Securing slopes on the Struma motorway by laying high-strength nets, anchors and ropes
"Jumbo 33" Ltd.
Struma Motorway from km. 31+690 to km. 33+820
A network of eroded rock slopes was completed using a system of high-strength steel meshes for rock reinforcement and protection – 15,118 m²;
Prior to the installation of the networks, extensive surface erosion control was carried out in order to remove unstable rock fragments that threaten the safety of the road infrastructure and traffic;
In areas with predominant soil and rock masses, a synthetic mat has been laid for erosion control and preparation for hydroseeding – 7,081 m²;
The nets are anchored to the rock slopes by drilling, installing and injecting IBO anchors R32-260KN with lengths of 6 m and 10 m, staggered every 2–3 m depending on the geological conditions – 22,492 m;
Installation of galvanized steel ropes Ø12 and Ø16 in a horizontal and vertical pattern for additional reinforcement and connection of the individual network panels has been completed – 5,360 m;
Concrete drainage ditches with a total length of 2000 m have been constructed to control and drain surface water and limit erosion processes in the road infrastructure area;
All activities are performed by certified technicians for working at height via rope access (industrial mountaineering) with proven experience in rock reinforcement and difficult-to-access terrain;
The project was implemented without stopping traffic on the Struma motorway, under the conditions of an approved temporary traffic organization (TRO), with strict safety measures and uninterrupted traffic.
The project is a large-scale rock reinforcement of road infrastructure on the Struma Motorway, including meshing and deep anchoring of rock slopes to ensure long-term stability and traffic safety.
The installation of high-strength steel meshes was carried out after extensive demolition and cleaning of the rock slopes from unstable and eroded sections, in order to remove potentially dangerous rock fragments.
In areas with mixed soil and rock masses, a hydroseeding mat was laid under the protective meshes, which allows for subsequent grassing and restoration of the natural vegetation cover, thus reducing surface erosion.
Depending on the geological characteristics of the individual sections, the length of the anchors varies between 6 and 10 meters, and they are located in a staggered pattern every 2 to 3 meters, ensuring optimal load distribution and stabilization of the rock masses.
All rock reinforcement activities through meshing and anchoring were carried out without interrupting traffic on the Struma motorway, which is one of the busiest roads in Bulgaria, and safety measures and minimal impact on traffic were implemented.
