scholarly journals 3D Numerical Simulation of Shield Tunnel Subjected to Swelling Effect Considering the Nonlinearity of Joint Bending Stiffness

2019 ◽  
Author(s):  
Qixiang Yan ◽  
Chuan Zhang ◽  
Wang Wu ◽  
Hongxue Zhu ◽  
Wenbo Yang
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Elastic Shell ◽  
Three Dimensional ◽  
Bending Stiffness ◽  
Shield Tunnel ◽  
Shell Elements ◽  
Swelling Soils ◽  
Internal Forces ◽  
Engineering Projects

In this paper, the authors developed a three dimensional shell-spring numerical model of a shield tunnel, in which the elastic shell elements were adopted to model the segments and the spring models were used for the simulation of the segmental joints. The highlight of this research is that the non-linearity of the joint bending stiffness was taken into consideration, which was first determined through the numerical simulation by using a refined 3D continuum model of the segment-joint structure. The automatic iteration of the joint bending stiffness was achieved through programming with the ANSYS ADPL software. Based on a specific engineering example, a 3D continuum-shell-spring model was established to analyze the internal forces of shield tunnel segmental linings subject to swelling soils. The developed numerical model and its application in the analysis of the internal forces of shield tunnel segmental linings in swelling ground will provide useful reference and guidance for the numerical calculation in similar engineering projects in future.

scholarly journals Blowing and drifting snow in Alpine terrain: numerical simulation and related field measurements

1998 ◽  
Vol 26 ◽  
pp. 174-178 ◽  
Author(s):  
Peter Gauer
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Three Dimensional ◽  
Field Measurements ◽  
Blowing Snow ◽  
Related Field ◽  
Drifting Snow ◽  
Physically Based ◽  
Snow Transport

A physically based numerical model of drifting and blowing snow in three-dimensional terrain is developed. The model includes snow transport by saltation and suspension. As an example, a numerical simulation for an Alpine ridge is presented and compared with field measurements.

scholarly journals 3D MODELLING OF TUNNEL EXCAVATION USING PRESSURIZED TUNNEL BORING MACHINE IN OVERCONSOLIDATED SOILS

2013 ◽  
Vol 35 (2) ◽  
pp. 3-17 ◽  
Author(s):  
Rafik Demagh ◽  
Fabrice Emeriault
Keyword(s):  
Numerical Simulation ◽  
Urban Areas ◽  
Three Dimensional ◽  
Ground Surface ◽  
Tunnel Boring Machine ◽  
Confining Pressure ◽  
Soil Mass ◽  
Shield Tunnel ◽  
Tunnel Boring ◽  
Boring Machines

Abstract The construction of shallow tunnels in urban areas requires a prior assessment of their effects on the existing structures. In the case of shield tunnel boring machines (TBM), the various construction stages carried out constitute a highly three-dimensional problem of soil/structure interaction and are not easy to represent in a complete numerical simulation. Consequently, the tunnelling- induced soil movements are quite difficult to evaluate. A 3D simulation procedure, using a finite differences code, namely FLAC3D, taking into account, in an explicit manner, the main sources of movements in the soil mass is proposed in this paper. It is illustrated by the particular case of Toulouse Subway Line B for which experimental data are available and where the soil is saturated and highly overconsolidated. A comparison made between the numerical simulation results and the insitu measurements shows that the 3D procedure of simulation proposed is relevant, in particular regarding the adopted representation of the different operations performed by the tunnel boring machine (excavation, confining pressure, shield advancement, installation of the tunnel lining, grouting of the annular void, etc). Furthermore, a parametric study enabled a better understanding of the singular behaviour origin observed on the ground surface and within the solid soil mass, till now not mentioned in the literature.

scholarly journals THE WOOD‐FRAMED WITH SHEATHING BUILDINGS ‐ ALTERNATIVE FOR HOUSING CONSTRUCTION

2006 ◽  
Vol 12 (2) ◽  
pp. 143-151 ◽  
Author(s):  
Mikołaj Malesza ◽  
Czesław Miedziałowski
Keyword(s):  
Numerical Model ◽  
Composite Structure ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Beam Element ◽  
Housing Construction ◽  
Residential Housing ◽  
Shell Elements ◽  
Linear Behaviour ◽  
Floor Diaphragms

Numerical model of the wood‐framed with sheathing structure and selected results of experimental tests are presented in the paper. Wall and floor diaphragms as the three‐dimensional composite structure are modeled applying plane shell elements representing framing and sheathing and beam element describing the fasteners. Experimental tests were conducted on typically disposed the wood‐framed wall and floor diaphragms in residential housing in Poland. Associated tests of materials and connections and their results are also included in the paper. Non‐linear behaviour of fasteners is examined in the numerical model. Results obtained from model and experiments are coincident.

Finite Element Analysis of the Surface Settlement Induced by the Shield Tunnel Construction

2014 ◽  
Vol 501-504 ◽  
pp. 111-114
Author(s):  
Ling Xia Gao ◽  
Xiang Jun Yang ◽  
Li Kun Qin
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Three Dimensional ◽  
Longitudinal Direction ◽  
Element Model ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Empirical Formulas ◽  
Element Analysis ◽  
Polynomial Expression

Three-dimensional non-linearity finite element model of shield tunnel was established on basis of the Z1 line of Tianjin subway. And then it was applied to simulate construction process of shield tunnel. Surface settlement of the tunnel during the construction was obtained. The settlement data of transverse and longitudinal direction from numerical simulation were fitted through a polynomial expression. Then a contrastive analysis of curves from numerical simulation and matching formulae were made. The result shows that it is feasible to utilize the empirical formulas like Pecks to predict surface settlement in Tianjin caused by shield construction.

Numerical Simulation of Vertical Forced Plume in a Crossflow of Stably Stratified Fluid

1995 ◽  
Vol 117 (4) ◽  
pp. 696-705 ◽  
Author(s):  
Robert R. Hwang ◽  
T. P. Chiang
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Cross Section ◽  
Three Dimensional ◽  
Experimental Measurements ◽  
Secondary Vortex ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Vortex Pairs ◽  
Plume Flows

In this study, an investigation using a three-dimensional numerical model, which treats conservation of mass, momentum, and salinity simultaneously, was carried out to study the character of a vertical forced plume in a uniform cross-stream of stably linear stratified environment. A k-ε turbulence model was used to simulate the turbulent phenomena and close the solving problem. The performance of the three-dimensional model is evaluated by comparison of the numerical results with some available experimental measurements. Results indicate that the numerical computation simulates satisfactorily the plume behavior in a stratified crossflow. The secondary vortex pairs in the cross section induced by the primary one change as the plume flows downstream. This denotes the transformation of entrainment mechanism in stratified crossflow.

A Study on the Evolution of Distributary Channels in River-Dominated Deltas Using Numerical Simulations of Hydrodynamic Behaviors

2015 ◽  
Vol 744-746 ◽  
pp. 1050-1055
Author(s):  
Yang Jun Wang ◽  
Tai Ju Yin ◽  
Zhi Hao Deng
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Quantitative Methods ◽  
Oil And Gas ◽  
Reference Model ◽  
Three Dimensional ◽  
Hydrodynamic Characteristics ◽  
Oil And Gas Exploration ◽  
Hydrodynamic Behaviors ◽  
Distributary Channel

The Fluvial-dominated delta is one of the extremely important deposition systems in oil and gas exploration. In this paper, the three-dimensional numerical simulation of hydrodynamics has been applied to the precise analysis of the formation of fluvial-dominated deltas and the evolution of their distributary channels. The model has been created using the Delft3D program, and the conditions of the numerical model have been set according to the hydrodynamic characteristics of modern rivers and deltas. The calculation field was 20.5 km in length by 10 km in width. With the Mor-Factor set to 60, the simulation time was 45 days. The formation and the avulsion of the mouth bar, as well as the extension, migration and bifurcation of distributary channels, have been observed and studied through analysis of the simulation results. The vertical cross-section shows that the distributary channel was filled multiple times. According to distributary channel evolution characteristics combined with quantitative methods, the terminal distributary channels can be extremely developed under ideal conditions. Due to the cross-cutting and reform effort of distributary channels, sediments were spread widely and continuously. The results show that the numerical model works well in explaining the process of evolution in fluvial-dominated delta distributary channels. This study not only enables us to quantitatively understand the dynamic processes of terminal distributary channels in fluvial-dominated delta systems, but also provides a reference model for numerical simulation of hydrodynamics in sedimentology study.

Numerical Simulation of Friction Stir Spot Welding

2016 ◽  
Vol 834 ◽  
pp. 43-48 ◽  
Author(s):  
Marius Adrian Constantin ◽  
Ana Boşneag ◽  
Monica Iordache ◽  
Claudiu Bădulescu ◽  
Eduard Niţu
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Spot Welding ◽  
Frictional Heating ◽  
Three Dimensional ◽  
High Strength Steels ◽  
High Strength ◽  
Friction Stir Spot Welding ◽  
Fe Model ◽  
Friction Stir

Friction Stir Spot Welding (FSSW) is a solid state joining process that relies on frictional heating and plastic deformation realized at the interaction between a non-consumable welding tool that rotates on the contact surfaces of the workpieces. Friction Stir Spot Welding (FSSW) is an evolving technique that has received considerable attention from automotive industries to replace electric resistance spot welding, which shows poor weldability for advanced high-strength steels as well as aluminium alloys. Because of the interest shown by the industry towards this process, an attempt to optimize it is imperative. But the experiments are often time consuming and costly. To overcome these problems, numerical analysis has frequently been used in the last years. The purpose of this paper is to develop a three-dimensional fully coupled thermal-stress finite element (FE) model of FSSW process for thin aluminium alloy Al 6061-T6. Numerical simulation being helpful for better understanding and observation of the influence of input parameters on the resulting phenomena. It is described the algorithm and are presented the activities needed to be performed in order to develop a valid numerical model for FSSW. The validation of the numerical model being achieved by comparing the resulted temperatures from the numerical simulation with the experimentally determined temperatures for the same material

The Application of Numerical Simulation in Feasibility Research of Ascending Mining

2014 ◽  
Vol 962-965 ◽  
pp. 1175-1178
Author(s):  
Bao Feng Zhao ◽  
Lian Jing Ma
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Coal Mining ◽  
Coal Mine ◽  
Fracture Zone ◽  
Three Dimensional ◽  
Ratio Method ◽  
Feasibility Research ◽  
Hydrogeological Conditions ◽  
Balance Analysis

In order to study the feasibility of the ascending mining in Maiduoshan coal mine, the “two belts” of 6# coal should be predicting. Based on the analyzing of mine hydrogeological conditions, the three-dimensional numerical model is established by the FLAC3D, the scope of “two belts” by lower coal mining is predicted. The results shows that the fracture zone height of 6# coal less than the distance between 6# coal and 2# coal, and Maiduoshan coal mine meet the requirement of ascending mining. At the same time, combining the ratio method and balance analysis of surrouding rock, ascending mining is feasible in Maiduoshan coal mine.

scholarly journals A Displacement-Based Theory for Predicting the Support Force on the Shield Tunneling Surface in Sandy Soil Layers

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guang Sun ◽  
Han Liu ◽  
Zhiyuan Guo ◽  
Ranjie Li ◽  
Tao Li
Keyword(s):  
Numerical Simulation ◽  
Sandy Soil ◽  
Soil Layer ◽  
Three Dimensional ◽  
Earth Pressure ◽  
Shield Tunnel ◽  
Soil Pressure ◽  
Pressure Balance ◽  
Shield Tunneling ◽  
Support Force

Due to the poor stability of the loose sandy soil layer, if the support force is not properly controlled during the construction process of the shield tunnel using the earth pressure balance method, it is easy to cause the ground to collapse or uplift. Therefore, understanding the support force of the excavation surface of shield tunneling in sandy soil layer is very vital to ensure the stability of the excavation surface. Firstly, it is assumed that the damaged soil is a three-dimensional wedge and a modified three-dimensional wedge in the active and passive failure modes, respectively. The shallow soil pressure theory and the soil plastic limit equilibrium theory are derived by analyzing the stress distribution on the damaged soil. The equation for revealing the inner essence between the support force of the shield excavation surface and excavation surface displacement under the condition of sand-covered soil is used. Secondly, the numerical simulation method analyzes the displacement of the excavation surface when the support force changes under different working conditions, and the relationship curve between the excavation surface support force and the shield tunneling displacement is obtained. The comparison and analysis between the numerical simulation calculation and the theoretical analysis indicate that the deduced calculation equation for the excavation surface support force based on the displacement earth pressure is reasonable.

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