DIS Seismic Isolater
Seismic testing equipment at the Energy Technology Engineering Center in California.The Need
As an earthquake protection technology to the specific needs and requirements for flexible structures, energy dissipation products are installed in the structural frame and wall and will reduce interstory drift cause by earthquakes. Dampers are introduced into structures in order to absorb much of the kinetic energy created by wind, mild tremors as well as major seismic events.The Technology
Seismic isolation bearings isolate a structure from the ground motion produced by an earthquake. The energy absorption devices are designed to absorb the energy associated with an earthquake. This seismic (Base) Isolator consists of alternate layers of rubber and steel bonded together, with a cylinder of pure lead tightly inserted through a hole in the middle. The rubber layers allow the isolator to easily displace sideways, reducing the earthquake loads felt by the building and its occupants. They also act as a spring, ensuring that the structure returns to its original position after the shaking has stopped.
Thick steel plates are bonded to the top and bottom surfaces to allow the isolator to be solidly bolted to the structure above and to the foundation below. The isolator lead core stops the structure from moving sideways under wind and other non-seismic loads. During earthquake events, the lead is pushed sideways by the rubber and steel layers absorbing a portion of the earthquake energy. This dampening affect helps to further reduce the earthquake forces and help control the lateral displacement of the structure.
Energy Dissipation (left) vs. Without Energy Dissipation (right)
Inter-story drift is reduced by a factor of approximately two with the installation of energy dissipaters.Seismic Isolation (left) vs. Without Seismic Isolation (right)
The deformation pattern of an isolated structure during an earthquake. Movement takes place at the level of the isolators. Floor accelerations are low; the building, its occupants and loose contents are safe.The deformation pattern of a conventional structure during an earthquake. Accelerations of the ground are amplified on the higher floors and the loose contents are damaged. Building deformations and distortions could be permanent.
