EPCOR 99 Avenue Sanitary Bypass Tunnel

Project Location: City of Edmonton, Alberta

The project consisted of constructing a stormwater tunnel along 99 Avenue between 150 and 139 Streets in the City of Edmonton, for a total length of approximately 1,600 m, in order to replace the existing sanitary tunnel. The tunnel is approximately 2 m in diameter, located 30 m below ground surface, and constructed using a tunnel boring machine (TBM).

SolidEarth was retained to install all geotechnical instrumentation and to provide monitoring of the instrumentation during construction. Slope inclinometers (SI) were installed at each shaft location as well as extensometer along the tunnel alignment to monitor ground movement.

SolidEarth monitored the installed instruments, processed the data, and provided reports at the required frequencies. The reports included a set of charts for each instrument showing the incremental and cumulative movement measured, if any. SolidEarth also provided engineering input and recommendations for the shaft walls and tunnel design, and engineering evaluation and direction in situations where recorded movements exceeded the review or alert levels. Potential cause(s) of displacement were evaluated and measures to control the displacement were assessed and recommended.