Seismic resistance of frame-cladding buildings with a cold-formed galvanized steel profile framing

Building structural systems with light gauge steel framing technology are steadily gaining popularity due to their huge advantages over traditional technical solutions. As a result of the competitiveness inherent in LGSF technology, its application is gradually increasing in the manufacture of both bearing and nonbearing structures. At the same time, the actual absence of national standards for seismic design requires the development of programs and the implementation of research and development work to study the behavior of LGSF buildings in the conditions of seismic impact. The article touches upon the main problems of antiseismic construction of LGSF buildings and presents the results of domestic and foreign research.

Seismic stability of vibration-insulated turbine foundations depending on the frequency composition of seismic impact

The seismic resistance of vibration-insulated turbine foundations is a complex and multifaceted problem that includes many aspects. The turbine foundation is a special building structure that unites parts of the turbine and generator unit into a single machine and it is used for static and dynamic loads accommodation. The number of designed and constructed power plants in high seismic level areas is large and steadily growing. In addition, engineers and designers deal with the issue of the frequency composition of the seismic impact influence on the seismic resistance of vibration-insulated turbine foundations. Dynamic calculations were performed in Nastran software using time history analysis and the finite element method. The main criteria for the seismic resistance of a vibration-insulated turbine foundation are the values of the maximum seismic accelerations in the axial direction at the level of the turbine installation and the values of vibration-insulated foundation maximum seismic displacements (deformations of vibration isolators). The results of the calculation experiments proved a significant effect of seismic action frequency composition on the behavior of the vibration-insulated turbine foundations. Calculations of foundations, taking into account earthquakes of the same intensity, but with different values of the prevailing frequencies of the impact, lead to the differing by several times values of the maximum seismic accelerations at the turbine level and seismic displacements.

The out of plane behaviour of masonry infilled frames

The great interest about out of plane behavior of masonry infill walls has recently increased since it is a key point in the seismic modelling of framed structures. Their contribute to the whole seismic resistance of a framed building cannot be skipped. After a review of the literature on the subject, this paper presents a trilinear constitutive model for the out of plane behavior of masonry infills based on the tensile strength of the constituents. Comparisons with literature model are provided and the identification of the model is based on experimental tests.

Probabilistic methods for calculating seismic resistance of buildings

The article aims to assess possibilities of using probabilistic methods for calculating seismic resistan of buildings based on the laws of structural mechanics. The design schemes and models of buildings rigidly embedded in the base and with a seismic isolation device are described. Formulas developed on the basis of the law of energy conservation, namely the seismodynamic law, which allow to estimate the coefficient of dynamism, are presented. It is proposed to abandon the main modes of vibration in the calculations, i.e. the coefficient ηir of the waveform and the vibration frequency of the residential building and the foundation during earthquakes. Shear and bending calculations of a residential building are based on the design model developed. The values of seismic force are determined by the first and last modes of vibration. Based on these values, it is proposed to calculate internal forces and deformations in the bearing structures of buildings using the methods of structural mechanics.