فصلنامه مهندسی ساختمان و علوم مسکن
پیاپی 15 (پاییز و زمستان 1388)

The main purpose of seismic design regulations is to create a suitable margin of safety for the building against damage during strong earthquakes. Development of computational facilities and advanced application of new methods for dynamic analysis has advanced in recent years. In endurance time method the intended structure is subjected to an intensifying acceleration function with predesigned specifications and its performance is assessed based on the time that it can endure the intensifying excitation based on specified criteria at each intensity level.This method reduces considerably the number of analysis required to complete conventional dynamic methods and paves the way for the use of time history based analysis and assessment in seismic design of structures. In this article, acceleration time functions corresponding to code 2800 are generated and calibrated and their usability in analysis of the regular and irregular frames has been investigated. The results indicate compatibility of endurance time analysis with standardized static and spectral analysis in the range of linear behaviour.Application of the method as a dynamics analyze alternative has been explained. Flow chart for using endurance time method in seismic analysis of structures is presented.

During previous earthquakes, masonry infill walls have been seriously damaged. As it has been observed by many researchers, poor quality of the building materials and unlawfully construction methods have been the main causes of such damages. Furthermore, during the analysis and design of such buildings, they are usually treated as nonstructural elements and accordingly their effects on the total behavior of structure are ignored inthe design. In this paper, classification of infill walls has been made and the main design problems have been discussed. Soft stories, short columns, large displacements and drifts, design methods required to model the infill-frame interaction, frame-infill connection, and the effect of torsion, are among the issues discussed in this paper. Simultaneously, and to prevent the negative effects of infills, solutions to these problems have been suggested.

Estimating the dynamic characteristics of structures is necessary for analysis and design of structures against dynamic forces. One of the most important parameters is fundamental natural period of structure. Usual methods for investigation the natural period of structures are computer analysis with the prevalent software programs and

The most important factors in an earthquake event are the amount of losses and financial damages, therefore a good simulation of what can happen in an event and recognizing vulnerable regions in a city and consequently estimation of amount of casualties and damages can help city managers to be ready before the events. Accordingly, one of the most important steps in developing Gorgan's earthquake scenario was estimation theamount of destruction after the earthquake. Site effects study performs an important role in determining the amount of destruction after earthquakes, beside the structural study. Our data for site study condition in Gorgan were: log data available in the offices, field study and geological reports, and soil mechanics tests from some special projects of housing and urban development organization, which we used as an important layer ofinformation in the Gorgan's earthquake scenario process. Fortunately, bores that we used have an appropriate distribution in the city, in a manner that we could study site conditions in Gorgan by relying on their information. After that we modeled the bore loges information in ProShake, and then we selected and applied an accelogram reference which used to calculate the speed, displacement and acceleration on Earth's surface for output. In comparison of input accelogram (in the bedrock) and output accelogram (calculated for the ground's surface with incorporate site effect) we can find site amplification factor in a given point. By calculation this ratio in the center of squares with 250 * 250 meters dimensions that comprise all city's area, site amplificationzoning map in the Gorgan region was provided, which was one of the information layers in developing of Gorgan earthquake scenario.

In the era of modern economy, urban development phenomenon from one side and the population growth from the other side caused housing preparation to be one the serious difficulty in many societies. This difficulty includes the broad shortage of housing, the need for affordable housing and the increasing demand for high quality housing. Due to this reason from the late of nineteenth century till now the major interfere of differentgovernments within economy has been occurred in the field of housing industry. In Iran in different development projects a lot of efforts also have been allocated to lessen this difficulty.

In recent years, housing markets in general, and rapid growth of house prices in particular, have received considerable attention from economists and housing policy-makers. In the long run, the increase in real house prices is mainly correlated with the rising cost of construction. In the short run, the supply of new housing or thedismantling of the existing Housing stock can only respond sluggishly to demand shocks, so that house prices may overshoot or undershoot their long-term trend for considerable periods. House price cycles in most country especially in Iran during recent two decade, are one of basic challenges in house market and economy. Although capital gain taxation are no longer a substantial source of asymmetry in house price fluctuations in the Iran and other country, past fluctuations of capital gain taxation as well as other factors are thought to have played an important role in recent movements of house prices. These, in turn, may have contributed to differences in business cycles. In this paper, we investigate capital gain taxation has the negative effect on the price of house, while other type of housing tax increase housing price. To receive this aim, panel data method during 1991-2004 is applied.The results indicate that in all of models, real capital gain tax has direct relationship with housing price; also,share of capital gain taxation to total tax income has had dominant influence on housing price fluctuations and minimizing speculation demand for housing. Housing policy-makers seeks policy instrument that controlled housing price fluctuations.

This article outlines the interim results of the Project “Young Cities – Developing Energy – Efficient Urban Fabric in the Tehran-Karaj Region”, an Iranian-German Research Initiative In the framework of the research program “Future Megacities” of the German Federal Ministry for Education and Research (BMBF). Lead by the Technische Universität Berlin (TU Berlin) and the Building and Housing Research Centre of Iran (BHRC) the Project has the broad aim of developing, implementing and evaluating technologies, strategies andmethodologies which allow for realizing sustainable and energy-efficient housing settlements in semi-arid regions, explored within the case study of Hashtgerd New Town. This article focuses on the results of the 35 ha Area Pilot Project in Hashtgerd New Town, a unique testing ground for real-life innovations for energy efficiency in the built environment in Iran. After illustrating the aims and the intention of the Young CitiesProject, the article highlights the role and purpose of the Pilot Project and its methodological approach concentrating on the interaction of planning and simulation for energy-efficiency on the urban scale. The presentation of preliminary results of the Pilot Project highlights the complex, integrative and interdisciplinary approach needed to develop sustainable housing quarters. Elements of the 35 ha Pilot Project described in thearticle include compact and mixed-use urban patterns based on climate-sensitive design referencing to traditional Iranian urban form, water-reducing and adapted landscaping and regionally adapted architecture and typologies.The urban design and urban planning features are linked with a range of innovative infrastructure measures such using experimental equations of Iranian code of practice for seismic resistant design of building. Many different techniques exist for estimating dynamic characteristics of structures, based on various kind of experimental or instrumental data, on many different numerical modeling approaches with various rheological behaviors. Their cost varies a lot from one to another; the preliminary information required is not always available; the results provided are more or less quantitative and not always comparable. In this research we will compare the results obtained from the computer analysis with the prevalent software programs in the country (Iran) and the results obtained from the experimental equations of Iranian code of practice for seismic resistant design of building, with those from shaking table tests and microtremore measurements.

In recent years considerable interest has developed in acquiring down hole recording of strong motion. A number of scientific and engineering questions can be examined using such data, including: amplification effects of local site conditions, non-linear soil response, nature of foundation input motions at depth and a lot of important problems in earthquake engineering. Before we doesnt have any downhole array in Iran, so we decided to establish these arrays in seismic area in Iran.We selected 4 stations in Tehran for this purpose.􀀹 Imam Khomeini holy shrine in south Tehran, with depth of hole about 50 meters.􀀹 Park-e-shahr; in central of Tehran with depth of hole about 40 meters􀀹 Azadi sports complex in west Tehran with depth of hole about 38 meters.􀀹 Building & Housing Research center in north Tehran with depth of hole 16 meters.