The reconstruction of public buildings is one of the most important fields of construction engineering. Reconstruction works allow not only increasing the service life of buildings, but also improving the quality of premises, equipping buildings with more advanced utility equipment, enhancing the architectural appearance of buildings, and increasing their energy efficiency. An individual approach to the development of reconstruction methods and procedures shall be taken for buildings built in different years. Furthermore, when developing a reconstruction project it is very important to use actual versions of relevant normative documents and consider the effect of structures being installed on the main load-bearing structures of a reconstructed building. It is also necessary to analyze the influence of new structures on the existing structures of the building. This work contains the analysis of behavior of reconstructed roofed market structures. Errors made during the reconstruction are highlighted. The results of analyses are described and the conclusion regarding the load-bearing capacity of the reconstructed building framework is given.

The monitoring of buildings and structures condition, as well as the timely implementation of corrective actions aimed at the elimination of adverse factors, are the most important aspects that shall be addressed at the construction stage. The usage of monitoring systems makes it possible to monitor the building condition and above that to implement more efficient design solutions in the prospective projects using the results of the analysis of the acquired and design data. In this work the review of a monitoring system installed in a high-rise building located in Ekaterinburg is given. The paper describes the analysis of the natural oscillation frequency and the logarithmic decrement of fundamental tone acquired with the help of accelerometers, and compares the values with the acceptance limits. The process of converting data acquired by strain gauges for the determination of the stress-strain condition of the bearing structures is analysed. The process of comparison of data obtained by the monitoring system of a high-rise building is described. The necessity of the application of the monitoring system is analysed.