The design core of U-type steel sheet piles lies in the fact that the interlocks are located on the Neutral Axis of the entire pile wall.
Mechanical Symmetry: Unlike Z-type piles, the individual cross-section of a U-pile is completely symmetrical. This ensures highly uniform internal stress distribution when subjected to lateral earth or water pressure, significantly simplifying structural calculation models.
Moment of Inertia & Section Modulus:
Hot Rolling Process: Hot-rolled U-shaped piles (such as the Larssen type) are produced through high-temperature rolling, resulting in a more scientific thickness distribution of the flanges and web. This allows for a very high section modulus (typically ranging from 745 cm³/m to 3,200 cm³/m) while maintaining a low unit weight.
Calculation Formula: Bending Stress sigma = M / W, where M is the bending moment and W is the section modulus. The high W-value of U-piles directly determines their overturning resistance when used in cofferdams.
