Strain Gage for Settlement Monitoring

[BadgerPE]

I am working on a project that has a long history (15+ years) of serviceability failures (i.e. cracking drywall, sticking doors etc.). The building in question is a simple single story wood-framed building on a continuous wall footing system. Post-installed jacking piles were installed about 15 years ago to attempt to mitigate the building movement. It appears that either this method didn't do what was intended or there is something else going on with the building that is unrelated to the foundation. Due to the long history of issues and employee turnover for the client there is not sufficient information documenting when/where all the issues have occurred. I am trying to establish if movement of the building has stopped or not so I can proceed with determining a fix, or can state with confidence that the movement has stopped.

Outside of basic monitoring (i.e. measuring cracking, grade shots, plumb checks) are there any more precise monitoring options to determine if movement has ceased? I was thinking strain gages placed across cracks in drywall, along with more global checks to monitor the issue. Perhaps I am overthinking this.

Any guidance would be greatly appreciated.

 

[oldestguy]

Define "global checks". Have you had a recent geotechnical study of soil conditions? Why was there a pile system installed for jacking? Is this a soil area with clays of high shrink-swell potential? Are there any trees nearby? Trees can grow near old buildings and gradually increase the problems of soil shrinkage, etc. Has there been any changes in the heating or cooling systems? What about climate differences or site drainage changes with time? Have there been plots of floor elevations to show contours and thus pin-pointing areas of more activity?

With your name implying the badger state (Wisconsin), where is it? Some areas have vicious soil problems related to moisture changes mainly.

 

[BadgerPE]

Sorry for missing this response Oldestguy....yes this project is in SW WI. We know that the building is moving and have started an intense monitoring process (floor elevations, wall crack mapping, & crack size observation using these: Humbolt Standard Crack Gauge). Without going into too much detail, this is a long-occurring issue that repairs have been attempted twice, but appear to have failed in execution. There appear to be significant geotech issues due to existing site that this building was constructed on circa 1990.