ground vibrations

[kags]

We like to assess some existing buildings for the effects of vibrations due to sheet pile driving. Is there any method, to measure the vibration near the building and check the design of the building like that of seismic loading.

 

[LPPE]

Your local Geotechnical Engineering company should have seismic equipment that will detect ground vibrations. As long as the pile driving operations produce vibrations under a certain limit, there should be no damage to existing structures.
There has been more research done lately in what are acceptable limits, especially in the blasting field. If I remember correctly, it is the low frequency vibrations that cause the most damage.
I would recommend contacting a local Geotech company.

 

[Watermelon]

Hello kags:

You should also post your question under "Foundation Engineering" which can be found elsewhere on this site.

 

[Busman]

We rent a seismograph from a company called Geosonics of Warrendale, Pennsylvania. They have different models and a few regional offices. The SSU2000DK is what I use and is very easy to learn.

"Damage" to the structure usually won't be a problem unless you are right on top of it. Damage to aesthetic coatings and wall hangings is a different story and usually results in many complaints that the building is "falling down", especially with homeowners. People feel and complain about continuous vibrations such as sheet piles and vibratory compactors much more than driven piles.

Here in Florida, the FDOT has specifications for the protection of existing structures. The recommended threshold for vibrations is 0.5 inches per second peak particle velocity. Above this, it is recommended that operations are stopped or energy reduced. O.5 ips is a conservative value. Check with your state's DOT Specifications for Protection of Existing Structures.

 

[PEinc]

No matter what type of analyses you perform, adjacent (and not so adjacent) building owners will claim damages from construction! The key to minimizing the bogus or frivilous claims is to perform a thorough preconstruction survey of the buildings (with the owners' knowledge and assistance), document all pre-existing damages, and continue monitoring the structures during construction. If the building owners know you are keeping a close eye on the situation, it discourages bogus claims.

 

[PEinc]

P.S. Also see Slope Stability Engineering Forum for today's Thread No. 260-46409 on Protection of Nearby Structures and Services. It has related information about appropriate sheeting systems.

 

[exploengineer]

Hi Kags,

It would be easy to montior this situation. You can lease or buy a commercial seismograph that has been developed for monitoring blast vibrations and pile driving. To monitor pile driving, T+he machine is used in histogram mode.

Pile driving causes low frequency vibrations but the vibration waves are usally low energy carriers so it is hard to cause damge unless the machine is extremely close to the structure. Then the damage would be cosmetic in nature.

You should monitor to prevent having bogus claims made in the future. I also recommend a preconstruction and post construction survey of the structure. Remember, all stuructures crack, especially with temperature and humidity changes, so you may want to do weekly checkups. Even if cracks/damage is found, it may not be caused by the pile driving.

In North America, the 2 best builders of seismographs are White Industrial Seismology out of Joplin, Missouri and Instantel from Canada. The largest Instantel distributor in the USA is Dr. Walter and Associates from Twinsburg, Ohio.

Good luck, Frank Lucca

http://www.terradinamica.com

 

[carlorom]

There are also survey techniques which can be used to monitor movements of buildings using a Total station with distance measurements to targets - some use lasers.

Your local surveyor should be able to advise on this in more detail.

 

[Wrightguy]

There are other product too.

You might do a search on "helical" soil anchors and the like for other altenatives.

A Geotech should always be consulted first thought.

my 2 cents..

MJ

 

[dicksewerrat]

Take many, many, many pictures with the bldg. owner present. Videos are good too. The more documentation on existing conditions the better.
But a local Geotech firm is a good investment too. There may be a hidden layer in the soil profile that they have had experience with and you overlooked.. Insurance is always cheaper than the claims.

 

[kags]

Hi ever one,

I am thankful to all of you for yor valuable informations.
I referred to the relevant British standards and following through that procedures for monitoring the building.