is a certain universal numerical analysis method, and could provide a direct reference for the analysis of other similar projects.