Construction procedures and methods of active protection net
(1) Use foreign shovels, steel drills, etc. to remove or temporarily treat floating soil and pumice that affect construction safety in the slope protection area, so as to eliminate construction safety hazards.
(2), setting out to measure the hole position of the bolt
According to the installation requirements of the system, use tape measure, steel ruler and other measuring tools to determine the anchor hole position according to the vertical and horizontal standard distance of 4.5m×4.5m (corresponding to the mesh block size of 4m×4m steel wire rope), and install the anchor hole position as much as possible In natural low-lying places, the standard distance of the bolt holes can be adjusted by about 0.3m (between 4.2m and 4.8m) to ensure that the system is as close as possible to the slope. When some areas need to add anchor rods to meet the requirements of being close to the slope, they should be measured and positioned at the same time.
(3) Drilling anchor holes
Considering the safety of the operation on the slope and the characteristics of the drilling depth and aperture, the system engineering drilling machine adopts a hand-held pneumatic drill, and a hand-held electric drill is used for the corresponding rock and soil area. In order to meet the design requirements, the drill bit is selected as a 42 (mm) drill bit (the design is not less than 42mm). A 3.5m drill pipe is used for the anchor hole corresponding to a depth of 3m, and a 4.5m drill pipe is used for a 4m anchor hole to ensure that the depth of the anchor rod entering the rock mass is not less than the planning requirements.
(4), grouting and piercing into the anchor rod
1. The anchor rod of this project is 2Φ16 galvanized steel wire rope anchor rod, and its standards and performance parameters are inspected by the manufacturer before leaving the factory. When it is transported to the construction site, it only needs to be visually inspected and a small amount of random inspection is required.
2. Grouting method
First, clean the hole to ensure that there is no debris in the hole, and confirm that the depth is sufficient before grouting. The grout should be manufactured in strict accordance with the ratio given by the laboratory. The stone rate and dehydration volume shrinkage rate should be Satisfy the standard requirements.
(5), vertical and horizontal support rope device
The vertical and horizontal support ropes of the system are all made of Φ16 high-strength galvanized steel wire ropes. Before installation, ensure that the steel cable anchor grouting grout is completely condensed and reaches its proper anchoring force before the installation process can be carried out.
(6), Lay and sew the steel wire grid
The steel wire grid used in this system project is made of high-strength hot-dip galvanized iron wire without kink. The mesh size is 50mm×50mm, and the mesh block standard is 2.25m×9.2m. The parameters of the product have been inspected by the manufacturer and the authoritative department. When arriving at the construction site, the construction site only needs to carry out visual inspection and a small amount of random inspection of appearance and scale.
(7), Lay and sew the wire rope net
The steel wire rope mesh of this system is made of Φ8 high-strength galvanized steel wire rope. The standard of the finished mesh block is 4.5m×4.5m. All technical parameters have been tested by the manufacturer and the authoritative department and sent to the construction site. The construction site only needs to conduct random inspection of appearance and scale.