ABSTRACT
Renovation or refurbishment of an in-service road tunnel can be as complex as the commissioning of a new road tunnel. Mostly, there are two tubes with an escape tunnel in between and space for the cabling of the tunnel safety equipment. The tunnel installations, providing the safety for the whole system, work as one system operating both tubes. Therefore, working on tunnel installations in one tube while operating in the second tube might interfere safety systems there. For instance, refurbishment works in one tube could lead to loss of lighting in the operated tube, which is dangerous. So, a complete closure of the tunnel would be preferred during refurbishment. However, sometimes the tunnel is so crucial in the traffic network, that the tunnel must be at least partly available. In such cases a tube-after-tube-approach is an option. After commissioning the first refurbished tube, the next tube is upgraded. This was the case for the Maastunnel in Rotterdam. In this project, the objective (and challenge) was to gradually increase the safety level from the existing level prior to the upgrade works to the final safety level in the refurbished situation. In the case of the combined Piet Heintunnel (one rail tube and two road tubes) in Amsterdam the rail connection will be operated during refurbishment of the road tunnel, starting in 2019. In this paper the pros and cons and the different lessons learned regarding simultaneous refurbishment and operation of tunnels are shared.
