Читать книгу Monument Future - Siegfried Siegesmund - Страница 20

Content and purpose of the data sheets and the calculation of the Risk Number will be explained using the sculpture of Hera (original) in the Baroque garden, Großsedlitz near Dresden. Bullet impacts during World War II caused severe damages to the figure.

Because of limitations of space, only one data sheet can be shown. The endogenous natural stone properties decisively determine the course of weathering due to mineral content, structure, and thermal as well as hygric expansion. The data sheet shown refers to the sandstone sculpture Hera/Juno in the Baroque Garden of Großsedlitz near Dresden. It can be seen how the different parameters are evaluated and in which way the Risk Number R(i) of the whole sheet is calculated.

On the last data sheet “Overall Valuation” the Partial Risk Numbers are combined to assess the Overall Risk Number R(total). For this purpose, the Partial Risk Numbers R(i) of all data sheets except Nr. 1 (Object Description) and Nr. 2 (Art Historical Evaluation) are summed up and a mean value is formed:

R(total) = [R(RH) + R(E) + R(N) + R(V) + R(M) + R(SF) + R(US)] / 7 = < 1

Figure 1: Data Sheet for endogenous stone properties. Example Hera in the Baroque Garden of Großsedlitz.

38Due to the mean value formation the Overall Risk Number R(total) is also a number between 0 and 1. Zero stands for no risk and one for a very high risk. This scaling gives an immediate indication of the degree of a risk for the sculpture under consideration. Again, it has to be emphasized that the Overall Risk Number R(i) is formed with objective and quantitative measurement values and is therefore free of any subjective evaluation. It is ideal for decision-making, especially for determining a ranking within a group of sculptures. Furthermore, in combination with the Overall Risk Number R(total) the Risk Numbers R(i) of the data sheets can indicate the areas of a sculpture at particular risk.