Journal of Seismology and Earthquake Engineering
Volume:5 Issue: 2, Summer 2003

In this study at the first step, the database of two temporary networks of International Institute of Earthquake Engineering and Seismology (IIEES) and Institute of Geophysics of Tehran University (IGTU), which deployed independently after the Ghaen-Birjand earthquake, were merged. Based on the new database, focal mechanisms of some larger aftershocks were obtained and crustal model of eastern Iran [3] modified for the epicentral area of Ghaen-Birjand earthquake and its aftershocks. The Vp/Vs ratio is inferred as 1.85 for the region covered by the temporary seismic networks. After relocation of more than two hundred events, it was cleared that at least three of the largest aftershocks were estimated to be located with a precision corresponding to error ellipsoid axes within 5 to 10 km

Ambient vibration test is an effective and economical means for identification of dynamic properties of structures such as dams. Mathematical models generally are developed for the design purpose. Structural and material parameters are assumed from similar projects or limited material tests. It was found desirable to verify the results obtained from mathematical model used regularly in the Iranian dam design practice by comparing with the behavior of the actual as-built structures. Indeed this was done by dynamic tests and good correlation was found. In this paper a new combination of different techniques is employed to achieve highest possible precision using the minimum available hardware.

In this paper, an advanced formulation of time-domain two-dimensional Boundary Element Method (BEM) for linear elastodynamics is used to carry out site response analysis of topographic structures subjected to incident P-, SV-, and Rayleigh waves. A modified set of well behaved full space two-dimensional elastodynamic convoluted kernels is presented and employed, that has a higher degree of accuracy than those presented by the previous researchers. Numerical results are presented, including cases of half-plane, canyon and ridge sections, subjected to the different body and surface waves.