Soil Nails Stabilize Permanently Slope at the Floeteberg

South of Brunswick, Germany, , On the State Road L 500 runs directly next to the Floeteberg linking the towns of Othfresen and Liebenburg in the South of Brunswick, Germany, is a mountain with a steep rock embankment that has generated many rockfalls in the past.

In order to permanently stabilize this area, the Lower Saxon Provincial Authority for Road Construction and Traffic asked the engineering company Dr. Spang GmbH to carry out a comprehensive geological analysis of the embankment and to design a long-term stabilization concept.

The engineers suggested covering the embankments with high-strength steel mesh. For this purpose, a fine mesh was fixed to the slope and covered by a coarse mesh. Both mesh varieties consist of a special steel alloy that is galvanized for corrosion protection. They were rolled down the face by climbers.

To tie back the steel protection mesh, DSI Koenigsbrunn supplied approx. 2,000 32mm Ø GEWI® Soil Nails with a total weight of 48t. The GEWI® Soil Nails were installed in the stable layers of the slope at a depth of up to 10m and grouted using a special mortar, thus ensuring the stability of the 6,500m² large mesh area.

The approx. 7,500m of GEWI® Soil Nails were galvanized on a 1m long section. At DSI Koenigsbrunn, the accessories, i.e. the couplers and domed anchor nuts – were reamed before galvanizing in order to ensure optimum threadability.

The permanent inventory of galvanized 25mm, 28mm and 32mm Ø GEWI® Bars including accessories that DSI Koenigsbrunn has maintained since 2014 ensured very short delivery times.


Lower Saxon Provincial Authority for Road Construction and Traffic, Germany

Joint Venture FS Flöteberg, consisting of Feldhaus Bergbau GmbH & Co. KG and Bergsicherung Ilfeld GmbH, both Germany

Dr. Spang Ingenieurgesellschaft für Bauwesen, Geologie und Umwelttechnik mbh, Germany