Resilient Structural Systems - Using Mechanisms to Optimize Performance

摘要

Including mechanical devices into structural systems can lead to innovative enhancement of performance of structures subjected to extreme loadings. These devices can be designed to provide required strength while controlling behavior to protect structural elements from damage. Systems can be designed to "fuse" during extreme events such as strong earthquake ground motions. The result is resilient structural systems - optimized structural systems that perform better than more conventional system. Until recently, the San Francisco International Terminal was the largest seismically isolated building in the world. Friction pendulum isolators were introduced to protect the superstructure of this essential facility and to assist in the goal of continued operation for the facility after a major seismic event. The 8 Washington Residential Project, also in San Francisco, is a new paradigm in high performance structures where protection of the initial investment is essential. Triple friction pendulum isolation bearings are used to control building behavior and reduce damage even with the potential of an extreme earthquake and marginal soil conditions. Structural steel pins combined with cast-in-situ reinforced concrete trusses provide links between large wing sections of the Huawei Research and Development Facility in Shanghai, China. Steel pins are designed to provide continuum over atria during wind and moderate seismic events. If the structure is subjected to extreme ground motions the pins are designed to fuse, dissipating energy while protecting the reinforced concrete structure from damage. Pin-Fuse Seismic Systems have been developed to dissipate energy in seismic events through friction rather than plastic deformation of primary steel systems. The Pin-Fuse Joints and Frames have been designed and tested as mechanisms that protect buildings from damage. Joints remain fixed during wind and low to moderate seismic conditions and fuse or slip during significant seismic events. Instead of linking reinforced concrete shear wall systems with conventionally reinforced link beams, a steel mechanism has been developed to provide full connection between wall elements during wind and moderate seismic conditions but can also fuse or slip during very significant seismic events. Link-Fuse Joints use friction to dissipate energy while maintaining elastic behavior in linking elements and neighboring wall elements.