基于正交-响应面法的砂土细观参数标定  

Calibration of Sand Mesoscopic Parameters Based on Orthogonal-Response Surface Method

作　　者：刘红帅 张东涛 Liu Hongshuai;Zhang Dongtao(College of Civil Engineering and Architecture,Hebei University,Baoding 071000,Hebei,China;Institute of Geotechnical Engineering,Hebei University,Baoding 071000,Hebei,China)

机构地区：[1]河北大学建筑工程学院,河北保定071000 [2]河北大学岩土工程研究所,河北保定071000

出　　处：《吉林大学学报（地球科学版）》2024年第4期1280-1290,共11页Journal of Jilin University：Earth Science Edition

基　　金：河北省自然科学基金项目(E2020201017);中国地震局工程力学研究所基本科研业务费专项项目(2019EEEVL0202);河北省高等学校科学技术研究项目(ZD2020157)。

摘　　要：颗粒离散元的模拟精度主要取决于所标定细观参数的准确性,为提升细观参数的标定精度和效率,本文首先采用抗转动线性接触模型模拟砂土三轴压缩试验;再利用正交试验中的方差分析法筛选出宏观参数的控制性细观参数;然后建立宏观参数与控制性细观参数的响应面方程,依据室内三轴试验确定的砂土宏观参数,代入所建的响应面方程求解得到控制性细观参数;最后结合三轴试验结果验证所标定细观参数的准确性。结果表明:宏观参数包括弹性模量、泊松比、峰值摩擦角和剪胀角,其中弹性模量的控制性细观参数为有效模量和摩擦系数,泊松比的控制性细观参数为刚度比与摩擦系数,峰值摩擦角和剪胀角的控制性细观参数都为摩擦系数;通过三轴试验得出宏观参数取值,弹性模量为83.83 MPa、泊松比为0.45、峰值摩擦角为34.47°、剪胀角为8.93°;进一步标定细观参数取值,有效模量为153.35 MPa,刚度比为2.16,摩擦系数为0.45;利用标定的细观参数进行三轴试验模拟,结果与室内试验结果在低围压(100 kPa)下峰值强度相差7.2%,在高围压(300、500 kPa)下误差都控制在了±15.0%以内,证明了所提出的标定方法具有准确性和可靠性。The simulation accuracy of the particle discrete element method(DEM)mainly depends on the accuracy of calibrated mesoscopic parameters.To improve the calibration accuracy and efficiency of mesoscopic parameters,firstly,the rolling-resistance linear contact model was used to simulate sand triaxial compression tests.Then,the variance analysis method in orthogonal experiments is used to select the controlling mesoscopic parameters(CMP),and response surface equations are established to relate the macro parameters to the CMP.By substituting the macro parameters determined from triaxial tests into the response surface equations,the values of the CMP are solved.Finally,the accuracy of the calibrated micro parameters is verified by comparing the simulation results with the triaxial test results.The results show that the macro parameters include elastic modulus,Poisson’s ratio,dilatancy angle,and peak friction angle.The CMP for the elastic modulus are effective modulus and friction coefficient,while the controlling micro parameters for Poisson’s ratio are stiffness ratio and friction coefficient.The CMP of the peak friction angle and dilatancy angle are the friction coefficient.The elastic modulus,Poisson’s ratio,peak friction angle and dilatancy angle from the triaxial tests,are 83.83 MPa,0.45,34.47°and 8.93°,respectively.The corresponding mesoscopic parameters are determined as follows:Effective modulus of 153.35 MPa,stiffness ratio of 2.16,and friction coefficient of 0.45.Comparing simulation results from the calibrated mesoscopic parameters with the triaxial tests,the difference in peak strength is 7.2%at a low level of confining pressure(100 kPa),and the errors are within 15.0%at higher level of confining pressures(300 and 500 kPa).

关 键 词：砂土 离散元法 细观参数 正交试验 响应面法 宏观参数 弹性模量 泊松比 

分 类 号：TU4[建筑科学—土工工程]