scholarly journals Comparison between Duncan and Chang’s EB Model and the Generalized Plasticity Model in the Analysis of a High Earth-Rockfill Dam

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Weixin Dong ◽  
Liming Hu ◽  
Yu Zhen Yu ◽  
He Lv
Keyword(s):  
Constitutive Models ◽  
Elastic Model ◽  
Plasticity Model ◽  
Rockfill Dam ◽  
Generalized Plasticity ◽  
Rockfill Materials ◽  
Confining Pressures ◽  
Mechanical Behaviours ◽  
Nonlinear Elastic ◽  
Relationship Of

Nonlinear elastic model and elastoplastic model are two main kinds of constitutive models of soil, which are widely used in the numerical analyses of soil structure. In this study, Duncan and Chang's EB model and the generalized plasticity model proposed by Pastor, Zienkiewicz, and Chan was discussed and applied to describe the stress-strain relationship of rockfill materials. The two models were validated using the results of triaxial shear tests under different confining pressures. The comparisons between the fittings of models and test data showed that the modified generalized plasticity model is capable of simulating the mechanical behaviours of rockfill materials. The modified generalized plasticity model was implemented into a finite element code to carry out static analyses of a high earth-rockfill dam in China. Nonlinear elastic analyses were also performed with Duncan and Chang's EB model in the same program framework. The comparisons of FEM results andin situmonitoring data showed that the modified PZ-III model can give a better description of deformation of the earth-rockfill dam than Duncan and Chang’s EB model.

3D Finite Element Analysis of Concrete Face Rockfill Dam

2012 ◽  
Vol 238 ◽  
pp. 264-267 ◽  
Author(s):  
Jian Wei Zhang ◽  
Sheng Zhao Cheng ◽  
Shu Fang Yuan ◽  
Yu Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Nonlinear Finite Element ◽  
Elastic Model ◽  
Analysis Software ◽  
Element Analysis ◽  
Rockfill Dam ◽  
Nonlinear Elastic ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

Concrete face rockfill dam has the certain superiority in the construction of dam. Duncan-Chang nonlinear elastic model is selected as the dam materials in ABAQUS, which is an nonlinear finite element analysis software. Stresses and deformations of the concrete face rockfill dam are analyzed during its completion, operation and water level drawdown periods. Study shows that all results meet the requirements of the project, and have referenced value for other similar engineering.

Applicability of Duncan-Chang Model and its Modified Versions to Methane Hydrate-Bearing Sands

2011 ◽  
Vol 347-353 ◽  
pp. 3384-3387 ◽  
Author(s):  
Ju Hua Xiong ◽  
Xiao Yong Kou ◽  
Fang Liu ◽  
Ming Jing Jiang
Keyword(s):  
Methane Hydrate ◽  
Constitutive Models ◽  
Constitutive Law ◽  
Triaxial Tests ◽  
Elastic Model ◽  
Clathrate Compound ◽  
Constitutive Response ◽  
Nonlinear Elastic ◽  
Hydrate Bearing Sediments ◽  
Chang Model

Methane hydrate is ice-like clathrate compound that attracts global attention due to its huge potential as a future energy source. The constitutive law of methane hydrate-bearing sediments remains unknown and becomes a barrier in sustainable exploitation of methane hydrate from marine sediments. The Duncan-Change model is a nonlinear elastic model which was widely accepted by the geotechnical community in approximating the constitutive response of geo-materials. This model and its evolved versions were employed in this study to model the stress-strain response observed in triaxial tests on methane hydrate-bearing sands. Duncan-Chang type models capture well the strain hardening behaviors. However, they fall short of incorporating the dependency of temperature and saturation degree of methane hydrate, which have to be taken into account in future constitutive models of methane hydrate-bearing deposits.

scholarly journals Modeling Static Behavior of Rockfill Materials Based on Generalized Plasticity Model

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Shihai Bian ◽  
Bo Wu ◽  
Yongzheng Ma
Keyword(s):  
Shrinkage Strain ◽  
Stress Path ◽  
State Theory ◽  
Plasticity Model ◽  
Static Behavior ◽  
Initial Void Ratio ◽  
Rockfill Material ◽  
Generalized Plasticity ◽  
Plastic Modulus ◽  
Rockfill Materials

Rockfill materials are commonly used for dam construction. Establishing an effective model that can reasonably describe the mechanical properties of rockfill material is very important for the calculation of earth-rock dam engineering. Based on the generalized plasticity model of sand, a modified generalized plasticity model suitable for rockfill material is established by modifying the plastic modulus. Focusing on three types of stress paths (e.g., CT test, CP test, and CR test), the stress path adaptability of the modified generalized plasticity is studied. Simulation results show that the proposed model can well predict the strength characteristics while it underestimates the shrinkage characteristics of rockfill materials for constant P test. It is difficult for the generalized plasticity model to predict larger radial shrinkage strain for constant stress ratio tests. This shortcoming can be improved by employing a modified dilatancy equation. Finally, by introducing critical state theory and considering the effect of initial void ratio on plastic modulus, a state-dependent generalized plasticity model is proposed and verified by experiment of granite rockfill materials and TRM with different void ratios. These works covers the most common stress paths related to the construction of earth-rock dams and can capture static behavior of rockfill materials.

scholarly journals An Enhanced Generalized Plasticity Model for Coarse Granular Material considering Particle Breakage

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
W. J. Cen ◽  
J. R. Luo ◽  
W. D. Zhang ◽  
M. S. Rahman
Keyword(s):  
Flow Direction ◽  
State Parameter ◽  
Particle Breakage ◽  
Triaxial Tests ◽  
Granular Soils ◽  
Plasticity Model ◽  
Generalized Plasticity ◽  
Confining Pressures ◽  
Coarse Granular Soil ◽  
Constitutive Parameters

In this study, an enhanced constitutive model is developed for coarse granular soil within the framework of generalized plasticity (Pastor, Zienkiewicz, and Chan, 1990). In this model, particle breakage is also considered by introducing the state parameter and the compression index into the plastic modulus, loading vectors, and plastic flow direction vectors of a generalized plasticity model. The calibration of constitutive parameters of the enhanced model is addressed in detail. The numerical simulation of triaxial tests for two types of coarse granular soils under different confining pressures is carried out to illustrate the particle breakage performance of the enhanced model. The good agreement between numerical results and experimental data indicates that the enhanced model can accurately characterize the influence of particle breakage on essential behavior of coarse granular soils.

scholarly journals Numerical Simulation on Slabs Dislocation of Zipingpu Concrete Faced Rockfill Dam during the Wenchuan Earthquake Based on a Generalized Plasticity Model

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Bin Xu ◽  
Yang Zhou ◽  
Degao Zou
Keyword(s):  
Finite Element ◽  
Wenchuan Earthquake ◽  
Plasticity Model ◽  
Element Analysis ◽  
Rockfill Dam ◽  
The Wenchuan Earthquake ◽  
Generalized Plasticity ◽  
Construction Joints ◽  
Materials Used ◽  
Water Elevation

After the Wenchuan earthquake in 2008, the Zipingpu concrete faced rockfill dam (CFRD) was found slabs dislocation between different stages slabs and the maximum value reached 17 cm. This is a new damage pattern and did not occur in previous seismic damage investigation. Slabs dislocation will affect the seepage control system of the CFRD gravely and even the safety of the dam. Therefore, investigations of the slabs dislocation’s mechanism and development might be meaningful to the engineering design of the CFRD. In this study, based on the previous studies by the authors, the slabs dislocation phenomenon of the Zipingpu CFRD was investigated. The procedure and constitutive model of materials used for finite element analysis are consistent. The water elevation, the angel, and the strength of the construction joints were among major variables of investigation. The results indicated that the finite element procedure based on a modified generalized plasticity model and a perfect elastoplastic interface model can be used to evaluate the dislocation damage of face slabs of concrete faced rockfill dam during earthquake. The effects of the water elevation, the angel, and the strength of the construction joints are issues of major design concern under seismic loading.

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