Evaluation of Common Interpolation Algorithms for Site Characterization

In this study point data useful for characterizing site conditions have been isolated from both a number of computer-generated models of simplified geologic features and from a series of boreholes advanced across a selected site. A number of common exact and smoothing algorithms have been used to interpolate three-dimensional surfaces from the point data, and these subsurface planes extrapolated to the site extents. The reconstructed solid models have been compared back to the original data and the accuracy of each algorithm assessed. Closely spaced piles were installed upon the considered project site, which, by onsite surveillance, allowed the development of a near-continuous profile of a specific subsurface interface. This documented profile was compared against the corresponding interface interpolated by each of the analysed algorithms based on the available borehole data, and an assessment of the suitability of each algorithm has been completed. Of the six algorithms compared, a ranking based on an assessment of the consistency of the provided results has been achieved. The inverse distance to a power algorithm was assessed to provide the closest match to the observed profile for the site analyzed.