Polygonal seismic isolation systems

Abstract

The invention is drawn to a methods and systems employing at least one seismic isolation bearing having a substantially polygonal shape in a top and / or bottom view. Preferably the polygonal shape is other than a square shape; preferably the shape is other than a rectangular shape. Such polygonal isolation bearings can be easily and securely joined to other components o the flooring or platform, and are of particular use in modular seismic isolation systems, in which the floor or platform can be assembled to suit the available space. In preferred systems the polygonal isolation bearings may be used in low profile systems, for example, in locations having restricted headroom.

Description

RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Patent Application No. 61 / 902,420, filed Nov. 11, 2013, the disclosure of which is hereby incorporated by reference in its entirety by reference.BACKGROUND OF THE INVENTION[0002]Although minor earthquakes are common, with thousands of smaller earthquakes occurring daily, larger magnitude seismic events can cause personal injury, death and property and environmental damage, particularly in heavily populated areas.[0003]Two approaches have been traditionally utilized to prevent or limit damage or injury to objects or payloads due to seismic events. In the first approach, used particularly with structures themselves, the objects or payload articles are made strong enough to withstand the largest anticipated earthquake. However, in addition to the relative unpredictability of damage caused by tremors of high magnitude and long duration and of the directionality of shaking, use of this method alone can be qu...

AI Technical Summary

Benefits of technology

The patent describes a special bearing that allows for equal movement in any direction, which eliminates the need for additional means to isolate non-linear forces. Additionally, the bearing surface automatically returns to its initial position after a seismic event. The seismic bearing plates can directly join to create a stable structure without the need for separate connector components. These technical effects improve the performance and reliability of the bearing.

Problems solved by technology

Although minor earthquakes are common, with thousands of smaller earthquakes occurring daily, larger magnitude seismic events can cause personal injury, death and property and environmental damage, particularly in heavily populated areas.

However, in addition to the relative unpredictability of damage caused by tremors of high magnitude and long duration and of the directionality of shaking, use of this method alone can be quite expensive and is not necessarily suitable for payloads to be housed within a structure.

Particularly for delicate, sensitive or easily damaged payload, this approach alone is not especially useful.

Such active systems are complex, and require service or routine maintenance.

Certain disadvantages to such pre-existing systems include the fact that it is difficult to establish the minimum acceleration at which the latch means is released; it is difficult to reset the latch means after the floor has been released; it may be difficult to restore the floor to its original position after it has moved in the horizontal direction; the dissipative or damping force must be recalibrated to each load; there is a danger of rocking on the vertical springs; and since the transverse rigidity of the vertical springs cannot be ignored with regard to the horizontal springs, the establishment of the horizontal springs and an estimate of their effectiveness, are made difficult.

However, the device disclosed is not designed to move horizontally in an acceleration-resisting manner.

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