Proceedings of the 29th Annual Conference on Deep Foundations, 2004, Vancouver, British Columbia, Canada "Emerging Technologies", (DFI)
Design Construction and Testing of Micropiles used to Support a Concrete Arch Bridge
William Auyeung PEng, Trevor Fitzell Peng
Micro-piles are small-diameter, drilled and grouted reinforced piles used for both structural support and in situ earth reinforcement. They were conceived in Italy in 1952, but have become popular in Canada and the United States only since the mid-1980s. The province of British Columbia completed a construction of a 265-km (165 miles) four-lane highway between Campbell River and Victoria in the year 2000. The construction of Big Qualicum Bridge was part of the above mentioned provincial government project and this bridge was made of twin cast-in-place concrete parabolic arch structures. The overall length of the bridge is 261 meters (856 feet) and the width is 24.2 meters (80 feet). The massive thrust from each arch is resisted by groups of 46 drilled micro-piles that are about 230 mm (9 inches) in diameter with No. 18 high strength Dywidag threaded bars with double corrosion protection up to 15 meters (50 feet) long. This paper will describe the micro-pile design and installation methods. The performance of the micro-piles in full scale testing in tension and compression monitored with electronic strain gauges will be presented. The impact of drilling methods on the performance of the micro-piles will also be discussed.
|article #1266; publication #68 (AM-2004)|