Vibration and cracks in the building
Vibration and cracks in the building
(OP)
In couple of days I need to inspect a building on clients request. She says that there are cracks formed in the building in underground parking garage ceiling etc. Adjacent to building is a vacant land where some one is trying to grade using a bulldozer dragging a steel beam behind. Client says building also vibrates when this grading operation is in progress.
Building is 8 years old, see picture attached. Isn't building too massive to be disturbed by one grading operation? Any tips!
Building is 8 years old, see picture attached. Isn't building too massive to be disturbed by one grading operation? Any tips!






RE: Vibration and cracks in the building
I don't think it's tough to monitor that kind of vibration. If they're still grading, have the vibration checked. If a person can feel them, the detectors can definitely pick it up.
RE: Vibration and cracks in the building
A fairly well know case locally is of a hotel's laundry extractor (squeezes the water out of the laundry before it goes to a dryer) vibrating the entire 20 story hotel so bad people could not sleep if they ran it at night. People in large adjacent buildings could feel the vibrations during the day.
The extractor only weighed about 1,000 pounds, but it could get entire buildings vibrating.
Vibrations are a whole different game, and should not be underestimate.
That said, I am not sure why these vibrations would casue cracking in a ceiling. It will be awefully hard to prove the grading was the casue of the cracks.
RE: Vibration and cracks in the building
It would be neat to put an accelerometer on the ground and measure the magnitude of the ground accelerations.
RE: Vibration and cracks in the building
Monitor the vibration using a sensitive seismograph. These are available for rental and will tell you conclusively that the magnitudes and frequencies are insignificant.
RE: Vibration and cracks in the building
Paint that dripped or was spread into the crack.
Weathered corners of cracks vs. sharp, feather edges.
Evidence of water leakage and calcium staining from inside the crack.
RE: Vibration and cracks in the building
I use a pocket microscope to check the cracks and look for pristine surfaces, discolouration and insect 'stuff' in wider ones.
Often cracks are 'discovered' during/after adjacent construction. Someone notices a crack that wasn't noticed before and then starts looking and finds others.
The photograph shows a building that appears very rigid and stiff and it is unlikely that it was damaged due to the small energy from the grading operation. As Ron notes, the frequency of vibration from the grading would likely be well outside the response spectrum of the building.
RE: Vibration and cracks in the building
RE: Vibration and cracks in the building