DESIGN OF LARGE-DIAMETER DRILLED SHAFTS FOR THE NORTHUMBERLAND STRAIT BRIDGE PROJECT

摘要

The Northumberland Strait bridge, recently named the Confederation Bridge, is a 12.9 km long bridge crossing Northumberland Strait between Borden, Prince Edward Island, and Bayfield, New Brunswick. The bridge must withstand large horizontal loads that are due to ice impact, wind, and wave action on the piers and superstructure. The abutment and the 14 shallow water approach piers located on the New Brunswick side of the strait are supported on groups of large-diameter drilled piles socketed into weak sedimentary rock. Pile designs are based on shaft resistance developed within the bedrock. Preliminary calculations indicated that piles were required with average socket lengths of about 13.5 m. A pile load test was carried out at the New Brunswick abutment for the purpose of refining the shaft design parameters. The pile load test was successful in allowing a 55% reduction in the average design socket lengths. [References: 13]