Risk evaluation in road tunnels based on CFD results

Abstract

Approaches to risk assessment in tunnelling and underground spaces were introduced in 2004 as a result of several serious accidents in tunnels such as Mont Blanc and Tauern Tunnel in 1999. The EU has published the minimum safety requirements for tunnels over 500 m on Trans-European Road Network. The risk assessment is mandatory and should cover all components of the system, i.e. infrastructure, operation, users and vehicles. The professional community has started using the QRA (Quantitative Risk Assessment) approach, where the crucial issue is the consequence analysis of fire scenarios in a tunnel. Fire development is a complex physical phenomenon and its calculation is time consuming; therefore, complex models have rarely been used in QRA approaches. This paper presents the methodology of integrating fast-processing risk assessment methods with time-consuming CFD (Computational Fluid Dynamics) methods for fire consequence analysis in the process of tunnel safety assessment. The main variables are soot density and temperature, which are analysed in one-minute time steps during the fire. Human behaviour is considered with the evacuation model, which is needed to evaluate fatalities during the fire process. The application of the methodology is presented based on the evaluation of the national tolerable risk for tunnel transport and compared with referenced EU risk criteria. Furthermore, the presented methodology links CFD simulation results and the QRA approach, still representing the collective risk with F-N curves.

Evaluating Tunnel Users’ Literacy on Expressway Tunnel Fire Safety: Questionnaire Analysis and Policy Decisions

“…Among them, the interest in tunnel fire safety has significantly increased, principally due to the rapidly increasing number of tunnels being built and catastrophic tunnel fire incidents that have occurred [23,24]. Extensive studies [25][26][27][28][29][30] have been conducted to study tunnel fire safety. Ren et al [5] considered tunnel fire accidents in China from 2000 to 2016, and the characteristics of the causes, frequency, and regional distribution of road tunnel fire accidents were obtained.…”

Improving Risk Assessment for Transporting Dangerous Goods through European Road Tunnels: A Delphi Study

“…Adequate knowledge of fluid mechanics is deemed necessary for understanding how smoke behaves during a tunnel fire [36], a critical element taken into consideration during the application of QRA [37]. Furthermore, according to the study of Petelin et al [38], the QRAM requires data on volumetric air flow along the tunnel section in case the tunnel has longitude ventilation.…”

Analysis of flow structure of tunnel fire based on modal decomposition

“…The research on the smoke movement of tunnel fire mainly focuses on the maximum temperature rise under the roof [14][15][16],smoke transport [17][18][19][20],critical wind speed [21][22][23],longitudinal attenuation law of temperature [24,25], and shaft smoke exhaust [26,27], fire risk assessment [28]. The research methods include full-scale experiment, model experiment and numerical simulation.…”