PROOFTESTING OF A STRUCTURAL PLATE PIPE WITH VARYING BEDDING AND BACKFILL PARAMETERS: SECTION II: ANALYSIS OF EXTERNAL LOADS

Settlement data obtained from 64 fluid settlement platforms, plate and rod platforms, and leveling at four zones of the BD Culvert, 120-in. (3048-mm), structural plate pipe, under 188 ft. (57m) of overfill are employed in calculation of quasi-theoretical crown loads, using methods developed by Marston and Spangler. Soil stresses measured by stressmeters near the soil-pipe interface and in the embankment are compared with quasi-theoretical stresses assessed with calculated settlement ratios. Some very encourageing correlations were observed between quasi-theoretical and measured soil stresses; however, on the average, the quasi-theoretical stresses tended to be significantly larger than measured ones. This approach is probably more valuable for structural plate than for rigid pipes, when used in conjunction with Ring Compression Theory. (FHWA)