An inversion method for transient rheological parameters of high rockfill dams based on response surface methodology

Abstract

The invention discloses a high-rockfill-dam transient-rheological-parameter inversion method based on the response surface method.The method includes the steps that a rockfill-dam three-dimensional finite element model is built in combination with dam body material sections and construction grading conditions, the sensitivity of the transient parameters and the rheological parameters of rockfill of the material sections is analyzed, and the transient parameters with the high sensitivity and the rheological parameters with the high sensitivity are selected as to-be-inversed parameters jointly; a material static force model is a Duncan EB model, and a rheological model is a Nanjing-Hydraulic-Research-Institute five-parameter model; the implicit relationship between the finite-element-calculated settling volume and the calculation parameters is represented through a specific-form response surface function, undetermined coefficients of a response surface equation set are solved through several times of finite element calculation, and therefore the nonlinear mapping relationship between the settling volume and the calculation parameters is built.On the bases of the response surface equation, the objective function aims at obtaining the minimum root-mean-square error between the calculated settling volume and the practically-measured settling volume, the transient parameters and the rheological parameters are inversed with the genetic algorithm at the same time, and the obtained set of optimal calculation parameters are the inversion result.

Description

technical field [0001] The invention belongs to the technical field of material mechanics and relates to an inversion method for transient rheological parameters of high rockfill dams based on the response surface method. Background technique [0002] It is one of the keys to ensure the safety and stability of rock-fill dams to reasonably evaluate the current working behavior of rock-fill dams and accurately predict their spatio-temporal deformation laws. The rockfill body is the main dam construction material of the face rockfill dam, so the accurate determination of its material mechanical parameters is the premise to improve the prediction accuracy of the stress and deformation of the rockfill dam. At present, the mechanical parameters of the rockfill body are mainly determined through indoor tests and engineering analogies. However, the prototype rockfill body of the upper dam has a large particle size (up to 800-1200 mm), so only indoor triaxial tests of scaled rockfill...

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Problems solved by technology

At present, this method can only invert the parameters of the static constitutive model of the rockfill body, without considering the rheological deformation of the rockfill body, and the rheological properties are an important characteristic of the rockfill body material that cannot be ignored, so the existing method cannot be applied to Prediction of Long-term Deformation of High Rockfill Dam

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