Safety first: Biberach is installing a huge steel net on the slope

Safety first: Biberach is installing a huge steel net on the slope

In Biberach, an impressive steel net is being installed to secure a dangerous slope area. Workers Muraru Razvan and Flavian Minbrila are currently working with an excavator and auger to make the necessary preparations for this project. Both are employees of Sachtleben Mining Services from Wolfach, which specializes in complicated rock protection. The edge of the slope, which is around 50 meters high, is a former gravel quarry that was active until the 1970s. After the gravel pit was closed, commercial developments, including a Shell gas station and a large car repair shop, found space at the foot of the slope.

The security measures are not only necessary, but urgent. The steep slope has repeatedly caused erosion problems in the past. The city has already built a cofferdam with a large fence to stop falling boulders. Engineer Matthias Schühle reports dangerous pieces of rock that can weigh up to ten tons. A particularly heavy chunk weighing 500 tons broke off in April 2020 and fortunately remained on the cofferdam, preventing potential damage to the gas station.

Security measures in detail

To counteract future dangers, the city administration has decided to install a 100 meter wide and 45 meter long steel net. This network will help divert debris and consists of sheets manufactured by the Geobrugg company from Romanshorn, Switzerland. For stabilization, around 60 steel anchors are used, which are drilled up to twelve meters deep into the slope. The first drilling began in October and is expected to be completed by the end of November. Each anchor is also tested for strength to ensure it can withstand the stress.

The final attachment of the steel net takes place in two steps in December: the first parts are assembled from the edge of the slope to half the height, then the remaining area is worked on with lifting platforms. The options for additional fastenings on the slope are significantly limited because the wall is not stable enough to justify further measures. The total cost of the project is around 800,000 euros, which will be invested in the safety of the buildings and people in the commercial area.

Challenges in rock protection

The specific challenges that exist in rock stabilization are also illustrated by the various techniques used in such projects. Rock stabilization includes different methods such as rock anchors, nailing, shotcrete, nets and barriers to ensure the stability of steep slopes. The targeted combination of these measures is crucial to protect people and infrastructure from the dangers of falling rocks, rock falls and erosion. This also requires a precise geotechnical assessment that analyzes the geology and the specific hazards.

The current case shows how important careful planning and execution are. Erosion protection and the reduction of weathering are essential in order to stabilize the slope in the long term and thus also protect the surrounding buildings. Such projects are not only expensive, but also require specialist knowledge and technical know-how to carry them out successfully.

In summary, the installation of the steel net in Biberach is a step in the right direction to protect citizens and the infrastructure from potential dangers caused by falling rocks. It remains to be hoped that the measures will have the desired effect and minimize future risks.