20/20 REVIEW OF PRE-QUALIFICATION AND DESIGN ASPECTS OF THE CITY OF CALGARY 15 STREET SIPHON TUNNEL PROJECT

摘要

The 15 Street Sanitary Sewer Siphon Upgrade is a 300 m long twin 1,650 mm diameter crossing of the Bow River just east of downtown Calgary, and is the first tunneled pipeline under the River in over 90 years. Construction of the project commenced in early 2008 and was successfully completed and put into operation in July of 2010. Drawing on the lessons learned during construction, this paper examines two aspects of the project: 1) Contractor Pre-Qualification and 2) Geotechnical Baseline Report (GBR). The Pre-Qualification process yielded eight contractors who qualified in one or more of the three permitted methods - tunneling, microtunneling and open shield pipe jacking. The suitability of the Pre-Qualification response categories relative to construction is examined. The performance of the GBR is reviewed from two perspectives: 1) influence on the bid phase and 2) how it served the Owner and Contractor during the construction phase.