## 2 Introduction to the Anchoring of the Casting Pedestal  
The continuous casting of slabs is currently the most widely used method, in which the solidification of steel leads to the production of long steel products. Its fundamental principle is that the liquid steel is first infused from a ladle into a tundish and then distributed through many sprues in a vertical direction into water-cooled copper moulds. The ladles, transported by an overhead bridge crane and a casting pedestal, are used to bring the liquid steel from the converter to the tundish. The casting pedestal is used for constraining the casting ladles and their rotation from the reserve (receiving, preparatory) position to the casting (working) position, and vice versa (in the mode of individual melting and in the mode of melting to melting). It also serves to drain the molten steel into the emergency containers in case of a failure of the slide cap, and for lowering and lifting the casting ladles during various technological operations. It is a two-position pedestal realised as a lifting and rotating pedestal with a load cell. The supporting structure of the casting pedestal is formed mainly by steel weldments. Their dimensions and shapes are designed in such a way that after the casting ladle filled with liquid steel is placed in the reserve position, the casting pedestal ensures its transfer around the axis of the casting pedestal to the casting position. After casting the steel from this ladle into the tundish to about 25% of the liquid steel content, the second full pan can be placed on the other/opposite traverse side (in the reserve position). If there is only molten slag left in the casting ladle (approximately 7000 kg), the pedestal is rotated so that the full ladle is moved from the reserve position to the casting position. Selected technical characteristics of the assessed casting pedestal (Figure 1) are:  
Maximum weight of the casting ladle with metal (steel) 260,000 kg  
Weight of empty ladle 70,000 kg  
Ladle lift height 800 mm  
Pedestal angular velocity 1 rpm  
Maximum angle of rotation 230\({}^{\circ}\)  
Roller track mean diameter 6400 mm  
As part of the overhaul of the casting pedestal, some supporting members were replaced, but replacement of the anchor bolts embedded in the concrete foundation was not possible. When the original structure was disassembled, damage to the first threads on the concrete foundation side of some of the anchor bolts was found. As already mentioned, their replacement was not possible, or very difficult. Therefore, it was necessary to design another solution to achieve safe operation at the required bolted joint preload. By numerical modelling, a design modification of the nut was proposed to lighten the first threads. Subsequently, experimental measurements were carried out, taking into account real operational conditions. Based on the results obtained, conclusions were drawn on the further operation of the casting pedestal. The value of the considered preload of 180 kN in the bolted joints was taken from the original static calculation. Figure 2 shows the layout of three types of anchor bolts (34 anchor bolts in total) with basic dimensions, which are used to fix the casting pedestal to the concrete foundation. For this reason, it was necessary to design the methodology of re-anchoring the casting pedestal so as not to damage the bolted connections (releasing the bolts in the concrete foundation), the repair of which would be not only technically and financially very difficult, but also time-consuming. In addition to the machining method, the lifespan of the anchor bolts under investigation is influenced, in particular, by the impact of notched effects, which is most significant and unfavourable during the fatigue loading of machine parts and structures. In the  
Figure 1: Basic parts of the casting pedestal: 1—hinging supporting baskets; 2—traverse beams; 3—connecting rods; 4—bearing support pedestals; 5—roller bed; 6—supporting structure; 7—concrete foundation; 8—casting ladles.