No concrete core was even used in the project, for structural stability. The structure’s stiffness comes exclusively from its solid cross-laminated timber walls.
Isenmann Ingenieur GmbH, located in Haslach, performed the structural static and dynamic analysis of the timber building in RFEM.
Structure and Seismic Analysis
The four-story timber structure is built on an underground reinforced concrete floor. A total of 45 bored piles with a maximum length of 59 ft further support the foundation.
The underground floor area is approximately 102 ft x 82 ft while the aboveground floors are 82 ft x 69 ft. The maximum height of the timber structure is 49 ft, 4 in.
The building is located in seismic zone 1. Preliminary calculations confirmed that seismic forces governed for the lateral design. Therefore, a modal analysis was performed on the 3D model in RFEM. In the calculation model, the individual components’ stiffnesses were set to the most realistic possible value.
For earthquake analyses, timber construction behaves more favorably than reinforced concrete structures. The acceleration design value is lower, while the decreased mass has a beneficial effect on the calculated seismic forces.
To counteract the tensile forces, welded plates were added to the ground-floor cross-laminated timber end walls. The walls are welded adjacently with steel anchors.
Investor | EGT Energy GmbH, Triberg, Germany www.egt.de |
Architect | Ketterer Architects, Konigsfeld-Neuhausen, Germany www.architekturbuero-ketterer.de |
Structural Design | Isenmann Ingenieur GmbH, Haslach/VS-Villingen www.isenmann-ingenieure.de |
Timber Structure | Holzbau Bendler, Nordrach www.holzbau-bendler.de |