Infrastructure Set for Seismic Strengthening

Wellington is set to get safer when strengthening works begin on the Karori Tunnel next year. The 111-year-old tunnel, located near Wellington’s main fault line, is used by 17,000 cars a day on average so Wellington City Council has deemed its upgrade essential. The works are expected to take nine months with the tunnel to be closed six hours a night. A contractor is expected to be chosen in December so works can be in full swing by February 2012.

The tunnel is 76m long, 7.71m wide and 5.8m high. The Wellington Fault lies within 20m of the eastern (Kelburn-side) tunnel entrance.

The first part of the work to earthquake-strengthen the tunnel and surrounds includes:

• building reinforced concrete walls and buttresses at both entrances
• building a major new retaining wall along Glenmore Street on the Kelburn approach to the tunnel recreating the historically significant façade and plaques on the tunnel.

Source: The Dominion Post, November 2011 and www.wellington.govt.nz/projects/all/karoritunnel.html