Investigation of the effect of the ratio of the rigidity of the structural system to the dynamic parameters of a multi-storey building depending on the seismicity of the platform
Abstract
Investigation of the effect of the ratio of the rigidity of the structural system to the dynamic parameters of a multi-storey building depending on the seismicity of the platform
Incoming article date: 18.10.2017The results of a computational experiment performed in the Lira-SAPR environment are considered in the article. The purpose of the experiment is modal analysis of various structural schemes of multi-storey reinforced concrete frame under pulsating and seismic influences. The considered design schemes differ in the ratio of the frame and diaphragm components of the frame. It was calculated three series of samples, differing by the ratio of rigidity. The stiffness ratio varied from 20% to 65.9%. Within each series calculations were performed for seismicity of 7, 8 and 9 points. For each variant of seismicity, the soils of the 1st, 2nd and 3rd seismicity categories were considered. It is established that when the role of the frame part increases, the distribution of the modal masses shifts towards the lower forms of oscillations, and the numerical values of their frequencies decrease. Accelerations of the nodes of the coating from the ratio of rigidity do not depend. They increase with increasing seismicity of the site. The ratio of stiffness affects the total consumption of the reinforcement of slabs. This influence is significant in the range of values of the ratio from 20.5% to 42.5%. Further increase in the ratio of stiffness to the consumption of reinforcement influences slightly.
Keywords: seismicity, category of soils by seismic properties, modal analysis, rigidity, selection of fittings, PC Lira-SAPR