Barnes, Randal J.2013-09-162013-09-161993-10https://hdl.handle.net/11299/156861Subgrade modulus values for roads around the State of Minnesota can be effectively modelled as spatially correlated lognormal random variables. Based upon this geostatistical model, this report presents guidelines and nomographs for selecting the preliminary sample spacing for assessing the subgrade modulus. The maximum sample spacing to achieve a required precision is represented as a function of the average, standard deviation, and correlation length.en-USGeostatisticsSubgrade characterizationReport