Enbridge Credit River- direct pipe crossing
As a part of the Enbridge GTA project, a nearly $1 billion, large diameter – 36” and 42”, gas pipeline is being constructed in the greater Toronto area. IPC, in coordination with Mears (a Quanta Company), was selected to use the Direct Pipe technology on one of the most environmentally sensitive water crossings on this project. IPC successfully completed the tunneling portion of the project at the end of April 2015. A 458m pre-welded and coated 42” diameter, 1” wall thickness pipeline was installed, crossing under both the Credit River as well as a set of railway tracks. This is the longest of the four Direct Pipe crossings completed in Canada to date.
The Credit River Valley and the completion of this trenchless crossing possessed many challenges that prevented it from being suitable for traditional trenchless drilling methods. The river valley in this area and the selected site for the crossing intersected both the credit river environmental conservation area as well as a set of rail road tracks. Because of the limited space around the river valley, the close proximity of the residential communities nearby, and concerns about even the slightest settlement surrounding the railroad tracks, the Direct Pipe method was chosen to execute this project. Direct Pipe offers the benefit of the bore hole being completely supported at all times during the tunneling process, which was one of the major concerns with HDD and the possible settlement of the railroad tracks. Several environmental and site coordination efforts needed to be undertaken to successfully execute this project as the tunneling site was in close proximity to power lines, a protected fish habitat as well as an Aboriginal burial area.
Another factor that also contributed to the complexity of this project was the need for construction to be completed within a specific window to comply with environmental regulations relating to working around migrating birds and other wildlife. The month of February was seasonally colder than normal, which caused delays to the installation of the launch pit. During the execution of the project, IPC also encountered unexpected geological conditions that resulted in additional project delays. However, once tunneling started, only 11 days were required to install the pipe.
During the execution of this project, IPC successfully tunneled underneath both the Credit River and the railroad tracks, without any safety or environmental incidents and no settlement around the railroad tracks. Using the 750 Ton pipe thruster and 42” TBM, IPC’s Direct Pipe installation was considered incredibly well-executed by Enbridge due to the low thrust force and entry/exit angles of 54 Ton and 6 degrees, respectively. Enbridge was pleased with the pipe inspection and testing findings post installation that reported no damage to the pipe or pipe coating. One of the major successes on this job was IPC’s ability to leverage the same team’s past experience from IPC’s previously executed Direct Pipe project in Calgary. IPC’s past experience in cold weather conditions allowed the company to make innovative adjustments to their equipment, heating and cooling systems that resulted in another successful Direct Pipe project.