Secondary Stress

Forces acting on the pipe in addition to the internal pressure such as those forces imposed due to soil loading and dynamic soil conditions.

Section Modulus

The moment of inertia of the area of a section of a member divided by the distance from the center of gravity to the outermost fiber.

Sectional Properties

End area per unit of widths, moment of inertial, section modulus, and radius o gyration.

Sediment

Particles that settles on the pipe invert, causing a reduction in cross sectional area.

Sediment Debris

Specifies the extent of the problem (defect) based on the judgment of the field crew.