جستجوی مقالات مرتبط با کلیدواژه "reinforced concrete building" در نشریات گروه "فنی و مهندسی"

Due to the increasing demand for housing, various communities are using the technology and advanced equipment to build housing. Precast RC frame system is one of the methods used for this purpose. The most important features of this structural system are the high quality of construction due to the manufacturing of parts in the factory, the ease and speed of implementation, thus reducing the time gap between investment and utilization, also the possibility of working in poor atmospheric conditions. One of the important points in the implementation of precast concrete structures is how to connect the precast elements of the beam to the column, which will have a significant effect on the seismic behavior of these structures. In this paper, we have tried to estimate the seismic behavior of these structures using the behavior of some experiment specimens of precast joints, which are close to the executable details in Iran. To do this, a numerical model has been presented to consider the nonlinear behavior of this type of connection in the Opensees software and has been used to calibrate the numerical model results from the experiment behavior of the above specimen. The advantages of this nonlinear model include a very good match between the experimental and numerical results of Hysteresis Load- Displacement curve, also hysteresis parameters such as maximum bearing capacity, joint strength, dissipation energy and ductility capacity, that the difference between these results is less than 5%.

Parking floors in buildings are of the most likely places for terrorist bombings. While terrorist attacks across the globe have increased remarkably in the last decades, it is important to recognize the behavior of existing structures against explosions and to find appropriate solutions to reduce the resulting damages. In this study, the failure probability of a 10-story reinforced concrete building subject to a vehicle bombing in random locations in the ground floor is evaluated. For this evaluation, reliability analysis of the building structure is conducted using a Monte Carlo simulation method and the results are obtained using a dynamic analysis of a finite element model and LS-DYNA software. The random variables considered herein are the location of the explosion, the time history of the blast loading, the gravity loads and the slab depth. In order to investigate the effect of the explosion location on the probability of failure, the building plan was first divided into three categories including the center, side and corner areas, then by randomly generating the explosion in each area, the probability of different level of damages to the building was calculated. Based on the results obtained in this study, the probability of failure in the central area of the plan is more significantly compared with those of the other areas. Finally, it is shown that by strengthening the central columns, the probability of heavy damages (damages greater than 55%) for blast loadings containing 600, 750 and 900 Kg TNT charge weights is reduced to 52%, 56% and 77%, respectively.

In Iran reinforced concrete are extensively used in construction. using rebar joint in this buildings is an unavoidable issue. mechanical splices is the common joint which used in constructions an the most important disadvantages of this joint is using big amount of rebar. Steel is a valuable material hence the optimum usage of it could be profitable for the next man kind generation an environment. One of the best approaches to use the optimum amount of rebar is to use mechanical splice in spite of overlap method. It has been recommended that to use mechanical splice in ACI 318 and the ninth issue of national building regulations. According to the problems of the operation issue in heavy concrete buildings due to thick rebar. Mechanical splices are the safe joints which could compensate other problems regarding to rebar density. In every concrete building 15% of used rebar will remains as overlap joint in concrete, therefore using mechanical splice could reduce the amount of rebar and it wastes. In this thesis Abaques software had been employed to analyze the reinforced concrete bar. The non-overlapped bars , mechanical splice equipped bars, and overlapped bars had been investigated in this study. To validate this research the problem had been analyzed experimentally by quick wedge method and straight sample.
In conclusion mechanical splice operation under stress is in good agreement with non-overlapped bars and will increase the load endurance as much as 15% in comparison with overlapped rebars.

In general, there are various reasons for the rehabilitation of structures, including earthquake-damaged buildings and buildings that are not adequately resisted due to changes in the rules of the building regulations or buildings whose use has been changed. In this regard, engineers and researchers of the country are trying to obtain the best solution with the lowest cost and highest reliability coefficient using computational methods. Due to the fact that some of the existing structures in the city of Kazeroon do not have the characteristics of an earthquake resistant structure, and most of them are constructed in accordance with the provisions of the second edition of Iran's earthquake before and after it, it is necessary to review them, Action. To be followed up with appropriate solutions, refurbish it. In this research, we first analyzed and evaluated the seismic retrofitting methods of conventional RC structures that were studied in Kazeroon city and then, using expert's opinion, and distributed and collected and analyzed by purposeful questionnaire and TOPSIS method To prioritize the appropriate method for seismic retrofit of conventional reinforced concrete buildings in Kazeroun city. The results of this research indicate that the main priorities of retrofitting of conventional reinforced concrete buildings in Kazeroon are steel armored vehicles, concrete armored concrete and concrete shear walls and the use of FRP.