scholarly journals The Ground Settlement and the Existing Pipeline Response Induced by the Nonsynchronous Construction of a Twin-Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Shicheng Sun ◽  
Chuanxin Rong ◽  
Houliang Wang ◽  
Linzhao Cui ◽  
Xin Shi
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Construction Process ◽  
Ground Settlement ◽  
Three Dimensional Model ◽  
Relative Stiffness ◽  
Twin Tunnel ◽  
Calculation Results ◽  
Negative Impacts ◽  
Final Settlement

Shielding tunnel construction always has negative impacts on the surrounding buildings. Because of repeated disturbances caused by the construction, more attention should be paid to the impacts of the nonsynchronous construction of a twin-tunnel. In this research, a three-dimensional model was established to simulate the construction process of a twin-tunnel in a section of the Hefei No. 4 metro line, and the calculation results were validated with the measured settlement data. Based on the model, the ground settlement and the existing pipeline responses were studied in detail. The results showed that, after the first tunnel (FT) construction, the settlement curves conformed to a Gaussian distribution. Additionally, after the second tunnel (ST) construction, the final settlement curves were no longer completely symmetrical. The influences of the twin-tunnel space and the pipeline-soil relative stiffness on the settlements were further studied. The results showed that the final settlement curves of the ground surface and the pipeline were mainly W-shaped, U-shaped, and V-shaped. As the twin-tunnel space increased and the pipeline-soil relative stiffness decreased, the settlement curve gradually changed from V-shaped to W-shaped. C was defined as the ratio of two maximum settlements in the W-shaped settlement curve. As the space increased, C started to decrease from 1 and then increased to 1.

Numerical Analysis of Composite Soil Nailing Wall

2014 ◽  
Vol 1065-1069 ◽  
pp. 48-52
Author(s):  
Shu Long Zhang ◽  
Fen Ting Lu
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Soil Nailing ◽  
Construction Process ◽  
Three Dimensional Model ◽  
Foundation Pit ◽  
Finite Element Software ◽  
Ground Surface Settlement ◽  
Composite Soil Nailing

Abstract. The horizontal displacement of soil in slope and the change law of ground surface settlement are dynamically analyzed by building three dimensional-model of foundation pit with the finite element software, ABAQUS, to simulate the construction process of excavation and support, to figure out the influence of micro pile and waterproof curtain on composite soil nailing wall. The study indicates that mechanical model of soil nailing, waterproof curtain, micro pile, pre-stressed anchor interacting with soil can better simulate the construction process of composite soil nailing wall support and have higher calculation accuracy. The calculation can provide a reference for the design and construction of composite soil nailing wall.

scholarly journals Numerical Analyses on the Stability of a Deep Coalmine Roadway Passing through a Fault Zone: A Case Study of the Gugui Coalfield in China

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2114
Author(s):  
Yongshui Kang ◽  
Congcong Hou ◽  
Jingyi Liu ◽  
Zhi Geng ◽  
Jianben Chen ◽  
...  
Keyword(s):  
Fault Zone ◽  
Distinct Element ◽  
Three Dimensional ◽  
Tectonic Stress ◽  
Three Dimensional Model ◽  
Support Strategy ◽  
Failure Theory ◽  
Calculation Results ◽  
Pass Through ◽  
The Stability

Massive deformation often occurs when deep coalmine roadways pass through a fault zone due to the poor integrity of rock mass and high tectonic stress. To study deformation characteristics of the surrounding rock in the fault zone of a coalmine, a roadway passing through the FD1041 fault zone in China’s Gugui coalfield was investigated in this research. The geo-stress characteristics of this fault zone were analyzed based on the Mohr failure theory. Furthermore, a three-dimensional model for the experimental roadway in the FD1041 fault zone was built and calculated by a numerical program based on the distinct element method. Stability conditions of the roadway, using several types of support methods, were calculated and compared. Calculation results indicated that pre-grouting provides favorable conditions for the stability of a roadway in a fault zone. Finally, an optimized support strategy was proposed and implemented in the experimental roadway. Monitored results demonstrated that the optimized support strategy is appropriate for this fault zone.

Study of Visual Simulation for Decomposition Assembly Tower by Derrick Supported by Inner Suspension and Inner Backstay

2013 ◽  
Vol 838-841 ◽  
pp. 388-391
Author(s):  
Yan Hai Wang ◽  
Ming Hu
Keyword(s):  
Transmission Lines ◽  
Three Dimensional ◽  
Organization Design ◽  
Visual Simulation ◽  
Construction Technology ◽  
Construction Process ◽  
Three Dimensional Model ◽  
Construction Technique ◽  
Scheme Optimization ◽  
Construction Organization

Derrick supported by inner suspension and inner backstay group tower is a construction technique commonly used in the construction of overhead transmission lines, the locale sketch and construction technique are complex, and not conducive to the analysis of the key construction and improve the level of decision-making. Through analysis assembly tower construction technology of derrick supported by inner suspension and inner backstay, using engineering visualization design software 3ds Max, the establishment of a three-dimensional model of the tower, the pole, tackle. According to the construction process for dynamic visual simulation, accurate image show the complexity of the construction process. Visual simulation provides an intuitive basis for the construction organization design and construction scheme optimization; enhance the level of construction management.

Analysis of the Containment Thermal-Hydraulic Behavior of a Small Reactor During Loss of Coolant Accident

2017 ◽  
Author(s):  
Qian Lin ◽  
Weizhong Zhang
Keyword(s):  
Cooling System ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Loss Of Coolant Accident ◽  
Lumped Parameter ◽  
Loss Of Coolant ◽  
Calculation Results ◽  
The One

The containment thermal hydraulics of a small reactor during loss of coolant accident (LOCA) is studied by a lumped parameter one-dimensional model and a three-dimensional model. The capability of a kind of heat exchanger type passive containment cooling system (PCCS) is analyzed by the one-dimensional model. The calculation results show that, the decay heat can be removed and the containment pressure can be decreased by the proposed PCCS. The steam and non-condensable gas (the air) distribution in the containment is investigated, the mixing and stratification behaviors are analyzed for several different cases, in which the PCCS and condenser are located at higher, base or lower position. The sensitivity analysis of the PCCS elevation shows that, in despite of the different gas stratification, the containment pressures are nearly the same. Similar conclusions can be obtained by the one-dimensional model and three-dimensional model. The preliminary results may indicate that, the designed PCCS and condenser can be located at a lower part, which will be benefit for the economy of the small reactor or meet other requirements.

Three Dimensional Numerical Analysis of Ground Settlement Induced by Shield Tunneling

2012 ◽  
Vol 182-183 ◽  
pp. 937-940
Author(s):  
Zhong Chang Wang
Keyword(s):  
Soil Layer ◽  
Three Dimensional ◽  
Ground Surface ◽  
Vertical Displacement ◽  
Ground Subsidence ◽  
Shield Tunnel ◽  
Ground Settlement ◽  
Shield Tunneling ◽  
Tunnel Face ◽  
Maximum Settlement

The fine numerical simulation is used to study the ground settlement of complex stratum owing to shield construction by ANSYS program. It is shown that the closer the distance between soil layer and the axis of tunnel is, the smaller the disturbance of construction is, the obvious the ground surface settlement is. The value of the maximum settlement at the center of the surface is 7.4mm. The maximum settlement of vault is 14mm. The ground subsidence in cross section distribution is shaped of normal distribution. The closer the distance between soil layer and ground surface is, the smaller the vertical displacement is, the bigger the width of settlement trough of soil layers is. The width of settlement trough is 25m. The volume loss rate of shield tunnel is about 0.32%. The width coefficient of ground settlement trough is 0.56. The tendency of ground settlement decrease to become gentle with the advance of shield construction. The ground settlement keeps constant after tunnel face advancing to 30m.

scholarly journals Development and Assessment of VR/AR Solution for Verification During the Construction Process

2018 ◽  
Vol 196 ◽  
pp. 04083
Author(s):  
Kostiantyn Protchenko ◽  
Piotr Dąbrowski ◽  
Andrzej Garbacz
Keyword(s):  
Three Dimensional ◽  
Information Modeling ◽  
Structural Members ◽  
Construction Process ◽  
Structural System ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Simple Manner ◽  
Building Information ◽  
Augmented Reality Technology

It is common occurrence that on-site workers misunderstand various detailing aspects of the provided documentation. Some of them can be unclear and should be discussed again due to construction related processes. In order to deal with this issue the application for mobile devices was proposed. The developed application allows to visualize two-dimensional print projects with the help of VR/AR (Virtual Reality/Augmented Reality) technology. The paper is focused on the assessment of the possibility to use the VR/AR technology during the process of construction. The feasibility of the solution is tested on the basis of a three-dimensional model created with the software operating in accordance with Building Information Modeling (BIM) technology. The developed mobile VR/AR solution was enhanced with basic functionality to verify structural members as well as entire structural system. Moreover, it allows to communicate in a simple manner, which can lead to the improving of the effectiveness and preventing the risk of construction errors.

scholarly journals Three-dimensional Discrete Element Simulation of Interaction between Aqueduct and Tunnel

2021 ◽  
Author(s):  
Vahab Sarfarazi ◽  
Hadi Haeri ◽  
Kaveh Asgari
Keyword(s):  
Three Dimensional ◽  
Ground Surface ◽  
Ground Settlement ◽  
Tunnel Wall ◽  
Geometrical Properties ◽  
Maximum Value ◽  
Element Simulation ◽  
Before And After ◽  
Effect Of Support ◽  
Support Lining

In this investigation the effect of interaction between aqueduct and tunnel on the ground settlement has been examined using PFC3D. At first, the calibration of PFC3D was conducted based on UCS test results rendered from three different ground layer. Then intact model with dimension of 70 m × 20 m × 34.5 m (x × y × z) was built. These models are consisted of 8 layers with different mechanical and geometrical properties. Four different configurations for aqueduct were created in four models. Diameter of aqueduct was 2 m and its depth was different in four models. After aqueduct generation, tunnel with diameter of 9 m and length of 20 m was drilled in depth of 22 m. After tunnel drilling, the settlement data of ground surface were picked up. After tunnel simulation, the effect of support lining was investigated on the ground settlement. For this purpose, after each step of tunnel drilling, lining support with diameter of 35 cm was performed. The results show that the maximum value of settlement occurred when aqueduct reach to head of tunnel. Also the safety has maximum value when the distance between aqueduct and tunnel wall was 4.5 m. the ground settlement before and after support lining shows that ground settlement reach to zero by support application.

scholarly journals Stability of Three-Dimensional Slurry Trenches with Inclined Ground Surface: A Theoretical Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Xiao-Fei Jin ◽  
Shu-Ting Liang ◽  
Xiao-Jun Zhu
Keyword(s):  
Safety Factor ◽  
Three Dimensional ◽  
Ground Surface ◽  
Theoretical Method ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Coulomb Type ◽  
The Stability ◽  
Inclined Angle ◽  
2D And 3D

Stability of slurry trenches is an important issue during the construction of the groundwater cutoff walls and diaphragm walls, and thus gradually draws attention. In this paper, a theoretical method for a three-dimensional trench model with an inclined ground was proposed. Based on the Coulomb-type force equilibrium, a safety factor assessing the stability was derived. The results showed that the existing two-dimensional model was conservative compared to the present three-dimensional model; concretely, a greater inclined angle of the inclined ground and trench length decreased the safety factor. This work could be used to assess the trench stability for both 2D and 3D cases with inclined ground surfaces.

Effects of twin-tunnel excavation on an existing horseshoe-shaped tunnel considering the influence of a settlement joint

2017 ◽  
Vol 54 (9) ◽  
pp. 1346-1355 ◽  
Author(s):  
Biao Jiang ◽  
Li’ang Chen ◽  
J.S. Yang ◽  
Shuying Wang ◽  
C.W.W. Ng
Keyword(s):  
Numerical Analysis ◽  
Adverse Effects ◽  
Transverse Direction ◽  
Three Dimensional ◽  
Ground Surface ◽  
Longitudinal Direction ◽  
Middle Section ◽  
Tunnel Excavation ◽  
Twin Tunnel ◽  
Centrifuge Tests

In urban centres, the construction of a new tunnel would cause ground disturbance and affect any adjacent existing tunnel. Tunnel–tunnel interaction problems have not yet been comprehensively studied. In particular, the response of an existing horseshoe-shaped tunnel to the construction of two perpendicularly undercrossing tunnels remains unclear. In this study, three-dimensional centrifuge tests and three-dimensional numerical analysis were designed and conducted in dry sand to investigate the effects of twin-tunnel undercrossing on an existing horseshoe-shaped tunnel considering the influence of a settlement joint. It is found that the adverse effects caused by the tunnel excavated later were smaller than those by the earlier one. For the existing tunnel without a settlement joint, the settlement at the invert and crown along the longitudinal direction showed sagging and hogging curves, respectively, owing to significant vertical elongation of the middle section. The presence of a settlement joint resulted in an increase in the settlement of the ground surface and the existing tunnel by over 100%. In both cases, larger bending strains were induced in the transverse direction than in the longitudinal direction, particularly around the corners.

Research of Wind Shear Dynamic Characteristics of Wind Wheels

2014 ◽  
Vol 1070-1072 ◽  
pp. 1888-1892
Author(s):  
Xiao Ming Chen ◽  
Shun Kang ◽  
Wei Zuo
Keyword(s):  
Wind Turbine ◽  
Wind Shear ◽  
Aerodynamic Characteristic ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Grid Method ◽  
Three Dimensional Model ◽  
Horizontal Axis Wind Turbine ◽  
Calculation Results ◽  
Object Of Study

In order to accurately analysis the aerodynamic characteristic variations of wind turbines under shear, the influence of axial and shear on the aerodynamic characteristic of a horizontal-axis wind turbine is simulated in this paper by using a sliding grid method based on FlowVision. By using the TJÆREBORG wind turbine as the object of study, a three-dimensional model of a uniform wind flow can be created. The CFD calculation results, the experimental results and the Bladed results can be used to confirm the reliability of the model. In order to investigate the effect of wind shear with regard to three-dimensional unsteady flow characteristics and a three-dimensional flow field in a wind turbine impeller, an analysis of wheel wind speed of 11m/s and an investigation of the influence of wind shear on turbine performance are carried out.

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