Seismic reinforcement - Mythencenter - Schwyz, Switzerland
Project Description
Situation
Today's Mythen Center in Schwyz - a shopping mall in central Switzerland - was built in three stages. The building complex is divided into an east, west and south section, which are connected by specially designed dilatation joints. The different parts of the building were built between 1971 and 1997. In 2017, the client initiated an earthquake review of all building complexes by BG Ingenieure und Berater AG. In the process, the experts examined the building sections separately. It was found that strengthening measures were necessary to reduce displacements in the event of an earthquake. This can minimise the risk of collision and thus prevent local overloading of the walls.
Solution
The retrofitting measures were implemented in various construction stages, while the building remained in operation. For a total of six stairwells and five other walls above one another, the engineers planned vertical FRP laminates with end anchors as reinforcement. In this way, the few walls in the building can be better activated in the event of an earthquake and meet the structural requirements. S&P special steel anchorages were used in some cases. They are designed and produced individually for the respective situation. An epoxy coating serves as corrosion protection and guarantees adhesion between the steel part and the epoxy adhesive. This ensures the force transmission laminate-adhesive-steel-concrete.
Furthermore, two parts of the building were joined together over two floors to create optimized load-bearing and vibration behavior for both parts. This was done by means of butt joints consisting of steel plates bolted across the dilatation joints.
