This method of amplification is sometimes used in these cases, when the integrity of load-bearing links has been violated in a given structural system or when there is a need to improve the working conditions of the structure or system, especially when new working conditions have arisen or the burden on the system has been increased.
The concept of how to amplify depends on everyone. case from existing conditions, therefore, when proceeding to the selection of the reinforcement method, the static scheme should be established first of all, which will correspond to the actual working conditions. In most cases, the change of the static scheme involves the introduction of additional structural elements. When reinforcement applies to walls and column supports, column supports can be the reinforcing elements, buttresses, gunshots, struts etc. In the case of ceilings and vaults, reinforcement can be obtained by changing the method of their attachment or by introducing additional elements, like beams, framework, various types of girders, cheat sheets, anchor, hangers etc. If, in turn, there is a need to hold or strengthen part or all of the cracked system, subject to rotation, wreaths may be used, cheat sheets, anchors or prestressing.
The choice of materials and the technique of execution in a given case usually dictates the type of damage, required functional and aesthetic conditions. Reinforced concrete elements can also be used, compressed and steel, especially then, when the reduction of the load on the reinforced elements is to be taken into account.
The need to use the system stabilization method with the introduction of a change in the static scheme can be illustrated by the instructive example of the restoration of the Collegium Maius building of the Jagiellonian University in Krakow <M).
The architectural complex of the present building was built in the period of the 14th and 16th centuries. from several houses, successively adapted and incorporated for the needs of the university. The structural system of the building is typically polystructural, at the same time completely devoid of a homogeneous static concept. Over the centuries, the building underwent numerous reconstructions, hence, next to the original gothic structures, there are layouts characteristic of later periods. This is especially visible in the masonry threads and in the vaulted and flat coverings used.
Some phases of shaping and spatial layout of the Collegium Malus building in Krakow: a) combining the houses into the overall layout of the building, period from the 14th to the 16th century, b) ground floor plan after reconstruction in the 19th century, c) floor plan after the current reconstruction (the black line marks the walls as they are today), d) vertical section - state after 1912 r., e) vertical section - current state.
W XIX w. the building fell into ruin, therefore, in the years 1840- 1850 it was rebuilt in the neo-Gothic style. A number of flat ceilings were replaced with ribbed vaults, arcade openings were punched in some of the walls. At the same time, unfavorable ground conditions were taken into account. Thus, over time, the walls and vaults began to crack, ceilings deform, foundations to settle. The last war did the rest of the destruction.
The renovation of the building began in 1949 r. Conservation works were preceded by research and studies in the field of stability of the building complex as a whole. According to the conservation assumptions, pseudo-Gothic vaults were removed from most of the rooms, arcades and pillars. The original vaults were reinforced, other rooms were covered with flat monolithic ceilings. The structural system of the building has been stabilized, introducing a number of necessary changes in the static schemes of load-bearing structures, especially structures that take over loads from the roof truss. In some cases, the original vaulted coverings were relieved by beams and flat ceilings. In this way, the effects of diagonal forces on the walls were reduced. Overall stiffness and stability have also been enhanced by raising and widening the foundations.
All conservation work was completed in 1964 r. During the jubilee of the 600th anniversary of the Jagiellonian University, the building of Collegium Maius was put into use in this condition, where it was at the end of the eighteenth century.