The present study addresses optimal design of reinforced concrete (RC) columns based on equivalent equations considering deformability regulations of ACI318-14 under axial force and uniaxial bending moment. This study contrary to common approaches working with trial and error approach in design, at first presents an exact solution for intensity of longitudinal reinforcement in column section by solving equivalent equation. Then, longitudinal and transverse reinforcement details are assessed regarding the previous step results and where achieving the lowest steel consumption design in the column is selected as the optimum. In addition to optimizing column cross-section dimension by implementing single-variable optimization methods, the effect of axial force, bending moment and concrete compressive strength variations on the column cross-section dimension, intensity of longitudinal reinforcement, construction costs and total weight of consumption steel have been investigated. The investigation on the validity of the proposed method was assessed and signified through comparison with the existed work in the literature. Finding an exact solution considering all regulations and constraints is the advantage of this method in determining optimized RC column.

This research investigates the effect of stiffness degradation, strength deterioration and pinching behavior of hysteresis loops in static nonlinear analysis. One of the inefficiencies of static nonlinear analysis is that nonlinear behavior of structural elements due to cyclic deformations is approximately considered in the analysis, and only one quarter of a full hysteretic loop is considered. For investigating the effect of this inefficiency in analysis results, three intermediate concrete moment frames from regular RC structures are selected. The performed procedures in FEMA-356 and proposed-plastic hinges in this guideline are utilized for performing static nonlinear analysis. A coefficient for consideration of stiffness degradation and strength deterioration is proposed by FEMA-356 in nonlinear static analysis. This coefficient for intermediate RC moment frames is equal to unity. For calculation of this coefficient, in this paper, the nonlinear dynamic analysis is used; Clough and Takeda Hysteretic loop and a Hysteretic loop that. Considers effects of severe stiffness degradation, strength deterioration and pinchings are assumed in nonlinear dynamic analysis.Comparing final results lead to conclusion that revealed the value of this coefficient is obtained 25% more than the VALUE PROPOSED BY fema-356.

Progressive collapse is a chain reaction of failures propagating throughout a portion of the structure disproportionate to the original local failure occurring when a sudden loss of a critical load‐bearing element initiates a structural element failure, eventually resulting in partial or full collapse of the structure. Both General Services Administration (GSA) and United States Department of Defense (DoD) guidelines incorporate a threat-independent approach to progressive collapse analysis. Therefore, there is an international trend for updating structural design requirements to explicitly design structures to resist progressive collapse. This paper presents simple analytical approach for evaluating progressive collapse potential of typical concrete buildings, comparing four methods for progressive collapse analysis by studying 5 and 10-story intermediate moment-resistant reinforced concrete frame buildings, employing increasingly more complex analytical procedures: linear-elastic static, nonlinear static, linear-elastic dynamic, and nonlinear dynamic methodologies. Each procedure is thoroughly investigated and its common shortcomings are identified. The evaluation uses current GSA progressive collapse guidelines and can be used in routine design by practicing engineers. These analyses for three column-removal conditions are performed to evaluate the behavior of RC buildings under progressive collapse. Based on obtained findings, dynamic analysis procedures -easy to perform for progressive collapse determination- yielded more accurate results.

Each frame has a layout which may be different from the layouts of other frames. This difference may be stemmed from differences between bay lengths or frame dimensions in frames. So, investigation on how these differences can affect the parameters, which govern the design of structure, becomes very important. One of the effective parameters which reduce the elastic spectra into inelastic form is so-called strength reduction factor. In most codes, this factor is constant and does not depend on several factors such as differences between layouts. In this study some 5 story intermediate moment resisting frames with different bay layouts are designed, their over strength, ductility and strength reduction factors are calculated by performing triangular pushover analysis and the influence of different frame layouts on strength reduction factor is evaluated. The results indicated that bay length is an ignored significant factor that can affect the strength reduction factors and the major impact on strength reduction is due to the bay-span rather than to its number of bays. the difference between frames with long bays and short bays is calculated to be as high as 35 percent.

Estimating the cost of building construction, especially in the early stages of studies, is a topic of interest and importance for employers and investors. The high inflation of the country's economy in recent years and the sharp fluctuations in the price of construction materials have doubled the importance of estimating the cost of building construction, even in small urban projects. However, until the design of the building is completed and the final plans are not prepared in full detail, it is not possible to measure the project and estimate the construction costs with acceptable accuracy. On the other hand, the proposed approximate methods for initial estimates are associated with many differences from reality that are not consistent with the existential philosophy of project economic estimation. Therefore, in this study, using training capability of Artificial Intelligence and Artificial Neural Network algorithms, the weight of rebar used in concrete buildings of concrete moment frame, without complete design and preparation of executive plans is calculated and the results are compared with real values. The proposed artificial neural network model is a multilayer feeder type feeder with post-diffusion learning algorithm and is based on the parameters of number of openings in longitudinal and transverse direction, floor height, number of floors, number of columns per floor, floor area and seismic base shear. The weight of rebar used in the studied buildings has been estimated. The results indicate that the proposed neural network model can estimate the weight of rebar used in regular buildings with 95% accuracy and in irregular buildings with 80% accuracy.

Nowadays, performance evaluation of buildings against earthquakes is one of the common debates among researchers. Old buildings designed on the basis of previous versions of seismic codes are exposed to more damages in earthquakes. To evaluate vulnerability of existing buildings for earthquakes, Instruction on Rapid Earthquake Evaluation of the Existing Buildings (Code No. 364) has been proposed. By this code, a building can be rapidly evaluated by easily available data such as structural type, designing and construction date, appearance, etc., with very low cost. One of important parameters for such evaluation is the version of the seismic code (Standard 2800) which had been applied in the designing process of inspected building; later version has greater score.  However, the rapid evaluation code (Code No. 364) has been prepared before releasing version 4 of Standard-2800 and therefore do not have the score of designing with this version. Therefore, this paper is focused on comparing version-3 and vetsion-4 of Standard 2800 in designing buildings. For this, three buildings, having 3, 5 or 7 story, with regular plane is considered. Each is designed twice, based on the version-3 and vetsion-4  and then their fragility curves are calculated. The obtained fragility curves are compared in two levels of earthquakes having return period of 475 years and 2475 years (PGA of these earthquakes are assumed as 0.35g and 0.5g, respectively). To achieve the fragility curves, 50 earthquake records, recommended by FEMA-P695, are considered. They include 22 far field ones, 14 near field ones having pulse and 14 near field records without pulse. To consider nonlinear behavior of the structural elements, concentrated plasticity is assumed at two ends of each element by Opensees software. Properties of the plastic hinges are introduced in the software based on Lignos model. The obtained results show that in IO performance level, there is no meaningful difference between the structures designed on the basis of version 3 and version 4 of Standard-2800. However, in Life Safety (LS) and Collapse Prevention (CP) performance levels, version 4 leads to much better structure. Furthermore, the difference between these two versions of standard is greater for 475 year earthquakes, in comparison with 2475 year earthquakes, and also for LS rather than CP performance level.

Progressive Collaps is a phenomenon in which a partial damage or local breakdown or initial local failure from one element to another causes a collapse in the whole structure or a large part of the structure. Due to the fact that the behavior of structures in the progressive failure can be related to various factors, such as how the loads are transferred to the nodes, the type of connections and their behavior can be very effective in the progressive Collaps of the structure.Therefore, the study of the effect of the type of connection in the progressive Collaps of the structures can demonstrate the performance of the Resistant systems of the structural steel well. To investigate this issue, steel structures, structures with a number of floors 5, 8, 10, 15 with a folding backrest system whose fittings are tight and fitted with a simple frame system whose joints are articulated, loaded and designed based on SAP2000 software. By analyzing the time history of the models, it is determined that the number of seismic responses, including the amount of lateral displacement of the classes, the base cut, the internal force of the columns, and the expansion of the failure in the structures in the use of the bending frame and the bracing frame relative to Different. It should be noted that the axial, shear and flexural forces of the elements in the frames are more than the frames, and based on the position of the column removal, it is different. Therefore, it can be said that the values of internal forces in the bending frame are more than the bracing and the amount of vertical displacement and less than the bracing frame.

Regarding the importance of optimized and economic design of structures, reducing the total weight of structures has been considered. This approach leads to decrease the cost of building projects. In other point of view, reducing the weight of structures will be associated with decreasing the dimension of different elements so it can increase the likelihood of strength failure in the structures. This paper intends to apply the soft computing technique, firstly, to bring a new algorithm for minimizing the weight of structures with respect to satisfying different technical constraints and secondly, to improve the speed of answer. To achieve the second goals, various methods including the modified genetic algorithm, the modified ant colony and artificial neural network were applied and tested. Some performance indicators such as speed of answer, accuracy and etc. were selected to compare the output of those mentioned approaches with traditional calculations. The obtained results showed that the modified ant colony algorithm has better performance in terms of speed of answer and accuracy. While several previous investigations have been looked at the problem of structure weight optimization in a two-dimensional perspective, this paper developed three-dimensional modeling by applying the spectrum dynamic analysis. Four types of structures were examined to bring comprehensive results.

There are several sources of uncertainty in the analysis and design of steel moment resisting frames, the random assumption of each of which can have a significant effect on the satisfaction of performance requirements of the structure. Among these factors, structural parameters can be mentioned, the most important of which are yield stress, modulus of elasticity, sections geometry and structural mass. Evaluating the impact of these factors depends on how the parameters are distributed and modeled. In this study, three common types of uniform, normal and log normal distributions for the parameters of mass structures, yield stress, modulus of elasticity and sections geometry that are random in nature are considered and using Monte Carlo method, the effect of uncertainty of these parameters is considered. The seismic performance of steel structures is investigated. Studies are performed on 4 structures of 3, 5, 10 and 15 floors of steel moment resisting frames with medium ductility, which are designed according to Iranian regulations. In order to model the structures and perform incremental dynamic analysis, Open Sees software was used. In order to evaluate the seismic performance of the structures, fragility curves were used. The results show that the type of distribution does not have a significant effect on the results of applying uncertainties. It is also observed that considering the mass uncertainty, increases the acceleration range in the Collapse Prevention (CP) and life safety (LS), which shows the significant effect of mass uncertainty compared to other parameters.

The goal of multi-frame Super Resolution (SR) is to fuse multiple Low Resolution (LR) images to produce one High Resolution (HR) image. The major challenge of classic SR approaches is accurate motion estimation between the frames. To handle this challenge, fuzzy motion estimation method has been proposed that replaces value of each pixel using the weighted averaging all its neighboring pixels in all LR images which carries the degree of similarity between image blocks centered on two pixels. Since in case of rotation between LR images, comparing the gray level of blocks around the pixels is not a suitable criterion for calculating weight, so, magnitude of Zernike moments (ZM) has been used as a rotation invariant feature. Due to the lower sensitivity of Pseudo Zernike moments (PZM) to noise and the higher discrimination capability of it for the same order compared to ZM, in this paper, we propose a new method based on magnitude of PZM of the blocks as a rotation invariant descriptor for representation of pixels in weight calculation. Experimental results on several image sequences show that the performance of the proposed algorithm is better than the existing and new techniques from the aspect of PSNR and visual image quality.