本文選題：堆石料 + 鄧肯-張模型�。� 參考：《水力發(fā)電》2017年08期

【摘要】：鄧肯-張非線性彈性模型是土石壩工程中最常用的本構(gòu)模型。水利行業(yè)《土工試驗規(guī)程》中根據(jù)應(yīng)力水平75%和90%兩點法進行計算時,得到的結(jié)果往往并不合理,有時n值還可能出現(xiàn)負數(shù)。一般的適線法僅僅對單個試樣結(jié)果進行優(yōu)化,而并不是針對整組試驗結(jié)果,因此無法得到最優(yōu)結(jié)果。提出了一種二步優(yōu)化的參數(shù)計算方法,首先對每級圍壓下單個試樣的試驗成果采用適線法優(yōu)化,得到每級圍壓下的參數(shù)a、b。在此基礎(chǔ)上,計算得到參數(shù)K、n、Rf的初值。然后以鄧肯-張理論為基礎(chǔ),根據(jù)獲得的參數(shù)初值針對整組試驗成果進行二次優(yōu)化,以理論計算與試驗的應(yīng)力應(yīng)變曲線差的平方和最小為目標(biāo)函數(shù),從而得到EB模型的主要參數(shù)。該方法簡單實用,能夠快速和準確地獲得鄧肯-張模型參數(shù),并結(jié)合糯扎渡大壩堆石料三軸試驗數(shù)據(jù),對方法進行了驗證。
[Abstract]:Duncan-Zhang nonlinear elastic model is the most commonly used constitutive model in earth-rock dam engineering. According to the stress level of 75% and 90%, the results obtained in geotechnical test code of water conservancy industry are often unreasonable, and sometimes the value of n may be negative. The general line fitting method only optimizes the results of a single sample, but not for the whole set of test results, so it is impossible to obtain the optimal results. In this paper, a two-step parameter optimization method is proposed. Firstly, the test results of a single sample under each stage of confining pressure are optimized by the method of fitting line, and the parameter a / b under each stage confining pressure is obtained. On this basis, the initial values of the parameter K _ (n) R _ f are calculated. Then based on Duncan Chang's theory, according to the obtained initial values of the parameters, the quadratic optimization of the whole set of test results is carried out, and the minimum sum of the square of the difference between the stress-strain curve calculated theoretically and the test is taken as the objective function. The main parameters of EB model are obtained. The method is simple and practical and can obtain the Duncan-Zhang model parameters quickly and accurately. The method is verified by combining with the triaxial test data of the Nuozhadu dam rockfill.
【作者單位】： 北京交通大學(xué)土建學(xué)院;
【分類號】：TV41
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本文編號：1825384