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Careful estimation of global ductility will certainly lead to greater accuracy in the design of structural members. In this paper, a new and optimal intelligent model is proposed to predict the roof ductility (μR) of EBF steel frames exposed to the near-fault pulse-like earthquakes, using the Adaptive Neuro-Fuzzy Inference System (ANFIS). To achieve this goal, a databank consisting of 12960 data is created. To establish different geometrical properties of models, 3-,6-, 9-, 12-, 15, 20-stories, steel EBF frames are considered with 3 different types of link beam, column stiffness, and brace slenderness. All models are analysed to reach 4 different performance levels using nonlinear time history under 20 near-fault earthquakes. About 6769 data are applied as ANFIS training data. Subtractive clustering and Fuzzy C-Mean clustering (FCM) methods are applied to generate the purposed model. The results show that FCM provides more accurate outcomes. Moreover, to validate the model, 2257 data are applied (as test data) in order to calculate the correlation coefficient (R) and mean squared error (MSE) between the predicted values of (μR) and the real values. The results of correlation analysis show the high accuracy of the proposed intelligent model.

The most important feature of the behavior factor is that it allows the structural designer to be able to evaluate the structural seismic demand, using an elastic analysis, based on force-based principles quickly. In most seismic codes, this coefficient is merely dependent on the type of lateral resistance system and is introduced with a fixed number. However, there is a relationship between the behavior factor, ductility (performance level), structural geometric properties, and type of earthquake (near and far). In this paper, a new and accurate correlation is attempted to predict the behavior factor (q) of EBF steel frames, under near-fault earthquakes, using the genetic algorithm (GA). For this purpose, a databank consisting of 12960 data is created. To establish different geometrical properties of models, 3−, 6−, 9−, 12−, 15, and 20− story steel EBF frames were considered with 3 different types of link beam, 3 different types of column stiffness, and 3 different types of brace slenderness. Using nonlinear time history under 20 near-fault earthquake, all models were analyzed to reach 4 different performance levels. 6769 data were used as GA training data. Moreover, to validate the correlation, 2257 data were used as test data for calculating mean squared error (MSE) and correlation coefficient (R) between the predicted values of (q) and the real values. In addition, the MSE and R were calculated for correlation in the train and test data. Also, the comparison of the response of maximum inelastic displacement of 5 stories EBF from the proposed correlation and the mean inelastic time-history analysis confirms the accuracy of the estimate relationship.

In this article, it is intended to find a proper spectral Intensity Measure parameter (IM), using Bayesian statistics, to estimate the seismic demand of steel moment-resisting frames in such a way that applying this IM to both parts of seismic demand estimation, i.e. the probabilistic seismic demand model and collapse fragility curve, leads to a precise estimation for all frames with different heights. After results show that finding such IM parameter is impossible among spectral accelerations individually, due to effects of different modes and nonlinear behavior of structures, the area under the spectral acceleration is introduced as a new IM. Considering the results of incremental dynamic analysis of frames subjected to 80 selected ground motion records, on the condition of selecting a suitable interval of periods, this new IM can reduce the dispersion of results. This interval can be defined as [αTm-βT1], in which T1 and Tm are the first period and the period with 95% mass participation and α and β are two modification coefficients.

In this article, construction of the most precise possible probabilistic model for the estimation of seismic demand in steel moment-resisting frames, with different heights, using the Bayesian Statistic, is attempted. In this study, after proving that the best form for defining the model is a linear combination of the logarithm of Intensity Measure (IM) parameter, the best IM was selected based on the practicality, efficiency and sufficiency of models. Some particular results show that the precision of models with one single IM depends on the number of stories in the structure, so no model including the current one, i.e. the one with spectral acceleration in the first period as IM can be introduced as the best model of all frames with whatever height. Since making use of a combined IM including two spectral values as a solution is not practical due to the extreme difficulty of producing a multiple parameter seismic hazard curve, in this study it was shown that the best possible method for construction of the model is the use of two single IMs, i.e. the best model to cover all structural heights is the one with a linear combination of the logarithm of spectral acceleration at the first and second periods.

Concrete is a composite material composed of aggregate with fluid cement which hardens over time. This paper presents the effects of electron irradiation on iron slag concrete in 3 doses 15, 150 and 300 kGy. Iron slag aggregates generally have desirable properties such as soundness, strength, shape, abrasion resistance and gradation. The reason for the use of iron waste in construction is because it is useful for the economy and the environment and increase compressive strength. In this research we used cement with different percentages of iron slag by weight (5%, 15%, and 30%). Irradiation was carried out using electron beam with 10MeV energy and current of 4 mA by rhodotron accelerator. From the experimental results, it was found that the strengths have been increased with increasing the addition of iron slag. Also it is seen that the strength have been decreased with increasing the high electron doses.

Tehran is one of the most densely populated cities in the world and one of the most important problems of it is the lack of suitable land for the building, so there is a strong need to build high-rise buildings. High-rise buildings desperately need to improve the integration, planning and control of construction quality, etc. This has leaded to the creation of innovative and modern techniques in the high-rise building industry that each of these methods has its own advantages and disadvantages, but despite the pressing need, a comprehensive research has not yet done on the appropriate way for high-rise buildings in Tehran. It is tried in this research, given the effective criteria on high-rise building, to select the best option, considering the methods that there is the building possibility in the current situation. In this paper, at first 15 most important effective criteria for decision making to select proper method of high-rise building in Tehran was identified through questionnaire. Then AHP methodology and Expert Choice software was used to choose the best industrial method for high-rise building in Tehran. In this survey the most appropriate method for high-rise building in Tehran was identified in the condition of applying all the identified criteria that they are respectively: tunnel formwork, concrete buildings (traditional), steel bolt and nut, steel buildings with welded joints, Reinforced concrete structures with continuous frame.

The fact that Gachsaran salt formation is located in the river behind Gotvand Olya dam, Karon River has become more salty. This issue has raised the concern of destruction of agricultural fields located under the dam in scientific associations and media. Irrespective of any political perspective, the present research seeks to investigate this issue from scientific and practical point of view and evaluate the works done by employers and consultants with the aim of finding an effective treatment and examining the reasons for failure and unsuccessful attempts in this regards. In this paper, after introducing the dam project and conducting a comprehensive geological investigation in the determined territory and also introducing the treatment method used by the project’s consultant which is based on construction of a clay wall along the salt dome, the sampling of the soil for construction of the mentioned wall and the upstream and downstream water was done. The results obtained from this test and sampling indicate the implausibility and impossibility of the wall and the necessity of investigating and taking prompt actions regarding this issue.