水力发电2017，Vol.43Issue(8)：52-55,75,5.
邓肯-张EB模型参数求解的二次优化法
Two Step Optimization Method for Parameters of Duncan-Chang EB Model
摘要
Abstract
Duncan-Chang nonlinear elastic constitutive model is the most used one in embankment dam engineering.The Specification of Soil Test in hydraulic industry proposes a computational method based on the values of two points from the stress-axial strain curve of the triaxial testing results.The stress levels of these two points are 75％ and 90％ respectively.However the proposed method cannot obtain reasonable results all the times,and sometimes even the parameter n maybe negative.Curve fitting methods make some progress,but still could not gain the optimal value for the parameters because these methods only based on single sample result.A two step optimization method for acquiring the optimal values of Duncan-Chang model is presented herein.First,the traditional curve fitting method is adopted to obtain the values of parameters a and b under each confining pressure.Then the parameters K,n and Rf are obtained.Using these parameters as initial values,a second optimization procedure is carried out to fit all the results of triaxial test to gain the parameters of Duncan-Chang model,in which,the minimum square sum of the differences of stress and strain curves of theoretical calculation and experiment is taken as the objective function.The method is simple and practical,and can quickly and accurately obtain the parameters of DuncanZhang model.The method is validated based on the triaxial test data of Nuozhadu Dam.关键词
堆石料/邓肯-张模型/优化方法/土石坝Key words
rockfill/Duncan-Chang model/optimization method/embankment dam分类
建筑与水利引用本文复制引用
陈立宏..邓肯-张EB模型参数求解的二次优化法[J].水力发电,2017,43(8):52-55,75,5.
