Study on Thermal and Structural Behavior of a Cable-Stayed Bridge under Potential Tanker Truck Fires

2012 ◽  
Vol 238 ◽  
pp. 684-688 ◽  
Author(s):  
Yong Jun Liu ◽  
Bo Ning ◽  
Yu Wang

Bridges are important parts of traffic systems and need to provide the necessary safety for the traveling public. Fire is one of the most severe hazards that bridges may subject to during their lifetime. In recent years, due to rapid development of transportation systems, as well as increasing transport of hazardous materials, bridge fires have become a concern. Bridge fires caused by crashing of vehicles and burning of gasoline are much more severe than building fires and are characterized by a fast heating rate and a higher peak temperature which could lead to bridge collapse. Bridge failures during a fire can result in the disruption of commerce and services, and most importantly the loss of human life. It has become necessary to consider the potential exposure of bridges to flames from oil or liquefied petroleum gas fires. In this paper, potential fire scenarios relevant for a cable-stayed bridge crossing the Yangtze River are analyzed firstly, then the temperature distribution in key elements and the global structural behavior of the bridge under tanker truck fires is calculated by using general purpose finite element analysis software ANSYS. Numerical simulation results demonstrate that cable-stayed bridge may collapse under some specific fire scenarios and it is necessary to consider fire safety in bridge design.

2012 ◽  
Vol 594-597 ◽  
pp. 2296-2300 ◽  
Author(s):  
Yong Jun Liu ◽  
Guang Yuan Wang ◽  
Yan Sheng Song

Fire is one of the most severe hazards to which bridges may be subjected during their lifetime. In recent years, due to rapid development of transportation systems, as well as increasing transport of hazardous materials, bridge fires have become a concern. Bridge fires caused by crashing of vehicles and burning of gasoline are much more severe than building fires and are characterized by a fast heating rate and a higher peak temperature which could lead to bridge collapse. Bridge failures during a fire can result in the disruption of commerce and services, and most importantly the loss of human life. In this paper, thermal and structural behavior of a steel girder of highway bridge overpass in the East Bay’s MacArthur Maze in Oakland collapsed on April 29, 2007 is studied by using general purpose finite element analysis software ABAQUS. Finite element analysis results demonstrate that unprotected steel bridge may collapse untimely under some fire scenarios and it is necessary to consider fire safety in steel bridge design.


2013 ◽  
Vol 353-356 ◽  
pp. 2263-2268
Author(s):  
Yong Jun Liu ◽  
Qi Liu ◽  
Fu Chun Song

During lifetime of a bridge, it may be subjected to many hazards, in which one of the most severe hazards is fire. In recent years, due to rapid development of transportation systems, as well as increasing transport of hazardous materials, bridge fires have become a concern. Bridge fires caused by crashing of vehicles and burning of gasoline are much more severe than building fires and are characterized by a fast heating rate and a higher peak temperature which could lead to bridge collapse. Bridge failures during a fire can result in the disruption of commerce and services, and most importantly the loss of human life. This paper presents an overview of bridge fire incidents, provides a state-ofthe-art review of studies on bridges in fire, and identifies the research needs in the future for protecting critical bridge structures.


2020 ◽  
Vol 19 (11) ◽  
pp. 2116-2135
Author(s):  
G.V. Savin

Subject. The article considers functioning and development of process flows of transportation and logistics system of a smart city. Objectives. The study identifies factors and dependencies of the quality of human life on the organization and management of stream processes. Methods. I perform a comparative analysis of previous studies, taking into account the uniquely designed results, and the econometric analysis. Results. The study builds multiple regression models that are associated with stream processes, highlights interdependent indicators of temporary traffic and pollution that affect the indicator of life quality. However, the identified congestion indicator enables to predict the time spent in traffic jams per year for all participants of stream processes. Conclusions. The introduction of modern intelligent transportation systems as a component of the transportation and logistics system of a smart city does not fully solve the problems of congestion in cities at the current rate of urbanization and motorization. A viable solution is to develop cooperative and autonomous intelligent transportation systems based on the logistics approach. This will ensure control over congestion, the reduction of which will contribute to improving the life quality of people in urban areas.


2021 ◽  
Vol 11 (15) ◽  
pp. 6831
Author(s):  
Yue Chen ◽  
Jian Lu

With the rapid development of road traffic, real-time vehicle counting is very important in the construction of intelligent transportation systems (ITSs). Compared with traditional technologies, the video-based method for vehicle counting shows great importance and huge advantages in its low cost, high efficiency, and flexibility. However, many methods find difficulty in balancing the accuracy and complexity of the algorithm. For example, compared with traditional and simple methods, deep learning methods may achieve higher precision, but they also greatly increase the complexity of the algorithm. In addition to that, most of the methods only work under one mode of color, which is a waste of available information. Considering the above, a multi-loop vehicle-counting method under gray mode and RGB mode was proposed in this paper. Under gray and RGB modes, the moving vehicle can be detected more completely; with the help of multiple loops, vehicle counting could better deal with different influencing factors, such as driving behavior, traffic environment, shooting angle, etc. The experimental results show that the proposed method is able to count vehicles with more than 98.5% accuracy while dealing with different road scenes.


2021 ◽  
Vol 13 (6) ◽  
pp. 3474
Author(s):  
Guang Yu ◽  
Shuo Liu ◽  
Qiangqiang Shangguan

With the rapid development of information and communication technology, future intelligent transportation systems will exhibit a trend of cooperative driving of connected vehicles. Platooning is an important application technique for cooperative driving. Herein, optimized car-following models for platoon control based on intervehicle communication technology are proposed. On the basis of existing indicators, a series of evaluation methods for platoon safety, stability, and energy consumption is constructed. Numerical simulations are used to compare the effects of three traditional models and their optimized counterparts on the car-following process. Moreover, the influence of homogenous and heterogeneous attributes on the platoon is analyzed. The optimized model proposed in this paper can improve the stability and safety of vehicle following and reduce the total fuel consumption. The simulation results show that a homogenous platoon can enhance the overall stability of the platoon and that the desired safety margin (DSM) model is better suited for heterogeneous platoon control than the other two models. This paper provides a practical method for the design and systematic evaluation of a platoon control strategy, which is one of the key focuses in the connected and autonomous vehicle industry.


Author(s):  
Shuai Ling ◽  
Shoufeng Ma ◽  
Ning Jia

AbstractThe rapid development of economics requires highly efficient and environment-friendly urban transportation systems. Such requirement presents challenges in sustainable urban transportation. The analysis and understanding of transportation-related behaviors provide one approach to dealing with complicated transportation activities. In this study, the management of traffic systems is divided into four levels with a structural and systematic perspective. Then, several special cases from the perspective of behavior, including purchasing behaviors toward new energy vehicles, choice behaviors toward green travel, and behavioral reactions toward transportation demand management policies, are investigated. Several management suggestions are proposed for transportation authorities to improve sustainable traffic management.


2021 ◽  
Author(s):  
Li Dong ◽  
Bin Xie ◽  
Dongli Sun ◽  
Yizhuo Zhang

<p>Cable forces are primary factors influencing the design of a cable-stayed bridge. A fast and practical method for cable force estimation is proposed in this paper. For this purpose, five input parameters representing the main characteristics of a cable-stayed bridge and two output parameters representing the cable forces in two key construction stages are defined. Twenty different representative cable-stayed bridges are selected for further prediction. The cable forces are carefully optimized through finite element analysis. Then, discrete and fuzzy processing is applied in data processing to improve their reliability and practicality. Finally, based on the input parameters of a target bridge, the maximum possible output parameters are calculated by Bayes estimation based on the processed data. The calculation results show that the average prediction error of this method is less than 1% for the twenty bridges themselves, which provide the primary data and less than 3% for an under-construction bridge.</p>


2021 ◽  
Author(s):  
Fatima Comartova ◽  
Andrey Pomazanskiy ◽  
Elena Nikitina ◽  
Saria Nanba ◽  
Timur Mel'nik ◽  
...  

The rapid development of modern biomedicine creates both hopes for solving global problems of humanity, and risks associated with the enormous potential of its impact on human nature. In this regard, the processes of development and application of biomedical technologies need timely and adequate legal regulation that defines the boundaries of biotechnological intervention in human life. This publication is devoted to the theoretical development of general legal approaches to the essence, content, social orientation and the main industry features of the regulation of relations in the field of biomedicine, which would allow to form a special legal regulation in this area. For researchers, teachers, postgraduates, students, practicing lawyers, employees of public authorities.


Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 89 ◽  
Author(s):  
Tan Van Nguyen ◽  
Cheolkeun Ha

With the rapid development of computer science and information and communication technology (ICT), increasingly intelligent, and complex systems have been applied to industries as well as human life. Fault-tolerant control (FTC) has, therefore, become one of the most important topics attracting attention from both engineers and researchers to maintain system performances when faults occur. The ultimate goal of this study was to develop a sensor fault-tolerant control (SFTC) to enhance the robust position tracking control of a class of electro-hydraulic actuators called mini motion packages (MMPs), which are widely used for applications requiring large force-displacement ratios. First, a mathematical model of the MMP system is presented, which is then applied in the position control process of the MMP system. Here, a well-known proportional, integrated and derivative (PID) control algorithm is employed to ensure the positional response to the reference position. Second, an unknown input observer (UIO) is designed to estimate the state vector and sensor faults using a linear matrix inequality (LMI) optimization algorithm. Then an SFTC is used to deal with sensor faults of the MMP system. The SFTC is formed of the fault detection and the fault compensation with the goal of determining the location, time of occurrence, and magnitude of the faults in the fault signal compensation process. Finally, numerical simulations were run to demonstrate the superior performance of the proposed approach compared to traditional tracking control.


Author(s):  
Samir N. Shoukry ◽  
Gergis W. William ◽  
Jacky C. Prucz ◽  
Thomas H. Evans

The hydrogen economy envisioned in the future requires safe and efficient means of storing hydrogen fuel for either use onboard vehicles, delivery on mobile transportation systems or high-volume storage in stationary systems. The main emphasis of this work is placed on the high -pressure storing of gaseous hydrogen on-board vehicles. As a result of its very low density, hydrogen gas has to be stored under very high pressure, ranging from 350 to 700 bars for current systems, in order to achieve practical levels of energy density in terms of the amount of energy that can be stored in a tank of a given volume. This paper presents 3D finite element analysis performed for a composite cylindrical tank made of 6061-aluminum liner overwrapped with carbon fibers subjected to a burst internal pressure of 1610 bars. As the service pressure expected in these tanks is 700 bars, a factor of safety of 2.3 is kept the same for all designs. The results indicated that a stress reduction could be achieved by a geometry change only, which could increase the amount of pressure sustained inside the vessel and ultimately increase the amount of hydrogen stored per volume. Such reductions in the stresses will decrease the thickness dimension required to achieve a particular factor of safety in a direct comparison to a cylindrical design.


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