Vibration Monitoring 3

[fish1]

Hello everyone,
I am looking for criteria regarding acceptable vibration limits at the foundations of historic buildings due to near by pile driving (construction activities). We are considering requiring vibration monitoring at an old building near the construction site. Is there a standard maximum particle velocity or standard monitoring method?

Thanks for your help,

 

[SlideRuleEra]

I have two articles from Concrete Construction Magazine (May 1983 & February 1985) that address external (blasting, pile driving, construction equipment, etc.) vibration limits (peak particle velocity) for fresh concrete. The articles are based on (old) information from ASCE & Portland Cement Association. This may not be what you are looking for but will be happy to email you .pdf scans of both.

 

[fish1]

Thank you for your response. i would be interested in reading those articles. you can email them to me at gallen@aldenlab.com. For residential buildings i have found that the most common value used for maximum particle velocity is 2 in/sec. I will probably write this into the specifications to the project. I would feel more comfortable if i had a solid reference. Thanks,

 

[GeoPaveTraffic]

Depending on the type of construction used in the "old building" 2 inches/sec may be more than the structure can stand.

I will look for some tables; I think I have them at home, which relate particle velocity and frequency to damage. The tables were generated by USBR among others.

My recollection is that for unreinforced masonry, that 1.0 inches/sec at low frequencies could cause damage. You also need to remember that most of the data you see is for blasting, not a continuous activity such as pile driving.

 

[Focht3]

Monitor. It's cheap insurance - and puts the contractor on the hot seat, not you. After all, the contractor should be the one choosing the means and methods...

Just be sure the monitoring equipment covers the important frequencies for the buildings in question. Most of the blast monitoring equipment only covers 10 Hz to 20 kHz, while the important frequencies may be in the 0.5 to 1 Hz range. Failure to identify this important issue could leave the owner and design team exposed to significant risks should the historic buildings sustain damage.



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[BigHarvey]

In Europe for a historic buildings, peak particle velocities would be limited somewhere between 5 and 10 mm/s.
The article from Ground Engineering is a good start to predict the level of vibrations as a function of the hammer size and the distance. If a simple analysis of this type gives values far above 10 mm/s, there is no point in putting a contractor in a hot seat, it's better to change the type of pile and go gor bored piles ( even if the price doesn't seem as attractive... ). If it is decided to go for driven piles, then I agree with Focht3, monitoring is a must because first of all you get the real level of vibration obtained and secondly because the cost is minimum.

 

[fish1]

Your responses have been a great help. The historic structure has a stone masonry foundation and is located about 100 ft from where the piles will be driven. i found a good article from the ASCE Construction Congress 6, Orlando, Florida, Feb 22, 2000. The title is "Construction Vibrations and Their impact on Vibration-Sensitive Facilities". The article has charts presenting estimated peak particle velocities at various distances for various construction activities. For driving piles i estimate the peak particle velocity will be approximately 1 mm/sec at the stone foundation. The article also has a table for typical vibration criteria addressing building damage. For "historic buildings" it lists a value of 3 mm/sec and for "historic and ancient buildings" it lists 2 mm/sec. What i do not know is how they define damage, is it defined as cracks in plaster lathe, or structural damage to an old foundation. The building of concern does not have plaster lathe and my only concern is the foundation. Of the information i have been reading the last two days i think 2 mm/sec would be a conservative peak particle velocity limit. Any comments or suggestions?

Thanks again.

 

[Ron]

The best reference I have used on this topic is Richart, Hall, and Woods on Vibrations. Their textbook is excellent and contains response-spectra charts for a variety of applications, including yours.

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[DRC1]

See thread 256-61566
Most published limits are for blast crteria. Pile driving involves lower amplitude vibrations that may cause settlement of the foundation soils which could result in signifcant and unacceptable differential settlement

 

[Focht3]

Here's the link to [blue]DRC1[/blue]'s thread: thread256-61566




Please see FAQ731-376 for great suggestions on how to make the best use of Eng-Tips Fora.