A new “Little Manhattan” in Zurich: the high-rise development project “Vulcano”

In Zurich-Altstetten a trio of high-rise buildings has steadily shot up out of the ground over the last three years. The “Vulcano” project is located right next to a railway site and consists of a basement structure, three 80-metre high towers and two cantilevered glass roofs. The impressive building was designed by Parisian star architect Dominique Perrault. Basler & Hofmann was involved in the project with specialists from several disciplines who focused on planning the foundations, supporting structures and soundproofing.

Rising high safely thanks to combined pile and raft foundations

The basement structure of the building complex, which is visible from a long distance, contains 320 hotel rooms. The three towers contain around 300 residential apartments. One of the big challenges in the project was the planning of a suitable foundation system: the buildings needed to be constructed in an area with a particularly high water table under restricted space conditions. To do this, Basler & Hofmann planned a cross-shaped combined pile and raft foundation under each tower, which directs the high foundation forces both via a ground slab and via large foundation piles into the foundation soil.

Sophisticated supporting structure behind an impressive façade

For high-rise buildings like Vulcano, wind represents a twofold challenge; as well as structural safety, it is also necessary to ensure the comfort of the residents. To eliminate the chance of noticeable vibrations under strong wind conditions, the behaviour of the towers was simulated with calculated models and tested in wind tunnel tests. Based on these investigations, so-called outrigger walls were carefully incorporated in individual storeys. These connect the reinforced concrete cores with the load-bearing façades and activate the latter as additional wind bracing – an attractive alternative to the standard solution of enlarging the cores at the expense of usable floor space.

Huge glass roofs offer protection against railway noise

Vulcano is situated on a former industrial site right next to the railway site of the Altstetten station. This required an appropriate noise protection solution. To do this, Basler & Hofmann worked together with the architect to develop a solution that is suitably attractive in terms of design: for the areas between the towers, two cantilevered steel structures extending in the direction of the railway tracks were planned and constructed with roof glazing totalling some 2,000 square metres of surface area. Together with the projecting basement structure, the two striking glass roofs protect the residential towers against railway noise.

Our services

Design and project planning for the excavation work, foundations and supporting structures in steel, glass and reinforced concrete. Surveying, inventorising cables/pipes, plus consultation and planning on vibration protection measures.