Switzerland – Construction work – N8 / Lungern Nord – Giswil Süd: Baulos 21 Trassee und Kunstbauten Nord

The area between the southern portal of the existing Giswil tunnel and the new Kaiserstuhl tunnel (separate, already awarded as contract 19) will have its road infrastructure expanded, so that in future the national and cantonal roads can be separated and run on two separate routes. The current route of the Brünigstrasse runs over the existing Buochholz bridge, past the OWi-Land to the Lungernersee. After the opening of the Kaiserstuhl tunnel, the existing Buochholz bridge will be used for the national road. For the cantonal road, a new road bridge will be constructed parallel to the existing bridge (separate, already awarded as contract 20). In the current contract 21, the services for the gap closure between the Griffeldossen/Buochholz area (contract 20) and the Kaiserstuhl tunnel (contract 19) are procured. The services include route works for national and cantonal roads with retaining structures as well as a SABA, a PW, landform modifications in the Marchgraben area, water engineering works and minor structures. With the current procurement, services for construction works for the main works described below are procured: Road construction and utility construction ------------------------------------------ New national road over approximately 500 m length (total approximately 7,500 m2 area) incl. ¾ connection Giswil South as well as road reconstruction of the existing Brünigstrasse over approximately 400 m length (total approximately 4,000 m2 area) and new rural roads. Each incl. substructure, drainage, surfacing and marking as well as various utility diversions, -provisions and -new constructions (including new firewater pipe for Kaiserstuhl tunnel). In the perimeter, the new SABA Schwendiboden and the Nordportal storage basin will be built (excavation pit securing with sheet pile and nail wall). In addition, with this contract, the services for the surfacing (approx. 16,000 m2) and marking (2.1 km length) of the Kaiserstuhl tunnel (contract 19) are procured. Landform modification and water engineering ------------------------------------------ Adaptation of the channel (upper and lower course) and the sediment trap Marchgraben (block stone base, approx. 2,500 m2), as well as new shallow-founded terminal structure Marchgraben (reinforced concrete culvert with 6.2 m span). Various landform modification works in the Marchgraben and route area (excavation approx. 25,000 m3 and fill approx. 35,000 m3). New retaining structures and structures: ------------------------------------------ Construction of two retaining walls each approximately 140 m long, up to 9 m high, incl. backfill (approx. 5,500 m3) and the north portal structure of the Kaiserstuhl tunnel in the area of the new N8 route. Excavation pits have already been constructed in a pre-contract (contract 17a). Work partly under traffic.