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The expected destructive earthquake of Istanbul in the near future urges the researches to determine the proper and effective measures in order to make sure that the Bosphorus related traffic is affected at the possible lowest level. By considering the fact that the traffic on this bridge corresponds to the busiest in Turkey, especially in the peak...
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... The towers are 165 m high constructed from hollow steel sections, supported with horizontal beams for enhanced lateral stability (Fig. 2). The bridge was designed to withstand a live load of 1.33 tons/m and wind speeds up to 45 m/s, supporting an average daily traffic of 3900 vehicles per hour [40]. After 40 years, it underwent a year-long maintenance in 2013, including the replacement of all hangers. ...
Records of bridge fire incidents illustrate that bridge fires can have catastrophic consequences. The severity of these fires can be influenced by various factors such as bridge type, vehicle size, and wind. Contrary to building fires that have been extensively studied, scant attention has been paid to bridge fires and more specifically fire exposure to the suspension bridges. In addition, existing bridge fire literature is mostly concentrated on fire exposure to girders or cables of suspension bridges. Therefore, this study focused on the post-fire condition of a fire-exposed suspension bridge tower using computational fluid dynamics (CFD) modeling techniques and finite element analysis (FEA). The impacts of the main bridge fire parameters including vehicle size, exposure duration, distance between the fire source and tower, and wind effects were also evaluated. Initially, fire dynamic simulator (FDS) was used to simulate 12 different fire scenarios. The time–temperature histories obtained from each scenario were transferred to the ABAQUS finite element (FE) software to conduct transient thermal analysis and obtain the temperature development within the steel tower of the bridge. The post-fire evaluation was performed with respect to the temperature-induced reduction in the yield strength of steel. The results show that fire exposure from a fuel truck in the proximity of a steel tower could significantly reduce the strength of the tower and lead to severe damage. Early control of the fuel truck fire is crucial in reducing the severity of the damage and preventing temperature development in higher areas of the tower. Although a wind toward the tower can significantly increase the fire-induced damage to the bottom parts of the tower, it considerably reduces the temperature exposure to the higher parts of the tower. Fire exposure from a normal vehicle does not put the tower at risk of failure, and an unprotected steel tower can withstand it. However, a bus fire may lead to minor damage. The thermal strengthening of the first 20 m of the tower can help in preventing the potential fire damage.
... Such a system may have even provided early warning about 26 seconds before upcoming strong-ground motion at Avcılar, a district of Istanbul took the blunt of the damage [31,32]. Though the warning time may have been much shorter for other sites in the earthquake struck area, a 5-10 seconds of early warning for a possible future earthquake can provide an opportunity for automatic trigger measures, such as the shutdown of high energy, gas distribution, manufacturing facilities, stoppage of the subway cars and the elevators, the opening of fire-exits and critical infrastructure such as bridges etc [33,34,35]. ...
Real-time seismology is a newly developing alternative approach in seismology to mitigate earthquake hazard. It exploits up-to-date advances in seismic instrument technology, data acquisition, digital communications and computer systems for quickly transforming data into earthquake information in real-time to reduce earthquake losses and its impact on social and economic life in the earthquake prone densely populated urban and industrial areas. Real-time seismology systems are not only capable of giving rapid earthquake source information such as magnitude and epicenter but also spatial distribution of ground shaking in order to quick emergency response and rapid recovery efforts. Moreover, it provides early warnings before upcoming strong ground shaking in location of interests to reduce damage in critical infrastructure. In addition to faulting mechanism, it also provides finite-fault and rupture process information, such as slip distribution and rupture directivity, for large earthquakes in near-real-time to further assess extent of faulting and damage. The real-time seismology systems would play a key role to increase urban resilience and sustainability post disaster situations. Various advanced systems are currently operating in the earthquake prone countries such as Japan, United States, Taiwan, Mexico, and Turkey and in development stage in many others. The present study summarizes how the real-time seismology has globally developed to what extent it has been capable of earthquake hazard mitigation and why it is important for reducing earthquake disaster.
One of the two bridges connecting Asia to Europe, Bosporus Bridge in Istanbul/Turkey, will be affected by the expected severe earthquake from the underneath of the Sea of Marmara in near future. As the traffic density on the bridge corresponds to the busiest in Turkey, utmost effort must be paid to keep the lives and casualties at the possible lowest level. No research hitherto has been conducted to explain the concept of risk management with regard to the lives of those people travelling on the bridge to be saved by combining both traffic management techniques and earthquake early warning system technology. This paper investigates the traffic operation techniques on Bosporus suspended bridge when a pre-known time period is available for the earthquake. Furthermore, this paper focused also on the issues of the strategies to manage the traffic by investigating the occurrence probability of the danger zone lengths and manipulating the average speeds of the vehicles on the bridge. Practical guideline and countermeasure strategies are offered through the use of real time earthquake information. The results indicated that to increase current average travel speed, 45 km/h, on the bridge would make tremendous changes to mitigate causalities.
The risk assessment in the process of transportation, installation and operation is becoming more and more important with the increasing offshore structures accident frequency, the surveys shown that the transportation and installation consists only 5% of the total cost but 80% of the risk. In this paper, the risk assessment for offshore jacket platform in transportation and installation is presented: firstly, the main task profile was identified according to the concrete operation process, the components and risk factors related to the assessment; secondly, the failure models of task profiles are analyzed and coefficient is assigned according to the platform accident database in recent years and the principle of As Low As Reasonably Practicable (ALARP). Finally, the FMEA/FMECA of the transportation process is established based on RELEX Studio 2011, and Fault Tree Analysis (FTA) was proposed to further safety assessment of the implantation process with respect to significant failure models of jacket This paper apply risk assessment in platform transportation, the work in this paper has great significance to the evaluation and future design of platform.
