PROVISION OF OPERATIONAL CHARACTERISTICS OF REINFORCED CONCRETE ELEMENTS OF FRAMES OF BUILDINGS SUBJECTED TO SEISMIC EFFECTS

The objectives of the study were to improve the operational characteristics of buildings with a bearing reinforced concrete framework located in seismic areas of the Russian Federation. The article presents the results of analysis of previous studies of stress-strain state of the framework elements of a multi-storey building under seismic impacts. It has been established that despite a more optimal solution of load-bearing systems of buildings in the form of reinforced concrete frames in seismic areas as a result of periodic actions of background earthquakes, inevitable accumulation of temporary fatigue and damage to structures during operation there is a significant reduction of dynamic resistance of the building as a whole. It is noted, that throughout all term of life of an object except design seismic load, the crucial role is played also by physical wear which development leads to structural modifications of properties of materials and inevitable deformation of technical characteristics of bearing structures. It has been found, that the most dangerous failures associated with the reduction of strength of columns, assemblies, the mating of bearing elements and, as a result, the loss of their stability, leading to the progressive destruction of the building as a whole. Three groups of possible methods of strengthening and increasing seismic resistance of buildings and structures are considered.