U-shape steel support (full name: the mine roadway support in hot rolled U steel) u-shape is a cross section like the English letter "U" steel, sometimes angled bystreet Japanese letters "ひ" shape.
The latest standard was released in 2008, and the national recommended standard GB/T 4697-2008u steel support began to be implemented on April 1, 2009. Main application: it is mainly used for secondary support of mine roadway, mine roadway and support of tunnel through mountain. The use of u-shaped steel support can effectively reduce the occurrence of roof caving and strip side accidents, which is safe and reliable and improves the stability of the mine ventilation system. The U section steel can be used to solve the problem of tunneling support. As the main section steel for making tunnel flexible metal support, U section steel is widely used at home and abroad. However, the cross section shape, geometric parameters and materials of u-section steel vary from country to country due to the different understanding of the properties and requirements of u-section steel itself. There are four types of u-section steel produced in China: 18U, 25U, 29U and 36U. The first two are products of the 1960s, belonging to the waist positioning; The latter two are from the 1980s and belong to ear positioning. U18 is rarely produced because of its low carrying capacity. In GB/T 4697-2008, in addition to the u-section steel of the above four models, a new 40U model is added. The single weight of each type of U section steel is as follows: 18UY 18.96 kg/m25UY 24.76 kg/m25U 24.95 kg/m29U 29 kg/m36U 35.87 kg/m40U 40.05 kg/m, in which the model with "Y" in the back represents the waist position.
