Understanding the Guiding Protection System
In practical applications, the open-type guiding protection system or the covering-type guiding protection system can be selected according to local conditions to effectively deal with high and steep slopes with severe slope weathering and difficult clearance of dangerous rocks, avoiding secondary disasters caused by the accumulation of main and passive protection systems at high positions. Moreover, the guiding protection system causes less damage to the original slope surface and promotes rapid vegetation recovery.
Category of Guiding Protection System
The open-type guiding protection system consists of an interception part and a guiding part. The protective capacity of the interception part should be consistent with the nominal protective level corresponding to the passive protective net.
The tensile strength of the flexible metal net in the guiding part must reach the tensile strength of the flexible metal net corresponding to the covering-type guiding protection system.The interception section will intercept the falling rocks on the upper part of the system and collect them in the guiding section. When the falling rocks impact the interception section, their kinetic energy is reduced. Then, the rebound of the falling rocks is restricted by the guiding area, and the rocks are guided to move to the designated accumulation area.
The covering-type guiding protective system is composed of flexible metal nets, longitudinal and transverse supporting ropes, anchor rods (reinforced steel anchor rods, steel wire anchor rods), and connection components such as shackles.
The covering-type guiding protection system mainly functions to limit the bouncing of falling rocks and guide their movement trajectory. It confines the movement range of the falling rocks within the internal space of the protection system, and gradually dissipates their impact kinetic energy during the rolling process of the falling rocks, ultimately guiding the movement of the falling rocks to the designated accumulation area.
Configuration and Parameters
| System model | GPS-050 | GPS-075 | GPS-100 | GPS-150 | GPS-200 | GPS-300 |
| Protective energy level (kJ) | 500 | 750 | 1000 | 1500 | 2000 | 3000 |
| Flexibility of metal mesh tensile strength（kN/m） | ≥15 | ≥30 | ≥45 | ≥75 | ≥105 | ≥165 |
| Threaded steel anchor bolt | Φ28 | Φ28 | Φ32 | Φ32 | Φ32 | Φ32 |
| Steel wire rope anchor bolt | 2Φ16 | 2Φ16 | 2Φ16 | 2Φ16 | 2Φ18 | 2Φ18 |
| Vertical drawstring | Φ14 | Φ16 | Φ18 | Φ20 | Φ22 | Φ22 |
| Horizontal drawstring | Φ10 | Φ12 | Φ14 | Φ14 | Φ14 | Φ16 |
Main construction requirements
- The layout of the system’s interception sections should follow the contour lines as much as possible, with the principle of intercepting the rolling rocks to the greatest extent.
- When laying out the positions of the steel column bases, each base should be placed as close as possible on the same level line. The height difference between adjacent steel column bases should be controlled within 0.5 meters.
- The anchor bolt cement mortar (cement slurry) should be injected from the bottom of the hole with reverse pressure to ensure a dense and full injection.
- The foundation is constructed using the manual vertical slotting method. It is advisable to carry out the construction during the dry season and on sunny days.
- When installing the protective net, the system should be segmented at 40 to 60 meters, usually at intervals of 50 meters.
- The energy dissipation device should not be installed between the steel columns. The distance from the steel columns should be ensured so that the energy dissipation device can fully exert its effect.
- The longitudinal main tension rope spacing L can be adjusted appropriately according to the local terrain. It should be within the range of 8 to 12 meters, usually 10 meters. The distance between the longitudinal main tension rope and the longitudinal secondary tension rope is L/3.
- The small flexible metal net is laid on the inner side (the side facing the mountain) of the large flexible metal net; for the interception part, the small flexible metal net should be overlapped with the large flexible metal net and folded outward by 15 cm; use steel wire to fix the small flexible metal net onto the large flexible metal net, with no less than 4 fixes per square meter; the connection points of each small flexible metal net should be overlapped by no less than 10 cm.
