Historic Roof Structure Calculated Digitally: Interview with Patrick Hauck

RSTAB as Bridge Between Historic Preservation and Modern Structural Design

The key aspect of this project was not merely a calculation. RSTAB served as an interface between the historic structure and the new design compliant with standards. Thanks to the spatial 3D modeling in RSTAB, design requirements and structural reality could be integrated into a single, robust model.

The software supported collaboration in a unique way: The historic preservation team provided their specifications based on the historical model, while the structural designer could test and evaluate different variants directly in RSTAB in a transparent manner. In this way, a specification compliant with historic preservation requirements was transformed into a structurally optimized and constructible solution. The result is not only code-compliant but also efficient—while remaining true to the historical character of the building.

Calculation Instead of Approximation – Using RSTAB in 3D Spatial Model

The advantage of a detailed three-dimensional calculation in RSTAB was particularly evident in the roof structure of the kitchen tower. The historical, partially curved structural geometry could not have been accurately modeled using simplified 2D approaches.

Using RSTAB, the entire roof structure could be modeled as a spatial truss model—including the actual support and connection conditions via spring stiffnesses. This combination of model accuracy and design according to standards made the analysis robust and transparent: Both the load-bearing capacity of each individual structural component and the overall structural behavior of the structural system could be reliably analyzed in compliance with currently valid standards.

Using RSTAB, we created a detailed 3D model of the roof structure.

This made it possible to design the load-bearing capacity and overall structural behavior according to standards.

Patrick Hauck ALS Ingenieure GmbH & Co. KG

Key Main Features: Import of Spring Stiffnesses & Support Reactions

Aside from project-specific applications, Dlubal software provides the ALS Ingenieure team with a tangible advantage, particularly in their day-to-day operations: recurring tasks are completed faster, in a more standardized manner, and with less manual effort. Two features stand out in particular:

• Spring Stiffness for Joints and Support (RSTAB): For the engineering office, this feature is indispensable when modeling historic roof structures. Real-world boundary conditions and the partially flexible connections between structural components can thus be accounted for in a nuanced manner—a calculation of existing structures that is close to reality would be virtually impossible without this feature.

• Import Support Reactions (RFEM): In concrete structures, this feature is a real time-saver: support forces from a submodel can be directly imported as loads into a downstream model. Work steps that would otherwise take several hours to perform manually are thus automated—keeping the workflow fast and transparent.