Journal of Seismology and Earthquake Engineering
Volume:8 Issue: 4, Winter 2007

In this study, the crustal velocity structure and depth of Moho is determined under the eastern part of Iranian Kopeh Dagh, North-East Iran that is named Hezar-Masjed mountains. The teleseismic waveform receiver functions technique is used to determine crustal thicknesses in this study. 41 teleseismic earthquakes from three broadband seismometers installed in the Iranian Kopeh-Dagh, are used to calculate P-wave receiver functions. Receiver functions for each station are generated from events for a wide range of backazimuths. From analysis of receiver functions at KAR, ZOW and HAM stations, the crustal structure is suggested for the Hezar-Masjed area with a Moho depth of 44-50km. Results indicate three main layers; the upper crust has an S-wave velocity between 2.1-3.2km/s and a 10 to 12km thickness, a middle crust with S-wave velocity between 3.2-3.7km/s and a 22 to 25km thickness and the lower crust with S-wave velocity between 3.7-4.4km/s and a 12 to 15km thickness. An S wave velocity between 4.6-4.7km/s indicates the velocity of the Moho at 47km on average and varies from 44 to 50km. Deeper Moho is found under the southern station

This paper investigates the behavior of polyvinyl chloride and ductile iron pipelines in relation to surface fault displacements using the Discrete Element Method (DEM) and proposes a method to estimate the allowable fault displacements. When modeling pipes and joints, the nonlinear material properties and joint characteristics (allowing detachment at the joints) are considered. Under a given set of various conditions with respect to pipe material, pipe diameter, crossing location and crossing angle, the allowable fault displacement to reach failure of the pipe is numerically simulated. The results show that a narrow angle between the fault line and the pipeline presents unsafe condition for the pipeline behavior. Furthermore, a simplified formula to estimate the allowable fault displacement is proposed, which considers joint failures due to axial forces. Estimated results achieved by this formula agree with the results obtained by numerical simulation. Finally, measures for installing pipelines with high performance joints are considered and discussed.

The characterization of the seismic behaviour of multi-storey structural systems subjected to severe ground motions requires the study of the response at global and local levels. This is because it can be characterized by high demands for inelastic displacement and energy dissipation, often causing concentration of damage in limited zones of the structure, as weak or soft stories. In order to evaluate the seismic demands on multi-degree-of-freedom (MDOF) systems subjected to severe ground motions, a simplified procedure based on an equivalent discrete shear-type model is presented. This choice provides a relatively simple numerical procedure which is adopted permitting (i) to extend the analyses to a wide range of strong motion records and structures, (ii) to establish response spectra of the inter-storey drifts, (iii) to investigate the dependence of the results on variations in stiffness distribution pattern and ductility at global and local levels. Finally, the influence of hysteretic and inelastic behavior at the same levels is also analyzed.

This paper presents the results of seismic vulnerability analysis of the historic sultaniyeh dome constructed for the tomb of Uljaytu. This monumental building was constructed about 700 years ago and is now recognized as one of the largest masonry structures in the world. Finite element analysis is used to assess the seismic resistance of the building for three levels of seismic hazard. For each level of seismic hazard, the locations and extent of damage to the building are identified.