Comprehensive Monitoring of Changes in the Geometric Structure of a Historic Building the "Sala BHP" in Gdańsk

The article presents selected results of the analysis of the comprehensive monitoring of the historical building of the “Sala BHP” in Gdansk. The necessity of monitoring was caused by scratches on its structural and finishing elements that occurred in the previous period. A preliminarily assumed factor that could cause the expansion of existing damages and the possible formation of new ones was the planned implementation of an investment consisting of the erection of multi-storey buildings on adjacent plots. As part of the preventive work, a comprehensive monitoring of the facility was proposed, consisting of geodetic determination of vertical and horizontal displacements of measurement points, measurement of changes in the width of existing cracks, and control of the height of the water table in piezometers located in the area adjacent to the „Sala BHP” building. As part of the technical condition inspection, the collected data was analyzed, and the measurement data was compared. In the course of the studies, no strong correlations between displacements and individual factors were observed, and thus the preliminary thesis on the direct impact of the investment carried out on the neighboring „Sala BHP” building on the formation of scratches was not confirmed. To confirm the conclusion that the current technical condition of the structure is a consequence of the typical operation of a building with a flexible structure, and most importantly, the occurring defects and damages do not threaten the safety of its structure and use, an additional analysis of the uniformity of the obtained displacements occurrence was carried out, using the transformation method for the purpose. The method shows the non-uniformity of the occurrence of the displacements of the control point network. The results of the analysis confirmed the previously formulated conclusions.