Evaluating the Dynamic Load on a High-Speed Railroad Car

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.

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Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

Shock and Vibration ◽

10.1155/2016/5310769 ◽

2016 ◽

Vol 2016 ◽

pp. 1-15 ◽

Cited By ~ 3

Author(s):

Ding Youliang ◽

Wang Gaoxin

Keyword(s):

Finite Element ◽

Dynamic Load ◽

High Speed ◽

Field Monitoring ◽

Generalized Extreme Value Distribution ◽

Monitoring Data ◽

Load Factor ◽

High Speed Railway ◽

Arch Bridge ◽

The Impact

Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF) to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

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Analysis of Dynamic Load Level of High-Speed Heavy Vehicle Imposed on Uneven Pavement

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.138-139.146 ◽

2011 ◽

Vol 138-139 ◽

pp. 146-152

Author(s):

Guo He Guo ◽

Yu Feng Bai ◽

Tao Wang

Keyword(s):

Dynamic Load ◽

High Speed ◽

Load Level ◽

Heavy Vehicle ◽

Vehicle Speed ◽

Destructive Effect ◽

The Road ◽

Wide Range ◽

On The Road ◽

Factor Interaction

Based on the significant destructive effect of heavy vehicle on uneven roads, two simplified models of pavement unevenness and vehicle dynamic load were established in accordance with D'A lembert principle, and Matlab software was used to analyze the changing law of dynamic load under the conditions of different road unevenness, vehicle speed and load. The results show that vehicles running on uneven road may produce more cumulative damages than static load, and DLC (dynamic load coefficient) changes in wide range, maximum up to 2.0 or more; the effect of speed and load on dynamic load is complex, and due to multi-factor interaction, DLC doesn’t consistently increase or decrease with speed and load increasing. Although the dynamic load level caused by high-speed heavy vehicle is not necessarily too high, its impact on the road can not be ignored.

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THE ANALYSIS OF BOT STRATEGIES BASED ON GAME THEORY – CASE STUDY ON TAIWAN'S HIGH SPEED RAILWAY PROJECT

Journal of Civil Engineering and Management ◽

10.3846/13923730.2012.723329 ◽

2012 ◽

Vol 18 (5) ◽

pp. 662-674 ◽

Cited By ~ 14

Author(s):

Tien-Chien Chen ◽

Yu-Cheng Lin ◽

Lung-Chuang Wang

Keyword(s):

Game Theory ◽

High Speed ◽

Market Competition ◽

Theory Model ◽

Competition And Cooperation ◽

Financial Difficulties ◽

The Game Theory ◽

The Government ◽

High Speed Railroad

Uncertainty in a contract for some BOT (Build-Operate-Transfer) projects may allow an opportunistic developer to take advantage of information asymmetrical factors, long-term external changes, and agency dilemma to request renegotiation and to alter the contact after it has been awarded. Such requests often entrap the government in hold-up problems and result in improper payments to the developers and may even create general public dissatisfaction with a project. In this paper, the Game Theory model is used to analyze the Taiwan High Speed Railroad project to examine how developers implement different strategies at the various stages of a project to alter the contract's conditions in order to continually creating competitive advantage after they have been awarded the contract. This project developer is now facing serious financial difficulties. In this study, the financial information on the Taiwan High Speed Railroad operations was used as the foundation for conducting a simulation to calculate the project's value after this project began operation. The results will serve as reference to the best decision-making strategy for renegotiating costs in competition and cooperation so that a developer can select the optimum project offering the maximum reward. Also, the result will be offered to industries involved in market competition or act as an approach to establish future BOT policies on renegotiation.

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Design and Implementation of High-Speed Dual-Modulus

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.109.271 ◽

2011 ◽

Vol 109 ◽

pp. 271-275

Author(s):

Jian Jun Song ◽

Liu Sun ◽

He Ming Zhang ◽

Hui Yong Hu

Keyword(s):

Power Supply ◽

Dynamic Load ◽

High Speed ◽

Operating Speed ◽

Switching Circuit ◽

Switching Sequence ◽

Phase Switching ◽

Measurement Result ◽

Design And Implementation ◽

Supply Current

This paper presents a new enhanced phase switching 15/16 dual-modulus prescaler. One more divide-by-2 stage was employed in the design compare to the conventional phase switching architecture. Since the operating speed of phase switching circuit is obviously reduced. The inverse phase switching sequence was employed in this circuit to implement glitch-free phase switching. Further more, a dynamic load master-slave DFF was employed as the first divide-by-2 stage which can increase the operating frequency of prescaler. Measurement result shows, this dual-modulus prescaler can operate at 3GHz-200MHz with 2.8mA supply current at 1.8V power supply.

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Identification of the Dynamic Load Supplied on Top Pier of High Speed Railway Bridge

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.831.348 ◽

2013 ◽

Vol 831 ◽

pp. 348-353

Author(s):

Ya Ping Li ◽

Meng Yang

Keyword(s):

Dynamic Load ◽

High Speed ◽

Transverse Direction ◽

Traffic Load ◽

Railway Bridge ◽

Load History ◽

Railway Transportation ◽

High Speed Railway ◽

Vibration Load ◽

Acceleration History

With the development of railway transportation, the traffic load increased continuously and it had the adverse effect on the system of pier-foundation. The quantitative analysis of the load supplied on the top pier is necessary for analyzing the dynamic response of pier-foundation system. Based on the theory of vibration inverse analysis and finite element method, the paper identified the dynamical load supplied on the top pier in vertical and the transverse direction. Combined with the vibration and acceleration history measured by the field test in Xiaolinhe Bridge, the vertical and transverse direction vibration-load history curves were calculated when the train speeds were 153 km/h and 206 km/h respectively. The results indicated that the amplitude of dynamic load increased with the higher speed of train.

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