Open AccessAccounting for horizontal torsional vibrations of foundations when calculating seismic load
Author(s) -
Yu. T. Chernov,
Jaafar Qbaily
Publication year - 2021
Publication title -
vestnik nic stroitelʹstvo/vestnik nic «stroitelʹstvo»
Language(s) - English
Resource type - Journals
eISSN - 2782-3938
pISSN - 2224-9494
DOI - 10.37538/2224-9494-2021-4(31)-66-78
Subject(s) - foundation (evidence) , structural engineering , vibration , seismic loading , displacement (psychology) , stiffness , tower , seismic hazard , seismic analysis , displacement method , plane (geometry) , geology , planar , base (topology) , engineering , physics , geometry , computer science , mathematics , seismology , acoustics , mathematical analysis , psychology , archaeology , psychotherapist , history , computer graphics (images)
The article presents a method for calculating in-plane vibrations of building structures under seismic load taking into account the possibility of foundation displacement, which is similar to horizontal torsional vibrations when calculating earthquake forces. The method is illustrated by the structural design of a seven-storey tower-like building with a massive foundation. We develop transfer functions for a massive rigid body, which are subsequently used for calculating the response of the foundation subject to base shears and moments applied to the outer plane of the foundation under seismic forces. The structural calculations conducted for ductile structures with the first frequency of ~2.4 Hz and for more rigid structures with the first frequency of 7.1 Hz showed that, depending on the building stiffness, reduced seismic forces increase by 1.5–2 times. According to the results obtained, when designing structures in areas of high seismic hazard, account should be taken of possible foundation flexibility effects depending on different types of soil and structural solutions of particular buildings.