This article is about the methods and techniques used in the building ＂retrofit＂ in modernist style designed by the architect Affonso Eduardo Reidy in the fifties, and also about the project of the new Rio de Janeir...This article is about the methods and techniques used in the building ＂retrofit＂ in modernist style designed by the architect Affonso Eduardo Reidy in the fifties, and also about the project of the new Rio de Janeiro MIS （Museum of Image and Sound）, under construction, by The North-American office Diller Scofidio ＋ Renfro, both located in the city of Rio de Janeiro. These constructions present a wide view of the concept of sustainability, not commonly used in public buildings in Brazil. In the building designed by Reidy, which belongs to the State of Rio de Janeiro, the regeneration to host the new headquarters of the State Department of Taxation and Finance respected its original characteristics and used smart and sustainable design techniques, as well as recyclable materials. On the other hand, the project of the new museum at Copacabana Beach was entirely planned on sustainable bases and it includes the application of building techniques concerning that purpose. This article presents a study of these two cases and evaluates the techniques and materials used in one another. Observing the principles of sustainability in construction is a pioneering initiative of the State Government. This article aims at making the scientific community aware of the needs of immediate adoption of sustainability techniques in Civil Engineering, not only in the construction of new buildings, but also in the regeneration of the existing ones, as well as the need of imperious adoption of sustainable techniques when it comes to maintainability.展开更多
Wind energy is a clean and renewable energy for which technology has developed rapidly in recent years.Wind turbines are commonly supported on tubular steel towers.As the turbine size is growing and the towers are ris...Wind energy is a clean and renewable energy for which technology has developed rapidly in recent years.Wind turbines are commonly supported on tubular steel towers.As the turbine size is growing and the towers are rising in height,steel towers are required to be sufficiently strong and stiff,consequently leading to high construction costs.To tackle this problem,a new type of prestressed concrete tower was designed employing a novel tower concept having a regular octagon cross section with interior ribs on each side,which was optimized by comparing the natural frequency and stress difference under the same lateral load in different directions of the tower.The designed tower features a tapered profile that reduces the area subjected to wind;the tapered profile reduces the total weight,applied moment and the capital cost.An optimization method was developed employing ABAQUS software and a genetic algorithm.A target function was defined on the basis of the minimum cost of the concrete and prestressed tendon used,and constraints were applied by accounting for the stress,displacements and natural frequency of the tower.Employing the method,a 100 m prestressed concrete tower system for a 5 MW turbine was optimized and designed under wind and earthquake loads.The paper also reports a systematic design procedure incorporating the finite element method and the optimization method for the prestressed concrete wind-turbine towers.展开更多
文摘This article is about the methods and techniques used in the building ＂retrofit＂ in modernist style designed by the architect Affonso Eduardo Reidy in the fifties, and also about the project of the new Rio de Janeiro MIS （Museum of Image and Sound）, under construction, by The North-American office Diller Scofidio ＋ Renfro, both located in the city of Rio de Janeiro. These constructions present a wide view of the concept of sustainability, not commonly used in public buildings in Brazil. In the building designed by Reidy, which belongs to the State of Rio de Janeiro, the regeneration to host the new headquarters of the State Department of Taxation and Finance respected its original characteristics and used smart and sustainable design techniques, as well as recyclable materials. On the other hand, the project of the new museum at Copacabana Beach was entirely planned on sustainable bases and it includes the application of building techniques concerning that purpose. This article presents a study of these two cases and evaluates the techniques and materials used in one another. Observing the principles of sustainability in construction is a pioneering initiative of the State Government. This article aims at making the scientific community aware of the needs of immediate adoption of sustainability techniques in Civil Engineering, not only in the construction of new buildings, but also in the regeneration of the existing ones, as well as the need of imperious adoption of sustainable techniques when it comes to maintainability.
基金supported by the National Natural Science Foundation of China(Grant No.51078231)
文摘Wind energy is a clean and renewable energy for which technology has developed rapidly in recent years.Wind turbines are commonly supported on tubular steel towers.As the turbine size is growing and the towers are rising in height,steel towers are required to be sufficiently strong and stiff,consequently leading to high construction costs.To tackle this problem,a new type of prestressed concrete tower was designed employing a novel tower concept having a regular octagon cross section with interior ribs on each side,which was optimized by comparing the natural frequency and stress difference under the same lateral load in different directions of the tower.The designed tower features a tapered profile that reduces the area subjected to wind;the tapered profile reduces the total weight,applied moment and the capital cost.An optimization method was developed employing ABAQUS software and a genetic algorithm.A target function was defined on the basis of the minimum cost of the concrete and prestressed tendon used,and constraints were applied by accounting for the stress,displacements and natural frequency of the tower.Employing the method,a 100 m prestressed concrete tower system for a 5 MW turbine was optimized and designed under wind and earthquake loads.The paper also reports a systematic design procedure incorporating the finite element method and the optimization method for the prestressed concrete wind-turbine towers.
