Efficient scaffolding solution with ALFIX MODUL MULTI 4.0
During the repair work on the flood relief structure of the Neunzehnhain II dam, a scaffolding system designed specifically for this project was required on the downstream side of the dam wall. One particular structural challenge was posed by the geometry of the approximately 27-metre-high dam, as well as by the planned placement of a rotary tower crane on the wall coping.
The initial designs for this project were submitted by the scaffolding company Gerüstbau Cyffka GmbH from Drebach, located in the Erzgebirge in eastern Germany. These preliminary designs formed the basis on which the project department of ALFIX GmbH, in close coordination with the scaffolding company, developed a technically and economically convincing scaffolding concept based on the ALFIX MODUL MULTI 4.0 modular scaffolding system (building authority approval Z-8.22-906).
Project-specific concept development in the ALFIX Technology & Design Department
For access to the downstream face, two options were considered: either a complete scaffolding of the dam from bottom to top, or the installation of a suspended scaffold mounted on the dam wall coping. The second option offered the user significant advantages in terms of material requirements, assembly time, and cost-effectiveness, and was therefore recommended by the project team.
Implementing this approach, however, required a structural span of approximately 7 m, as the necessary and planned tower crane needed to be positioned centrally on the top of the coping. Only after a structural analysis conducted by an engineering firm chosen by the client was it possible to confirm that the loads from the suspended scaffolding, from the ballast, and from the crane operation could be safely transferred into the structure of the dam. This approval formed the basis for the subsequent detailed design and construction.
In order to meet the planned construction start date in September, short-notice coordination took place within a tight timeframe between the client, the executing construction company Trinitz Bauwerksanierung GmbH, the test engineering firm in Leipzig, and the ALFIX project team. Despite the narrow timeframe, as the initial coordination only took place after the final contract was awarded in July and August, the timely completion was achieved thanks to the smooth cooperation of all project participants. The scaffolding was then able to be erected as planned by the scaffolding company Gerüstbau Cyffka GmbH.
Technical implementation using ALFIX MODUL MULTI 4.0
The support system was constructed using the heavy-duty ALFIX MODUL MULTI 4.0 modular scaffolding system, which is especially impressive due to its varied connection options and the resulting flexible adaptability to a variety of building designs. As a stable base for the suspended scaffolding structure, the scaffolding bays for receiving the statically required ballast were first erected on the coping of the dam wall.
Using system-independent steel lattice girders in combination with MULTI vertical diagonal components, a load-bearing cantilever was created that served as a load-safe supporting structure for the approximately 6 m high and 40 m long suspended scaffold. Curved to match the radius of the dam, appropriate bay divisions had to be selected. This scaffold, in its configuration as a suspended structure, was designed and assembled as a W09 scaffold with a width of 1.09 m in load class 3 (i.e., 200 kg/m² evenly distributed).
Access to the nine spillway arches of the dam wall presented a particular planning challenge. Since these arches were not located within the regular scaffolding grid, the lower scaffolding levels had to be extended using 2.0 m inner brackets, constructed using 2.07 m MULTI U-ledgers and their corresponding vertical diagonals. In order to adequately support the brackets located outside of the scaffolding axis, system-independent steel lattice girders were installed horizontally and vertically in an alternating pattern. This allowed the brackets to be positioned in such a way that all spillway points within the arch area could be accessed efficiently and safely by the various trades.
In the suspended scaffolding, MODUL vertical standards with screwed-in tube connectors as well as integrated tube connectors were used, ensuring a particularly load-bearing and robust connection. The proven MODUL vertical standards with press-fitted tube connectors were used in the load-bearing scaffolding. They are also able to be used in suspended scaffolding constructions in combination with ALFIX suspended scaffolding connectors to strengthen existing equipment. Detailed solutions for the various standard connections are available in the corresponding Instructions for Assembly and Use in the Downloads section of the ALFIX website.
User-friendly access via ALFIX stairway tower
Comfortable and practical access to the suspended scaffolding was provided via continuously arranged external aluminium platform stairways. This ensures standards-compliant access, as stair access is preferred over ladder access or access through openings. Thanks to the well-designed stair system, varying elevation levels could be optimally compensated for. Components from both width classes W06 (0.73 m) as well as W09 (1.09 m) with corresponding heights of 1.0 to 2.0 m were used, allowing for the seamless adaptation to the dam wall’s specific curve.
The successful implementation of a suspended scaffolding system at the reservoir dam Neunzehnhain II enabled a practical and cost-effective solution to be achieved even within a short planning phase. The close and smooth collaboration between the scaffolding company, the construction company and the ALFIX Project Department resulted in an efficient solution that fully met all of the client’s requirements.
Securely Scaffolded for 2026?
As the year comes to a close, the ALFIX technical team will continue to provide expert support to your customers in the new year. With static calculations, 3D visualisations, and the creation of detailed assembly plans complete with parts lists, a safe and efficient implementation can be ensured right from the planning phase. ALFIX experts develop customer projects in great detail on the computer during the planning phase and make these digital models available to the user. Following the link, the 3D visualisation of the described project is able to be accessed directly Autodesk Viewer | Free Online File Viewer.
Individual requests may be submitted at any time by using the Contact section of the ALFIX website