Page 331 - Buried Pipe Design

302 Chapter Six

4.0. A factor of 2.0 should be adequate for most controlled instal-
lations. Where no control is exercised, the design engineer must
use his or her judgement.
4. Longitudinal seams are generally adequate.

Tests on spiral ribbed pipe
Introduction. Tests were conducted on a ribbed steel pipe (approxi-
mately 29.4-in inside diameter). The pipe has a rib profile wall with a
smooth bore. It is a helical pipe with an interlocking helical joint. The
tests were conducted at Utah State University in the small soil load
cell (see Fig. 6.9 and 6.10).
The soil used for the tests was a silty sand. It was selected because
of the wide range of possible densities, which makes it ideal for pipe

Figure 6.9 Placement of ribbed steel pipe in test cell.