Support arch main features: high pressure, long support time, easy installation and deformation.
Support arch main use: mainly used for the secondary support of mine roadway, mine roadway, and the support support of tunnel through the mountain.
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 support arch 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.
