7/17/2019 MTO Scugog_Micropiles

http://slidepdf.com/reader/full/mto-scugogmicropiles 1/1

Year:

Technology:

2009

Micropiles

In contemplating foundation options for the twinning of Highway

7 over the Scugog River, Ontario’s Ministry of Transport (MTO)

had for years struggled with a dilemma: shallow foundations, that

would not jeopardize the existing bridge footings, would not suf-

fice to meet stringent new design codes (particularly with re-

spect to scour), and a conventional deep foundation, while meet-

ing code, would almost certainly disturb or damage the existingstructure.

The solution to this dilemma was micropiles, a deep foundation

system capable of being socketed into bedrock in close proximity

 to the existing bridge’s spread footings without risk of damage to

 the existing bridge’s spread footings. In late 2009, Geo-Founda-

 tions, as subcontractor to Aecon Construction and Materials Ltd.,

constructed 38 micropiles as the foundations for 2 in-river piers

for the twinned bridge at Lindsay, ON. The work was staged from

barges, and all drilling took place inside fully flooded cofferdams.

Each micropile was socketed 7.5 metres into rock and reinforced with

273mm permanent casing and galvanized 57mm /517MPa threadbar

Pre-production static compressive and static tensile load testing was

performed on sacrificial piles on dry land, and post-production load

 testing was performed on 4 piles inside the dewatered cofferdams

MTO Scugog River Bridge

GEO-FOUNDATIONS CONTRACTORS INC.302 Main Street North, Acton, Ontario, Canada L7J 1W9

Toll Free: 888-846-7858 Phone: 519-853-3216 Email: enquiries@geo-foundations.com Web: www.geo-foundations.com

The East Pier piling template

Micropile construction ongoing at the West Pier 

Pile cap construction inside the dewatered East Pier cofferdam

Case Study