Influence of Backfill Compaction on Mechanical Characteristics of High-Density Polyethylene Double-Wall Corrugated Pipelines

Figure 23

(a) Location of loose backfill; the circumference strain nephogram of the (b) interior wall and (c) exterior wall when the left sides of Lay 01, Lay 02 and Lay 03 were loose.

(a)

(b)

(c)