Dissipation Capacity of Steel Building with Fiction Pendulum Base-Isolation System

Use of base isolators in the seismic design of structures has attracted considerable attention in recent years. The major concern in the design of these structures is to have enough lateral stability to resist wind and seismic forces. There are different systems providing such isolation, among them there are friction- pendulum base isolation systems (FPS) which are rather widely applied nowadays involving to both affordable cost and high fundamental periods. These devices are characterised by a stiff resistance against wind loads and to be flexible to the seismic tremors, which make them suitable for different situations. In this paper, a 3D numerical investigation is done considering the seismic response of a twelve-storey steel building retrofitted with a FPS. Fast nonlinear time history analysis (FNA) of Boumerdes earthquake (Algeria, May 2003) is considered for analysis and carried out using SAP2000 software. Comparisons between fixed base, bearing base isolated and braced structures are shown in a tabulated and graphical format. The results of the various alternatives studies to compare the structural response without and with this device of dissipation energy thus obtained were discussed and the conclusions showed the interesting potential of the FPS isolator. This system may to improve the dissipative capacities of the structure without increasing its rigidity in a significant way which contributes to optimize the quantity of steel necessary for its general stability

Seismic energy dissipation study of linear fluid viscous dampers in steel structure design

Energy dissipation systems in civil engineering structures are sought when it comes to removing unwanted energy such as earthquake and wind. Among these systems, there is combination of structural steel frames with passive energy dissipation provided by Fluid Viscous Dampers (FVD). This device is increasingly used to provide better seismic protection for existing as well as new buildings and bridges. A 3D numerical investigation is done considering the seismic response of a twelve-storey steel building moment frame with diagonal FVD that have linear force versus velocity behaviour. Nonlinear time history, which is being calculated by Fast nonlinear analysis (FNA), of Boumerdes earthquake (Algeria, May 2003) is considered for the analysis and carried out using the SAP2000 software and comparisons between unbraced, braced and damped structure are shown in a tabulated and graphical format. The results of the various systems are studied to compare the structural response with and without this device of the energy dissipation thus obtained. The conclusions showed the formidable potential of the FVD to improve the dissipative capacities of the structure without increasing its rigidity. It is contributing significantly to reduce the quantity of steel necessary for its general stability

Assessment of a historical railway bridge toward traffic regulationrequirements

Not far away from the Algerian town of Tlemcen, an arch bridge was built, in 1889, with the purpose of enabling the railway link to cross a rather sharp mountain area. The structure was named the El Ourit bridge, and its design was conceived by the world-famous French engineer Gustave Eiffel. The bridge is now 123 years old and it is demanded to satisfy the present safety requirements, resulting from new train traffic features and from the updated seismic code. The different components of the bridge were deeply inspected by a geometric, topographic and pathological survey. Specimens of wrought iron were tested in the laboratory to characterize the behavior of the bridge constitutive material,. A finite element model of the bridge was then created on the basis of its actual geometry. A historical ground motion record was used to carry out the dynamic analysis. The structural safety was checked with reference to the last version of the Algerian seismic code. It was possible to conclude that the original design is consistent even with the seismic hazard update

Dissipative Capacity Analysis of Steel Buildings using Viscous Bracing Device

Abstract — Energy dissipation Systems in civil engineering structures are sought when it comes to removing unwanted energy such as instability, earthquake and wind. Among these systems, there is the combination of structural steel frames with passive energy dissipation provided by Fluid Viscous Dampers (FVD). This device is increasingly used to provide better seismic protection for existing as well as new buildings and bridges. A 3 D numerical investigation is done considering the seismic response of a twelve-story steel building moment frame with diagonal FVD that have linear force versus velocity behaviour. Nonlinear time history, which is being calculated by Fast nonlinear analysis (FNA), of Boumerdes earthquake (Algeria, May 2003) is considered for the analysis and carried out using the SAP2000 software and comparisons between unbraced, braced and damped structure are shown in a tabulated and graphical format. The results of the various systems are studied to compare the structural response with and without this device of the energy dissipation thus obtained were discussed. The conclusions showed the formidable potential of the FVD to improve the dissipative capacities of the structure without increasing its rigidity. It is contributing significantly to reduce the quantity of steel necessary for its general stability