Safe Offset to Avoid Pile-Driving Impact

[Ammonite]

Here's my setup: a very old timber bulkhead (16 ft exposed) adjacent to an operational timber dock is in bad shape: bowing in places, timber deteriorated, etc. I need to locate a new dock structure in shallow water nearby but am concerned about vibrations and impact waves from piling (both sheet-piles and pipe piles)triggering a collapse of the wall and impacting the existing dock. Profile I'd be driving in: up to 13 feet of fine alluvial sand and silt, some organics; then med. dense to dense sand and gravel.

What I'd like to know is how far away do I have to be from the timber bulkhead to be sure the disturbance from the piling activity has attenuated? Is there a way to quantify the relationship between magnitude of ground vibration and its propagation distance depending on the soil? Thank you very much for any input you might have.

 

[Ron]

Not accurately...usually have to measure it for site specific conditions. If it's any consolation, your conditions tend to attenuate vibrations more than some others.