Parameter optimization method for the Pastor-Zienkiewicz model based on empirical mode decomposition and cloud theory

Journal article (2019)

Authors

Zhang Hongyang 2Collaborative Innovation Center of Water Resources Efficient Utilization and Protection Engineering of Henan Province, North China University of Water Resources and Electric Power
Zhang Wenxin North China University of Water Resources and Electric Power
Ding Zelin North China University of Water Resources and Electric Power
Li Shuai North China University of Water Resources and Electric Power
Copyright: © 2019 Zhang Hongyang, Zhang Wenxin, Ding Zelin, Li Shuai, W. Ge
DOI: https://doi.org/10.25103/jestr.126.06
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Published Date

2019

Language

English

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Abstract

The key to simulating the mechanical properties of earth-rockfill dam materials is selecting a reasonable constitutive model. The traditional constitutive model targets specific earth-rockfill dam materials and involves many hypotheses in theory, resulting in large common errors in applications. The Pastor-Zienkiewicz model (P-Z model) based on generalized plastic mechanics theory has a strict theoretical base, but it involves many parameters. Moreover, the determination of parameter a entails high discreteness because of experimental conditions, and this discreteness influences the accuracy of simulation analysis. The mechanical properties of earth-rockfill dam materials were simulated using the P-Z model in this study to optimize parameter a of the model and decrease its discreteness. First, conventional triaxial shear test results of earth-rock materials were denoised with the empirical mode decomposition method. Second, a method to optimize parameter a was proposed by using cloud theory. Lastly, a numerical simulation analysis of the triaxial shearing test was performed with the optimized P-Z model. Research results demonstrate that the entropy error and hyper entropy error rates of the triaxial shearing test data decline by 35% and 67%, respectively, and the cloud droplet range of parameter a is narrowed by 32%. The discreteness of the values decreases significantly. The simulation calculation results are consistent with the test results, thereby confirming the reasonability of the proposed parameter optimization method. The optimized P-Z model can simulate the mechanical properties of earth-rockfill dam materials accurately. This study can provide a theoretical reference for finite element simulation analysis of earth-rockfill dam structures.