The Sellhorn Ingenieurgesellschaft mbH was commissioned by St. Michael's Main Church to conduct structural examinations and conceptual planning for the restoration of the cornice on the church nave and tower of St. Michael's. The cornice exhibits damages that needed to be documented and analyzed in the initial phase. To accomplish this, the entire cornice was surveyed using a drone.
In the second step, the roof structure was inspected, and the cornice was thoroughly examined from the exterior by a certified structural inspector. Damages were documented and mapped. Using a lift, crack widths were measured on-site, and samples were taken from the cornice to determine material properties and conduct further laboratory tests.
Simultaneously, extensive historical records in the construction archive were reviewed to gain insights from the construction phase over 110 years ago.
Based on the video data, a photogrammetric 3D model was created, into which all damages were recorded. The cornice can be viewed from all sides in the 3D model, and damages can be filtered based on their characteristics and severity.
Using this data, along with the laboratory results, Sellhorn developed a conceptual plan for the restoration of the cornices, divided into three phases. In addition to a short-term restoration of concrete corners that could otherwise become detached, measures for crack injection and securing with a durable coating are planned. Furthermore, strengthening measures are proposed to prevent the formation of new cracks.
We are delighted to be involved in the preservation of this protected Hamburg landmark.