Support arch is widely used in China, especially when the deformation and pressure of the surrounding rock of the roadway is large, using the support arch has its advantages.
The U-shaped steel support arch retractable bracket has a relatively simple structure, large load-bearing capacity, and good shrinkability. Therefore, it is the most widely used U-shaped steel retractable bracket.
The U-shaped steel support arch retractable bracket is generally composed of the following 5 parts:
(1) The top frame is a circular arc arch. According to the size of the roadway section, there are one or more sections of the bracket, such as the force of the support, shrinkage, and transportation conditions. One or two sections are used in China.
(2) There are two main types of column legs: one is circular in the upper part and straight in the lower part; the other is curved, which has one or two radii of curvature. A rectangular or square base is welded on the lower part of the leg.
(3) The connecting piece is a device for connecting and clamping the shaped steel, and is a key component to ensure that the arched bracket has a certain working resistance and a certain amount of shrinkage.
(4) The inter-rack rod can connect the brackets longitudinally to enhance the integrity and stability of the bracket.
(5) The backing material is the filling and isolation material between the support and the surrounding rock. There are mainly various backplanes and metal meshes. The purpose is to improve the stress condition of the support and keep the surrounding rock stable.
