Traditionally, the Pennsylvania Department of Transportation has been very rigid with their pile driving criteria, with 20 blows to the inch standard regardless of the pile type or size.
With half of the bridges on the US Route 219 reconstruction in Bradford, PA designed on Monotubes, which cannot take the stresses of high blowcounts, the contractor enlisted the help of GRL. Together they approached PennDOT with a driving system using WEAP Analysis to show they could achieve the required bearing at less than 20 blows per inch, which would prevent overstressing the Monotubes.
The contractor submitted several J&M hydraulic hammers for approval and PennDOT accepted both the J&M Model 82 that they own, with a 8,200 lb ram rated at 32,800 ft/lbs as well as the J&M Model 70B, with a 7,000lbs ram rated at 21,000 ft/lbs.
APE/J&M supplied 2 rental 70B’s in addition to the contractor owned Model 82. Because the hydraulic hammers have an infinitely adjustable stroke inbetween the minumum and maximum, dynamic testing was used on all hammers to determine the optimal hammer stroke. This testing confirmed that the bearing was achievable at something other than 20 blows per inch, in this case 10 blows per inch, which enabled the contractor to drive the Monotubes without fear of destroying them because at 10 blows per inch, the compressive stresses were comfortably below the yield of the Monotube’s steel.
This is the 1st time a hydraulic hammer has been used on a PennDOT project. We look forward to many more.
The Mighty APE 9.5 Low Headroom Hydraulic Impact Hammer is the most powerful hammer in its class! Why is that? Because there are no other hammers in its class! With over 43,000ftlbs energy and only nine and a half feet tall the 9.5 hydraulic impact hammer is perfect for low headroom projects! Especially when you load it onto an APE ST75 low over head leader system. Running on a 245 Cat excavator and using the excavators hydraulics eliminates the need for a power unit which makes this package totally mobile! There is no hammer available like an APE low head room hammer which comes in many sizes to fit your most difficult situations. Just ask ACC West Coast and they will tell you the results!
Don Schroeder with Wilder Construction and crew install the temporary bridge piles in the wet lands outside Carnation, WA. The main foundations will be drilled shafts. The way the crew tackled the batter piles on the work trestle is very creative. Using a swinging set of leads and a simple pin arrangement, the batter piles installed very smoothly.
In addition to the swinging leads, there is a pile monkey and fixed pile gate holding the pile in the leads.
For more information on APE lead systems feel free to contact us here at the main office or one of our satellite locations.