The Refurbish merit of the Terrace and Mt Victoria Tunnels, Wellington, New Zealand

摘要

This paper examines the fire life systems implemented in two existing tunnels and discusses whether the standards used were appropriate. It focuses on the Terrace Tunnel as this upgrade and refurbishment is complete. The New Zealand Transport Agency (NZTA) manages six tunnels on the State Highway network with two of these built in the last seven years. The Terrace Tunnel, opened in 1978, was refurbished with modern fire life safety systems in 2010-2012. An interim upgrade of the Mt Victoria Tunnel, opened in 1931, was also carried out at this time. In present times, few existing tunnels have undergone significant upgrades and refurbishments. The Terrace Tunnel required: new power supplies, control buildings, lighting, wall panels and jet fans, a deluge system, emergency exit lights and way-finding lights, a public address (PA) system, a radio rebroadcast system, lane control sign (LCS) and variable message sign (VMS), an over-height detection system (OHD) and a new tunnel management system. In the absence of suitable guidelines, various standards were used to carry out the refurbishment. The Austroad Guide to Road Tunnels and AS4825 Tunnel Fire Safety, although designed for new tunnels and not specifically intended for existing tunnels, provided a framework. A multi-criteria assessment of risk (MCAT) was carried out to determine the systems to be provided. The Terrace Tunnel has perhaps set a benchmark for refurbishing existing tunnels as few projects of this type have been completed recently. This paper examines the process and the outcomes.