Dynamic Accumulation Damage Characteristics of Initial Cracks for the Lining of High-Speed Railway’s Tunnel

2014 ◽  
Vol 580-583 ◽  
pp. 1311-1314
Author(s):  
Xiang Qiu Wang ◽  
Bin Cai
Keyword(s):  
High Speed ◽  
Damage Zone ◽  
Damage Mechanism ◽  
Initial Crack ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Limit Values ◽  
Lining Structure ◽  
Initial Cracks

After have been analysed the initial dynamic cumulative damage mechanism of lining structure of the high speed railway tunnel,the conclusions have been gained that, under the effect of the long-term vibrating load of high speed train, When the damage energy accumulation reached a limit values, the damage zone caused by the initial crack which has been existed in the tunnel lining will be expansed further more. for the more, based on the accumulation damage theory linear elasticity and the analysis method dynamic finite element, The extension characters and calculation method of initail crack in the tunnel lining structures for the high railway have been proposed.

Numerical Simulation on Mesoscopic Damage Evolution Mechanism of High-Speed Railway Tunnel Lining Concrete

2011 ◽  
Vol 90-93 ◽  
pp. 2248-2253
Author(s):  
Yun Dong Ma ◽  
Bo Li ◽  
Bin Fan
Keyword(s):  
High Speed ◽  
Damage Mechanism ◽  
Tunnel Lining ◽  
Concrete Lining ◽  
Railway Tunnel ◽  
High Speed Railway ◽  
Main Research ◽  
Elastic Module ◽  
Fatigue Loads ◽  
Research Stage

For the high-speed railway tunnel concrete lining, there have been some such initial damages as initial pores or cracks, therefore the initial damages will be expanded gradually under aerodynamic fatigue loads resulting from the high-speed train passing by tunnel, elastic module attenuation laws of concrete was adopted to reflect the effects of fatigue loads on the tunnel lining mesoscopic concrete, taking the second stage of the elastic module attenuation as the main research stage, the mesoscopic damage mechanism and fatigue damage cracks developing-and-changing laws of high-speed railway lining concrete were simulated under the repetitive aerodynamic loads. Study indicates: for the concrete lining with initial damages, under the repeated aerodynamic fatigue loads, the mechanical properties of the tunnel lining concrete will gradually deteriorate to the whole damage of the concrete structure, which will cause serious inference on the durability of the tunnel especially during the middle and later periods of the high-speed railway tunnel serving.

scholarly journals Fatigue Life Characteristics of Segmental Lining Structure for the Shallow Buried Metro Tunnel under the Dynamic Load of a High-Speed Railway

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Wangping Qian ◽  
Taiyue Qi ◽  
Qing Zhao ◽  
Bingrong Pu ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Failure ◽  
Dynamic Load ◽  
High Speed ◽  
Dynamic Loads ◽  
High Speed Railway ◽  
Segmental Lining ◽  
Lining Structure ◽  
Metro Tunnel

Shallow buried shield metro tunnels constructed underneath subgrade project of high-speed railways are becoming increasingly common in China, but the lower metro tunnel bears the fatigue effect of dynamic load induced by the upper high-speed railway, so the long-term durability of segmental lining is a nonnegligible problem. The segmental lining structure of metro tunnel is in a state of static-dynamic loads for a long time, especially when a high-speed railway passes above the metro line, and the long-term durability of segmental lining needs further research. Based on theoretical analysis, the effect of different forms of loads on the fatigue life was analyzed, the change law of the static-dynamic loads on segmental lining was summarized, and the method was put forward to evaluate the fatigue life characteristics of segmental lining. The research results reveal that the additional dynamic load is the fundamental reason for the fatigue failure of the structure, and the existence of static load can cause and accelerate the occurrence of structural fatigue failure simultaneously. The results indicate that the fatigue life decreases gradually with the increase of static-dynamic load. Based on coupling analysis of static-dynamic loads of segmental lining, the fatigue life increases first and then decreases with the increase of buried depth of metro tunnel, and it remains unchanged when the depth exceeds a certain value. According to the actual metro tunnel engineering, by using ABAQUS software, a three-dimensional numerical simulation was carried out to analyze the characteristics of the fatigue life and evolution rules of segmental lining. Based on the modified fatigue life formula and metro service life, the optimization design of the buried depth was carried out to determine the most reasonable range of the buried depth. This study provides a valuable reference for safe operation and long-term durability of metro tunnels under high-speed railways.

scholarly journals The Influence Evaluation of the Waste Slag Above Tunnel on the Safety of the Structure of the High-Speed Railway Tunnel

2020 ◽  
Author(s):  
Weigong Ma ◽  
Weibo He
Keyword(s):  
High Speed ◽  
Great Influence ◽  
Back Analysis ◽  
Tunnel Lining ◽  
Tunnel Structure ◽  
Destructive Testing ◽  
High Speed Railway ◽  
Lining Structure ◽  
Design Documents ◽  
The Stability

A high-speed railway loess tunnel being built is in the Shallow-Buried Section because the construction party violates the design, and the slag discarded at the top of the tunnel is just down-pressing the main line. In order to ensure that the stability of tunnel structure does not affect the safe operation in the later period, a stratum structure model is established based on non-destructive testing and on-site tunnel monitoring measurement. The parameters of surrounding rock are determined by displacement back analysis method, and the influence of waste slag on the safety of tunnel structure is checked by the parameters obtained from back analysis. Through the comparative analysis of the stress of tunnel lining under two working conditions, combined with relevant codes and design documents, it is considered that the slag has a great influence on the stress of tunnel lining structure, but the sectional strength and maximum crack width of eccentrically compressed components of tunnel lining meet the design requirements, and the structure is within the safety range.

Application Study of Polypropylene Fiber Reinforced Concrete Railway Tunnel Lining Structure within Hard Rock Mass Using Wet-Sprayed Technique

2009 ◽  
Vol 610-613 ◽  
pp. 76-80
Author(s):  
Tai Quan Zhou ◽  
Yuan Hua
Keyword(s):  
Rock Mass ◽  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Tunnel Lining ◽  
Fiber Reinforced Concrete ◽  
Railway Tunnel ◽  
Sprayed Concrete ◽  
Rock Mass Stability ◽  
Lining Structure ◽  
Polypropylene Fiber Reinforced Concrete

The wet sprayed concrete technique has good virtue of improving the working condition within the tunnel, fewer reflective concrete loss and higher sprayed concrete quality. The concrete mixed with polypropylene fiber could improve the concrete inner structure, the flexural strength, tensile strength and anti-penetrating ability. The application of the wet sprayed polypropylene fiber reinforced concrete in the construction of tunnel lining structure could improve the stability of tunnel rock mass. The nonlinear finite element analysis is performed on rock mass stability of the railway tunnel lining structure and the rock mass stability is analyzed both for the un-lining tunnel and the lining tunnel. The computation result shows that the rock mass plasticity zone distribution with the lining structure is fewer than that without lining structure. To measure the deformation behavior, tunnel deformation measurement sensors are installed in the railway tunnel transverse section. The measured railway tunnel deformation result also shows that the lining structure deforms little and the rockmass is in stable state.

scholarly journals Analysis on Vibration Characteristics and Suppression Strategy of Vehicle Mounted GPR Detection Device for Tunnel Lining

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 309
Author(s):  
Yang Lei ◽  
Yong Zou ◽  
Tian Tian ◽  
Falin Qi ◽  
Bo Jiang
Keyword(s):  
High Speed ◽  
Control Program ◽  
Vibration Characteristics ◽  
Tunnel Lining ◽  
Railway Tunnel ◽  
Tunnel Detection ◽  
Adaptive Adjustment ◽  
And Control ◽  
Suppression Strategy

The GPR antenna is installed on the high-speed railway tunnel detection vehicle through the detection device to carry out non-contact nondestructive and rapid detection of the lining condition. Through simulation calculation and field vibration test data analysis, the vibration characteristics of the detection device are obtained. Vibration excitation is applied to GPR antennas to explore the amplitude-frequency sensitivity of echo signal affected by vibration when GPR detects tunnel lining, thus as to provide a basis for mechanism design and vibration control strategy. Through the optimization of the material properties, structural design, and control program of the detection device, the vibration frequency and amplitude of the detection device are optimized, the adaptive adjustment stability of the control system is improved, and the quality of GPR detection data is enhanced.

Early Stage Tunnel Lining Experimental Study of Jinhuashan Railway Tunnel Construction within Soft and Weak Rock Mass

2012 ◽  
Vol 204-208 ◽  
pp. 1532-1537
Author(s):  
Li Qiao Jin ◽  
Tai Quan Zhou ◽  
Bao Hua Lv
Keyword(s):  
Rock Mass ◽  
Reinforced Concrete ◽  
Early Stage ◽  
Tunnel Lining ◽  
Fiber Reinforced Concrete ◽  
Concrete Lining ◽  
Fiber Reinforced ◽  
Railway Tunnel ◽  
Tunnel Section ◽  
Lining Structure

Polypropylene fiber reinforced concrete can improve the common concrete flexibility and it is beneficial for interaction between concrete lining structure and rock mass. The use of fiber reinforced concrete with wet sprayed concrete technique can improve the concrete lining structure construction quality and improve the rock mass self-bearing capacity. The wet-sprayed fiber reinforced concrete is first introduced in Jinhuashan railway tunnel early stage lining structure within soft and weak rock mass. The design of Jinhuashan railway tunnel lining structure using fiber reinforced concrete is introduced and the requirement of material used is explained. To evaluate the lining effect using wet-sprayed fiber reinforced concrete, the online monitoring method is used to measure the rock mass pressure and the concrete lining layer stress for both the experimental tunnel sections and comparison tunnel section. The monitoring data result shows that the rock mass pressure in experimental section is even distribution with lower rock mass pressure and lower concrete lining layer stress. The value of rock mass pressure and tunnel lining layer stress in comparison tunnel section is a little higher than that in experimental tunnel section. The experimental tunnel section using fiber reinforced concrete has good lining effect.

Optimization Design of Single Track Railway Tunnel Lining Structure

2014 ◽  
Vol 638-640 ◽  
pp. 813-816
Author(s):  
Ze Lin Niu
Keyword(s):  
Continuum Model ◽  
Optimization Design ◽  
Structure Design ◽  
Tunnel Lining ◽  
Single Track ◽  
Railway Tunnel ◽  
Safety Coefficient ◽  
Structure Thickness ◽  
Lining Structure ◽  
Coefficient Method

Based on the traditional safety coefficient method,Continuum Model and single track railway tunnel lining structure, the paper does numerical simulation calculates and compares effects of actions on tunnel lining structure, analyses and get the effect of actions in different section of tunnel lining.According to the tunnel lining element’s safety coefficient and standard requirements, reasonable lining structure thickness is gave by comparison and optimization of lining structure thickness,and this provides the theory support for the structure design of track railway tunnel .

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