Page 333 - Buried Pipe Design
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304 Chapter Six
Percent Finer
Grain Diameter (mm)
Figure 6.11 Gradation curve and classification for the silty-sand
soil used in the tests. Atterberg limits: liquid limit, NA; plastic
limit, NA. Soil classification: SM. Specific gravity: 2.72.
Description of pipes tested. The pipe is ribbed and is formed by helical
winding. The closed rib is 1 in tall and is spaced on 10.25-in centers.
The lockseam is spaced midway between the ribs.
Three tests were conducted by installing the test pipe in the small
soil load cell. The test data are reported in terms of height of cover.
Dry Density (lb/ft 3 )
Water Content (w %)
Figure 6.12 Compaction (standard Proctor) curve for silty-sand soil used in
3
tests. Maximum dry density: 124.7 lb/ft . Optimum moisture: 9.5 percent.
