Seismic base isolation system for barrel racks

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.

1 . A base isolation system for a container comprising:
 a plate sliding on a foundation, positioned between the container and the foundation such that the plate contacts a surface of the foundation, the plate comprising:
 a plate base; 
 an underlayer comprising a polymer and affixed to a surface of the plate facing the foundation; 
 a coating located between the underlayer and the foundation; and 
   a releasable connector to couple the container to the plate, wherein the polymer of the underlayer and the coating are configured such that, in combination, a coefficient of static friction and a coefficient of kinetic friction between the coating and the foundation prevents relative movement at an interface between the plate and the foundation in normal operation and permits the plate to move relative to the foundation during a seismic event,   wherein the surface of the foundation is altered to achieve the coefficient of static friction and the coefficient of kinetic friction between the coating and the foundation, and   wherein the plate is an only plate between the container and the foundation and the container is placed directly on the plate.   
     
     
         2 . (canceled) 
     
     
         3 . The base isolation system of  claim 1 , wherein the foundation is a concrete floor. 
     
     
         4 . The base isolation system of  claim 1 , 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 . (canceled) 
     
     
         7 . The base isolation system of  claim 1 , wherein the coating is 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 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . A method of isolating the base of a container comprising:
 positioning a plate between the container and a foundation such that the plate contacts a surface of the foundation and slides on the surface, the plate comprising a plate base, an underlayer, and a plate coating;   adding the underlayer to the plate comprising a polymer with an underlayer material composition to create an isolation pad;   securing the container to the plate with a releasable connector;   polishing a surface of the foundation; and   positioning a plate coating such that the coating is located between the underlayer and the foundation,   wherein a coefficient of static friction and a coefficient of kinetic friction between the coating and the foundation are configured such that the polymer of the underlayer and the coating, in combination, prevent relative movement between the plate and the foundation in normal operation and permit the plate to move relative to the foundation during a seismic event,   wherein the polishing of the surface of the foundation alters the coefficient of static friction and the coefficient of kinetic friction between the coating and the foundation, and   wherein the plate is an only plate between the container and the foundation and the container is placed directly on the plate.   
     
     
         12 . The base isolation system of  claim 1  wherein the polymer is selected from one of the following: high density polyethylene (HDPE), ultra-high molecular weight polyethylene (UHMW), polyester triglycidyl isocyanurate (TGIC polyester), polyester powder coating, and silicone-epoxy. 
     
     
         13 . A base isolation system for a container comprising:
 a plate sliding on a foundation, positioned between the container and the foundation such that the plate contacts a surface of the foundation, the plate comprising:
 a plate base; 
 an underlayer with a material composition is affixed to a surface of the plate facing the foundation; 
 a coating deposited such that the coating is located between the underlayer and the foundation; and 
   a releasable connector to couple the container to the plate,
 wherein the material composition of the underlayer and the coating are configured, in combination, as a means for providing a coefficient of static and kinetic friction between the coating and the foundation that prevents relative movement between the plate and the foundation in a normal operation while permitting the plate to move relative to the foundation during a seismic event, 
 wherein the surface of the foundation is altered to achieve the coefficient of static friction and the coefficient of kinetic friction between the coating and the foundation, and 
 wherein the plate is an only plate between the container and the foundation and the container is placed directly on the plate. 
   
     
     
         14 . (canceled) 
     
     
         15 . The base isolation system of  claim 1  wherein the plate coating is a lubricating fluid. 
     
     
         16 . The base isolation system of  claim 13  wherein the plate coating is a lubricating fluid. 
     
     
         17 . A base isolation system for a container comprising:
 a plate sliding on a foundation, positioned between the container and the foundation such that the plate contacts a surface of the foundation, the plate comprising:
 a plate base; 
 an underlayer sliding directly on the foundation, the underlayer comprising a polymer and affixed to a surface of the plate facing the foundation; 
 a coating deposited located between the underlayer and the foundation; and 
   a releasable connector to couple the container to the plate,    wherein the polymer of the underlayer and the coating are configured such that, in combination, a coefficient of static friction and a coefficient of kinetic friction between the coating and the foundation prevents relative movement at an interface between the plate and the foundation in normal operation and permits the plate to slide relative to the foundation during a seismic event, and    wherein the surface of the foundation is altered to achieve the coefficient of static friction and the coefficient of kinetic friction between the coating and the foundation, and    wherein the plate is an only plate between the container and the foundation and the container is placed directly on the plate.   
     
     
         18 . The base isolation system of  claim 1  wherein the underlayer is made of high density polyethylene. 
     
     
         19 . The base isolation system of  claim 1  wherein the underlayer is made of silicone epoxy. 
     
     
         20 . The base isolation system of  claim 17  wherein the underlayer is made of high density polyethylene. 
     
     
         21 . The base isolation system of  claim 17  wherein the underlayer is made of silicone epoxy. 
     
     
         22 . The base isolation system of  claim 1  wherein the underlayer slides without restriction on the foundation during a seismic event. 
     
     
         23 . The base isolation system of  claim 1  wherein the underlayer slides continuously across the foundation during a seismic event. 
     
     
         24 . The base isolation system of  claim 1  wherein the sliding of the underlayer on the foundation is unbounded.