Structural Stability Analysis Of High Concrete Faced Rockfill Dam Under The Effect Of Rockfill Rheology

In recent years,concrete face rockfill dam(CFRD)has been developed rapidly,and it has been accepted by designers due to its strong adaptability,high material utilization,low dam construction cost,and convenient construction.Scholars have analyzed and studied high-CFRDs,such as Shuibuya,Tianshengqiao,Gongboxia,etc.,and found that operation period of rockfill rheology occur,resulting in the destruction of panels and peripheral joint cracking and other engineering problems,resulting in damage to the structure of the dam seepage,endangering the safe operation of the dam.Therefore,in the design and construction stage,the finite element analysis of the highCFRD with reasonable consideration of the rheological effects of the rockfill is of great significance to the control of the pre-settlement period,the design of the joints,and the safety protection of the anti-seepage structure.Based on the construction of the Xujixia CFRD and the idea of "real-time inversion of parameters and prediction of deformation at any time",this paper tracks the presettlement process of the dam,and predicts the deformation process during the operation period.Select the model,and constitutive parameters are important to ensure the accuracy of the finite element.Therefore,the main work carried out in this paper are:1)Establish a three-dimensional model for finite element calculation and analysis of the Xujixia CFRD;2)Carry out secondary development in ABAQUS,and compile related UMAT subroutines based on the seven-parameter rheological model of rockfill considering particle breaking;3)Establish the mapping relationship between the rheological parameters and rheological results that can be used for real-time inversion of parameters through the neural network response surface,and compare and analyze the mapping pros and cons of the BP and RBF neural network response surfaces.Establish an objective function for real-time inversion of parameters.Obtain real-time deformation monitoring data during the pre-settlement period of the Xujixia CFRD for back-analysis of displacements to achieve the purpose of real-time tracking of the pre-settlement process;4)Study the influence of different two-stage pre-settlement period on the stress and deformation of the dam and its development trend in order to find a reasonable pre-settlement plan5)According to the reasonable construction plan,the finite element model of the dam,the rheological constitutive and the parameters obtained by real-time inversion,the finite element calculation of the Xujixia CFRD was carried out to achieve the purpose of predicting deformation at any time.