SEISMIC BASE ISOLATION SYSTEM FOR BARREL RACKS
20220104620 · 2022-04-07
Inventors
Cpc classification
F16F7/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
A47B81/007
HUMAN NECESSITIES
F16F15/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
This base isolation system protects barrel racks from earthquake motions through a pad designed to slide on a prepared surface to critically reduce the amount of energy otherwise transferred to a stack of barrels. The pad is comprised of two layers: a plate, usually steel, and an underlayer, usually a high density plastic. The interaction of the underlayer with the prepared surface depends on a coefficient of static and kinetic friction between the underlayer and the surface that prevents relative movement in normal operation and yet allows the isolation pad to move relative to the surface during a seismic event.
Claims
1. An base isolation system for a container comprising: a plate positioned between the container and a foundation; an underlayer affixed to a surface of the plate facing the foundation; and a releasable connector for securing the container to the plate wherein the underlayer is selected to provide a coefficient of static and kinetic friction between the underlayer and the foundation that prevents relative movement of the isolation pad and foundation in normal operation and yet allows the isolation pad to move relative to the foundation during a seismic event.
2. The base isolation system of claim 1, wherein the foundation is altered to achieve the coefficient of static and kinetic friction between the underlayer and the foundation that prevents relative movement of the isolation pad and foundation in normal operation and yet allows the isolation pad to move relative to the foundation during a seismic event.
3. The base isolation system of claim 2, wherein the foundation is a concrete floor.
4. The base isolation system of claim 2, wherein the alteration to the foundation is polishing.
5. The base isolation system of claim 1, further comprising a container holding structure between the container and the plate.
6. The base isolation system of claim 1, further comprising a damper connected to the foundation and the plate.
7. The base isolation system of claim 1, further comprising a lubricant disposed between the underlayer and the foundation to reduce the coefficient of static and kinetic friction.
8. The base isolation system of claim 1, wherein the releasable connector is a toggle bolt.
9. The base isolation system of claim 5, wherein the releasable connector is operably located between the container holding structure and the plate.
10. The base isolation system of claim 5, further including a receiving structure for inserting a part of the container holding structure.
11. A method of isolating the base of a container comprising: positioning a plate between the container and a foundation; adding an underlayer to a plate to create an isolation pad wherein the underlayer is selected to provide a coefficient of static and kinetic friction between the underlayer and the foundation that prevents relative movement of the isolation pad and foundation in normal operation and yet allows the isolation pad to move relative to the foundation during a seismic event; securing the container to the plate with a releasable connector; and optionally polishing or otherwise altering the foundation (e.g., floor or ground) to refine the coefficient of friction.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0031] Described herein is a technology for, among other things, providing base isolation to protect wine barrels, casks, or other any other container from sudden ground motions, such as an earthquake, blast wave, or other event. In one example, the disclosure relates to a seismic isolation pad comprising at least a plate and a underlayer. In this example, the plate and underlayer are affixed to each other. The container or container holding structure rests on the plate. The underlayer rests on a foundation which can be the ground, floor, building foundation, or any similar structure. One of ordinary skill in the art will recognize that a foundation can be any supporting layer of a structure, and a floor can be the walking surface of a room, which may vary from simple dirt to many-layered surfaces using modern technology, such as stone, wood, bamboo, metal, or any other material that can hold a person's or equipment's weight.
[0032] In addition, the coefficients of static and kinetic friction between the underlayer and the foundation can prevent relative movement of the two plates with normal operation and yet allow the plate to move relative to the foundation during a seismic event. In an example, the coefficient of kinetic friction is low so that the underlayer can move relative to the foundation during a seismic event, but not too low so that the stability of the system is maintained when the isolation pad is moving in the seismic event. More particularly, the coefficient of static friction is low so that the isolation pad can begin moving when a seismic event occurs, but is sufficiently high to prevent movement of the pad in normal operation. Similarly, the coefficient of friction of the plate and the container or container holding structure must be sufficiently high that the isolation pad does not move relative to the containers, if it is not affixed.
[0033] In one example, the underlayer is in communication with the foundation and the plate is in communication with the container or container holding structure. The plate can be textured, so that the interface between the plate and the container or container holding structure is not smooth. The underlayer (which interfaces with the foundation) is smooth or non-textured, resulting in the desired coefficients of kinetic and static friction between the underlayer and the surface. In another example, an additional material (e.g., a lubricating fluid, plate coating, etc.) may be deposited between the underlayer and the foundation to achieve an optimal or desired coefficient of friction.
[0034] In one example, the plate and underlayer may be designed to an optimal thickness. In one example, the plate is 0.25″ steel plate. In another example, the plate may be corrosion-resistant.
[0035] In some examples, the plate is welded to the container holding structure. In another example, the disclosed plate is textured with diamond-shaped ridges. Such diamond-shaped ridges create a textured surface and optimize the coefficients of static and kinetic friction between the plate and the container or container holding structure in order to maximize the stability of seismic isolation system both when the foundation is moving and when the foundation is not moving.
[0036] In accordance with the present disclosure, a sliding surface (e.g., the foundation or the plate) has a coating forming the underlayer in order to achieve the desired coefficients of kinetic and static friction. The underlayer coating may be made of a material such as polyethylene. For instance, in one example, the plate is made of a suitable material (e.g., steel) and coated with an underlayer of polyethylene. It is appreciated that one of ordinary skill could utilize high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMW), polyester triglycidyl isocyanurate (TGIC polyester), a commercially available polyester powder coating, or a silicone-epoxy, low surface energy coating, depending on the situation and desired coefficient of friction.
[0037] In operation, the disclosed seismic isolation pad is first placed above a foundation. For example, the underlayer can be set directly on a ground, floor, building, or floor tile. Moreover, one of ordinary skill in the art will recognize that the number, size, and shape of the plate or plates may vary as desired. The container or container holding structure is placed on top of the plate and optionally affixed to it. In one example, the container holding structure is welded to the plate. One of ordinary skill would appreciate that the plate could also be affixed to the container or container holding structure with any conventional means including adhesives, mechanical fasteners, or the like. The coefficients of static and kinetic friction between the underlayer and the foundation prevent relative movement of the two plates with normal operation and yet allow the top plate to move relative to the base plate during a seismic event.
[0038] If the coefficient of friction between the foundation and the underlayer is not desirable the floor can be altered to change this property. For instance, if the floor has too low of a coefficient of friction, texture can be added such as ridges in the foundation. More commonly, the coefficient of friction is too high especially because many storage facilities use some form of concrete floors. These conventional floor types include conventional concrete, cementious urethane, epoxy suspended marble and quartz, and epoxy finished flooring.
[0039] In the concrete floor example, the floors can be machined or polished to lower the coefficient of friction. For a concrete floor, one example process is done in a series of steps beginning with a coarse diamond wheel. The diamond segments in the wheel are coarse enough to remove minor pits, blemishes, stains, or light coatings from the floor in preparation for final smoothing. This initial rough grinding is generally a three to four step process. The next steps involve fine grinding and lapping of the concrete surface using an internal impregnating sealer. Alternatively, an additional material (e.g., lubricate liquid) may be added between the base plate and the top plate to achieve the desired coefficients of kinetic and static friction.
[0040] The graph of
[0041] The present disclosure also relates to a seismic isolation system with a damping system. In one example, one or more external dampers are mounted besides the isolation pad and affixed to the plate, container, or container holding structure, in order to limit and/or dampen the movement of container or container holding structure in an earthquake. The damping system can further include one or more internal dampers (e.g., neoprene dampers) mounted on the uncovered part of the plate or the foundation under the container or container holding structure and capable of limiting or damping any movement.
[0042] The present disclosure also relates to methods for providing base isolation against earthquake forces. The disclosed method includes at least one of the following steps: adding an underlayer to a plate to create an isolation pad wherein the underlayer is selected to have a suitable coefficient of friction with a foundation to keep the container or container holding structure still under normal operation but allow movement in a seismic event; locating and affixing the isolation pad under the container or container holding structure; and optionally polishing or otherwise altering the foundation (e.g., floor or ground) to refine the coefficient of friction.
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[0050] Although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited hereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalent.