Felsanker

Felsanker is a term used in geotechnical engineering to describe an anchoring device embedded in rock to stabilize rock masses or support excavation faces. The purpose is to transfer loads from potentially unstable rock to a firmer rock mass, thereby reducing movement and increasing stability in applications such as slopes, tunnels, and caverns.

There are several types of Felsanker. Mechanical anchors rely on steel rods or bolts that deform or expand within a drilled hole to grip the surrounding rock. Bonded anchors, also called chemical anchors, use resin or epoxy grout to bond the anchor to the rock, often providing higher pullout resistance in fractured or weaker rock. Tiebacks or cable bolts may be used in combination with anchors to achieve greater reinforcement. Selection depends on rock quality, load requirements, and project conditions.

Installation typically involves drilling a hole, placing the anchor, and either expanding it mechanically or injecting grout to secure it. Tensioning or grouting may occur after insertion, and curing time is required for chemical anchors. Design takes into account rock quality, hole diameter, orientation, and long-term factors such as corrosion and creep. Proper installation and testing are essential to ensure reliability and safety.

Applications of Felsanker include slope stabilization, support for underground excavations in mining or civil construction, stabilization of rock faces adjacent to structures, and rockfall protection. They are a common element in geotechnical reinforcement strategies and are designed to work as part of an integrated stabilization system.