What Are The Forms Of Steel Support
May 21, 2022
Steel support [steel grid (① rectangular section grid, ② triangular section grid), section steel support (① H-shaped steel support ② I-shaped steel support ③ U-shaped steel support), steel pipe support]. Steel grilles can be divided into rectangular and triangular sections. In order to facilitate construction, each pair of steel grilles is divided into several sections, generally 3 ~ 5 sections. Flanges are processed between the sections and welded with the method of bolt fixation and connection. Features: it can be used as an ordinary steel frame support in the initial stage to support the surrounding rock in time, and can form reinforced concrete with formwork or shotcrete in the later stage. The steel is fully utilized.
Features of profile steel support: high strength and convenient installation, which is beneficial to the safety of initial construction. However, because the U-shaped steel frame joints are nested up and down, rather than flange butt joint, when the surrounding rock deformation is large and the load on the support construction is too large, the U-shaped steel support can produce certain shrinkage deformation, reducing the pressure on the steel support, so as to ensure that the steel support is not damaged and maintain the stability of the surrounding rock with greater support capacity.
U-shaped steel also has the characteristics of compressibility. The steel pipe support is usually used for the reinforcement of surrounding rock in local unfavorable geological sections of the tunnel. The diameter of the steel pipe is about 10cm, and the sand filling cold bending method is often used on site. During the construction, the assembly and butt welding are carried out according to the division of labor. Grouting holes and exhaust holes are reserved at the frame bottom and arch crown. After the installation in place, the grouting pump is used to pour mortar into the pipe from the grouting hole at the frame bottom until the grouting is discharged from the exhaust hole at the arch crown. The characteristic of steel pipe is that the mechanical properties of steel pipe are symmetrical, and the bearing capacity of steel support is significantly increased by late grouting.
