With nearly 4% of Minneapolis land area sitting on artificial fill from the city's milling and river-industry past, assuming uniform soil is a gamble that has delayed more than one foundation pour in the North Loop. The grain size analysis—combining mechanical sieves for the coarse fraction and a hydrometer for the fines—maps the exact distribution from gravel down to clay colloids. For a city where glacial Lake Agassiz outwash sands meet silty Mississippi River terraces, that distribution dictates everything from frost-heave susceptibility to drainage design under the IBC. We run the test in our accredited lab following ASTM D6913 and D422, and the report becomes the common language your geotechnical engineer and the City of Minneapolis plan reviewer both need.
A 2% difference in fines content can change the frost classification from S1 to F3 under Minnesota DOT specs—and that changes the entire subgrade design.
