Examination of the damaged support in Wrocław Spire
Purpose of the test: To determine the causes of bolt fracture in the needle support during renovation works
We are a very flexible laboratory and sometimes we test elements of architecture or construction on well-known objects. One such realization was an examination, commissioned by Hala Ludowa in Wrocław, of a damaged pin of an articulated spire support.
We made fractographic observations of the prop screw, which enabled us to assess the morphology of the fracture and determine the nature and direction of the forces acting on it. We also subjected macroscopic observations to the welded joint of the positioning nut with the prop bolt. We examined the microstructure and hardness of the joint. Metallographic observations made by us, on the basis of which it was found that the microstructure of the material is appropriate for structural steels. Spectral analysis of the chemical composition of the screw material made it possible to match the steel grades closest to the material used. Several grades of steel from the applicable European standard (PN-EN 10025-2) and several equivalents from the former Polish standard PN-88 / H-84020 from 1990 were adjusted.
Based on the analysis of the obtained results and subject standards, a design solution was proposed that enabled the renovation of the Wrocław spire to be completed.
