scholarly journals Vibration reduction performance of rubber concrete backfill layer in high-speed railway tunnel

2018 ◽  
Vol 50 (1) ◽  
pp. 22-32
Author(s):  
Yanke Liang ◽  
Xiaopei Cai ◽  
Yanrong Zhang ◽  
Yanglong Zhong

A novel approach to reduce vibration was put forward by applying rubber concrete as backfill layer of the high-speed railway tunnel, and its feasibility was analyzed based on the vibration isolation theory. A three-dimensional spatial coupling model of vehicle-track-tunnel-rock mass was established by means of vehicle-track coupling dynamics theory. The dynamic response of the vehicle, track, and tunnel structure under common and rubber concrete backfill layer was compared. The vibration reduction performance and the characteristics of rubber concrete were discussed. The change in tunnel vibration under different elastic modulus and damping ratios of backfill layer was analyzed, and the vibration reduction effect of rubber concrete combined with damping cushion was studied. Results show that the influence of the rubber concrete backfill layer on the dynamic indices of vehicle and track structure can be neglected. Because of the application of rubber concrete, the vibration acceleration of tunnel decreases by about 40%, and 4–8 dB can be reduced in the corresponding frequency of 100–200 Hz. With decrease in the elastic modulus and increase in the damping ratio, the vibration of the tunnel decreases gradually. Moreover, the influence of damping ratio is more significant than that of elastic modulus. The combination of rubber concrete backfill layer and damping cushion demonstrates a superior effect in reducing vibration, which decreases the vibration level by 3–5 dB compared with setting the damping cushion only. The article is expected to provide theoretical guidance for the application of rubber concrete in the high-speed railway.

2014 ◽  
Vol 919-921 ◽  
pp. 865-868 ◽  
Author(s):  
Rui Zhen Fei ◽  
Li Min Peng ◽  
Wei Chao Yang ◽  
Wei Guang Yan

According to the 100㎡ high-speed tunnel cross-section which is generally used in high-speed railway of China, this paper develops a tunnel-air-train simulation model, based on the three-dimensional incompressible Navier-Stokes equations and the standard k-e turbulence model. Time-history variation rules and space distribution characteristics of train wind are studied respectively. The results show that: train wind is complex three-dimensional flow changing with time and space, air at the front of train flows away from the train head, while air at the rear of train flows to the train tail.


2011 ◽  
Vol 243-249 ◽  
pp. 3670-3675
Author(s):  
Yun Dong Ma ◽  
Bo Li ◽  
Bin Fan

The aerodynamic numerical simulation model of high-speed railway tunnel was established based on the analyzing of the aerodynamic effect characteristics of high-speed railway tunnel. FLUENT three dimensional compressible flows SIMPLE algorithm was adopted, the three dimensional aerodynamic effect of high-speed railway tunnel was simulated on the condition that the high-speed train was in motion. The pressure changes law in the tunnel was obtained during the whole process when high-speed train traveling, and the pressure-time curve in the tunnel middle cross-section was plotted. It laid a foundation for the further development of tunnel lining dynamics analysis.


Author(s):  
Yipeng Xie ◽  
Junsheng Yang ◽  
Cong Zhang ◽  
Jinyang Fu

The Yujingshan high-speed railway tunnel crosses a giant cavern system with a 108 × 104 m3 volume chamber and an 18 km long underground river. The massive project, which lasted three years, was eventually awarded the “Overcoming the Challenges” award by the International Tunneling and Underground Space Association (ITA) in 2020. However, since the cave chamber was filled with large-scale rockfill, structural settlement is a non-negligible problem. This paper presents the unique structures of a bridge supporting railway tracks wrapped by tunnel lining and the settlement control of the Yujingshan tunnel crossing massive rockfill in the giant cave. The geological characteristics and design considerations are systematically introduced. A three-dimensional coupling discrete element method (DEM) and finite difference method (FDM) numerical model and 13 months of long-term settlement monitoring were conducted to evaluate the settlement behavior. The results indicate that the morphology of cavern and internal deposits caused the whole rockfill to migrate to the lower left. The tunnel structure consequently developed a significant inclined settlement. The continuous construction load would increase the settlement value by 31.4%. The bottom reinforcement of steel-pipe pile with grouting could effectively inhibit settlement and differential settlement. Considering the simulation results, the tunnel bottom had greater settlement than the limit standard for high-speed railway embankment, which means this special structure form is reasonable for operation. Meanwhile, the monitoring results show that the tunnel bottom settlement in D3K279+891~D3K279+947 had not performed an apparent convergence trend after 13 months. Further structural monitoring and compensation grouting should be actively considered for operation maintenance.


2020 ◽  
Vol 79 (5) ◽  
pp. 2201-2212
Author(s):  
Shunhua Zhou ◽  
Zhiyao Tian ◽  
Honggui Di ◽  
Peijun Guo ◽  
Longlong Fu

2013 ◽  
Vol 842 ◽  
pp. 445-448
Author(s):  
Wei Chao Yang ◽  
Chuan He ◽  
Li Min Peng

This paper describes the results of numerical work to determine the flow structures of the slipstream and wake of a high speed train on platforms of underground rail station using three-dimensional compressible Euler equation. The simulations were carried out on a model of a simplified three-coach train and typical cross-section of Chinese high-speed railway tunnel. A number of issues were observed: change process of slipstreams, longitudinal and horizontal distribution characteristics of train wind. Localized velocity peaks were obtained near the nose of the train and in the near wake region. Maximum and minimum velocity values were also noticed near to the nose rear tip. These structures extended for a long distance behind the train in the far wake flow. The slipstream in platform shows the typical three-dimensional characteristics and the velocity is about 4 m/s at 6 m away from the edge of platform.


2014 ◽  
Vol 716-717 ◽  
pp. 342-346
Author(s):  
Xiao Jun Zhou ◽  
Bo Jiang ◽  
Yue Feng Zhou ◽  
Yu Yu

On the basis of different landform and multifarious topography in rugged mountainous area in southwest China, typical tunnel portals for single track tunnels in a new high speed railway line have been presented in the paper. The portal comprises headwall, shed tunnel, bridge abutment and its support. Portal with headwall is suitable for tunnel to resist front earth pressure on high and abrupt slope. Shed tunnel is placed in front of headwall so as to prevent rockfall; its outward part is built into a flared one. Meanwhile, the installation of bridge and its abutment are also included in the portal according to landform in the paper.


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