The NZ Transport Agency (NZTA) has confirmed that the severely damaged Lyttelton tunnel canopy must be demolished.
NZTA’s Networks Operations Manager for Canterbury Pete Connors says the agency is this afternoon arranging for the specialist staff and machinery required to safely carry out the demolition work. Removal of the canopy is expected to begin tomorrow and be completed within 48 hours.
The tunnel was re-opened for use by emergency vehicles at 6:30pm last night, and Mr Connors says a steady stream of emergency services have been using the tunnel to travel to and from Lyttelton. While alternate access to Lyttelton is available for private vehicles via local roads, the NZTA is urging people to avoid all non-essential travel in order to keep the roads as clear as possible for emergency services.
The Lyttelton tunnel was closed immediately following yesterday's earthquake, as rockfalls caused significant damage to the tunnel canopy and to the tunnel control building. The NZTA's immediate priority was to re-establish the tunnel as a route for emergency services in and out of Lyttelton.
Mr Connors says that while the tunnel itself has been inspected and remains structurally sound, the canopy and the tunnel control building have both been severely damaged.
“In its present state the canopy is a significant safety hazard. There are also risks from ongoing rockfalls on the tunnel approaches, and we’re working now to retrofit containment devices to catch any falling rocks,” Mr Connors said.
The tunnel control building has been deemed unsafe to occupy. The tunnel’s electrical systems and exhaust fans acre currently operating on back-up generators.
Mr Connors said a section of SH74 (Anzac Drive from Travis Rd to Metro Pl) which is currently closed is also expected to be re-opened within 48 hours. The Chaney's on-ramp on the Northern Motorway has also re-opened to a single lane.
All state highways and state highway bridge structures in and around the city were inspected overnight, and while some have sustained minor damage all of the bridge structures are safe, and all other state highways in the region are open.
The earthquake does not appear to have had any impact on state highways on the West Coast or the Otago and Southland regions.
There has been significant damage to local roads and bridges in the city, as well as liquefaction and surface flooding. The NZTA advises motorists to limit travel to essential trips and to use extreme caution when driving until further notice.
Information on earthquake damage to state highways in Canterbury will be regularly updated on www.highwayinfo.govt.nz(external link) or is available by phoning 0800 44 44 49.
Assessments of bridges and other structures on the state highway network will continue throughout the week, and new information will be provided as it becomes available.