Rigid Pipe Proof Testing Under Excess Overfills with Varying Backfill Parameters. Section II. Analysis of External Embankment Loads on the Pipe (Soil Stresses), Part 2, Appendices II.J through II.GG

摘要

Soil stresses due to embankment loads were measured at 10 locations about the outer periphery of the Cross Canyon, reinforced concrete culvert, in eight separate zones, subjected to varying backfill conditions. Two or three meters were placed at each location where a soil stress was to be measured to improve the accuracy of measurements. In three zones (4, 6 and 10), one of these meters was of special design to permit assessment of tangential tractions. Stressmeter readings were not, in general, indicative of pipe static equilibrium, even where tangential tractions were measured. Attempts to establish vertical equilibrium by adjustments in normal tractions, in many instances, required prohibitively large modifications, resulting in negative normal tractions. These adjustments were therefore made, rather, by synthesizing tangential tractions which (together with measured tangential tractions in Zones 4, 6 and 10) would establish static equilibrium in the vertical and rotational directions. Additional, small adjustments were made in the normal tractions to establish pipe equilibrium in the horizontal direction.