Steel sheet piling is a kind of section steel with lock. Its section has straight plate shape, groove shape and Z shape, etc., and there are various sizes and interlocking forms. The common ones are Larson type, Lackawanna type and so on. Its advantages are: high strength, easy to drive into hard soil; it can be constructed in deep water, and if necessary, it can be added with oblique supports to form a cage. Good waterproof performance; cofferdams of various shapes can be formed according to needs, and can be reused many times, so it has a wide range of uses.

According to the production process, steel sheet piling products are divided into two types: cold-formed thin-walled steel sheet pilings and hot-rolled steel sheet pilings.

(1) There are two types of cold-formed steel sheet piles: non-snap-type cold-formed steel sheet piles (also known as channel plates) and bite-type cold-formed steel sheet piles (divided into L-type, S-type, U-type, and Z-type) . Production process: use thinner plates (commonly with a thickness of 8mm to 14mm) to be continuously rolled and formed in the cold bending machine. Advantages: less investment in production line, lower production cost, flexible control of product sizing. Disadvantages: The thickness of each part of the pile body is the same, the cross-sectional size cannot be optimized, resulting in an increase in steel consumption, the shape of the locking part is difficult to control, the buckle at the joint is not tight, and the water cannot be stopped, and the pile body is prone to tearing during use.

(2) Hot-rolled steel sheet piles The hot-rolled steel sheet piles in the world mainly include U-type, Z-type, AS-type, H-type and dozens of specifications. The production, processing and installation process of Z-type and AS-type steel sheet piles are relatively complicated, and they are mainly used in Europe and the United States; domestically, U-type steel sheet piles are mainly used. Production process: It is formed by high-temperature rolling in a section steel rolling mill. Advantages: standard size, superior performance, reasonable cross-section, high quality, and tight water-repellent lock joint. Disadvantages: high technical difficulty, high production cost, inflexible specification series.