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Geotechnical investigation to take place on Yonge Street

What is a geotechnical investigation?

A geotechnical investigation involves the collection and testing of soil samples. As part of the Conceptual Design Study for the proposed Yonge Subway extension, we need to determine what the ground conditions are along the proposed subway alignment. When the project receives funding, this will inform future design and costing decisions associated with materials, construction methodology, and tunnel depth.

Drilling will occur at predetermined locations along the alignment and will take soil samples at varying depths. Two borehole drilling machines will be working in parallel to expedite the schedule. Samples collected from the boreholes will be tested to determine their physical properties.

Where will this work be done?

The work is being done along Yonge Street from Steeles Avenue to High Tech Road. The majority of the boreholes are off the travelled portion of the road. However, there are two locations where the work will be located in the roadway and will require lane restrictions on Yonge Street. Additionally, there are three locations which are in close proximity to the road and may impact traffic flow.

When will this work be done?

Working from the south end to the north end, soil samples will be taken from 12 locations along Yonge Street over five weeks (see chart below), from 9:30 am – 3:30 pm.

Who is doing this work?

SPL Consultants Limited is conducting the investigations.

spadina subway

Yonge Subway Extension

Yonge Subway Extension

The planned Yonge subway extension will extend 6.8 kilometres north from Finch Station to the Richmond Hill/Langstaff Urban Growth Centre at Highway 7. It will include up to six stations. This urban centre will be a major transit hub where transit riders will be able to make seamless and convenient connections to GO Trains, GO Buses, TTC Subway, YRT\Viva buses, the future 407 Transitway and other transit services. To put it into perspective – a Union Station of the north!

In April 2009, the Ontario Ministry of the Environment unconditionally approved the Environmental Project Report (PDF) for the Yonge subway extension. In 2012, the Conceptual Design Study that looked at specific engineering elements was completed and approved by the Toronto Transit Commission and The Regional Municipality of York.

What really sets this project apart from other proposed transit projects is the role it plays in the GTHA’s overall transportation network – roads and transit. No other project can do more to advance the need for improving transportation in the GTHA. This project can combine with market forces to unleash significant economic, environment and development benefits.

Whether from a plane, from the ground or underground on the subway, it is easy to see that Yonge Street is one of the main arteries in the GTHA – and has been for generations. That is why it is vital to move this project forward along with other proposed transit projects, steadily improving the overall transportation network.

Dealing with existing congestion on the Yonge line is a challenge, and while over 60% additional capacity is already being added to Yonge Subway from these current projects now underway, growth beyond 2030 will continue to create capacity concerns on the Yonge line:

.   Automatic Train Control (adds 36% capacity);
.   New Signals (adds 10% capacity);
.   Six-car Trainsets [Rocket Trains] (adds 10 capacity); and
.   Toronto-York Spadina Subway Extension (adds 8% capacity).

With the environmental assessment approved, the conceptual design study completed and its identification as a priority project by Metrolinx in their next wave of funding projects, this project is truly in a state of readiness for capital funding and provides the critical missing link to the GTHA transit network.

To that end, we are working together with Metrolinx, TTC and City of Toronto on a Regional Relief Strategy to develop a comprehensive plan to improve transit along the Yonge corridor and improve the daily lives of people for generations to come. This is a comprehensive approach that is looking at all options, including service improvements, fare and network integration, and new rapid transit projects so that you can go where you want, when you want – comfortably, conveniently and reliably. Future land use, development and other benefits of different alternatives will be considered as phasing for new projects and service improvements will be recommended.

To read about why the Yonge Subway extension to Highway 7 is considered a top priority, see The Missing Link.


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