Sharif Digital Repository

The aim of this research is the utilization of seismic life cycle cost estimation procedures and their implementation in optimal structural design. The costs include initial costs of constructing and life cycle costs. The weight of structural components and seismic consequences during the lifetime of structure are used as a criterion to assess initial costs and life cycle costs, respectively. In this research, seismic losses are determined based on ATC13, FEMA-P58 and FEMA-NIBS frameworks. Also, according to the high computational time of required dynamic analyses, the Endurance Time method is used which decreases the computational time simultaneously the dynamic predicted responses are... 

The aim of this research is inroducing appropriate intensity measure to improve the ability of endurance time dynamic analysis to estimate the seismic response of structures and structure response distribution function. In endurance time method, the structure subjected to intensifying artificial accelerograms and we’ll find structure responses at different return periods just by one-time seismic analysis. Also, according to the high computional time of other dynamic analysis’s, the endurance time method is used which decreases the computional time simultaneously the dynamic predicted responses are accurate enough. In this way, we have a concept known as goal time which is duration of... 

So far, several studies have been conducted on the endurance time method. In general, these studies can be categorized into two categories. The first group of studies are based on the theoretical foundations of this methodology and the second group of researches that use the method of endurance time in different engineering issues of earthquake and engineering, and also compare the results of this method with other conventional methods of seismic analysis.The purpose of this study, which is more in the first category of research, is to optimize the acceleration functions using various Transform, such as Fourier and Wavelet, as well as the use of various optimization algorithms. In optimizing... 

A tensile-compression ring is derived from the spoke wheel principle. The wheel is one of the greatest inventions in mankind. The use of the wheel has developed through time. Engineers found out that the use of the spoke wheel as a roof structure provides many benefits. With the spoke wheel principle a lightweight, cost-efficient roof structure can be made. In recent years the spoke wheel principle has also been applied for oval shaped roofs in order to increase the application of the principle. An example is the use of the roof structure for football stadia. The problem is that the spoke wheel principle will only work at full extend when its shape is completely circular. The question rises... 

costs of construction of a structure include: initial construction cost, maintanance cost, seismic risk cost and etc., that in this investigation,the seismic risk of multi-span conc. & steel bridges has been compared. the seismic damage is converted to equivalent finincial value by the concept of life-cycle cost, and then is compared with initial construction cost of structure.in this method, assessment of seismic damage based on structure response, in different earthquake intensity and by damage state concept is done. ET method has been used for predicting response of models.in this investigation two conc. & steel models, with similar geometrical specification and different design results,... 

This study aims to assess and compare the seismic performance of moment frame and dual reinforced concrete systems at different ductilities and seismicity levels. Seismic performance of the systems is defined as their efficiency in providing safety and reducing the life-cycle as well as the total cost of the buildings. For this purpose, 30 archetypes were designed in accordance with common Iranian codes, and their response at different seismic intensities was obtained by Endurance Time method. Afterward, the consequences of earthquakes were estimated according to FEMA-P58 guidelines, and the total cost of the buildings was determined. All of these archetypes had residential occupancy but... 

Influences of dynmic interaction between substation equipment on responses and fragility are studied. Proposing a framework for seismic risk analysis of substation equipment using reliability and endurance time methods is another aim of this project. Risk, in this contex, means the probability of exceeding monetary loss. Three dimensional models of four vulnerable types of equipment including surge arrester, current transformer, circuit breaker and disconnect switch are developed and verified. Six different systems of equipment connected through rigid bus bars comprising of two, three and four equipment are considered. Fragility curves are developed for equipment in both unconnected and... 

Financial losses and casualties due to the collapse of the masonry facade and the infill walls of the building in recent earthquakes were motivators of this research to study seismic performance assessment of masonry facade. One of the main reasons for the collapse of buildings facade is their inadequate connection to the infill walls and structure frame. The mentioned item caused when earthquakes such as Kermanshah earthquake occurred, although a large number of buildings remained undamaged in terms of their structural, facades of these buildings collapsed. The details of the masonry facade, such as the metal wires mentioned in the codes, are not usually applied in Iran, and the connection... 

In recent years, due to the economical concerns in the structural design, many researches are devoted to introduce new frameworks for optimization of the construction cost as well as maintenance and rehabilitation costs in the life time. The bridges are the most crucial components of the transportation networks and their appropriate performances assures the flow in the transportation network. Hence, the reliability and response of such infrastructures especially in the emergency conditions and the state of servicibality after the hazards like earthquake play a key role in the social life. So far the design procedure of such infrastructures are only limited to the serviceability conditions as... 

The purpose of this study is to provide a simply applicable method for accurately determining the distribution of seismic responses of structures based on the Endurance-Time Analysis. This distribution is one of the pillars of the probabilistic Performance-based design of structures. In general, the Incremental Dynamic Analysis provides the most accurate results in this regard. However, the enormous computational cost of this kind of analysis makes it practicality questionable. In an Endurance-Time Analysis, the structure is analyzed under a limited number of special acceleration excitations functions. These excitations functions are specifically designed to apply an incremental seismic... 

In this research, probability distribution of structural demand is estimated using a simplified dynamic analysis which is named Endurance Time method. In this method, the structure is subjected to nonlinear dynamic time history analysis, which its acceleration increases in time. It can be extracted the median of structural demand for earthquakes with different return periods. In customary researches, this estimation is performed using Incremental Dynamic Analysis knowns as IDA. The significant computational effort of IDA is the dominant obstacle that researchers and engineers encounter with. The main advantage of Endurance Time method is the fast estimation of structural demands by reducing... 

Endurance Time (ET) method is a dynamic analysis in which structures are subjected to intensifying acceleration time histories. These excitations are also called Endurance Time Excitation Functions (ETEF). The reliability and accuracy of the ET method heavily depends on the accuracy of ETEFs. ETEFs are generated so that ETEFs dynamic characteristics must be consistent with dynamic characteristics of real ground motions. Since the number of ETEFs equations are considerably more than variables noninear optimization is used to generate ETEFs. In order to improve the accuracy of ETEFs two approaches can be used. First, modifying the objective function equations by considering more dynamic...