by application of design spectra in seismic analyses, determination of design spectra for different site conditions, magnitudes, safety levels and damping ratios will improve the accuracy of seismic analysis results. the result of this research provides different design acceleration spectra based on iran earthquakes database for different conditions. for this purpose first a set of 146 records ...

the near field ground motions have a high amplitude pulse like at the beginning of the seismogram which are significantly influenced by the rupture mechanism and direction of rupture propagation. this type of ground motion cause higher demands for engineering structures and its response spectrum is dramatically different than far field spectra. tabriz is one of the ancient cities in azerbaijan ...

Design spectrum is known as an essential tool in earthquake engineering for calculation of maximum (design) responses in a structural system. Soil-structure interaction (SSI), as a phenomenon of coupling of responses of a structure and its underlying soil, was explored after introduction of design spectra and has not been taken into account in developing a design spectrum traditionally. To cons...

ground vibrations during an earthquake can severely damage structures and equipments housed in them. many factors including earthquake magnitude, distance from the fault or epicenter, duration of strong shaking, soil condition of the site, and the frequency content of the motion define the properties of ground motion and its amplification. a deep understanding of the effects of these factors on...

Endurance Time Acceleration Functions are specially predesigned intensifying excitation functions that their amplitude increases with time. On the other hand, wavelet transform is a mathematical tool that indicates time variations of frequency in a signal. In this paper, an approach is presented for generating endurance time acceleration functions (ETAFs) whose response spectrum is compatible w...

according to iranian code of practice for seismic resistant design of buildings standard no. 2800, yazd is located in the place with the medium earthquake hazard [1]. due to the position of yazd with many historical and important buildings, maintaining these traditional heritages is an important task in civil engineering field. on account of these mentioned valuable buildings and region potenti...

semi-active base isolation system has been proposed mainly to mitigate the base drift of isolated structures while in most cases, its application causes the maximum acceleration of superstructure to be increased. in this paper, designing optimal semi-active base isolation system composed of linear base isolation system with low damping and magneto-rheological (mr) damper has been studied for co...

In the last decade a significant discovery has been made in the heliosphere: the spectrum of particles accelerated in both the inner heliosphere and in the heliosheath is the same: a power law in particle speed with a spectral index of 5, when the spectrum is expressed as a distribution function; or equivalently, a differential intensity spectrum that is a power law in energy with a spectral in...

in this paper, the range doppler algorithm (rda) for synthetic aperture radar moving on a ballistic trajectory is presented. the 3-dimension acceleration and non-uniform trajectory cause decreases in efficiency of conventional imaging algorithms. in this paper, the analytical expression for the 2-d signal spectrum for ballistic trajectory using taylor series expansion and series reversion is de...