scholarly journals Comparative Study on Grouting Protection Schemes for Shield Tunneling to Adjacent Viaduct Piles

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Kan Huang ◽  
Yiwei Sun ◽  
Jun He ◽  
Xianqiang Huang ◽  
Meng Jiang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Shield Tunnel ◽  
Shield Tunneling ◽  
Protection Measures ◽  
Dimensional Finite Element ◽  
Different Depths ◽  
Pass Through ◽  
Under Construction ◽  
Three Dimensional Finite Element

Shield tunnels will inevitably pass through viaduct piles at a close distance due to the extensive construction of subways and viaducts in the city. In order to understand the influence of shield tunneling on the deformation of existing pile foundation and grouting protection measures, based on an engineering case, Changsha Metro Line 5 (from South Gaoqiao station to Guitang station), a three-dimensional finite element model was established to analyze the deformation of bridge pile using grouting protection wall with different depths and shapes when the shield tunnel is under construction. The analytical results indicate that the grouting protection wall can effectively reduce the pile displacement; especially the grouting depth is 3 m below the bottom of the tunnel. Moreover, the L-shaped grouting protection wall can effectively reduce the longitudinal displacement of the piles. The present findings may provide a reference for the design and construction of shield tunnels passing through viaduct piles.

3D Numerical Analysis of Metro Station by PBA Method to Enlarge Existing Large-Size Shield Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 1673-1678
Author(s):  
Mei Yan ◽  
De Yun Ding ◽  
Xiu Ren Yang ◽  
Xiu Ren Yang ◽  
Wei Dong Lu ◽  
...  
Keyword(s):  
Soil Structure ◽  
Three Dimensional ◽  
Element Model ◽  
Shield Tunnel ◽  
Interaction Theory ◽  
Metro Station ◽  
Large Size ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Station Structure

There is no engineering experience for metro station construction by the PBA (Pile-Beam-Arch) method to enlarge an existing large-size shield tunnel in China. During enlarging construction by the PBA method, the spatial mechanical and deformational characteristics of metro station structure are still not clear. In this paper, the Gaojiayuan station is taken as an engineering background to study the spatial mechanical and deformational characteristics during enlarging construction by the PBA method. Based on soil-structure interaction theory, a three-dimensional finite element model is built to simulate the enlarging construction by the PBA method. The three-dimensional numerical results can be regarded as a valuable reference for enlarging construction by the PBA method in Beijing metro line 14.

Three Dimensional Finite Element Modeling and Analysis of Different Subway Tunnels Stray Current Fields

2014 ◽  
Vol 8 (1) ◽  
pp. 124-132
Author(s):  
Guo Wang ◽  
Xiao-Xiang Pei
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Shield Tunnel ◽  
Geological Condition ◽  
Subway Tunnel ◽  
Stray Current ◽  
Modeling And Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In order to analyze the distribution rules and influence of stray current on subway rectangulartunneland subway Shield tunnel, threedimensional models were built separately. By changing the values of carry-current, ansys was used toanalyzeunder different geological conditions.Simulations show that the potential attenuation is nonlinear from the subway tunnel to the surrounding underground.The potential of the same location of surrounding media is different with different carry-current.The amount of leakage stray current of rectangular tunnel is less than Shield tunnel under same geological condition and same carry-current. Each points stray current in situation of surrounding soil media subway tunnel shield can be analyzed by the three-dimensional finite element model, and provide the basis for the protection range of stray current and the protection at a specific location.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

Numerical Analysis of Metro Station Construction by Large-Diameter Shield and Pile-Beam-Arch Method

2011 ◽  
Vol 368-373 ◽  
pp. 2711-2715 ◽  
Author(s):  
De Yun Ding ◽  
Xiu Ren Yang ◽  
Wei Dong Lu ◽  
Wei Ning Liu ◽  
Mei Yan ◽  
...  
Keyword(s):  
Ground Deformation ◽  
Large Diameter ◽  
Element Model ◽  
Construction Method ◽  
Shield Tunnel ◽  
Outer Diameter ◽  
Shield Tunneling ◽  
Metro Station ◽  
Dimensional Finite Element ◽  
New Construction

In more and more complicated urban building environment, a new construction method that metro engineering is constructed by large-diameter shield and shallow mining method can be regarded as a great attempt in China. By taking the Gaojiayuan station of Beijing metro line 14 as an engineering background, the main construction steps for the platform of the metro station built by a large-size shield with an outer diameter of 10 m and the Pile-Beam-Arch (PBA) method are introduced. Based on the soil-structure interaction theory, a two-dimensional finite element model is used to simulate the shield tunneling and the platform construction by the PBA method to enlarge the shield tunnel. The ground deformation and structural stress of the platform are predicted. The numerical results can be regarded as a valuable reference for the application of the new construction method in Beijing metro line 14.

Process Modeling in Laser Deposition of Multilayer SS410 Steel

2007 ◽  
Vol 129 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Liang Wang ◽  
Sergio Felicelli
Keyword(s):  
Phase Transformation ◽  
Temperature Distribution ◽  
Three Dimensional ◽  
Element Model ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Dimensional Finite Element ◽  
Net Shaping ◽  
Three Dimensional Finite Element ◽  
Continuous Cooling Transformation Diagram

A three-dimensional finite element model was developed to predict the temperature distribution and phase transformation in deposited stainless steel 410 (SS410) during the Laser Engineered Net Shaping (LENS™) rapid fabrication process. The development of the model was carried out using the SYSWELD software package. The model calculates the evolution of temperature in the part during the fabrication of a SS410 plate. The metallurgical transformations are taken into account using the temperature-dependent material properties and the continuous cooling transformation diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity due to lack of fusion is also discussed. The results show that the temperature distribution, the microstructure, and hardness in the final part depend significantly on the processing parameters.

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