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Displacement-based back-analysis of the model parameters of the Nuozhadu high earth-rockfill dam.

Wu Y, Yuan H, Zhang B, Zhang Z, Yu Y - ScientificWorldJournal (2014)

Bottom Line: Displacement back-analyses were performed at different stages of the construction period, with and without considering the creep and wetting deformations.The comparison of calculation results based on different sets of back-analyzed model parameters indicates the necessity of taking the effects of creep and wetting into consideration in the numerical analyses of high earth-rockfill dams.With the resulting model parameters, the stress and deformation distributions at completion are predicted and analyzed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.

ABSTRACT
The parameters of the constitutive model, the creep model, and the wetting model of materials of the Nuozhadu high earth-rockfill dam were back-analyzed together based on field monitoring displacement data by employing an intelligent back-analysis method. In this method, an artificial neural network is used as a substitute for time-consuming finite element analysis, and an evolutionary algorithm is applied for both network training and parameter optimization. To avoid simultaneous back-analysis of many parameters, the model parameters of the three main dam materials are decoupled and back-analyzed separately in a particular order. Displacement back-analyses were performed at different stages of the construction period, with and without considering the creep and wetting deformations. Good agreement between the numerical results and the monitoring data was obtained for most observation points, which implies that the back-analysis method and decoupling method are effective for solving complex problems with multiple models and parameters. The comparison of calculation results based on different sets of back-analyzed model parameters indicates the necessity of taking the effects of creep and wetting into consideration in the numerical analyses of high earth-rockfill dams. With the resulting model parameters, the stress and deformation distributions at completion are predicted and analyzed.

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Displacement back-analysis method based on neural network and evolutionary algorithm.
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Related In: Results  -  Collection


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fig3: Displacement back-analysis method based on neural network and evolutionary algorithm.

Mentions: Figure 3 shows the flowchart of the back-analysis method, including three main steps: (1) performing forward FEM analysis on the training parameter sets to generate samples and then using evolutionary algorithm and Vogl's algorithm to train and optimize the neural network; (2) constructing testing parameters sets randomly, and accessing the accuracy of the trained neural network for the testing parameters sets by comparing its results with that of the FEM analysis, and if the error criterion is not satisfied, adding several training parameter sets, and then going back to step (1) to optimize and train the neural network again until the error criterion is met; and (3) optimizing the soil parameters using evolutionary algorithm, observation data and the trained neural network.


Displacement-based back-analysis of the model parameters of the Nuozhadu high earth-rockfill dam.

Wu Y, Yuan H, Zhang B, Zhang Z, Yu Y - ScientificWorldJournal (2014)

Displacement back-analysis method based on neural network and evolutionary algorithm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4121011&req=5

fig3: Displacement back-analysis method based on neural network and evolutionary algorithm.
Mentions: Figure 3 shows the flowchart of the back-analysis method, including three main steps: (1) performing forward FEM analysis on the training parameter sets to generate samples and then using evolutionary algorithm and Vogl's algorithm to train and optimize the neural network; (2) constructing testing parameters sets randomly, and accessing the accuracy of the trained neural network for the testing parameters sets by comparing its results with that of the FEM analysis, and if the error criterion is not satisfied, adding several training parameter sets, and then going back to step (1) to optimize and train the neural network again until the error criterion is met; and (3) optimizing the soil parameters using evolutionary algorithm, observation data and the trained neural network.

Bottom Line: Displacement back-analyses were performed at different stages of the construction period, with and without considering the creep and wetting deformations.The comparison of calculation results based on different sets of back-analyzed model parameters indicates the necessity of taking the effects of creep and wetting into consideration in the numerical analyses of high earth-rockfill dams.With the resulting model parameters, the stress and deformation distributions at completion are predicted and analyzed.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China.

ABSTRACT
The parameters of the constitutive model, the creep model, and the wetting model of materials of the Nuozhadu high earth-rockfill dam were back-analyzed together based on field monitoring displacement data by employing an intelligent back-analysis method. In this method, an artificial neural network is used as a substitute for time-consuming finite element analysis, and an evolutionary algorithm is applied for both network training and parameter optimization. To avoid simultaneous back-analysis of many parameters, the model parameters of the three main dam materials are decoupled and back-analyzed separately in a particular order. Displacement back-analyses were performed at different stages of the construction period, with and without considering the creep and wetting deformations. Good agreement between the numerical results and the monitoring data was obtained for most observation points, which implies that the back-analysis method and decoupling method are effective for solving complex problems with multiple models and parameters. The comparison of calculation results based on different sets of back-analyzed model parameters indicates the necessity of taking the effects of creep and wetting into consideration in the numerical analyses of high earth-rockfill dams. With the resulting model parameters, the stress and deformation distributions at completion are predicted and analyzed.

Show MeSH