Pile Driving Vibrations 5

[geodoc]

Piles will be driven within 10 to 25 ft of existing building. It is likely that vibrations from the pile driving will exceed allowable levels. Besides drilling the piles in, does anyone have any proven methods for driving the piles and keeping the vibrations to acceptable limits? Obviously, I do not want to damage the buildings but I also want a method that works so that the contractor does not have to stop because of vibration concerns. I have seen options such as drilling a casing to a predetermined depth (seems arbitrary), removing the soil, and then driving the pile. How effective is this technique? Any help?

 

[dirtguy4]

I agree with dmoler. Predrilling is a pretty good option, but it always depends on you soil types. Predrilling may add a little more to the cost, but experienced predrilling contractors are very fast. Predrilling can not only decreases the driving vibrations but also reduce some of the driving stresses on the steel (pile/h-pile - normally prevents mushrooming and damaging your piles)

So this begs the question, what type of soil are you driving into? High plastic clay, silt, Till, clay shale, shale, weathered sandstone, granite?? Where I'm from, most of the piles have 20' embedment depths, however, that varies with the type of soil and where you are at (ie - northern Canada has adfreeze/frost jacking concerns and Florida probably doesn't have to worry about this).