Steel struts refer to inclined connecting members such as steel pipes, H-beams, and angle steels used to enhance the stability of engineering structures; the most common forms are herringbone and cross shapes. At present, steel struts are widely used in subways and foundation pit retaining. Because steel struts can be recycled and reused, they are economical and environmentally friendly. 

1. Steel struts (grids) should be prefabricated in a factory, set out at a 1:1 scale, and the accuracy of the axis, dimensions, and joint splice plate alignment should be strictly controlled to meet the specification requirements for welds.

2. The positioning of steel struts (grids) and the layout of locking foot anchor bolts shall be carried out after the excavated section is inspected and accepted, and shall be installed strictly at the designed locations. The drilling orientation, direction, angle, and depth of the anchor bolts shall meet the design requirements.