Tunnelling works have commenced beneath Adelaide Street, as part of the next stage of delivering the Brisbane Metro bus rapid transit project.
Civic Cabinet Chair for Transport Ryan Murphy said more than 170 piles had now been completed as part Brisbane Metro’s Adelaide Street tunnel.
“The 213-metre Adelaide Street tunnel will deliver a missing link in Brisbane’s public transport network, providing a direct dedicated connection between the South East Busway and the Inner Northern Busway for Brisbane Metro vehicles and buses.
“In Brisbane, two thirds of all public transport commuters travel by bus, which is why unclogging the bottlenecks in our bus network is so important.”
“The tunnel will reduce the number of buses clogging CBD streets by up to a third, during the morning and evening peaks.
“The Adelaide Street Tunnel will run underneath one of Brisbane’s oldest streets, in amongst a complex network of utilities, services and heritage buildings, including Brisbane City Hall.
“In some sections, the tunnel roof will be just three metres below the surface, with the deepest point seven metres underneath Adelaide Street.
“To protect the surrounding streetscape, we have employed a delicate and precise construction methodology that will see the tunnel excavated in three sections.”
There will be 16 Olympic swimming pools worth of soil and rock removed to deliver the 213-metre tunnel, connecting North Quay and the King George Square Bus Station.
A purpose-built drill rig is being used during construction to install over 20 kilometres of steel canopy tubes, which will help form the tunnel’s arched roof section.
“The Brisbane Metro project is using a highly advanced tunnelling method, compressing the time we’ll spend digging, from two and a half years to about 12 months,” Cr Murphy said.
“This is the first time in Australia that this tunnel construction methodology has been employed in an urban environment.
“This tunnelling solution was chosen to minimise disruption to businesses, pedestrians, and commuters along Adelaide Street.
“The alternative was to cut and cover, which would have caused the significant re-routing of buses, and resulted in adverse impacts to city businesses who are already doing it tough.”
Work on the tunnel started in November 2021, with works in the past 12-months focusing on preparing the tunnel portal at North Quay.
More than 170 piles have now been completed as part of the tunnel works.
Cr Murphy said there were around 115 people working on the tunnelling activities, while more than 2600 jobs were supported throughout the entire project.
“The works have uncovered several heritage artefacts, including bricks and bottles, and the perimeter of a convict-era stone wall,” he said.
Some of the artefacts uncovered during project construction are now on display at the Brisbane Metro Information Centre at 63 Adelaide Street, where they can be viewed by the public.
Work on the surface of Adelaide Street is now underway to transform the 1.7km stretch of Adelaide Street between Edward St and North Quay.
Adelaide Street will receive wider and better-connected footpaths, kerb buildouts, improved crossings, extra seating and public art.
Lord Mayor of Brisbane Adrian Schrinner said Adelaide Street has some fantastic shady trees already however it’s also a very busy bus thoroughfare.
“Brisbane Metro’s Adelaide Street tunnel means many services will go underground which creates this opportunity to make the surface more pedestrian friendly ahead of the Brisbane 2032 Olympic and Paralympic Games.”
Lord Mayor Adrian Schrinner said bus stop improvements will also deliver a seamless transport spine down Adelaide Street.
“Six new bus shelters will replace 31 tired structures to declutter the street and create a more streamlined service.”
Cr Schrinner said Brisbane Metro’s high frequency services will increase the capacity of Brisbane’s busway network by 30.4 million passengers per year.
“Adelaide Street will be the gateway to our CBD and these upgrades deliver an entry point that’s distinctive of Brisbane’s character – green, shady, inclusive and accessible,” he said.
Adelaide Street surface works will take place at night from Sunday to Thursday, between 7pm and 5am. Works are due to be completed by late 2024.