Project Soil Inspections (When a Geotechnical Report Does Not Exist)

PROJECT DILEMMA: The project is small and measures about 4,500 square feet in plan dimensions and about 18 feet in height. A geotechnical report does not exist, and the contract documents do not address the twenty feet of compacted fill beneath the future building. The earthwork operations started yesterday. According to code, what do you do about the compacted fill beneath the building?

The quandary above occurs more often than you may think – especially in the states of Virginia and North Carolina, where both of the STATEWIDE building codes contain language stipulating that small projects like this are exceptions to the International Building Code (IBC) and are not required to have special inspections performed. The IBC code narrative at the bottom of the page addresses this project problem insofar as the compacted fill is concerned.

The solution to this particular project predicament is for the testing agency to simply enforce the contract documents. Chances are that the construction documents do require soils inspection on the fill beneath the building to verify some degree of satisfactory bearing capacity. Even poorly written construction documents usually require minimum testing and inspection of compacted fill beneath the building and some minimum magnitude of testing and inspection on concrete, masonry, and structural steel elements.

The verbiage in the IBC code, Section 1705.6 Exception, does address the compacted fill portion of this project; therefore, all fill soils should be compacted to 90 percent of the maximum dry density as determined with ASTM D1557 (Modified Effort). All other structural building elements should be tested and inspected to verify compliance with the contract documents and applicable building code.

IBC Code, Section 1705.6 Exception

When a geotechnical report does not exist on a project and where Section 1803 does not require reporting of materials and procedures for fill placement, the special inspector shall verify that the in-place dry density of the compacted fill is not less than 90 percent of the maximum dry density at optimum moisture content determined in accordance with ASTM D1557.

For more information or further enthusiastic discourse on topics of CODE, please contact Alan Tuck at: [email protected] or 540.344.7939