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1. Steel Sheet Pile

In Japan, it has been nearly a half century since the start of rolling of steel sheet piles, and Japan hasnow become at the top of the world in production of steel sheet piles, being active in export to foreigncountries not only supply to the domestic market.

For the steel sheet piles allowing mass production, with advancing production techniques, variousdesign standards and production techniques have been rapidly developed. Then the steel sheet piles havebeen widely used in civil engineering and construction works for permanent and temporary structures.

In the recent trend towards increasing scale of structures and more elaborated urban redevelopment, asdemonstrated by the introduction of wide design steel sheet piles in April 1997 for higher cost effectiveness,geometrical shapes and intended uses of steel sheet piles have become diversified.

1) Types and features of steel sheet piles

The steel sheet piles currently in production may be broadly divided into three types, lightweight steelsheet piles, steel sheet piles, and steel pipe sheet piles. The steel pipe sheet piles are mostly used forpermanent structures, while the lightweight steel sheet piles and the steel sheet piles are used for bothpermanent and temporary structures according to different application needs.

The lightweight steel sheet piles were developed initially in a simple design without joint. However,through a number of improvements since then, joint-incorporated design is now prevailing. Of thelightweight steel sheet piles, the most popularly used is the U-shaped design, which is available in twodifferent cross sections when constructed to form a wall; one, in which the neutral axis of wall becomes inline with the neutral axis of each sheet pile, and the other, in which the neutral axis of wall becomes in linewith the joint of sheet pile.

The steel sheet piles are manufactured by hot rolling of steel ingot, thus essentially different from thelightweight steel sheet piles which are manufactured by the cold rolling of steel sheets. The steel sheetpiles are available in various designs, U-shaped, Z-shaped, H-shaped, and straight, which are usedaccording to different application needs.

(1) U-shaped steel sheet pile

The U-shaped steel sheet piles feature the most available types. They also offer different effectivewidths, 400 mm, 500 mm, and 600 mm, as well as section modulus ranging from 529 cm2/m to 3,820cm2/m, thereby allowing optimum selection for required mechanical strengths. The joints are available intwo types, Lackawanna and Larsen, though the production of Lackawanna type is discontinued at present.The U-shaped steel sheet piles feature the coincidence between the joint position and the neutral axis ofwall in the wall application. In the curved application, a standard turning angle is six degrees in eitherside, right and left, in relation to the neutral axis.

(1) Lackawanna type (2) Larsen type

Web

Neutral Axis

Flange

Neutral Axis

Web

Flange

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(2) Z-shaped steel sheet pile

The Z-shaped steel sheet piles feature the joints located outside in the right and left when fit witheach other. They are chiefly used for permanent structures. The section modulus ranges from 2,510cm2/m to 4,550 cm2/m.

(3) Straight steel sheet pile

The straight steel sheet piles feature very high mechanical strength of engaged joints, thus ideal-suited for cell structures.

(4) Steel pipe sheet pile

The steel pipe sheet piles are made up from a single pipe with joints, and used for stand-alonepermanent structures. The joints are available in three types, L-T, P-P, and P-T.

(1) L-T Type (2) P-P Type (3) P-T Type

2) Advantages of steel sheet pile press-fit method

The steel sheet pile press-fit method offers the advantages listed below over the other methods.(1) Simplified work without the need for any large scale equipment and facility for execution of work(2) Available rapid execution of work, contributing to considerably reduced construction period(3) Allowable selection of optimum cross section/length of steel sheet pile for different soil conditions,

contributing to reasonable and cost-effective planning(4) Available lightweight walls, allowing advantageous earthquake-resistant design different from

gravity-type structureFurthermore, recently, development of construction machines have advanced rapidly, allowing execution ofwork even in the sites where the driving method encounters some difficulties in the upper section by addingshorter steel sheet piles in succession or in narrow roads or rivers where large scale machines fail toapproach. In addition, for the purpose to prevent possible liquefaction caused by earthquake, in thevicinity of critical structures and/or for revetments of rivers as a part of reinforcement, those steel sheetpiles have become used featuring a capability of water drainage. For those many marked advantages, theyare finding wide application in various purposes including quaywall, revetments, and temporary works.

Straight

Curved Claw

Neutral Axis

Angle Steel

Base Steel Pipe

Base Steel Pipe

T-Steel

Base Steel Pipe

Steel Pipe

Base Steel Pipe

Base Steel Pipe

Steel Pipe

Base Steel Pipe

T-Steel

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3) Classification of steel sheet pile walls according to application

Quaywall & Lighter's wharf

Revetments

Retaining wall

Breakwater

Training wall

Dolphin

Dock

Lock gate & Sluice

Permanent structure

Consolidation of foundation,Prevention of corrosion, & Cut-off wall

Breasting

Temporary revetments

Coffering

Application

Temporary structure

Temporary coffering island

4) Classification of steel sheet pile press-fit methods according to structure design

Stand-alone

Tie-rod

Anchor plate

Bracing steel sheet pile

Bracing vertical pile

Bracing combined pile

Cell

Double steel sheet piling

Strut

Diagonal stay pile

Structuredesign

Shelf