city looking at massive 'single-bore' tunnel for green line - green line laser level

A huge, single
The bore' tunnel can be built for the underground part of the Green Line, which will reduce the street --
Level disruption during construction of $4. 6-Billion projects
The design will involve a big-
The diameter tunnel, large enough to accommodate two tracks stacked together, extends 4 kilometers from 20 Avenue
On Thursday, the city council's transportation committee heard the views of the McLeod trail. The single-bore tunnel —a less-
Common Configuration ratio
Drilling Design for most subway tunnels
It may have a significant impact on the station design and final operating budget of the Green Line.
Project manager Paul Giannelia told committee members on Thursday that the construction of the underground part of the line would mean responding to the "barren soil" in Calgary and the risks associated with the deep foundation needed for the station.
Giannelia said the project team concluded that
DRILLING tunnels will be the most expensive
Effective and user
Friendly route design.
One of the main benefits of this approach, he said, is that it needs to reduce road tearing and utility disruptions. Double-
The drilling design is usually closer to the surface and requires more excavation, Giannelia said.
"During construction, both pedestrians and vehicles have less impact on the tourist public.
This is a great advantage and a great harvest.
Giannelia said no final decision has been made on the tunnel project.
The project team is expected to return to the council in December and provide additional details, including the impact on the Green Line station access point.
But as the project work moves into the next phase of construction preparation, some council members are concerned that the flow of information from the Green Line team "becomes silent ". ”Coun.
Drew Farrell complained on Thursday that it was difficult to meet with the Green Line team and that communication had stopped after years of consultation with the public and members on the project.
"I feel like a firewall has been put up," Farrell said in the parliamentary chamber on Thursday . ".
"It worries me because I want to know what has changed.
"The community is super
After years of engagement, it was silent.
"How the tunnel rig works: Farrell says she is concerned that previous discussions about the Green Line station development vision are losing, while technical and budgetary issues dominate --
The same view was expressed by Cohn. Jyoti Gondek.
Giannelia replied that there is no intention of "firewall" anyone, but it is difficult to get in touch with the community while the key details of the project are still being addressed.
The chairman of the committee, Shane Keating, played down the concerns raised by his colleagues as a natural response to the project's entry into a new phase.
"Every time you enter a different stage or stage, there is uncertainty," he said . ".
"We have three years of contact, planning, talking to the public (and)
Then it entered the silent area.
"We changed from 'let's talk to people about what they want, 'to 'let's start building now '.
Mpotkins @ postmedia.