Comprehensive Analysis of Steel Sheet Pile Specifications

In modern infrastructure and underground engineering, sheet piles are indispensable due to their high strength and excellent waterproofing performance. Understanding the specifications, material grades, and cross-sectional characteristics of sheet piles is a core step in ensuring project safety and controlling costs. This article will provide a comprehensive analysis of the specifications and technical parameters of mainstream sheet piles.

1. International Standards and Mainstream Steel Grades

The mechanical properties of sheet piles directly determine their performance in support structures. Currently, sheet piles on the market typically need to meet strict international standards.

The mainstream global standards for sheet pile production include the French NF 35 520, European standards (Euronorm), American ASTM, and British BS 4360 standards.

Taking the Japanese standard as an example, the minimum yield strength of SY 295 material is 294 N/mm², the minimum tensile strength is 490 N/mm², and the minimum elongation after fracture is 17%.

In permanent works, the recommended working stress for BS.4360 43A grade or ASTM A328 low-carbon steel is 140 N/mm².

If BS.4360 50A grade high-yield steel is used, the recommended working stress for permanent works can be increased to 180 N/mm².

2. Core Dimensions and Section Properties of U-Type Steel Sheet Piles

U-type steel sheet piles are widely used in various projects due to their excellent section modulus and convenient construction and installation performance. Common series include YSP, FSP, and the widened KSP series.

The following is a comparison of the physical dimensions of several typical models:

Model Series	Width (W)	Height (h)	Flange/Wing Plate Thickness (t)
YSP I	400 mm	75 mm	8.0 mm
FSP II	400 mm	100 mm	10.5 mm
KSP IIw	600 mm	130 mm	10.3 mm

For YSP I type, the cross-sectional area per meter of wall width is 116.2 cm².

For FSP II type, while maintaining a width of 400 mm, the height is increased to 100 mm, and its cross-sectional area per meter of wall width reaches 153.0 cm². The KSP series features single-pile widths up to 600mm. For example, the KSP IIw has a cross-sectional area of 131.2 cm² per meter of wall width. This wider size helps reduce the overall number of interlocks required in the wall.

3. Strict Manufacturing Tolerances

To ensure smooth interlocking of the sheet piles during actual driving and the straightness of the wall, strict manufacturing tolerances must be followed. According to JIS A 5528: 2000 standard for hot-rolled U-shaped sheet piles:

Height Tolerance: The allowable deviation is controlled within ±4%.

Width Tolerance: The allowable deviation for width is +10mm to -5mm.

Thickness Tolerance: The thickness tolerance varies with the sheet thickness. For example, the tolerance is ±1.0mm for thicknesses less than 10mm, and ±1.5mm for thicknesses greater than or equal to 16mm.

End cutting: The error of the vertical cutting section is required to be limited to within 4% of the total width.

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