On the Kirchberg plateau in Luxembourg, residential buildings with a total surface area of more than 36,000 m² are currently under construction. On a previously undeveloped site in this emblematic district (home to the Luxembourg Philharmonie, European institutions and Arcelor’s headquarters), the project is rising between John F. Kennedy Avenue and Rue du Fort Thüngen. It is divided into two lots.
The first lot consists of four towers of up to thirteen storeys, linked together by a shared base. Along Rue du Fort Thüngen, which lies below John F. Kennedy Avenue, townhouses are planned. Lot 2 follows a similar configuration, with a maximum of six storeys for the apartments. Numerous terraces punctuate the buildings, which are connected by landscaped esplanades. In total, more than 245 new homes are being built.
An optimised approach
The layout of the apartments, with limited repetition from one floor to the next, combined with interruptions in the structural cores at the parking levels, presented significant structural challenges. To maximise underground space (circulation and parking areas), many vertical load-bearing elements do not continue downwards, adding complexity to the structural design.
To resolve these constraints, the engineers developed a solution based on coupled shear walls combined with high-strength concrete, applied strategically in the most heavily loaded areas.
Built on rocky ground (marl), the buildings rest on an optimised raft foundation with a standard thickness of only 25 cm. This slenderness-made possible through detailed modelling of soil and concrete behaviour-reduces concrete volumes and steel quantities by half compared to a conventional design. This optimisation also helps to minimise rock excavation, aligning the project with a more sustainable approach.
Wind loads and earth pressure imbalances, exacerbated by the difference in levels between John F. Kennedy Avenue and Rue du Fort Thüngen, are resisted by the available shear walls. For Lot 2, foundation pits ranging from 1 to 6 metres deep are provided to ensure overall stability.
The actors of the project
- Client: SNHBM
- Architect: STDM
- Structural Engineering Office: Bureau greisch
- MEP Engineering Office: SNHBM
- Contractor: Soludec
- Landscape Architect: Art & Landscape Architecture
