Class of Bearings to Protect Structures from Earthquake and Other Similar Hazards

Abstract

A class of bearings, each of them can be used as a connector to connect two parts in a structural system and as a supporter to transfer loads from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. While performing load transmission, it is able to reduce the transmission of transient vibrations between connected two structural parts and preserve the integrity of entire structural system; for examples, to protect a bridge's structural integrity when either an earthquake strikes its pier and foundation or a tsunami hits its superstructure or both occur simultaneously.

1 . An apparatus that is used as a connector to connect two parts in a structural system while as a supporter to transfer forces from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. As the conventions in this claim and associated claims, a “structural part” refers to a part of said structural system, for example, super or substructure; whereas a component of said apparatus is termed “a piece” or “a piece of said apparatus”.
 Said apparatus can provides robust connection between two connected structural parts when said system is under static load condition or is struck by the dynamic loads under a designed level; it is also able to reduce the transmission of transient vibrations and associated inertia force through relative-sliding in one or multiple V-shape contact surface-pairs in said apparatus when said system is struck by the dynamic loads above said designed level; it also has the capability to self-restore said system's original state after said relative sliding; wherein 
 (a) said apparatus comprises at least two pieces along its vertical direction; 
 (b) said vertical direction is the direction of the force with the largest amplitude among all said forces transferred by said apparatus under static conditions or the dynamic loads under said designed level; earth gravity is such a force for buildings and bridges; therefore, a horizontal plane of said apparatus is parallel to earth surface; 
 (c) said apparatus comprises at least one V-shape contact surface-pair; wherein a V-shaped contact surface in a said surface-pair is concave and formed by at least two facets; whereas another V-shape contact surface is convex and formed by the equal or less number of facets in its counterpart; wherein a said facet is a piece of plane that is not parallel to said horizontal plane of said apparatus; 
 (d) said V-shape contact surface-pair in said apparatus, wherein the two V-shape surfaces in a pair can be either bonded together through adhesive or simply overlaid without additional bonding material or separated by single or multiple mate sheets in-between; for the last two cases, a relative sliding along at least one facet pair of said contact surface-pair is permissible; 
 (e) said mate sheet contained between two surfaces in a V-shape contact surface-pair; wherein said mate sheet is made of the material selected from the group that includes metal, composite, and elastomer, so as to be able to accommodate relative rotation while no loss of contact occurs within all involved contact surface-pairs when said mate sheet is make by the material that is softer than the material of said V-shape surface-pair, and to adjust contact friction coefficient when said mate sheet contains pre-made cuts to adjust contact area; 
 (f) said apparatus comprises at least one V-shape contact surface-pair; wherein the top-most V-shape contact surface belongs to an apparatus' piece that is mounted either directly, or through other pieces, to a superstructure of a said structural system; similarly, the bottom-most V-shape contact surface belongs to an apparatus's piece that is mounted either directly, or through other pieces, to the substructure of said structural system; the super and substructure are connected through all said V-shape contact surface-pairs within said apparatus; 
 (g) when said apparatus connects super and substructure of a said structural system for the purpose of seismic isolation while the superstructure's weight is transferred through said V-shape contact surface-pairs to the substructure, the angles between each facet and said apparatus' horizontal plane determines said “designed level” that allows to start temporal sliding when amplitude of a dynamic load is beyond the level, which is quantified according to the peak-ground-acceleration (PGA) predicted by USGS-published earthquake hazard map that is effective at the time for the site of the structural system inside US or by an effective earthquake hazard map published in the country where said apparatus applies. 
 
     
     
         2 . An apparatus that is used as a connector to connect two parts in a structural system while as a supporter to transfer forces from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. As the conventions in this claim and associated claims, a “structural part” refers to a part of said structural system, for example, super or substructure; whereas a component of said apparatus is termed “a piece” or “a piece of said apparatus”.
 Said apparatus can provides robust connection between two connected structural parts when said system is under static load condition or is struck by the dynamic loads under a designed level; it is also able to reduce the transmission of transient vibrations and associated inertia forces in both horizontal and vertical directions through a sliding-pin guided relative-sliding between the two connected parts of said system when the latter was struck by the dynamic loads above said designed level; it has the capability to self-restore the original state said system's after said relative sliding; wherein 
 (a) said apparatus comprises at least three pieces along its vertical direction; 
 (b) said vertical direction is the direction of the force with the largest amplitude among all said forces transferred by said apparatus under static conditions or the dynamic loads under said designed level; earth gravity is such a force for buildings and bridges; therefore, a horizontal plane of said apparatus is parallel to earth surface; 
 (c) said apparatus comprises at least one V-shape contact surface-pair; wherein a V-shaped contact surface in a said surface-pair is concave and formed by at least two facets; whereas another V-shape contact surface is convex and formed by the equal or less number of facets in its counterpart; wherein a said facet is a piece of plane that is not parallel to said horizontal plane of said apparatus; 
 (d) said apparatus comprises at least one V-shape contact surface-pair; wherein the top-most V-shape contact surface belongs to an apparatus' piece that is mounted either directly, or through other pieces, to a superstructure of a said structural system; similarly, the bottom-most V-shape contact surface belongs to an apparatus's piece that is mounted either directly, or through other pieces, to the substructure of said structural system; the super and substructure are connected through all said V-shape contact surface-pairs within said apparatus; 
 (e) said V-shape contact surface-pair in said apparatus, wherein the two V-shape surfaces in a pair can be either bonded together through adhesive or simply overlaid without additional bonding material or separated by single or multiple mate sheets in-between; for the last two cases, a relative sliding along at least one facet pair of said contact surface-pair is permissible; 
 (f) said mate sheet contained between two surfaces in a V-shape contact surface-pair; wherein said mate sheet is made of the material selected from the group that includes metal, composite, and elastomer, so as to be able to accommodate relative rotation while no loss of contact occurs within all involved contact surface-pairs when said mate sheet is make by the material that is softer than the material of said V-shape surface-pair, and to adjust contact friction coefficient when said mate sheet contains pre-made cuts to adjust contact area; 
 (g) said apparatus comprises at least one sliding-pin and a means for said guided-sliding; wherein said sliding-pin has two straight parts along its longitude direction; the two parts bend towards each other with the angle that coincides to an angle between two opposite facets in a V-shape contact surface within said apparatus; the transverse section's geometry along one straight part of said pin is designed to fit into a guiding-rail that is built into a piece of said apparatus with one V-shape contact surface in said surface-pair; whereas the section of another straight part of said pin is with designed geometry that is able to sliding through an open-slit in a side-stopper that is a part of or fastened to another piece of said apparatus with another V-shape contact surface in said surface pair; so the sliding-pin is able to move freely along said guiding-rail or through said side-stopper's open-slit or doing the both simultaneously, establishing a sliding-able connection between the two pieces within said apparatus that originally was contacted through V-shape surface-pair but forbid any other relative motions between the pair; 
 (h) said apparatus with additional damping core; wherein said apparatus contains at least one cavity; wherein at least one said cavity starts at a point in the apparatus' piece that is with said top-most V-shape contact surface and at least one said cavity ends at the point in the apparatus' piece that is with said bottom-most V-shape contact surface; all the cavities are filled with damping medium that is selected from the group of materials with high capacity of plastic deformation, for example, Lead and Tin, or a mixing of this class of materials. 
 (i) when said apparatus connects super and substructure of a said structural system for the purpose of seismic isolation while the superstructure's weight is transferred through said V-shape contact surface-pairs to the substructure, the angles between each facet and said apparatus' horizontal plane determines said “designed level” that allows to start temporal sliding when amplitude of a dynamic load is beyond the level, which is quantified according to the peak-ground-acceleration (PGA) predicted by USGS-published earthquake hazard map that is effective at the time for the site of the structural system inside US or by an effective earthquake hazard map published in the country where said apparatus applies. 
 
     
     
         3 . Said apparatus in  claim 1  or  2  with additional vertical reinforcement mechanism; wherein the apparatus comprises at least one vertically-aligned pin; wherein one end of each said vertically-aligned pin is fastened to the apparatus' piece that is or above the piece with said top-most V-shape contact surface; whereas another end of the pin is fastened to the apparatus' piece that is or below the piece with said bottom-most V-shape contact surface; none of vertically-aligned pins is able to rotate freely around either of its ends after fastened to the corresponding pieces of said apparatus 
     
     
         4 . An apparatus that is used as a connector to connect two parts of a structural system and as a supporter to transfer loads from one part to another, for examples, gravity of a superstructure to a substructure in a bridge or a building, or that of a machine to its foundation. As the conventions in this claim, a “structural part” refers to a part of said structural system, for example, super or substructure; whereas a component of said apparatus is termed a piece or a piece of the apparatus; a piece or a structural part is a component of the structural system.
 Said apparatus can provides robust connection between two connected structural parts when said system is under static load condition or is struck by the dynamic loads under a designed level; it is also able to reduce the transmission of transient vibrations and associated inertia forces in both horizontal and vertical directions through at least one vertically-reinforced pin between the two connected parts of said system when the latter is struck by the dynamic loads above said designed level; it has the capability to self-restore the original state said system's after said relative sliding; wherein 
 (a) said apparatus comprises at least four pieces; 
 (b) said vertical direction is the direction of the force with the largest amplitude among all said forces transferred by said apparatus under static conditions or the dynamic loads under said designed level; earth gravity is such a force for buildings and bridges; therefore, a horizontal plane of said apparatus is parallel to earth surface; 
 (c) said apparatus comprises at least one V-shape contact surface-pair; wherein the top-most V-shape contact surface belongs to an apparatus' piece that is mounted either directly, or through other pieces, to a superstructure of a said structural system; similarly, the bottom-most V-shape contact surface belongs to an apparatus's piece that is mounted either directly, or through other pieces, to the substructure of said structural system; the super and substructure are connected through all said V-shape contact surface-pairs within said apparatus. 
 (d) said contact surface-pair in said apparatus, wherein the two surfaces in a pair can be bonded together by adhesive or they are just overlaid without additional bonding material; for the latter case a relative motion between the two surfaces is permissible; wherein said relative motion between a contacted surface-pair refers to the case that there is difference in displacements between the two surfaces but this difference does not result in loss of contact between all facet-pairs of the contact surface-pair, in other word, at least one contact facet-pair remains contacted; 
 (e) said apparatus comprises at least two vertically-aligned pins; wherein one end of each said vertically-aligned pin is fastened to the apparatus' piece that is with said top-most contact surface; whereas another end of the pin is fastened to the apparatus' piece that is with said bottom-most contact surface; so none of vertically-aligned pins is able to rotate freely around either of its ends after fastened to the corresponding pieces of said apparatus. 
 (f) when said apparatus connects super and substructure of a said structural system for the purpose of seismic isolation while the superstructure's weight is transferred through said V-shape contact surface-pairs to the substructure, the angles between each facet and said apparatus' horizontal plane determines said “designed level” that allows to start temporal sliding when amplitude of a dynamic load is beyond the level, which is quantified according to the peak-ground-acceleration (PGA) predicted by USGS-published earthquake hazard map that is effective at the time for the site of the structural system inside US or by an effective earthquake hazard map published in the country where said apparatus applies; 
 (g) said apparatus with additional damping core; wherein said apparatus contains at least one cavity; wherein at least one said cavity starts at a point in the apparatus' piece that is with said top-most V-shape contact surface and at least one said cavity ends at the point in the apparatus' piece that is with said bottom-most V-shape contact surface; all the cavities are filled with damping medium that is selected from the group of materials with high capacity of plastic deformation, for example, Lead and Tin, or a mixing of this class of materials