Hergiswil N2 gantry roof

In this project, PORR was contracted by the Nidwalden Canton Construction Office to create a 200m-long gallery to protect a section of the national route N2 and its central railway line from falling rock. Works included the construction of protective walls and a protective tunnel over the roadway and platforms. The need to maintain traffic on the four-lane highway throughout the construction period presented a particular challenge.

In detail, the project included the following tasks:

• Rerouting utility lines
• Pile structure and temporary construction pit system
• Foundations and roadway construction
• Bored concrete piles and anchoring works
• Construction of noise protection elements
• Construction of walls, covering and arched ceiling from reinforced concrete
• Finishing, slit gutter, drainage and sealing works
• Filling in arched roof