• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.460-467
• /
• 2006

Some large accidents in tunnels in recent years, such as Mont Blanc, Gotthard and Tauern tunnels, have lead to an increasing attention for tunnel safety and necessity of tool for quantitative risk assesment of road tunnel. And the purpose of this study is to develop the quantitative risk assesment tool for the application of road tunnel. The objectives of this paper are as follows : (1) analyze of traffic accident rates in tunnel, (2) make out scenario for fire accidents, (3) develop the evacuation model and FED calculation model, (4) Present the results from quantitative risk assesment for the model tunnel according with the fire heat release rates and distances of cross passage.

• The Journal of the Korea Contents Association
• /
• v.17 no.3
• /
• pp.222-230
• /
• 2017

The Ministry of Public Safety and Security plans to expand fire safety education infrastructure to provide customized fire safety education, spread fire safety culture and develop a tailored fire safety education system as a part of the 2016 Citizens' Safety Improvement Policy. This study has also been designed to improve safety problems in the Republic of Korea. Even though safety education has been given, citizens aren't still able to experience a close-to-real situation. In addition, their understanding and satisfaction with the curriculum are very low. Therefore, this study offers VR fire-extinguishing experience education contents as an effective alternative. With a goal of having the participants experience fire extinguishing and evacuation drill in a virtual space, this program has the following advantages: i) safe fire-extinguishing experience; ii) UI to create fun ; iii) useful in fire-extinguishing education; iv) budget saving. we configure the VR fire experience system structure and hardware by applying UX design methodology. We also develop for VR-specific motion recognition plug-in and controller that can be feeling in HMD environment.

• Fire Science and Engineering
• /
• v.24 no.3
• /
• pp.145-151
• /
• 2010

The fire in tunnel, when failed to extinguish at early stage, tends to easily develop to high temperature and spread to entire area of the tunnel because of considerable level of fire load and smoke control facility within the tunnel, resulting in severe damage to the people and tunnel structure. This study was intended to carry out the fire test with MHC fire curve, a scenario, which has the most rapid fire rise, on assumption of load ratio of 1, 20, 40, 60 and 70%, so as to identify the thermal characteristics of the concrete against spalling and the range of fire damage. The specimen was small scale sample as defined by EFNARC and the mixing ratio was based on 24 MPa, which is considered to be the normal strength. As a result of test, 16mm spalling was occurred on the lining under the non-load condition, while no spalling was occurred with 20% and 40% of load ratio. In case of 60% of load ratio, 24 mm of spalling was occurred and it failed in 10 minutes after heating in case of 70% load condition.

• Computers and Concrete
• /
• v.29 no.4
• /
• pp.263-278
• /
• 2022

Limestone calcined clay cement (LC³) is a low carbon alternative to conventional cement. Literature shows that using limestone and calcined clay in LC³ increases the thermal degradation of LC³ pastes and can increase the magnitude of fire risk in LC³ concrete structures. Higher thermal degradation of LC³ paste prompts this study toward understanding the fire performance of LC³ concrete and the associated magnitude of fire risk. For fire performance, concrete prepared using ordinary Portland cement (OPC), pozzolanic Portland cement (PPC) and LC³ were exposed to 16 scenarios of different elevated temperatures (400℃, 600℃, 800℃, and 1000℃) for different durations (0.5 h, 1 h, 2 h, and 4 h). After exposure to elevated temperatures, mass loss, residual ultrasonic pulse velocity (rUPV) and residual compressive strength (rCS) were measured as the residual properties of concrete. XRD (X-ray diffraction), TGA (thermogravimetric analysis) and three-factor ANOVA (analysis of variance) are also used to compare the fire performance of LC³ with OPC and PPC. Monte Carlo simulation has been used to assess the magnitude of fire risk in LC³ structures and devise recommendations for the robust application of LC³. Results show that LC³ concrete has weaker fire performance, with average rCS being 11.06% and 1.73% lower than OPC and PPC concrete. Analysis of 106 fire scenarios, in Indian context, shows lower rCS and higher failure probability for LC³ (95.05%, 2.22%) than OPC (98.16%, 0.22%) and PPC (96.48%, 1.14%). For robust application, either LC³ can be restricted to residential and educational structures (failure probability <0.5%), or LC³ can have reserve strength (factor of safety >1.08).

• Fire Science and Engineering
• /
• v.30 no.1
• /
• pp.57-62
• /
• 2016

This study evaluated the risk of forest fires due to climate change in Jeju using the VESTAP. The study primarily aimed at assessing the risks posed to Jeju city and Seogwipo city, and uses actual and projected date from the period of 2000's to 2040's based on RCP 8.5 scenario. Forest fire vulnerability throughout Jeju-do was determined through the standardization of vulnerability index. The highest vulnerability was determined for the towns of Chuja-myeon, Udo-myeon, two downtown areas in Jeju city, Daejeong-eup, and five downtown areas in Seogwipo city, respectively.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.477-480
• /
• 2008

In tunnel, though the frequency of fire occurrence is relatively lower than other structures, the characteristics of sealed space tends to cause the temperature to rapidly rise to more than $1000^{\circ}C$ within 5 minutes after fire, which might eventually lead to a large fire that usually results in a loss of lives and the damage to the properties, not to mention a huge cost necessary for repair and maintenance after fire. Referring to foreign tunnel fire scenarios, it clarified the heat transfer characteristics of concrete PC panel lining depending on fire intensity (ISO, MHC, RWS), and to identify the range of thermal damage, the evaluation was carried out using ITA standard. As a result, 39mm under ISO fire condition, 50mm under MHC and 100mm under RWS were measured. And when it comes to spalling, 30mm was measured under RWS. When PC panel was designed to serve the support, a fire resistance to the minimum depth of 100mm of the concrete that might be damaged under the fire shall be maintained, and in case of a non-support structure, PC lining shall have at least 100mm thickness.

• Structural Engineering and Mechanics
• /
• v.50 no.6
• /
• pp.755-772
• /
• 2014

A simplistic approach towards evaluation of complete load deflection response of Reinforced Concrete (RC) flexural members under post fire (residual) scenario is presented in this paper. The cross-section of the RC flexural member is divided into a number of sectors. Thermal analysis is performed to determine the temperature distribution across the section, for given fire duration. Temperature-dependent stress-strain curves for concrete and steel are then utilized to perform a moment-curvature analysis. The moment-curvature relationships are obtained for beams exposed to different fire durations. These are then utilized to obtain the load-deflection plots following pushover analysis. Moreover one of the important issues of modeling the initial stiffness giving due consideration to stiffness degradation due to material degradation and thermal cracking has also been addressed in a rational manner. The approach is straightforward and can be easily programmed in spreadsheets. The presented approach has been validated against the experiments, available in literature, on RC beam subjected to different fire durations viz. 1hr, 1.5hrs and 2hrs. Complete load-deflection curves have been obtained and compared with experimentally reported counterparts. The results also show a good match with the results obtained using more complicated approaches such as those involving Finite element (FE) modeling and conducting a transient thermal stress analysis. Further evaluation of the beams during fire (at elevated temperatures) was performed and a comparison of the mechanical behavior of RC beams under post fire and during fire scenarios is made. Detailed formulations, assumptions and step by step approach are reported in the paper. Due to the simplicity and ease of implementation, this approach can be used for evaluation of global performance of fire affected structures.

• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.1337-1345
• /
• 2007

The present study is a basic investigation for systematically proceeding disaster prevention studying the effect of platform screen door in case of fire at the subway station. In the paper, the characteristics of screen door were surveyed and described. The fully closed platform screen door and the island type of subway station were employed for simulation-study. Numerical simulations of fire driven flow at the subway station with platform screen door were performed with commercial fire CFD code. For analyzing of the effect of platform screen door, the fire simulations with and without the platform screen door were compared. For the fire location, the one is located on the platform and the other case on the railway. The Ultrafast model was taken as fire growth scenario. The maximum heat release rate was 10MW. The propagated time of the heat and smoke to stairs was within 4 minute when the fire is located on the platform. However the heat and smoke propagation was block off by screen door when the fire is located on the railway.

• Fire Science and Engineering
• /
• v.34 no.2
• /
• pp.141-146
• /
• 2020

This study examines the development of content scenarios to facilitate the training of on-site commanders in firefighting activities. To establish the training content scenario system, the three core competencies of the on-site commanders were set as situation judgment, communication, and decision-making. A system of scenarios was established to actively reflect these three core competencies when designing the scenarios. All the contents of these scenarios are based on Standard Operating Procedures (SOP). The scenarios comprise 14 stages that are divided into four steps with the exception of stages 1 and 14, which mark the beginning and end of the training. It consists of the situation setting stage and the first, second, and third decision-making stages. Specifically, situation judgment and communication are important factors in each stage.

• Structural Monitoring and Maintenance
• /
• v.5 no.3
• /
• pp.363-377
• /
• 2018

The proper functioning of critical points on transport infrastructure is decisive for the entire network. Tunnels and bridges certainly belong to the critical points of the surface transport network, both road and rail. Risk management should be a holistic and dynamic process throughout the entire life cycle. However, the level of risk is usually determined only during the design stage mainly due to the fact that it is a time-consuming and costly process. This paper presents a simplified quantitative risk analysis method that can be used any time during the decades of a tunnel's lifetime and can estimate the changing risks on a continuous basis and thus uncover hidden safety threats. The presented method is a decision support system for tunnel managers designed to preserve or even increase tunnel safety. The CAPITA method is a deterministic scenario-oriented risk analysis approach for assessment of mortality risks in road tunnels in case of the most dangerous situation - a fire. It is implemented through an advanced risk analysis CAPITA SW. Both, the method as well as the resulting software were developed by the authors' team. Unlike existing analyzes requiring specialized microsimulation tools for traffic flow, smoke propagation and evacuation modeling, the CAPITA contains comprehensive database with the results of thousands of simulations performed in advance for various combinations of variables. This approach significantly simplifies the overall complexity and thus enhances the usability of the resulting risk analysis. Additionally, it provides the decision makers with holistic view by providing not only on the expected risk but also on the risk's sensitivity to different variables. This allows the tunnel manager or another decision maker to estimate the primary change of risk whenever traffic conditions in the tunnel change and to see the dependencies to particular input variables.