The scope of this study is the investigation of the rehabilitation of structures retrofitted by use of carbon-fb01brereinforced plastics (CFRPs) to achieve a safe, economic and practicable level of seismic damage. This paper investigates analytically the efficiency of the strengthening technique for improving the seismic behavior of damaged structures. 4 beam-column connections are tested under reversed cyclic load. The connections have none-seismic detailing of rebars, i.e., no transverse rebar and seismic stirrups are used in the joint core and beam and column critical end zones. The joints are damaged in different levels and then retrofitted by CFRP sheets. The strengthened joints are tested again to reach the ultimate drift capacity. Then, the tested joints, such as reference joint and retrofitted joints, are analyzed by Opensees nonlinear software. The results of joint analysis are compared with experimental behavior of specimens. The hysteresis curves of the modeled joints had a high level of accuracy in terms of stiness degradation, moment carrying capacity, capacity degradation and energy dissipation. In the following, a multi-story/multibay moment-resisting frame is selected for assessment of seismic response of damaged frames. So, a step-by step pushover analysis is done in order to find the plastic hinge positions and the level of plasticity on the moment resisting frame. The plastic hinges are developed on the beam ends and middle length of the frame beams. As the analysis progresses, the damaged frames are categorized in 7 levels according to performance levels defined by FEMA 356. The damaged Frames are retrofitted by CFRP sheets, considering the level of damage similar to the tested joints mentioned above. At the end, the retrofitted frames are subjected to El-Centro base acceleration. The root mean square parameter of roof displacement is also calculated for nonlinear time history response of frames. The retrofitting of the plastic hinges improved the RMS of the responses and compensated the lost capacity and stiffness. The results show that Reparability level of frames retrofitted by CFRP sheets is equal to the level that the hinges on all of the beams are formed in collapse-preventing performance level. This level for specific frame investigated in this study is equal to 1.03% storey drift. Also, the results show that structures could be retro fitted by external bonding of FRP sheets to a limited level. If the damage level of structures is higher than this Reparability level, other rehabilitation methods may be useful.

In this article economic loss means those losses occurring independently of physical damage to things or to a person's body or health. There are two main positions about Reparability of these losses: In some countries like French, Belgium, Spain, Italy and Luxembourg as a principle rule economic loss is recoverable and there is no difference between economic loss and other losses. But in some other countries like Germany, England, America, Canada, Switzerland, Scandinavian countries and Austria there is a rule of no-recovery in tort for pure economic loss and such losses is recoverable only in exceptional cases. Considering some laws in Iran's legal system and their foundations in Islamic jurisprudence, we can set Iranian law in last group. It seems that considering social and economic observations this is a positive feature of Islamic law and Iran's legal system and not its defect.

This paper briefly reviews the development of earthquake resistant design of buildings. The state-of-the-art of seismic design is discussed from the viewpoint of the performance criteria of buildings. These are (a), serviceability from frequent minor-intensity earthquake motions, (b) Reparability from an infrequent but major-intensity earthquake motion, and (c) life safety from the maximum possible earthquake motion. The relation between the strength and ductility is discussed in length. With the introduction of performance-based engineering, the importance of Reparability and serviceability criteria is emphasized. The concept of capacity design is outlined. A weak-beam strong-column mechanism is selected as an example of the target yielding mechanism for design.

This paper introduces a novel design concept for the development of efficient, sustainable Rocking-Wall Moment Frames (RWMFs) under seismic conditions. The proposed concepts lead to a novel structural configuration with provisions for Collapse Prevention (CP), Self-Centering (SC), Reparability, performance control (PC), damage reduction, and energy based seismic analysis. It introduces the merits of design led analysis (DLA) over the traditional methods of approach, followed by the development of a lateral resisting system that is more efficient than its conventional counterparts. The fundamental idea behind the proposed methodology is that seismic structural response is mainly a function of design and construction, rather than numerical analysis. In design led analysis the rules of mechanics and structural design are induced rather than followed. The new system is a combination of grade beam restrained moment frames and articulated shear walls, tied to each other by means of post tensioned (PT) stabilizers and Gap Opening Link Beams (GOLBs).

The research leading to this paper was prompted by the need to estimate strength and stiffness of Rigid Rocking Cores (RRCs) as essential elements of resilient earthquake resisting structures. While a limited number of such studies have been reported, no general study in terms of physical properties of RRCs, their appendages and adjoining structures have been published. Despite the growing knowledge on RRCs there are no design guidelines on their applications for seismic protection of buildings. The purpose of the present article is to propose effective rigidity limits beyond which it would be unproductive to use stiffer cores and to provide basic guidelines for the preliminary design of RRCs with a view to collapse prevention, re-centering and post-earthquake repairs/replacements. Several examples supported by computer analysis have been provided to demonstrate the applications and the validity of the proposed solutions.

The paper introduces a new earthquake resistant rocking-wall moment frame (RWMF) that is capable of damage reduction, collapse avoidance and self-centering due to strong ground motion. The system consists of a grade beam restrained moment frame, (GBRMF) attached to a co-planar, post tensioned (PT) rigid rocking core (RRC) by means of gap opening link beams (GOLBs) and buckling restrained braces (BRBs). Several practical details aiming at damage reduction have been presented. Worked examples have also been provided to demonstrate the validity of the proposed solutions. All results have been verified by independent computer analysis. The proposed formulae are ideally suited for preliminary design and teaching purposes.

The need to improve the seismic performance of buildings has brought about innovative systems such as rocking wall-moment frame (RWMF) combinations. The behavior of RWMFs can best be visualized by the moment frame (MF) restraining the wall in place, and the rigid rocking wall (RRW) providing additional damping and imposing uniform drift along the height of the frame. A novel method of analysis followed by the development of a new lateral resisting system is introduced. The proposed concepts lead to an efficient structural configuration with provisions for self-centering, Reparability, performance control, damage tolerance and collapse prevention. Exact, unique, closed form formulae have been provided to assess the collapse prevention and self-centering capabilities of the system. The objective is to provide an informative account of RWMF behavior for preliminary design as well as educational purposes. All formulae have been verified by independent computer analysis. Parametric examples have been provided to verify the validity of the proposed solutions.

Various solutions have been proposed to enhance the ductility of the bracings system in recent years. Accordingly, the development of steel rings as structural fuses could be counted as one of the successful attempts which need to be further studied. In this respect, this paper addresses a novel diamond-scheme bracing system equipped with a steel ring whose function is to act as a sacrificial fuse. This system has been majorly developed to improve ductility and energy absorption of the conventional bracing system that is known as the prime shortfalls of this system. In this system, diagonals and ring are arranged in such a way to act in parallel. to conduct the analyses, a test specimen with pinned and semi-rigid connections was studied using ABAQUS software. Furthermore, numerical analyses were carried out on large-scale models once including the ring with varying thicknesses and also, on the bracing system without the ring (i. e. a link element with high rigidity was replaced for the ring) and lastly, the results were compared with the performance of a concentrically-braced frame (CBF). The results indicate that promisingly, the presence of the link enhances the load-carrying capacity of the system by 9 and 1. 75 greater than that of the semi-rigid model and CBF. In general, it was concluded that despite adequate Reparability, the proposed system benefits from sufficient ductility and energy absorption capacity.