The 1st phase started with the construction of the east river pier and the installation of 5 each 1500mm diameter concrete caissons by 14m deep. They were excavated using temporary casing installed to pile tip. The very dense clay shale bedrock (N100+) would not seal off and all piles were poured using tremie concrete procedures. The temporary casing was extracted as the concrete was tremied. Caissons were tested for H2S gas during the entire drilling process.
The east abutment was also installed in the 1st stage with -35 degree weather.
During the spring of 2012, the berm installed to support the installation of the girders, flooded due to extremely high water levels. Sheet piles were installed to reinforce the berm cofferdam as extra work.
The second stage work started in September, 2012 with the installation of the west abutment h-piles. Excavation for the 3rd pier was completed after the abutment piles were driven. 5 each 1500 mm diameter shafts were completed at the third pier. The drill rig and crew moved from the 3rd pier to the 2nd pier and the shafts were installed. All shafts were wet and tremie concrete procedures were used to complete the shafts.
|Flatiron Construction Ltd.
|Final Contract Value:
|September 2011 to June 2012
|Pile Driving Rig Setup – Abutment Piles
|Supply and drive – Abutment Piles
|Drill Rig Setup – Pier caissons