Settlement Analysis and Monitoring of Approach Fills for the 50th Street Grade Separation Project in Edmonton, AB

About the presentation:

Serving as a key north/south arterial road in Edmonton, 50 Street functions as both a major goods

movement and commuter corridor. The existing at-grade Canadian Pacific Kansas City Limited (CPKC)

railway crossing presented a major bottleneck to traffic movements, resulting in significant delays for the

travelers.

To alleviate congestion and improve traffic flow, the 50 Street widening and grade separation project

involved constructing an approximately 70 m long overpass over the railway crossing, with Mechanically

Stabilized Earth (MSE) Wall-supported approach fills up to 11 m high, widening 50 Street to three lanes in

each direction.

A comprehensive geotechnical investigation and PLAXIS 3D finite-element settlement analyses were

completed to assess subsurface conditions and predict short- and long-term settlements under staged

construction. Wick drains were installed beneath higher sections of the approach fills to accelerate the

embankment settlement. A geotechnical instrumentation program was implemented to monitor the

performance of the MSE wall fill placement.

The instrumentation data provided real-time feedback, allowing continuous evaluation of foundation

behaviour and confirmation of design assumptions throughout construction. The measured settlements

generally agreed with the estimated settlements by the 3D numerical analyses, supporting the design and

construction methodology for the overpass.