Soil Vapor Extraction - causing settlement in building over sand with sub layer of peat?

[pskornia]

thread193-340322

I have a 50 year old single story masonry building with soil contamination from an adjacent gas station under the building. They have been doing soil vapor extraction for the past several years and we are now having major settlement issues with the building. One corner needed to be jacked back into place with helical piles.

From soil borings there is a layer of peat about 8 - 10 feet below grade and just above and below the water table and all of the way under our building.

Is it reasonable to conclude that after 45 years of the building experiencing no settlement; that now after the remediation company did the SVE the activities are related?

Thanks,

pskornia

 

[oldestguy]

There may be other reasons for the problem. Give us a rough profile of site soil borings and their classifications, moisture contents and density or consistency, as well as locations. Is that settlement area on the part of the building closest to the extraction? Any trees on site and where located? Photos will help also. Any historical water table elevation data? Foundation depth? Settlement data locations? Contours of floor settlements.