PROJECT SUMMARY

A high voltage power line was required to run underneath Sarcee Trail: one of Calgary’s main arteries, connecting commuters from the west end of the city to downtown and the south. The construction firm in charge of the project felt it would be beneficial to bring the civil engineering firm and The Tunneling Company together at the project’s outset to discuss the most practical and cost effective route.

The Tunneling Company supported the option that would involve the shortest distance. We would be required to hit the exit pit on the other side of the roadway, so a guided boring machine (GBM) was used.

KEY CHALLENGES

At 75 m (246 ft) of the pilot hole, we hit difficult ground. A large rock directly in the drill path caused the GBM to veer slightly off course, which affected our ability to see the LED guide. The Tunneling Company would have to complete the final 10 m without the benefit of the guidance system. This is where the operator’s skill and experience came into play. He remained confident the drill would emerge in the exit pit, despite the deviation – and proved to be correct. Both the construction contractor and utility company were extremely satisfied with The Tunneling Company’s work and the insights we contributed to the planning process. This led to an ongoing collaboration, which has resulted in six additional projects – and counting.

SERVICES PROVIDED

GUIDED BORING MACHINE (GBM)