Test of Buried Structural-Plate Pipes Subjected to Blast Loading

摘要

Two 20-ft-long 7-ft-diameter 10-gauge structural-plate pipes, having longitudinal joints with eight bolts per foot, were buried and tested at predicted pressure levels of 195 and 265 psi (actual pressure levels of approximately 190 and 245 psi). The depth of burial was 10 ft over the crown of the pipe. The principal measurements taken of each pipe were the transient changes in horizontal and vertical diameters vs. time, vertical and horizontal accelerations of the pipe invert, and the maximum interior overpressure. Supplementary data were the preshot and postshot measurements of horizontal and vertical diameters, joint slip, distances between end bulkheads, and elevations of the ground surface. Soil properties obtained included density, percentage of compaction, gradation, and the coefficient of internal friction. Maximum transient changes in vertical and horizontal diameters, which were measured by self-recording gauges, were about 7/8 in. and 3/8 in., respectively. Maximum residual changes in the same diameters were about 3/4 in. and 1/4 in., respectively. Discrepancies were found between measurements of the residual changes recorded by the gauges and measurements obtained visually before and after the event. Slip in the bolted joints was negligible. (Author)