Vibration Cracking
Vibration Cracking
(OP)
We were called to a job to investigate cracking in a brick building which was said to be caused by the vibrations from driving in sheet piling for a gas line. The distance from the sheet to the corner of the single story building is 108' the front face of the building is 46' long and goes back 80' and there were no expansion joints. What I found odd was that there were only cracks on the front of the building and no where else. Is this typical in buildings which have seen cracking caused by vibration?






RE: Vibration Cracking
Mike McCann, PE, SE (WA)
RE: Vibration Cracking
A lot of times the cracking was from previous foundation settlements, south-facing walls with larger thermal effects, etc.
If you look at the crack you can sometimes find soft, worn edges or paint/sealant inside the crack that suggests an older crack.
Per Mike above, without more info we are just suggesting issues to consider.
Check out Eng-Tips Forum's Policies here:
FAQ731-376: Eng-Tips.com Forum Policies
RE: Vibration Cracking
Other factors, such as control joints (or lack), sun exposure, age or work, etc. proof of condition before and after enter.
RE: Vibration Cracking
RE: Vibration Cracking
Same happens with insurance claims after a damaging weather event. Even if the property isn't damaged some people will try to claim "other damages" on insurance.
RE: Vibration Cracking
As for the vibration, a lot depends on the soil conditions and water table location. While there will be both airborne vibration and direct transmission, the direct transmission is the one more likely to cause damage. A lot of vibration energy can be dissipated in 100 feet and there's a reasonably large difference between perceptibility and structural damage when considering vibration. As OG noted, there should be testing to determine the actual vibration levels as this is site-specific.
The group doing the work that causes the vibration has an obligation to protect adjacent structures. In some states, it is a law. In others, though not a law, it's a prudent thing to do because of potential liability. The approach I recommend when dealing with adjacent structures is to do a detailed pre-construction survey (with video) of buildings that would potentially be affected by the vibration, then set vibration monitoring devices up at various locations with alarm triggers if the vibration levels reach certain set points. All cracks on existing buildings should be mapped, measured and marked to see if they grow during the vibration events.
RE: Vibration Cracking
RE: Vibration Cracking