PCL GOES APE -DRIVING 30-INCH CONCRETE PILES, 300-FEET LONG.
PCL is the bid winner for the Lake Underhill Bridge in Orlando Florida. This bridge will be built on 30-inch concrete piles many of which are over 200-feet long with some approaching 300-feet.
Due to the length of the piling, it will be necessary to splice. Some of the longer piles will have two splices in order to get the length. PCL is using the Sure-Lock mechanical splice system.
After weap analysis and a field test, PCL choose the Ape/J&M Model 220 hydraulic hammer to do the work. The 220H was chosen because it has a heavy ram (22,000 pounds) and a totally controllable stroke. For this project, the 22,000-pound ram will be operated at short strokes (up to two feet) in order to minimize the stress in the pile while driving.
It is interesting to note that in Florida, when a pile is spliced, the amount of stress permitted during driving is about one-half of the stress permitted in a non-spliced pile. Therefore, hammer selection becomes a little more difficult and we see increased use of hydraulic hammers because of the excellent stroke control and heavy rams.
The hammer in use at Lake Underhill has also been equipped with an e-Saximeter. This is a device, which electronically transmits data regarding the hammer’s energy output. This information is valuable to the engineers in monitoring pile stress levels and writing hammer operation criteria.
Although the project is just starting, to date, hammer operation has been flawless and the pile stress levels are acceptable.