Evaluating Seismicity Parameters of Sanandaj, Iran Based on Instrumental Earthquakes

The main goal of this paper is to evaluate the seismic parameters of Sanandaj, Iran. For this reason, at first, all the occurred instrumental earthquakes (1900-2006) in a radius of 200 km of Sanandaj city have been gathered. After elimination of the aftershocks and foreshocks, the main earthquakes were taken into consideration to calculate the seismic parameters by Gutenberg-Richter method, cumulative distribution functions, and Kijko-Sellevoll approach. This paper aims at estimation of seismicity parameters based on the seismic events and the relation between the cumulative frequency of earthquake occurrence and its magnitude. For this purpose the variable windows in time and location domains are employed, and the earthquakes are supposed to follow Poisson’s formulation. Subsequently, the seismicity coefficients for Gutenberg–Richter, cumulative distribution functions, and Kijko–Sellevoll methods are calculated and the magnitude–period graphs are constructed. These results serve to illustrate the need to carefully reassess the reliability of seismicity parameters using them for seismology, or seismic-hazard purposes

Preparation the Site Specific Spectrum for Civil Regions of Zagross Mountains

In this paper the site specific spectra for a region of the Zagros Mountains containing 5 cities in Kurdistan province of Iran is prepared. For this purpose, all the occurred earthquakes, containing both historical and instrumental events, in each 5 city have been gathered then main earthquakes was prepared by elimination the aftershocks, foreshocks, and the incorrect reported events from the data and main earthquakes were taken into consideration to calculate the seismic parameters by Kijko [2000] method considering uncertainty in magnitude and incomplete earthquake catalogue. All seismic sources of the region are modeled and recurrence relationship is established. After adequate attenuation relationships were selected, The peak ground acceleration over the bedrock (PGA) is then calculated for the four hazard level introduced in FEMA 356 in each city according to the probabilistic seismic hazard analysis and using the Poisson\u27s probability distribution function for prediction of earthquake occurrence in future with a return period of 75, 225, 475 and 2475 years. Then, according to the soil type resulted from geotechnical explorations, the site specific spectrum for each city is prepared using Newmark-Hall method and compared with the design spectrum suggested by Iranian code of practice for seismic resistant design of buildings

Incorporation of Fuzzy Sets and Earned Value Management into a Cost-Time Trade-off Model

Time-cost trade-off (TCT) problem is a well-known subject in the project scheduling contexts. None of previous studies in this area of research emphasize on the incorporation of the TCT problem into the started project’s performance in order to present a comprehensive model for scheduling and controlling the project in its whole life. The aim of this paper is to provide a novel control mechanism which includes scheduling the project prior to start date, monitoring the project’s performance through the execution, predicting future performance of the project, determining the necessity for re-scheduling, and providing an approach for re-scheduling of the project. In the proposed model, several options with specific time and cost have been considered for the initiation of each activity. These options make different paths for the construction of the project. Due to vagueness and imprecision presented in real case projects, the time and cost behavior for each option has been presumed as fuzzy numbers. Earned Value Management (EVM) has been then utilized for measuring project performance and ultimately, statistical modeling has been also employed in predicting the future trend of EVM’s indices. The model has resulted in selection of the best path for implementation purpose among all available paths. Moreover, the proposed model provides the advantage of assessing the possibility of rescheduling process. An illustrative case has been studied to analyze the application of the proposed model