What is a passive protection net

The passive protection net is composed of four main parts: a wire rope net, a ring net, a fixing system, a pressure reducing ring and a steel column. The combination of steel pillars and steel wire nets constitutes a whole, which forms a surface protection for the area to be protected, thereby preventing the falling of the collapsed rock and soil and acting as a slope protection.

What are the technical requirements for passive protective nets and accessories?

The diameter of the passive protection wire is 2.2mm, and the double-wound hexagon or diamond is used as the mesh is suitable. The diameter of the mesh is 50mm. The wire conforms to GB / T343-1994, and the coating is> 230 / m2.

The length of the lap joint of the passive protective net (R / 3/300) is not less than 100mm, and the lap joint should be firmly fixed. Each ring should be connected with the four surrounding rings. The steel wire conforms to GB / T343-1994, and the coating is> 245 / m2.

The steel column of the passive protection net uses 20b I-beam steel. The length of a single steel column is not allowed to be spliced. Both the steel column and the base are hot-drenched with zinc and conform to GB / T13912. The grade is not lower than AB and the coating is ≥180g / m2. The inclination angle of the steel column should meet the preset and construction requirements, and the error is + -5. If it is not satisfactory, it can be re-adjusted or an additional pull-down anchor rope can be added. Unless otherwise specified, steels are considered suitable and Q235B is used, which conforms to GB / T700-2006.

Passive protective net support ropes, anchor ropes, and suture ropes comply with the requirements of GB8918-2006. The strength of the steel wire is not less than 1770MPa, and the hot-dip galvanizing is in accordance with GB / T13912, and the grade is not lower than AB. GS-8002 is suitable for reducing the pressure ring. It is suitable for φ20—φ22 steel wire rope.

The upper and lower support ropes are considered suitable and φ20 steel wire ropes are used; the pull anchor system consists of 2φ16 steel rope anchor rods, φ18 pull-up anchor ropes and 2φ18 side pull-anchor ropes. When the length of the protection system is more than 50m, a semi-mid waist reinforcement anchor rope is added. The length of the side-pull anchor rope is not less than 2.5m, the length of the pull-up anchor rope and the half-middle-waist reinforced anchor rope is not less than 2m, and the drilling hole diameter is not less than φ50. The force is ≥40KN, and the pull-out resistance of the side pull anchor is ≥50KN.