ERNEplus: New Stapo Zurich building
October 18, 2021
Total contractor contract for new building for the KIMINALPOLIZEI ZÜRICH
In 2018, ERNEplus Generalunternehmung won the overall management competition for the construction of a new multi-storey building with offices and investigation rooms for the Zurich City Police. Construction work on the total contractor project began in October 2018. There were a number of challenges to overcome during the civil engineering and building construction work. The time-lapse video impressively shows how quickly construction progressed.
Excavation work and dewatering next to the Limmat
The civil engineering team excavated 14,065m³ of material for the construction pit. The gravelly excavated material was screened and reused for the material replacement of the soil. The pit was thus leveled in a resource-saving manner. The excavation pit was secured and sealed using sheet piling. The groundwater level was lowered using filter wells and the resulting water was fed back into the Limmat. The excavation base, which forms the basis for the subsequent structure, was protected from loosening and soaking by the dewatering measures. Once the structure has been completed, the groundwater lowering measures will be removed.
Space on the construction site is tight
In the middle of the city of Zurich, adjacent to neighboring commercial buildings, busy roads and a railroad viaduct, the space available for construction was limited. The processes on the construction site had to be optimally planned and executed. The already constructed entrance to the underground parking garage served as an unloading and handling area for materials and machinery. Not only did logistical processes have to work well, the use of cranes also had to be precisely coordinated on this building construction site. The railroad viaduct runs alongside the new building at the level of the third/fourth floor. Trains pass the track every few minutes. The two construction cranes were equipped with a 3D control system and automatically measured how close the jibs and material were to the overhead lines. If the crane was maneuvered too close to the railroad line, it stopped automatically. The safety concept ensured the protection of passing trains and was approved by SBB before construction work began.
Sound-absorbing bearings prevent vibrations in new buildings
A building that stands directly next to a railroad viaduct must be protected against vibrations. People working in the building should not feel when a train passes next door. The upper floors of the new building therefore rest on so-called sound-absorbing bearings on the basement, with cams holding the building in place. Depending on how much load will later rest on an individual component, sound insulation bearings with different properties were used. What looks beautifully colorful in the photos is systematic: the ERNE building construction teams laid the correct panels in the desired position according to a plan defined by the engineer. Harder sound insulation panels support greater loads, but panels that are too hard would transmit vibrations to the building.
Steel girders set in concrete support the overhang
The new building, which blends in beautifully with the existing surroundings, has upper floors that project above the first floor on the south side of the building, near the entrance. The building was reinforced at these points with load-bearing steel girders. The weight of the façade and the storeys above was carefully calculated so that the exact position and location of the steel girders could be determined for optimum cantilevering. The heavy beams, fitted with headed bolts, were inserted with a precise fit and then set in concrete using self-compacting SCC concrete.
An optimized construction process saves time
In addition to sound decoupling measures and steel girders, the construction process needed to be optimized in order to save time and speed up the construction work. Project managers, site managers and foremen from the ERNE structural engineering team therefore developed a suitable process in which the external wall construction was brought forward and the ceilings were suspended in between with screw reinforcement. This made it possible to dispense with formwork for the ceilings. With an external wall length of around 200 meters per floor, this optimization paid off.
Concrete beauticians refine the surfaces
The ERNE teams also had a lot to do inside the building. Concrete elements with round recesses for windows were used in the atrium. These allow additional light into the rooms. The walls were kept in exposed concrete and coated with a glaze that seals the surface easily, is easy to clean and keeps dirt away. The ERNE concrete cosmeticians took care of every detail and gave the exposed concrete an optimal appearance. In addition to cosmetics, safety is also important. For the detention cells, furniture parts were even made from concrete, such as bed frames and tables with rounded edges that are set in concrete.
A construction project with a wide range of ERNE services
After completion of the façade and master builder work, the interior fit-out began, which was coordinated by ERNEplus as total contractor. The subsequent use by the criminal investigation department presented a number of challenges in terms of implementation, particularly with regard to security.
Various teams from the ERNE Group were involved in the new building for the city police. ERNEplus took on the coordination and management of all the work, with the structural engineering, civil engineering and drilling and cutting teams working on the shell construction. The concrete cosmeticians optimized the exposed concrete, the road connections to the sewage system were carried out by Gebr. Meier AG Rohrleitungsbau, while Husner AG Holzbau planned the façade, produced parts of the formwork elements and installed the glass fibre concrete elements. We were very pleased to be able to realize this exciting and challenging construction project together.
Facts about the construction site
Project goal | New building for the criminal investigation department in Zurich |
Project management | Nicolas Scherer (Structural Engineering), Kilian Glauser (TU) |
Site manager | Davide Restaino |
Foremen | Beat Senn, Roman Frei, Dieter Kern, Till Wälchli |
Services | Total contractor project, excavation pit, special civil engineering, reinforced concrete and exposed concrete construction, new construction |
Construction time | October 2018 to fall 2021 |
