Classification of steel sheet piles
Steel sheet pile products are divided into two types according to the production process: cold-formed thin-wall steel sheet pile and hot-rolled steel sheet pile.
(1) There are two kinds of cold-formed steel sheet piles: non-biting cold-formed steel sheet piles (also known as channel plates) and biting cold-formed steel sheet piles (divided into L-shaped, S-shaped, U-shaped and Z-shaped). Production process: The thin sheet (commonly used thickness 8mm ~ 14mm) is continuously rolled and formed in the cold bending unit. Advantages: less investment in the production line, lower production costs, flexible product size control. Disadvantages: the thickness of each part of the pile is the same, the section size cannot be optimized, resulting in the increase of the amount of steel used, the shape of the lock part is difficult to control, the buckle at the connection is not strict, and the water cannot be stopped, and the pile is easy to tear during use.
(2) Hot rolled steel sheet piles in the world are mainly U-shaped, Z-shaped, AS, H-type and other categories of dozens of specifications. The production, processing and installation technology of Z and AS steel sheet piles is more complicated, which is mainly used in Europe and America. It is mainly U-shaped steel sheet pile in China. Production process: forming by high temperature rolling of section steel mill. Advantages: standard size, superior performance, reasonable cross-section, high quality, lock bite with tight water insulation. Disadvantages: high technical difficulty, high production cost, and inflexible specification series.
In engineering construction, the application range of cold-formed steel sheet pile is relatively narrow, mostly as a material supplement for application, and hot-rolled steel sheet pile has been the leading product for engineering application. Based on the many advantages of steel sheet pile in construction operations, the General Administration of Quality Supervision, Inspection and Quarantine of the State and the Standardization Administration of the State issued the "Hot rolled U-shaped steel sheet pile" national standard on May 14, 2007, and was formally implemented on December 1, 2007. At the end of the 20th century, Masteel Co., LTD., with the introduction of universal rolling mill production line from abroad, produced more than 5,000 tons of U-shaped steel sheet piles with a width of 400mm, and successfully applied to the Nenjiang Bridge cofferdam, Jingjiang New Century Shipyard 300,000 tons dock and Bangladesh flood control projects. However, due to low production efficiency, poor economic benefits, less domestic demand and insufficient technical experience during trial production, it could not continue to produce. According to statistics, the annual consumption of steel sheet piles in China is maintained at about 30,000 tons, accounting for only 1% of the world, and is limited to some permanent projects such as port, dock, shipyard construction and temporary projects such as bridge cofferdam and foundation pit support.
The cold-formed sheet pile is a steel structure which is continuously rolled and formed by the cold forming unit, and the side lock can be continuously bonded to form a sheet pile wall. The cold-formed steel sheet pile is made of thin sheet (the usual thickness is 8mm ~ 14mm) and processed by the cold-formed forming unit. Its production cost is low and the price is cheap, and the size control is more flexible. However, due to the simple processing method, the thickness of each part of the pile body is the same, and the section size cannot be optimized, resulting in the increase of steel use; The shape of the lock part is difficult to control, the buckle at the connection is not strict, and the water cannot be stopped; Limited by the capacity of cold bending processing equipment, it can only produce products with low steel strength and thin thickness; Moreover, the stress generated in the process of cold bending is large, and the pile is easy to tear during use, so the application has great limitations. In engineering construction, the application range of cold-formed steel sheet piles is relatively narrow, and most of them are only used as a material supplement for application. Characteristics of cold-formed steel sheet pile: According to the actual situation of the project, the most economical and reasonable section can be selected to achieve the optimization of engineering design, and the material saving is 10-15% compared with the same performance of hot-rolled steel sheet pile, which greatly reduces the construction cost.
Now due to the production conditions and scale restrictions, there is no production line in China, and the hot-rolled steel sheet piles used in China are from abroad.
The common hot-rolled steel sheet pile manufacturers are modern steel mills in South Korea, Nippon Steel mills in Japan, Sumitomo Steel Mills in Japan, JFE steel mills in Japan, and some manufacturers in Europe and the United States.