Study the Axial Force-Time History of Reinforced Retaining Wall under Earthquake Loading

2012 ◽  
Vol 268-270 ◽  
pp. 802-805
Author(s):  
Jia Liang
Keyword(s):  
Axial Force ◽  
Retaining Wall ◽  
Time History ◽  
Nonlinear Fem ◽  
Plastic Model ◽  
Elastic Plastic ◽  
Backfill Soil ◽  
Before And After ◽  
Force Time ◽  
Reinforced Retaining Wall

In this analysis, 3-D nonlinear FEM model is built in consideration of the cooperation and interaction among backfill soil, panel and reinforcement strip; the backfill soil is simulated by nonlinear static and dynamic elastic-plastic model; the reinforcement is simulated by the dual-phase enhanced linear elastic-plastic model which can describe the intensified features of the reinforcement; the interaction of soil and retaining structures is simulated by the friction-element. By comparison of before and after earthquake, result is get of the axial force difference reinforcement layer. The increased maximum location is close to toe of the wall.

Study on the Behavior of Reinforced Retaining Wall Under Earthquake Loading Using FEM Analysis

2011 ◽  
Vol 421 ◽  
pp. 713-716
Author(s):  
Liang Jia
Keyword(s):  
Retaining Wall ◽  
Fem Analysis ◽  
Mechanical Analysis ◽  
Distribution Law ◽  
Nonlinear Fem ◽  
Plastic Model ◽  
Elastic Plastic ◽  
Backfill Soil ◽  
Pulling Force ◽  
Reinforced Retaining Wall

Nonlinear FEM (ADINA) is used for the mechanical analysis of reinforced retaining Wall. In this analysis,3-D nonlinear FEM model is built in consideration of the cooperation and interaction among backfill soil, panel and reinforcement strip; the backfill soil is simulated by nonlinear static and dynamic elastic-plastic model; the reinforcement is simulated by the dual-phase enhanced linear elastic-plastic model which can describe the intensified features of the reinforcement; the interaction of soil and retaining structures is simulated by the friction-element. The application to a project yields the distribution law of the strip’s most dollar point of force and the changing rules of the strip’s pulling force around earthquake.

Seismic Analysis of Soil Nailed Wall Using Finite Element Method

2012 ◽  
Vol 535-537 ◽  
pp. 2027-2031 ◽  
Author(s):  
Jian Chun Wu ◽  
Rong Shi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Seismic Analysis ◽  
Retaining Wall ◽  
Plastic Behavior ◽  
Soil Nailing ◽  
Nonlinear Fem ◽  
Elastic Plastic ◽  
Flexible Retaining Wall ◽  
Element Method

Using dynamic elastic-plastic finite element method, on the base of works together and interaction between loess and flexible retaining wall, 3-D nonlinear FEM (ADINA) is used to analyze and discussed the dynamic response of slope protected by soil nailing retaining wall under the EL-Centro and man-made Lanzhou accelerogram. A model that is capable of simulating the nonlinear static and dynamic elastic-plastic behavior of soil is used to model the soil, and a bilinear elastic-plastic model that has hardening behavior is used to model the soil nailing. Friction-element is employed to describe the soil-structure interaction behavior.The results show that the method is safe and credible. The results of the FEM dynamic analysis can be a useful reference for engineers of the design and construction of the soil nailed wall.

Finite Difference Study on Seismic Reinforcement Force of Geo-Grid Reinforced Soil Retaining Wall

2014 ◽  
Vol 488-489 ◽  
pp. 354-358
Author(s):  
Li Yan Wang ◽  
Xiao Lei Du ◽  
Fu Xing Zhang ◽  
Rong Qiu Xue
Keyword(s):  
Finite Difference ◽  
Seismic Design ◽  
Retaining Wall ◽  
Reinforced Soil ◽  
Design Parameters ◽  
Soil Stiffness ◽  
Backfill Soil ◽  
Reinforced Retaining Wall ◽  
Grid Reinforcement ◽  
Sensitive Parameters

For the geo-grid reinforced retaining wall, the reinforcement mechanism of seismic behavior is unclear, and there is no reasonable standard for seismic design. A non-linear finite difference method which is based on Lagrange method was applied to analyze internal reinforcement force of geo-grid under different design parameters. The elastic-plastic model is simulated to backfill soil and foundation, and the coupled elastic parameters are used to describe the interaction of soil and geo-grid. The design parameters include geo-grid reinforcement spacing, reinforcement length, backfill soil stiffness, and thickness of panel. Some distribution characters and sensitive parameters to the internal reinforcement force of geo-grid were achieved, which will be helpful to the seismic design of geo-grid reinforced soil retaining wall with integral panel.

Physical and numerical modelling of a geogrid-reinforced incremental concrete panel retaining wall

2016 ◽  
Vol 53 (12) ◽  
pp. 1883-1901 ◽  
Author(s):  
Yan Yu ◽  
Richard J. Bathurst ◽  
Tony M. Allen ◽  
Renald Nelson
Keyword(s):  
Numerical Modelling ◽  
Numerical Models ◽  
Retaining Wall ◽  
Compaction Pressure ◽  
Constitutive Models ◽  
Plastic Model ◽  
Elastic Plastic ◽  
Constant Stiffness ◽  
Linear Elastic ◽  
Physical Measurements

The paper presents the numerical modelling details using the finite difference method (FDM) to simulate the performance of a well-instrumented geogrid-reinforced incremental concrete panel soil retaining wall. Two different constitutive models were investigated for the backfill soil (linear elastic–plastic model and nonlinear elastic–plastic model). Both constant stiffness and strain-dependent secant stiffness models were used for the reinforcement elements. The paper provides valuable lessons to modellers to simulate the performance of this type of earth retaining structure. For example, parametric investigation of the effect of a constant Young’s modulus ranging from 40 to 120 MPa for the linear-elastic Mohr–Coulomb model had only minor influence on the wall facing displacements and reinforcement loads. However, the choice of magnitude of transient compaction pressure near the facing can result in large differences in facing displacements. The paper also demonstrates that the method of construction including the location, sequence, and stiffness of the temporary supports used to construct the wall plays an important role on measured and predicted wall performance. The physical measurements reported in this paper provide a benchmark for numerical modellers to verify other numerical models for walls of the type investigated here.

Response and Parameter Analysis of Reinforced Retaining Wall under Earthquake Loading

2012 ◽  
Vol 268-270 ◽  
pp. 702-705
Author(s):  
Jia Liang
Keyword(s):  
Seismic Response ◽  
Axial Force ◽  
Retaining Wall ◽  
Seismic Loading ◽  
Mechanical Analysis ◽  
Seismic Intensity ◽  
Parameter Analysis ◽  
Earthquake Loading ◽  
Reinforced Retaining Wall ◽  
Physical Mechanics

FEM is use for the mechanical analysis of reinforced retaining wall under earthquake loading. The main results are as following. The displacement and axial force increased with the increased seismic intensity. The displacement and axial force decreased with the increased the length of bar strip. The displacement and axial force decreased with the decreased the spacing of bar strip. The displacement and axial force decreased with the increased physical mechanics parameters of filling. Seismic response was similar under bilateral seismic loading and horizontal seismic loading, seismic response was slightly larger under bilateral seismic loading.

Effects of activation frequency and force on low-frequency fatigue in human skeletal muscle

1999 ◽  
Vol 86 (4) ◽  
pp. 1337-1346 ◽  
Author(s):  
Stuart A. Binder-Macleod ◽  
David W. Russ
Keyword(s):  
Healthy Subjects ◽  
Human Skeletal Muscle ◽  
Low Frequency ◽  
Variable Frequency ◽  
Activation Pattern ◽  
Constant Frequency ◽  
Mean Frequency ◽  
Before And After ◽  
Low Frequency Fatigue ◽  
Force Time

No comparison of the amount of low-frequency fatigue (LFF) produced by different activation frequencies exists, although frequencies ranging from 10 to 100 Hz have been used to induce LFF. The quadriceps femoris of 11 healthy subjects were tested in 5 separate sessions. In each session, the force-generating ability of the muscle was tested before and after fatigue and at 2, ∼13, and ∼38 min of recovery. Brief (6-pulse), constant-frequency trains of 9.1, 14.3, 33.3, and 100 Hz and a 6-pulse, variable-frequency train with a mean frequency of 14.3 Hz were delivered at 1 train/s to induce fatigue. Immediately postfatigue, there was a significant effect of fatiguing protocol frequency. Muscles exhibited greater LFF after stimulation with the 9.1-, 14.3-, and variable-frequency trains. These three trains also produced the greatest mean force-time integrals during the fatigue test. At 2, ∼13, and ∼38 min of recovery, however, the LFF produced was independent of the fatiguing protocol frequency. The findings are consistent with theories suggesting two independent mechanisms behind LFF and may help identify the optimal activation pattern when functional electrical stimulation is used.

Elastic-Plastic Time History Analysis of MR Damping Structure Based on LQG Algorithm

2016 ◽  
Vol 858 ◽  
pp. 145-150
Author(s):  
Yu Liang Zhao ◽  
Zhao Dong Xu
Keyword(s):  
Optimal Control ◽  
Time History ◽  
Mr Damper ◽  
Time History Analysis ◽  
Control Force ◽  
Control Effect ◽  
Damping Force ◽  
Optimal Control Strategy ◽  
Elastic Plastic ◽  
History Analysis

This paper discussed an elastic-plastic time-history analysis on a structure with MR dampers based on member model, in which the elastoplastic member of the structure is assumed to be single component model and simulated by threefold line stiffness retrograde model. In order to obtain better control effect, Linear Quadratic Gaussian (LQG) control algorithm is used to calculate the optimal control force, and Hrovat boundary optimal control strategy is used to describe the adjustable damping force range of MR damper. The effectiveness of the MR damper based on LQG algorithm to control the response of the structure was investigated. The results from numerical simulations demonstrate that LQG algorithm can effectively improve the response of the structure against seismic excitations only with acceleration feedback.

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