Flexibility during the construction process - Roche Tower 2

Individual requirements planned efficient and safely implemented

Data & Facts

  • Project
    • Roche New Office Building 2, Basel, Switzerland
  • Principal
    • Hoffmann-La Roche AG
  • Contractor
    • ARGE Marti Roche Bau 2 (Marti AG Zurich/Basel)
  • MEVA systems
  • Engineering and support
    • MEVA Schalungs-Systeme AG, Seon, Switzerland and MEVA Schalungs-­Systeme GmbH, Haiterbach, Germany

The Roche Tower Building 2 in Basel is the tallest office building in Switzerland.

The Roche Tower Building 2 in Basel is the tallest office building in Switzerland. With a total of 50 storeys, the new building reaches a height of 205 metres and is thus the first office building in Switzerland taller than 200 metres. The building shell was completed ahead of schedule in December 2020.

As trusted partners, MEVA and Marti AG have jointly taken on the project. Thanks to the experience gained during the construction of Roche Tower Building 1, whose shell was completed in 2014, the MEVA engineers immediately understood what was important when erecting the second tower, and convinced through tried-and-tested concepts and detailed planning. Also based on the insights and experience gained during the construction of Building 1, the civil engineers commissioned by the principal also recommended that the formwork planning should be performed at an early on during the design process together with a formwork partner.

Under the tower
First of all, three basement levels were built in a 20-meter-deep construction pit. After the first excavation phase, a bracing slab with a ring-shaped opening was poured. The construction of the walls below was planned using the STB 450 support frame. As it was not possible to move the formwork using a crane, mobile support frames were used in the cramped construction pit.

Split core
Due to the logistical challenge of operating a large construction site in a central location, automatic climbing formwork was used for the construction. Having successfully worked on two cores at the same time during the construction of Building 1, the decision was also made to erect the core of Building 2 using a similar method. “The core is split into two by a so-called lobby, allowing us to work with two climbing systems concurrently”, explains MEVA engineer Volker Götz. “This allows us to profit from an important time advantage.”

New dimensions
The walls of the two cores were first of all poured up to a height of 3.80 metres using the Mammut 350 wall formwork. While doing so, it was necessary to pay attention to the complicated geometry of the numerous shafts. These were drawn is three dimensions. It was thus possible to depict the construction phases spatially in order to more precisely plan important details.

Bespoke climbing system
As the next step, the automatic MAC climbing system was installed on the conventionally formed layout of the cores. It was planned individually for every cycle together with the hydraulics. The relevant system parts were delivered in the special dimensions required to ensure that the set-up proceeded without a hitch on-site. “The team on the construction site was already familiar with the MEVA systems”, says foreman Armin Looser. “A large proportion of the team had already been involved in the construction of Building 1 and is familiar with the assembly processes. This means that we have no idle times and also that the set-up and the use of the MAC was no trouble at all thanks to the support provided by MEVA.”

Precise transport in the core
In order to place the prefabricated staircases in the shafts during the construction work, the MAC was equipped with hinged hatches in the platforms. The prefabricated parts were lowered through the climbing system into the shafts using a crane. A crane runway attached beneath the MAC by MEVA then enabled the components to be moved precisely in the shaft without tying up expensive crane time.

Modifications during ongoing operation
During the course of the construction work, the building professionals from Marti noticed additional potential for process optimisation. “In order to improve our processes and save costs, we wanted to make a number of subsequent modifications to the MAC and MGS. MEVA provided us with excellent support and helped us to implement all of our ideas”, says construction foreman Toni Würsch.

Flexible disassembly
Flexibility was an important criterion throughout this construction project. The rail-guided MGS screen system offers comprehensive all-round protection when working at great heights. However, the floor plan becomes progressively smaller above the 14th floor. On the north side the slabs are set back by 2.90 metres. This process is repeated every three storeys.

Safety according to plan
The required conversion of MAC and MGS was planned in detail by MEVA in order to make the work easier and safer. The systems were designed so that the individual components can be removed as a single unit and quickly disassembled. The safety concepts developed by MEVA and Marti formed the basis for detailed work instructions. This enabled the construction work on Roche Tower Building 2 to be planned and executed step by step in safe work cycles.