LONG DISTANCE MICROTUNNELING IN CALGARY AVOIDS LANDSLIDE HAZARD FOR THE NOSE CREEK PROJECT

Abstract

The City of Calgary's Nose Creek Sanitary Sewer Trunk Phase B project will accommodate future growth in northern Calgary, Alberta. The project was designed by Jacobs and includes installation of approximately 1.4 miles of HDPE-lined reinforced concrete sewer pipe. The trenchless portions involve an 850-foot-long skewed and vertically curved siphon beneath Nose Creek and CPKC tracks and a 5,000-foot-long section beneath the toe of an unstable hillside abutting a residential area. The contractor is Ward and Burke. The project was designed and bid to allow conventional 2-pass tunnelling as well as pipe jacking. Technical challenges discussed in this paper include hard pervious sandstone, high groundwater inflows, slaking claystone, deep shafts, slope stability, foundation protection, railroad permitting, and long curved microtunnel drives.