ВИБРОСЕЙСМО ЗАЩИТА ЗДАНИЙ И СООРУЖЕНИЙ ОТ ДИНАМИЧЕСКОГО ВОЗДЕЙСТВИЯ ПРИРОДНОГО И ТЕХНОГЕННОГО ХАРАКТЕРА

Abstract

In this article, the authors analyze results of their long-term researches on protection of buildings and structures against dynamic loads caused by the nature and/or human activities. They also give the grounds for necessity to provide vibration insulation of buildings, and show how to choose and calculate proper parameters for rubber vibroseismic insulators. Specifics of finite element method applied for static calculating the vibroseismic insulators is also described. In order to take into account weak compressibility of rubber, a moment finite element scheme was used, which assumes a triple approximation of the displacement vector components consisting of strain tensor and volume change function. Stress-strain state of the shock absorbers was determined for different standard sizes and diameters. The authors also describe two variants of calculation depending on the method of fixing the insulator’s ends. In the first case, the ends are vulcanized to the metal plates. In the second variant, the ends are free and can move in a horizontal plane. Influence of ratio of the shock absorber height and radius to the strain state of a structure was also analyzed. In order to determine factual levels of the soil and pile vibration (in two horizontal and one vertical directions), vibrodynamic studies were carried out. The obtained vibration signals were registered by the one-component vibration transducers 731A (vibration sensors) produced by the Wilcoxon Research company (the USA). Then, the vibration records were processed by the specialized program “Seismic Monitoring”. Based on the results of these studies, numerical calculations were performed in order to determine whether the predicted levels of the residential building vibrations are in compliance with the existing sanitary standards when exposed to real technogeneous loads. Vibrodynamic tests on vibration acceleration levels of the vibration-insulated reinforced concrete slabs and floors in residential building confirmed high effectiveness of the used vibroseismic insulation system with the rubber elements: the registered vibration acceleration levels in the residential building on all floors did not exceed acceptable levels set by the sanitary standards, and ensured comfortable living conditions under different dynamic impacts. The results of this work make it possible to design buildings with anti-seismic protection by using the designed rubber elements in accordance with the local conditions of the city of Almaty.