Numerical Simulation of Subway-Induced Environment Vibration

2013 ◽  
Vol 405-408 ◽  
pp. 1264-1267
Author(s):  
Pei Zhen Li ◽  
Zhao Hui Pan ◽  
Xiu Qiang Li ◽  
Jian Yong Yue
Keyword(s):  
Numerical Simulation ◽  
Frequency Domain ◽  
Ground Surface ◽  
Vertical Displacement ◽  
Displacement Amplitude ◽  
Loading Frequency ◽  
Soil Layers ◽  
Tunnel Model ◽  
Element Boundary ◽  
Abaqus Software

The ABAQUS software was used to establish an actual soil layers-tunnel model in which the infinite element boundary was adopted. Then, frequency domain analyses were conducted on the model under vertical train loads with different frequencies. The attenuation of the vertical displacement amplitude on ground surface under each load was computed in the area ranging from 0m to 30m. The results show that the displacement amplitude may rebound in a particular area under some loading frequencies and this phenomenon is closely related with the loading frequency.

Three Dimensional Elastic-Plastic Numerical Simulation of Tunnel Excavation Sequence of Dalian Speed Railway

2012 ◽  
Vol 170-173 ◽  
pp. 1474-1478
Author(s):  
An Nan Jiang ◽  
Hong Wei Yang ◽  
Hong Fu Xin ◽  
Bing Bai
Keyword(s):  
Numerical Simulation ◽  
Damage Zone ◽  
Three Dimensional ◽  
Ground Surface ◽  
Soft Rock ◽  
Vertical Displacement ◽  
Stability Control ◽  
Surrounding Rock ◽  
Railway Tunnel ◽  
Elastic Plastic

Dalian speed railway tunnel is located in complex soft rock and soil, the road foundation deform and surrounding rock stability control is a concern problem. Along with the unloading process of excavation, surrounding rock moving to inner hole, while exceeding the elastic limitation, the plastic deform and the surrounding rock destroy then occurred. The paper adopted three dimensional elastic-plastic method based on Mohr-Coulomb yielding criterion and carried out numerical simulation of excavation process, in order to analyze and compare the surrounding rock vertical displacement contour, ground surface settlement and damage zone corresponding to different construction sequence. The elastic-plastic numerical method can reflect the damage and destroy character of nonlinear soil material of surrounding rock corresponding to different construction scheme, the simulation result has active guiding meaning for the Dalian speed railway tunnel construction design and dynamic analysis.

scholarly journals Field Measurement and Numerical Simulation of Train-Induced Vibration from a Metro Tunnel in Soft Deposits

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Qiang Huang ◽  
Pan Li ◽  
Dongming Zhang ◽  
Hongwei Huang ◽  
Feng Zhang
Keyword(s):  
Numerical Simulation ◽  
High Frequency ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Surface ◽  
Soil Layers ◽  
Acceleration Amplification ◽  
Metro Tunnel ◽  
Train Vibration ◽  
Train Induced Vibration

Train-induced vibration is increasingly attracting people’s concern nowadays. In the coastal areas, many metro tunnels are built in the soft deposits, so the train-induced vibration effect is more serious. Nevertheless, the existing research studies mainly focus on the dynamic responses in the tunnel or on the ground surface while vibration characteristics in the ground are seldom studied. In this paper, a comprehensive field measurement was performed by installing accelerometers in the tunnel and soil layers and on the ground surface to capture the response characteristics of the track-tunnel-ground system. Elastoplastic numerical simulation considering the soil-water coupling was conducted to reveal the responses of acceleration, dynamic displacement, and excess pore water pressure using FE code DBLEAVES. Measurement results indicate that high-frequency contents (>500 Hz) attenuate rapidly in the propagation process; the dominant frequency of the rail concentrates in the middle- and high-frequency bands, about 25–400 Hz and 1000–1500 Hz, while the frequencies of the track bed, soil layers, and ground surface drop to below 400, 200, and 100 Hz, respectively. The vertical ground acceleration decreases like an arc in the transverse direction while there is transverse acceleration amplification phenomenon at a distance from the upper haunch and lower haunch of the tunnel. Overall, the area affected by train vibration in the soft deposits is about 30 m away from the metro tunnel. Numerical simulation based on soil-water coupled analysis is feasible to model the vibration characteristics in the soft deposits and confirms that there is acceleration amplification in the ground. Moreover, numerical results indicate that excess pore water pressure can be accumulated during each train vibration, so the train-induced settlement will be a potential problem in the long term for the metro tunnel.

Numerical Simulation Analysis for Scroll of Scroll Compressor Based on ABAQUS

2014 ◽  
Vol 488-489 ◽  
pp. 1047-1051
Author(s):  
Qing Qian Zheng ◽  
Bin Yang ◽  
Ning Chen ◽  
Hui Min Yang ◽  
Min Hu
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Thermal Deformation ◽  
Vortex Flow ◽  
Simulation Analysis ◽  
Temperature Load ◽  
Stress And Deformation ◽  
Finite Method ◽  
Abaqus Software ◽  
Main Factor

In this paper, the finite method is applied and ABAQUS software is used, the vortex flow field is loaded as boundary condition of wraps. The stress and deformation in scroll under the action of gas pressure, temperature load and both of them is analyzed, the stress distribution and deformation of wraps in different shaft rotation angles is discussed, the stress distribution and deformation discipline of wraps are also respectively obtained. The results show that the overall stress and deformation in scroll are the largest when compression chamber is moving near the vent position and the thermal deformation is the main factor of affecting the overall deformation of scroll.

scholarly journals Deformation Monitoring of Earth Fissure Hazards Using Terrestrial Laser Scanning

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1463 ◽  
Author(s):  
Yunfeng Ge ◽  
Huiming Tang ◽  
Xulong Gong ◽  
Binbin Zhao ◽  
Yi Lu ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Ground Surface ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Vertical Displacement ◽  
Deformation Monitoring ◽  
Earth Fissure ◽  
Displacement Analysis ◽  
Remote Sensing Technique ◽  
Noise Data

Deformation monitoring is a powerful tool to understand the formation mechanism of earth fissure hazards, enabling the engineering and planning efforts to be more effective. To assess the evolution characteristics of the Yangshuli earth fissure hazard more completely, terrestrial laser scanning (TLS), a remote sensing technique which is regarded as one of the most promising surveying technologies in geohazard monitoring, was employed to detect the changes to ground surfaces and buildings in small- and large-scales, respectively. Time-series of high-density point clouds were collected through 5 sequential scans from 2014 to 2017 and then pre-processing was performed to filter the noise data of point clouds. A tiny deformation was observed on both the scarp and the walls, based on the local displacement analysis. The relative height differences between the two sides of the scarp increase slowly from 0.169 m to 0.178 m, while no obvious inclining (the maximum tilt reaches just to 0.0023) happens on the two walls, based on tilt measurement. Meanwhile, global displacement analysis indicates that the overall settlement slowly increases for the ground surface, but the regions in the left side of scarp are characterized by a relatively larger vertical displacement than the right. Furthermore, the comparisons of monitoring results on the same measuring line are discussed in this study and TLS monitoring results have an acceptable consistency with the global positioning system (GPS) measurements. The case study shows that the TLS technique can provide an adequate solution in deformation monitoring of earth fissure hazards, with high effectiveness and applicability.

scholarly journals Locomotion Control of Snake-Like Robot with Rotational Elastic Actuators Utilizing Observer

2019 ◽  
Vol 9 (19) ◽  
pp. 4012 ◽  
Author(s):  
Shunsuke Nansai ◽  
Takumi Yamato ◽  
Masami Iwase ◽  
Hiroshi Itoh
Keyword(s):  
Numerical Simulation ◽  
Control System ◽  
Dynamic Model ◽  
Ground Surface ◽  
Surface Conditions ◽  
Luenberger Observer ◽  
Key Points ◽  
Switching Dynamic ◽  
Head Control ◽  
Frictional Coefficients

The purpose of this paper is designing a head control system capable of adapting to passive side-slipping. The environments in which snake-like robots are expected to be utilized generally have ground surface conditions with nonuniform frictional coefficients. In such conditions, the passive wheels of the snake-like robot have a chance of side-slipping. To locomote the snake-like robot dexterously, a control system which adapts to such side-slipping is desired. There are two key points to realizing such a system: First, a dynamic model capable of representing the passive side-slipping must be formulated. A solution for the first key point is to develop a switching dynamic model for the snake-like robot, which switches depending on the occurrence of the side-slipping, by utilizing a projection method. The second key point is to adapt the control system’s behavior to side-slipping. An idea for such a solution is to include the side-slipping velocity in the weighting matrices. An algorithm to estimate the occurrence of side-slipping and the particular side-slipping link is constructed, to formulate the dynamic model depending on the actual side-slipping situation. The effectiveness of the designed Luenberger observer and the head control system for side-slipping adaptation is verified through numerical simulation.

Prediction of Shield Tunnelling-Induced Ground Settlement Considering Soil-Water Coupled and around Soil Disturbance Damage

2010 ◽  
Vol 168-170 ◽  
pp. 357-364
Author(s):  
Ji Feng Liu ◽  
Bo Liu ◽  
Hui Zhi Zhang
Keyword(s):  
Numerical Simulation ◽  
Soil Water ◽  
Ground Surface ◽  
Soil Disturbance ◽  
Surface Settlement ◽  
Shield Tunnel ◽  
Tunnel Construction ◽  
Ground Settlement ◽  
Ground Surface Settlement ◽  
Shield Tunnelling

to evaluate the influence of soil-water coupled and shield tunnel construction induced around soil disturbance damage on ground surface settlement, the process of shield tunnel construction induced around soil disturbance is analyzed, the FLAC3D numerical simulation are carried out, and a newly-modified tunnelling-induced ground settlement calculation method based on disturbance degree of around soil and soil-water coupled is presented, and these methods are applied in case of Beijing Metro 10thLine. It is indicated that considering the influence of the shield tunnelling-induced around soil disturbance damage, and soil-water coupled induced soil properties weakening and the excess pore water pressure dissipating induced soil consolidation to the ground surface settlement are necessary, the calculating result of the newly-modified surface settlement prediction method, and the result FLAC3D numerical simulation all agree well with in-site observed data of Beijing Metro 10th Line.

Numerical Simulations of a Ground Source Heat Pump System With Pile Heat Exchangers

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Masahito Oguma ◽  
Takeshi Matsumoto ◽  
Takao Kakizaki
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Heat Supply ◽  
Ground Surface ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source

Feasibility of a ground source heat pump (GSHP) system with pile heat exchangers for use in houses is evaluated through a numerical simulation. This GSHP system differs from ordinary borehole-type GSHP systems because short foundation piles installed at close intervals are used as heat exchangers. It is shown that the annual heat supply provided by this GSHP system is able to satisfy the demand of a house due to the air-source exchange at ground surface.

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