Driving Pre-cast Piles 2

[nader666]

Hi everyone,

Does anybody know the difference between driving a conventional (regular reinforcement) pre-cast pile and pre-stressed pile, the conventional pile cross section is 10" x 10" and the pre -stressed is 12" x 12" (if there is a difference). Do we need different type of equipment to drive a pre-cast pile vs driving the pre-stressed pile.

Also, If there is a difference , how much roughly the cost difference would be per foot?

Thanks

 

[BAretired]

I suggest that you call your local pile installer and ask. The answer will vary according to the equipment available in your area.

BA

 

[hokie66]

The size may affect the pile driver to be used, but whether the pile is reinforced with piles or strands won't. As BA says, use your phone.

 

[GeoPaveTraffic]

The big difference between "standard" and "pre-stressed" piles is the driving forces they can resist. When you drive a pile the energy wave that travels down the pile causes tensile forces at the bottom of the pile. Pre-stressed piles can resist a higher tensile force and therefor higher driving stresses. This allows for larger pile hammers to be used resulting in deeper driving and/or higher capacities without damaging the pile. Capacity and driving forces can be apporximated by your, or at least a good, geotechnical engineer.

So in a way there is a difference in the equipement used to drive the piles. As for the cost difference, call a supplier.

Also, there will be a capacity difference since the piles are a different size.

Mike Lambert

 

[dik]

The prestressing is generally used to provide a compressive stress for the length of the pile. When the hammer strikes, a compressive wave is transmitted down the length of the pile. This reflects off the bottom of the pile and becomes a tension wave. The tensile wave can cause the concrete to crack/break. That's the difference... driven piles in these environs are generally tensioned. Pretensioned piles generally use a high strength concrete and are very elastic... the shockwave is readily transmitted.

If there is inadequate tensioning, the pile breaks and there is a 'puff' of 'dust' at the fracture point,,, generally above grade where there is little restraint from the soil to resist the tension wave.

Dik