Shi Y.,Transportation Institute |
Zhao W.,CAS Wuhan Institute of Rock and Soil Mechanics
Modern Tunnelling Technology | Year: 2013
Considering the structure of a large-diameter shield tunnel and the characteristics of the force applied on its joint, this paper presents the calculated formula of flexural rigidity of the segment joint that was established by theoretical analysis and then compared to the measured force of the Shanghai shield tunnel. The results showed that the calculations are in agreement with the experimental values. Several common computation models for force analysis of segments and joints are compared, with the results indicating that the application of the above mentioned formula to a beam-spring model with appropriate joint rigidity can accurately predict the mechanic characteristics of segments and joints and allow for their evaluation.
Guanquan C.,Transportation Institute |
Jinhui W.,Shanghai Maritime University
Reliability Engineering and System Safety | Year: 2012
Event tree analysis (ETA) is a frequently-used technique to analyze the probability of probable fire scenario. The event probability is usually characterized by definite value. It is not appropriate to use definite value as these estimates may be the result of poor quality statistics and limited knowledge. Without addressing uncertainties, ETA will give imprecise results. The credibility of risk assessment will be undermined. This paper presents an approach to address event probability uncertainties and analyze probability distribution of probable fire scenario. ETA is performed to construct probable fire scenarios. The activation time of every event is characterized as stochastic variable by considering uncertainties of fire growth rate and other input variables. To obtain probability distribution of probable fire scenario, Markov Chain is proposed to combine with ETA. To demonstrate the approach, a case study is presented. © 2011 Elsevier Ltd All rights reserved.
Seo Y.,Transportation Institute
Journal of Testing and Evaluation | Year: 2010
In Korea, a 7.7 km-long test road was constructed with an aim to better understand the behavior of pavements and to develop a mechanistic-empirical pavement design guide (MEPDG). This two lane highway consisted of asphalt and concrete pavements that were further divided into diverse sections: 33 asphalt sections and 25 concrete sections. Construction of the test road began in 1997 and ended in 2002. It opened to traffic in March 2004. So far, many field tests have been carried out to evaluate the response and performance of pavements. At asphalt sections, the first attempt was made to correlate design parameters with the performance of pavements, and this is the focus of this paper. Performance was characterized by the evolution of failures, such as rutting, cracking, and longitudinal road profile. Design parameters included surface type, base type, base thickness, and anti-frost layer. Field surveys were made with an automatic road analyzer for the 2002-2007 period, and trends in pavement failures were analyzed with respect to individual design parameters. Also, a highway present condition index (HPCI) was adopted to assess the overall performance of individual sections. Findings of this study are being used to validate pavement performance models incorporated into the MEPDG that is scheduled to be released in 2010. Copyright © 2010 by ASTM International.
Monios J.,Napier University |
Lambert B.,Transportation Institute
Journal of Transport Geography | Year: 2013
This paper examines the development process of the Heartland Intermodal Corridor from Norfolk, Virginia to Columbus, Ohio in the United States, opened in September 2010. The aim of the project was to decrease transport costs and increase competitiveness for peripheral regions such as West Virginia by upgrading existing branch lines to double-stack capacity and building new intermodal terminals.The paper develops a theoretical framework for institutional analysis, combining the overall institutional setting with the roles of individual actors confronting a collective action problem. Results suggest that the project represents an observable trend in freight funding policy in the United States, moving away from congressional earmarks which have been criticised in the past for their subjective nature, and towards a more transparent, bid-based system. Findings from the research demonstrate that the institutional setting has been transformed, moving towards a reconciliation between top-down planning approaches and market-driven private sector development. Furthermore, encouragement of multi-state public-private consortia will potentially make it easier to develop national corridors that can support new markets, while generating both public and private benefits. © 2012.
Wang Q.,Hefei University of Technology |
Ping P.,Hefei University of Technology |
Zhao X.,Hefei University of Technology |
Chu G.,Transportation Institute |
And 2 more authors.
Journal of Power Sources | Year: 2012
Lithium ion battery and its safety are taken more consideration with fossil energy consuming and the reduction requirement of CO 2 emission. The safety problem of lithium ion battery is mainly contributed by thermal runaway caused fire and explosion. This paper reviews the lithium ion battery hazards, thermal runaway theory, basic reactions, thermal models, simulations and experimental works firstly. The general theory is proposed and detailed reactions are summarized, which include solid electrolyte interface decomposition, negative active material and electrolyte reaction, positive active material and electrolyte reaction, electrolyte decomposition, negative active material and binder reaction, and so on. The thermal models or electrochemical-thermal models include one, two and three dimensional models, which can be simulated by finite element method and finite volume method. And then the related prevention techniques are simply summarized and discussed on the inherent safety methods and safety device methods. Some perspectives and outlooks on safety enhancement for lithium ion battery are proposed for the future development. © 2011 Elsevier Ltd. All rights reserved. All rights reserved.