The project
Since 1932, the Tüfisteg has formed an important link across the Sihl and is also part of the Sihluferweg, which is actively used by the people of Adliswil. The bridge from 1932 was already replaced by a new bridge in 1985. Now, 45 years later, this bridge has also reached its zenith. In a first step, the company Timbatec was commissioned to record the condition of the existing bridge. The analyses showed that the bridge would have to be comprehensively rehabilitated or replaced immediately. The city of Adliswil decided to build a new bridge in the same style. The bridge in Adliswil is the first bridge in Switzerland with a pure beech wood construction.
The construction
The 45-meter-long blast structure was planned and executed entirely with beech wood from the region. For the highly loaded compression bars, packages of small bar cross-sections were assembled rather than the usual large glued-together cross-sections. This allows for better structural and chemical wood protection. This is because the components can dry more easily and be better impregnated.
The challenge
The planning of an open bridge with beech wood requires precise planning of the construction as well as the construction process from the cutting of the logs to the finished bridge. The close cooperation of the planners with the sawmill, the impregnation plant and the good communication were the key to success.
Construction Data
- Solid beech wood 26 m3
- Steel 10 t
Construction costs
- BKP 1-9: 650,000 Swiss francs
Services of Timbatec
- SIA Phase 11 Condition analysis
- SIA Phase 21 Structural analysis
- SIA Phase 31 Preliminary design
- SIA Phase 32 Construction project
- SIA Phase 41 Tendering and comparison of offers
- SIA Phase 51 Implementation project
- SIA Phase 52 Execution
- SIA Phase 53 Commissioning
- Structural analysis and design
- Cost estimation
- Technical site supervision and site inspections
Architect
Timbatec Holzbauingenieure Schweiz AG, 8005 Zurich
Client
City of Adliswil, 8134 Adliswil
Timber construction engineer
Timbatec Holzbauingenieure Schweiz AG
Timberconstruction
Holzbautechnik Burch AG, 6060 Sarnen
Construction management
Timbatec Holzbauingenieure Schweiz AG
Photography
Nils Sandmeier, 2501 Biel
Impregnation plant
Imprägnierwerk AG, 6130 Willisau
Wood cutting
Konrad Keller AG, 8476 Unterstammheim