Pampanin 2010
In this paper, recent developments and emerging solutions for seismic performance and damage control based on traditional materials and available technology are explained. The purposes of these applications are to create affordable architecturally appealing, high seismic performance structures with limited or negligible damage resulting from earthquakes. Joint ductile articulated systems, replaceable fuses, floor to lateral load resisting system connections and post tensioned timber buildings are discussed, followed by on-site applications and case studies.
The Joined Ductile Articulated Systems
The purpose of this system is to concentrate damage in a selected region. In this system, dry joined ductile connections are used to connect the frames and the walls, creating high performance, low damage structural systems. Unbounded post tensioned bars/tendons are used in these joints. Under seismic forces, precast elements are subjected to a controlled rocking mechanism and also provide the structure with a self-centering property. Moreover, the level of damage is reduced by opening and closing an existing gap in these connections. In addition to self-centering and controlling rocking, energy dissipation capabilities are provided by internal mild steel bars. These ductile connections are able to accommodate high inelastic demand without suffering extensive material damage. They can be implemented in a number of structural systems including frames, walls, and dual systems.
The Replaceable Fuses
Internal mild steel bars or external replaceable dissipaters are used as energy dissipaters. The external fuse system is replaceable and formed by inserting the steel fuse into a steel tube that acts to restrain buckling of the fuse. The external dissipater exhibits very stable flag-shape hysteresis loops. In addition, there is no stiffness degradation due to bond losses when compared to the internally mild steel bars. Either metallic or advanced materials such as SMAs could also be used as an alternative type of energy-dissipating mechanism. The major benefit of the current configuration is replacement and cost effectiveness.
The Articulated Floor System
This system is composed of standard precast rocking/dissipative frame connections with an articulated or “jointed” floor system. The floor is connected to the lateral beams by slider/shear mechanical connectors. These connectors act as shear keys when the floor moves perpendicular to the beam and as sliders when the floor moves parallel to the beam. As a result, the system is able to accommodate the displacement compatibility demand between floor and frame by creating an articulated or jointed mechanism, effectively decoupled in both directions.
The Pres-Lam System
This system exhibits high homogeneity and good mechanical properties; therefore, apres-lam system provides high quality resistance to seismic hazards for buildings.
Reference
Pampanin, S. (2010). “Damage-Control Self-Centering Structures: From Laboratory Testing to On-site Applications,” M.N. Fardis (ed.), Advances in Performance-Based Earthquake Engineering, Geotechnical, Geological, and Earthquake Engineering 13, pp. 297-308.