Temperature and structural responses of a single-section utility tunnel throughout fire exposure

Abstract

In this study, fire tests of four single-section scaled-down utility tunnels were conducted. By analyzing temperature and structural responses of the utility tunnel throughout the fire exposure, the effects on the fire behavior of two different construction methods, cast-in-situ and prefabricated, and of two different materials, ordinary concrete and full lightweight concrete, were explored. The results of the study showed that the shear failure of the cast-in-situ utility tunnel occurred at the end of the top or bottom plate, and the failure of the prefabricated utility tunnel occurred at the junction of the prefabricated member and post-cast concrete. As the temperature increased, the temperature gradient along the thickness direction of the tunnel became apparent. The maximum temperature difference between the inner and outer wall surfaces was 531.7 °C. The highest temperature occurred in the cooling stage after stopping the heating, which provided a reference for the fire protection design and rescue of the utility tunnel. The displacement of the top plate of the prefabricated utility tunnel was 16.8 mm, which was 41.8% larger than that of the cast-in-situ utility tunnel. The bearing capacities of the ordinary concrete utility tunnel and full lightweight concrete utility tunnel after the fire loss were 27% and 16.8%, respectively. The full lightweight concrete utility tunnel exhibited good ductility and fire resistance and high collapse resistance.

Graphical abstract

Keywords

full lightweight concrete / construction methods / temperature response / structural response / fire test

References

[1] Beard A, Carvel R. The Handbook of Tunnel Fire Safety. London: ICE Publishing, 2012, 1–30

[2] Ingason H, Li Y. Tunnel Fire Dynamics. New York: Springer, 2014, 1–20

[3] Kim H S, Hwang I J, Kim Y J. Characteristic of fire-induced thermal-flowfields in an underground utility tunnel with ventilation. In: Proceedings of the KSME Conference. Tokyo: Japan Society of Mechanical Engineers, 2003, 1845–1850

[4] Ko J. Study on the fire risk prediction assessment due to deterioration contact of combustible cables in underground common utility tunnels. Journal of the Korean Society of Disaster Information, 2015, 11(1): 135–147

[5] Beji T, Verstockt S, Zavaleta P, Merci B. Flame spread monitoring and estimation of the heat release rate from a cable tray fire using video fire analysis (VFA). Fire Technology, 2016, 52(3): 611–621

[6] Huang X, Zhu H, Peng L, Zheng Z, Zeng W, Bi K, Cheng C, Chow W. Burning behavior of cable tray located on a wall with different cable arrangements. Fire and Materials, 2019, 43(1): 64–73

[7] Huang X, Wang Y, Zeng W, Peng L, Cheng A C H, Chow W K. Compartment temperature estimation of a multiple-layer cable tray fire with different cable arrangements in a closed compartment. Journal of Fire Sciences, 2019, 37(4−6): 303–319

[8] Zavaleta P, Suard S, Audouin L. Cable tray fire tests with halogenated electric cables in a confined and mechanically ventilated facility. Fire and Materials, 2019, 43(5): 543–560

[9] Liang K, Hao X, An W, Tang Y, Cong Y. Study on cable fire spread and smoke temperature distribution in T-shaped utility tunnel. Case Studies in Thermal Engineering, 2019, 14: 100433

[10] Zhang H, Zhao Y. Study on underground utility tunnel fire characteristics under sealing and ventilation conditions. Advances in Civil Engineering, 2020, 2020: 1–11

[11] RingTZeimlMLacknerR. Underground concrete frame structures subjected to fire loading: Part I—Large-scale fire tests. Engineering Structures, 2014, 58: 175–187

[12] Ring T, Zeiml M, Lackner R. Underground concrete frame structures subjected to fire loading: Part II—Re-analysis of large-scale fire tests. Engineering Structures, 2014, 58(58): 188–196

[13] Marshall A M, Haji T. An analytical study of tunnel–pile interaction. Tunnelling and Underground Space Technology, 2015, 45: 43–51

[14] Bennett R M, Wood S M, Drumm E C, Rainwater N R. Vertical loads on concrete box culverts under high embankments. Journal of Bridge Engineering, 2005, 10(6): 643–649

[15] Dasgupta A, Sengupta B. Large-scale model test on square box culvert backfilled with sand. Journal of Geotechnical Engineering, 1991, 117(1): 156–161

[16] Zhang Y, Zeiml M, Maier M, Yuan Y, Lackner R. Fast assessing spalling risk of tunnel linings under RABT fire: From accoupled thermo-hydro-chemo-mechanical model towards an estimation method. Engineering Structures, 2017, 142: 1–19

[17] Zhang Z, Kumar A V. Immersed boundary modal analysis and forced vibration simulation using step boundary method. Finite Elements in Analysis and Design, 2017, 126: 1–12

[18] Zhang Y, Zhuang X. Cracking elements method for dynamic brittle fracture. Theoretical and Applied Fracture Mechanics, 2019, 102: 1–9

[19] Zhang Y, Huang J, Yuan Y, Mang H A. Cracking elements method with a dissipation-based arc-length approach. Finite Elements in Analysis and Design, 2021, 195: 103573

[20] Zhou S, Zhuang X, Zhu H, Rabczuk T. Phase field modelling of crack propagation, branching and coalescence in rocks. Theoretical and Applied Fracture Mechanics, 2018, 96: 174–192

[21] JGJ55-2011. Specification for Mix Proportion Design of Ordinary Concrete. Beijing: China Architecture & Building Press, 2011 (in Chinese)

[22] JGJ/T12-2019. Technical Standard for Application of Lightweight Aggregate Concrete. Beijing: China Architecture & Building Press, 2019 (in Chinese)

[23] GB/T17431.2-2010. Lightweight Aggregates and Test Methods. Beijing: China Architecture & Building Press, 2010 (in Chinese)

[24] PengH SChenJHC WTangY PChen. Fire performance and thermal insulation of reinforced lightweight aggregate concrete. Applications of Engineering Materials, pts(1−4): 287−290

[25] NFPA92:2012. Standard for Smoke Control System. Quincy: NFPA (National Fire Protection Association), 2012

[26] ISO834-1. Fire-resistance Tests—Elements of Building Construction—Part 1: General Requirements. Geneve: International Organization for Standardization, 1999

[27] YanHLeiBWangQ. Study on mechanical properties of concrete after high temperature of tunnel fire. Journal of Sichuan University: Engineering Science Edition, 2008, 40(5): 77−81 (in Chinese)

[28] GuoZ. Principles of Reinforced Concrete. Oxford: Butterworth-Heinemann, 2014

Acknowledgments

The research was financially supported by the Jilin Provincial Department of Science and Technology Key Research and Development Project (20200403071SF), and National Emergency Management Department Safety Accident Prevention Science and Technology Project (Jilin-0001-2018AQ).

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2022 Higher Education Press