scholarly journals Structural Dynamic Response of a Shield Tunnel under Aircraft Taxiing Load

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Zhanyou Luo ◽  
Kuangqin Xie ◽  
Baoping Zou ◽  
Mingyao Jiang ◽  
Wei Zheng
Keyword(s):  
Dynamic Response ◽  
Three Dimensional ◽  
Shield Tunnel ◽  
Transverse Displacement ◽  
Tunnel Structure ◽  
Subway Tunnel ◽  
Structural Dynamic ◽  
Sliding Speed ◽  
Time Space ◽  
Space Effect

Dynamic load is an important factor affecting the safety and stability of subway tunnel structures. To obtain the variation law of shield tunnel structure dynamic response under aircraft taxiing load, a three-dimensional numerical simulation of such tunnel under the action of aircraft taxiing load is performed on the basis of a project involving a shield tunnel orthogonal underpass taxiway. The effects of sliding speed and tunnel depth on the structure of the shield tunnel are also analyzed. The results show that the transverse displacement and acceleration response of tunnel segment exhibit evident time-space effect under the action of aircraft taxiing load. The transverse displacement and arch waist acceleration of the shield segment increase first and then decrease. The transverse displacement of the arch waist reaches its maximum when the aircraft taxis directly above the tunnel. The sliding speed exhibits an evident influence on the dynamic response of shield tunnel structure. The vertical and convergence displacements of tunnel segments increase with the increase in sliding speed. The dynamic response of tunnel structure is significantly affected by the factors of tunnel buried depth. The vertical and convergence displacements of tunnel segments decrease with the increase in tunnel buried depth. Therefore, the safety of the shield tunnel structure can be ensured by controlling the taxiing speed when the aircraft taxis directly above the tunnel. The measures of increasing the buried depth of the tunnel or strengthening the tunnel structure need to be considered when the taxiing speed is large.

scholarly journals Vibration Response Characteristics of the Cross Tunnel Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Jinxing Lai ◽  
Kaiyun Wang ◽  
Junling Qiu ◽  
Fangyuan Niu ◽  
Junbao Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Time History ◽  
Element Model ◽  
Vibration Response ◽  
Shield Tunnel ◽  
Tunnel Structure ◽  
Response Characteristics ◽  
Vehicle Load ◽  
Metro Tunnel

It is well known that the tunnel structure will lose its function under the long-term repeated function of the vibration effect. A prime example is the Xi’an cross tunnel structure (CTS) of Metro Line 2 and the Yongningmen tunnel, where the vibration response of the tunnel vehicle load and metro train load to the structure of shield tunnel was analyzed by applying the three-dimensional (3D) dynamic finite element model. The effect of the train running was simulated by applying the time-history curves of vibration force of the track induced by wheel axles, using the fitted formulas for vehicle and train vibration load. The characteristics and the spreading rules of vibration response of metro tunnel structure were researched from the perspectives of acceleration, velocity, displacement, and stress. It was found that vehicle load only affects the metro tunnel within 14 m from the centre, and the influence decreases gradually from vault to spandrel, haunch, and springing. The high-speed driving effect of the train can be divided into the close period, the rising period, the stable period, the declining period, and the leaving period. The stress at haunch should be carefully considered. The research results presented for this case study provide theoretical support for the safety of vibration response of Metro Line 2 structure.

Three-Dimensional Dynamic Response Analysis of Shield Tunnel under Train Loads

2011 ◽  
Vol 90-93 ◽  
pp. 2062-2067 ◽  
Author(s):  
Zhan Rui Wu ◽  
Tai Yue Qi ◽  
Lin Zhong
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Shield Tunnel ◽  
Response Analysis ◽  
High Speed Train ◽  
Lining Structure ◽  
Design Speed

The vibration loads will be produced between wheel and rail on the running of the high-speed Train. The vibration energy will be transferred to the ground formation through the rail, guiding bed and tunnel lining structure, thereby causing vibration between the formation and surface and environmental interference effect problems. Thus the research of related issues caused by the high-speed train vibration has the vital great significance. The train design speed of the Shiziyang shield tunnel for Guangzhou-Shenzhen-Hong Kong passenger dedicated line is up to 350km/h. In this paper the research object is located in the segment of the homogeneous formation of the Shiziyang shield tunnel. The analysis of this paper includes the dynamic response rules of the shield tunnel and formation under the single high-speed train loads and the law of the pore water pressure accumulation and dispersion under train cyclic loading.

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.

The Finite Element Simulation Analysis of Urban Subway Shield Tunnel

2014 ◽  
Vol 711 ◽  
pp. 514-519
Author(s):  
Feng Qi Zhu ◽  
Huan Qin Liu ◽  
Jian Zhang
Keyword(s):  
Finite Element ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Internal Force ◽  
Ground Subsidence ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Subway Tunnel ◽  
Underground Engineering ◽  
Lining Structure

Shield tunning method has been used widely in urban underground engineering. Based on a certain range of Wuhan subway shield tunnel, the subway shield tunnel segment of the internal force and deformation were studied by the load structure method and stratum structure method. Influence of the formation parameters and the parameters of the lining structure on the segment internal force and deformation was analyzed. And the tunnel construction was modeled by three-dimensional dynamic finite element method. The influence of the construction process about ground subsidence and segment stress was discussed, in order to guide urban subway tunnel construction design.

scholarly journals Analysis of Three-Dimensional Vibration Characteristics of Single-Circle Double-Track Subway Tunnel under Moving Load

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chunquan Dai ◽  
Mengying Yang ◽  
Quanlei Wang ◽  
Tingzhi Yang ◽  
Kun Jiang
Keyword(s):  
Dynamic Response ◽  
Moving Load ◽  
Compressive Strain ◽  
Three Dimensional ◽  
Urban Rail Transit ◽  
Time Interval ◽  
Subway Tunnel ◽  
Double Line ◽  
Double Track ◽  
The Impact

With the development of urban rail transit, subway lines are becoming more and more denser, the departure time interval is short, and the probability of subway trains meeting is high. The impact of vibration caused by double-line subway meeting on the surrounding environment cannot be ignored. Taking the typical cross-section of a single-circle double-track subway tunnel as an example, a single running scenario and three typical meeting scenarios, namely, 4 s meeting, 6 s meeting, and 8 s meeting scenarios were considered, and a track-tunnel-foundation three-dimensional ABAQUS finite element model was established. The dynamic response of monitoring points at different distances between the center of the track bed and the center line of the track was analyzed. Results showed that due to the consistent load action period, the center acceleration of the track bed increases significantly during the meeting, the main frequency of vibration and the peak value of the 1/3 octave spectrum were increased by about 5 Hz, and the vibration level at the dominant frequency was increased by about 7 dB. The center displacement of the track bed and the peak compressive strain increased significantly under the 4 s meeting and 6 s meeting working scenarios; while the 8 s meeting and 4 s single running scenarios were basically the same, only the action time was doubled. The dynamic response of the 4 working scenarios decreases with the increase of distance, and the attenuation rate gradually decreases and has gradually stabilized within 15–19 m above the vault.

Probabilistic analyses of structural dynamic response with modified Kriging-based moving extremum framework

2021 ◽  
Vol 125 ◽  
pp. 105398
Author(s):  
Cheng Lu ◽  
Cheng-Wei Fei ◽  
Yun-Wen Feng ◽  
Yong-Jun Zhao ◽  
Xiao-Wei Dong ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Structural Dynamic

A Computational Analysis of Flow Field in Twin-Track Subway Tunnel to Improve Air Quality

2013 ◽  
Vol 319 ◽  
pp. 599-604
Author(s):  
Makhsuda Juraeva ◽  
Kyung Jin Ryu ◽  
Sang Hyun Jeong ◽  
Dong Joo Song
Keyword(s):  
Air Quality ◽  
Computational Model ◽  
Stokes Equations ◽  
Ventilation System ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
Navier Stokes ◽  
Subway Tunnel ◽  
Air Supply ◽  
And Performance

A computational model of existing Seoul subway tunnelwas analyzed in this research. The computational model was comprised of one natural ventilationshaft, two mechanical ventilationshafts, one mechanical airsupply, a twin-track tunnel, and a train. Understanding the flow pattern of the train-induced airflow in the tunnel was necessary to improve ventilation performance. The research objective wasto improve the air quality in the tunnel by investigating train-induced airflow in the twin-track subway tunnel numerically. The numerical analysis characterized the aerodynamic behavior and performance of the ventilation system by solving three-dimensional turbulent Reynolds-averaged Navier-Stokes equations. ANSYS CFX software was used for the computations. The ventilation and aerodynamic characteristics in the tunnel were investigated by analyzing the mass flowrateat the exits of the ventilation mechanicalshafts. As the train passed the mechanical ventilation shafts, the amount of discharged-air in the ventilationshafts decreased rapidly. The air at the exits of the ventilation shafts was gradually recovered with time, after the train passed the ventilation shafts. The developed mechanical air-supply for discharging dusty air and supplying clean airwas investigated.The computational results showed that the developed mechanical air-supplycould improve the air quality in the tunnel.

scholarly journals Dynamic response analysis for multi-degrees-of-freedom parallel mechanisms with various types of three-dimensional clearance joints

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110177
Author(s):  
Jia Yonghao ◽  
Chen Xiulong
Keyword(s):  
Dynamic Response ◽  
Multibody Systems ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Response Analysis ◽  
Parallel Mechanisms ◽  
Dynamics Model ◽  
Clearance Joints ◽  
Clearance Joint ◽  
Spatial Parallel Mechanism

For spatial multibody systems, the dynamic equations of multibody systems with compound clearance joints have a high level of nonlinearity. The coupling between different types of clearance joints may lead to abundant dynamic behavior. At present, the dynamic response analysis of the spatial parallel mechanism considering the three-dimensional (3D) compound clearance joint has not been reported. This work proposes a modeling method to investigate the influence of the 3D compound clearance joint on the dynamics characteristics of the spatial parallel mechanism. For this purpose, 3D kinematic models of spherical clearance joint and revolute joint with radial and axial clearances are derived. Contact force is described as normal contact and tangential friction and later introduced into the nonlinear dynamics model, which is established by the Lagrange multiplier technique and Jacobian of constraint matrix. The influences of compound clearance joint and initial misalignment of bearing axes on the system are analyzed. Furthermore, validation of dynamics model is evaluated by ADAMS and Newton–Euler method. This work provides an essential theoretical basis for studying the influences of 3D clearance joints on dynamic responses and nonlinear behavior of parallel mechanisms.

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