Finite element back analysis of loaded MSW vertical cut

2019 ◽  
pp. 61-67
Author(s):  
Michal Topolnicki
Keyword(s):  
Finite Element ◽  
Back Analysis

Finite Element Modeling of a Mechanically Stabilized Earth Trial Wall

2021 ◽  
pp. 036119812110164
Author(s):  
Andrew Lees ◽  
Michael Dobie
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Retaining Wall ◽  
Back Analysis ◽  
Soil Parameters ◽  
Failure Behavior ◽  
Valuable Insight ◽  
Deformation And Failure ◽  
First Case ◽  
Soil Shear Strength

Polymer geogrid reinforced soil retaining walls have become commonplace, with routine design generally carried out by limiting equilibrium methods. Finite element analysis (FEA) is becoming more widely used to assess the likely deformation behavior of these structures, although in many cases such analyses over-predict deformation compared with monitored structures. Back-analysis of unit tests and instrumented walls improves the techniques and models used in FEA to represent the soil fill, reinforcement and composite behavior caused by the stabilization effect of the geogrid apertures on the soil particles. This composite behavior is most representatively modeled as enhanced soil shear strength. The back-analysis of two test cases provides valuable insight into the benefits of this approach. In the first case, a unit cell was set up such that one side could yield thereby reaching the active earth pressure state. Using FEA a test without geogrid was modeled to help establish appropriate soil parameters. These parameters were then used to back-analyze a test with geogrid present. Simply using the tensile properties of the geogrid over-predicted the yield pressure but using an enhanced soil shear strength gave a satisfactory comparison with the measured result. In the second case a trial retaining wall was back-analyzed to investigate both deformation and failure, the failure induced by cutting the geogrid after construction using heated wires. The closest fit to the actual deformation and failure behavior was provided by using enhanced fill shear strength.

3D Back Analysis of Initial Stress Field Based on Neural Network RBF Model

2011 ◽  
Vol 243-249 ◽  
pp. 3223-3228
Author(s):  
Zhong Fu Wang ◽  
Han Dong Liu ◽  
Tong Jiang ◽  
Si Wei Wan
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Initial Stress ◽  
Linear Regression Analysis ◽  
Back Analysis ◽  
Element Model ◽  
Training Sample ◽  
Geological Condition ◽  
Initial Stress Field ◽  
Factory Building

Based on geological condition of underground factory building in Hohhot pumped storage power station, research and analysis are taken for the fundamental element which affect initial stress field, 3D finite element model of underground factory building is build for the analysis. Beigin with regrssion analysis, adopt linear elasticity caculation of finite element method to take linear regression analysis, and obtain range of optimized parameters. Adopt homogeneous design to definite various assemblies of optimized parameters at different levels. Obtain training sample by elasto plastic caculation of finite element, train for RBF model in oder to get inverse model of ground stress field. The calculation result shown that: RBF model overcome the disadvantages such as slow calculating speed and overfitting of BP model, and it could obtain distrubution rule of initial stress filed by inverse analysis in a reasonable way.

Performance of gravity caisson on sand compaction piles

2008 ◽  
Vol 45 (3) ◽  
pp. 393-407
Author(s):  
Chun Fai Leung ◽  
Rui Fu Shen
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Field Study ◽  
Tilt Angle ◽  
Back Analysis ◽  
Numerical Results ◽  
Container Port ◽  
The Finite Element Method ◽  
Quay Cranes ◽  
Element Method

Gravity caissons were employed as part of the wharf front structures for a container port terminal in Singapore. This paper reports the movements of eight consecutive gravity caissons supported on sand compaction piles (SCPs) with highly variable lengths of penetration. It is established that the caisson movements increase with an increase in the length of the SCP, as longer SCPs are necessary when hard strata are at greater depth. The large caisson movements observed during caisson infilling and backfilling do not pose a concern because the wharf deck beams connecting adjacent caissons can be adjusted. However, the caisson movements under service loads would affect the operation of the overlying quay cranes on top of the caissons. The present field study reveals that preloading the caissons is effective in reducing the caisson movements under service loads because the observed caisson movements are insignificant during subsequent unloading–reloading of the caissons. Back-analysis using the finite element method (FEM) shows that the observed caisson movements at different construction stages can be reasonably replicated. The numerical results are also used to evaluate the caisson tilt angle, which could not be measured in the present field study. The caisson tilt is found to be independent of the length of SCPs underneath a caisson.

Intelligent Simulation and Recognition of Metro Station Excavation Based on Differential Evolution and Finite Element

2010 ◽  
Vol 168-170 ◽  
pp. 2641-2647
Author(s):  
An Nan Jiang ◽  
Jun Xiang Wang ◽  
De Hai Yu
Keyword(s):  
Finite Element ◽  
Differential Evolution ◽  
Yield Criterion ◽  
Differential Evolution Algorithm ◽  
Equivalent Plastic Strain ◽  
Back Analysis ◽  
Implicit Integration ◽  
Element Analysis ◽  
Integration Algorithm ◽  
Metro Station

Differential Evolution (DE) is a new algorithm. Displacement back analysis method based on the algorithm can effectively solve the problems of rock mechanics parameters which are not accurate. Constitutive integration algorithm divided into explicit and implicit integration is the key points of finite element analysis, which affect the convergence and accuracy of the results. Return mapping algorithm avoiding directly solving the equivalent plastic strain is a kind of implicit integration algorithm, which would achieve rapid and accurate for the solution of constitutive equations. This article describes the theoretical framework based on elastic-plastic, von Mises yield criterion conditions, using C + + language to carry out plastic simulation of Dalian metro station CRD excavation and parameter identification based on differential evolution algorithm. The calculated stress, displacement and deformation can determine the surface subsidence and the development of plastic zone, the stability analysis to provide a reference for the construction.

A New Finite Element for Back Analysis of a Geogrid Reinforced Soil Retaining Wall Failure

2017 ◽  
Vol 16 (4) ◽  
pp. 435-441 ◽  
Author(s):  
Omid Reza Barani ◽  
Majid Bahrami ◽  
Seyed Amirodin Sadrnejad
Keyword(s):  
Finite Element ◽  
Retaining Wall ◽  
Back Analysis ◽  
Reinforced Soil

scholarly journals Finite Element Optimised Back Analysis of In Situ Stress Field and Stability Analysis of Shaft Wall in the Underground Gas Storage

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Yifei Yan ◽  
Bing Shao ◽  
Jianguo Xu ◽  
Xiangzhen Yan
Keyword(s):  
Finite Element ◽  
Stress Field ◽  
Geometric Model ◽  
Back Analysis ◽  
Gas Storage ◽  
In Situ Stress ◽  
Underground Gas Storage ◽  
Measured Stress ◽  
In Situ Stress Field

A novel optimised back analysis method is proposed in this paper. The in situ stress field of an underground gas storage (UGS) reservoir in a Turkey salt cavern is analysed by the basic theory of elastic mechanics. A finite element method is implemented to optimise and approximate the objective function by systematically adjusting boundary loads. Optimising calculation is performed based on a novel method to reduce the error between measurement and calculation as much as possible. Compared with common back analysis methods such as regression method, the method proposed can further improve the calculation precision. By constructing a large circular geometric model, the effect of stress concentration is eliminated and a minimum difference between computed and measured stress can be guaranteed in the rectangular objective region. The efficiency of the proposed method is investigated and confirmed by its capability on restoring in situ stress field, which agrees well with experimental results. The characteristics of stress distribution of chosen UGS wells are obtained based on the back analysis results and by applying the corresponding fracture criterion, the shaft walls are proven safe.

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