Classifications

• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
  • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
  • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
  • E04H9/022—Bearing, supporting or connecting constructions specially adapted for such buildings and comprising laminated structures of alternating elastomeric and rigid layers
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
  • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
  • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D27/00—Foundations as substructures
  • E02D27/32—Foundations for special purposes
  • E02D27/34—Foundations for sinking or earthquake territories
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04H—BUILDINGS OR LIKE STRUCTURES FOR PARTICULAR PURPOSES; SWIMMING OR SPLASH BATHS OR POOLS; MASTS; FENCING; TENTS OR CANOPIES, IN GENERAL
  • E04H9/00—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate
  • E04H9/02—Buildings, groups of buildings or shelters adapted to withstand or provide protection against abnormal external influences, e.g. war-like action, earthquake or extreme climate withstanding earthquake or sinking of ground
  • E04H9/021—Bearing, supporting or connecting constructions specially adapted for such buildings
  • E04H9/0237—Structural braces with damping devices

Definitions

• the present invention discloses a class of apparatuses.
• a said apparatus is used as a structural component in a large-scaled civil engineering system such as a building, a bridge, or a machine and its foundation, which has at least the following three functions: being a support to bear the weight of a part of said system, connecting different parts of the system to assure structural integrity, and transferring designed force-flows other than gravity between connected parts while damping out or isolating undesired vibrations.
• the superstructure such as a bridge's spans and deck that carries designed live loads
• the substructure that includes the bridge's piers, footing, and foundation, which supports carried superstructure.
• said bearing is a structural component that connects super and substructure, transferring carried superstructure's weight and live loads to substructure
• An earthquake is a sudden tectonic-plate's movement at a spot inside earth's crust, radiating stress waves to surrounding and resulting in earth surface's vibrations.
• ground acceleration that causes inertia forces
• resonance that accumulates the energy associated with the acceleration in structure.
• acceleration-induced internal inertia force is the key factor to cause structural damages.
• Ground acceleration can be divided into vertical (parallel to gravity direction) and horizontal component, which are respectively characterized by the corresponding peak values, teamed "Peak Ground Acceleration" (PGA) for design consideration.
• the horizontal PGA is generally higher than the verticals according to past experiences.
• Fig. 2 is the prediction of horizontal PGA for far eastern Asia.
• FIG. 3 Design of seismic-resistant buildings and bridges is one of the most active and innovative areas in the field of civil and structural engineering. Using a three-storage building, Figure 3 illustrates various arts and technologies required, proposed or already been applied in practices. The arts disclosed in this article can be used as the seismic bearing in the left-low corner of the building or in a bridge.
• bearing products can be generally divided into three categories: (i) dumper-joints that utilize traditional mechanical devices, such as piston- cylinders damper, cams-pin-friction damper, and so on, for which some modern arts are implemented with shape memory alloys and controlled by electric sensors; (ii) common structural bearings such as elastomeric that has certain enhanced lateral resistance; (iii) the bearings based on friction-pendulum mechanism that focusses on seismic isolation.
• Fig. 4 illustrates a prior art "energy absorber” (WO97/25520), whereby various zigzag-shaped interfaces, including wavy and V-shaped interface, are designed for force transmission while no sliding between the core material and the frame containing it. Obviously, it can be used as lateral bracing in Fig. 3 to damp shear force but is incapable to carry gravity.
• energy absorber WO97/25520
• Fig. 5 is the prior art (US4187573) that uses elastomer 5 to damp vibrations while the frame 11 to confine relative horizontal displacement between the contacted two parts, by which, obviously, no confinement of vertical displacement is provided.
• Fig. 6 is another prior art(WO2008/004475), a variation of conventional elastomer bearing, by which the key components are the composite block, which is made of the laminar structure by elastomer 2b and reinforce plate 2c, and the center core 3 that is made of high plasticity material. The latter' s functions are to reinforce lateral deformation resistance while improve the capacity of damping.
• the core material is Lead, this kind of bearings is also termed "Lead-Rubber Bearing (LRB)".
• Fig. 7 is the prior art (US6021992), termed friction pendulum sliding bearing (FPS). It belongs to a group that includes dozen of US patents and tens in other countries which are based on the principal of the pendulum depicted on the right-hand side of the figure, utilizing carried superstructure's weight as a natural force to resist horizontal inertia caused by ground motion. Once the spectrum of ground motion passed, the gravity restores the bearing back to its original position.
• FPS friction pendulum sliding bearing
• a pendulum is a conservative system that does not dissipate energy. Therefore, if there is no friction, an actual pendulum can swing around its static position forever once the motion is triggered. Therefore, friction between the contact surface-pair is also a key-mechanism in a FPS bearing, which requires considerable large contact area to assure enough friction force and capacity for carrying heavy superstructure. On the other hand, certain height of curved surface, at least for the bottom seat of the bearing in Fig. 7, is required to gain enough lateral resistance.
• Fig. 8 is another prior art (US5669189), termed antiseismic connector (ANSC). It is actually an assembly of a laminated elastomeric bearing 3 plus the cables (tendons) 6 fastened to the connected super and substructure by the rotatable fastener 21.
• tendons and rotatable fasteners have limited capabilities against horizontal sliding and high structure's rotation.
• this application disclose a new class of apparatuses that can be used as structural bearings that aim at the satisfaction of following criteria:
• (B) Fuser capable to accommodate a temporal separation between connected parts when one of them is struck by a transient accelerated motion that may be caused by earthquake, hurricane, barge or vessel's collision, or explosion, so as to minimize the damage to other parts.
• the first key-embodiment is the V-shape contact surface-pair, as the core of a class of the disclosed bearings, see Fig. 9; wherein said bearing is an apparatus to connect different parts of a structural system while transfer designated service-loads, for example, weight, along the direction vertical to said surface-pair between connected parts; wherein a said V-shape contact surface comprises at least two facets and fillet at the intersection between adjacent facets; wherein said "vertical” refers to the direction of a straight line that is perpendicular to the intersection line between said two adjacent facets and that has equal declinate angles to its respective projections onto the two facets.
• a said service-load introduces lateral force component on a facet with declined angle.
• the service-load introduced lateral forces from all contact facet-pair conceal each other.
• a sliding along one or multiple said facet-pairs in said V-shape surface-pair means loss of contact between the rest facet-pairs in said surface-pair; the un-balanced lateral forces tend to push said V-shape surface-pair back to fully-contacted position. Therefore, the lateral forces on a said V-shape surface assures the bearing to be a solid connecter in regular service condition and works as a resistance against lateral sliding when the structural system is suffering an external impact-induced acceleration, see Fig. 10.
• the bearings with the design of disclosed V-shape contact surface-pair are able to meet all the aforementioned criteria except the criterion (C).
• mate sheet there can be multiple or single or no mate sheet between the top and bottom pads of the bearing in Fig. 9.
• the functions of the mate sheets are to lubricate the sliding surfaces and to damp the vibrations along vertical direction.
• an additional novel design of a sliding-pin becomes necessary. This embodiment is described in Fig. 11, which makes the device satisfying the criterion (C).
• VDP vertically embedded dissipation pin
• VRP vertical reinforcement pin
• VRP vertically-reinforced pin
• Figure 1 Earthquake hazard map provided by USGS (United States Geological Survey); the iso-contour lines in the map indicate the values of the predicted horizontal "peak-ground-acceleration (PGA) with 7.5% probability of exceedance in the next 75 years. This map is used by US bridges and buildings design standard.
• PGA peak-ground-acceleration
• Figure 2 Predicted horizontal "peak-ground-acceleration (PGA) with 10% probability of exceedance in the next 50 years, in Continent of Far-Eastern Asia (excluding Pacific-Rim seismic area such as Japan ), source: Global Seismic Hazard Assessment Program (see www.usgs.gov) .
• PGA Peak-ground-acceleration
• Figure 3 Technologies currently applied for a seismic-resistant designed three-storage building; the art disclosed in this article is a class of new seismic isolation bearings showing in the left-low corner.
• Figure 4 Prior art: an energy absorber to damp lateral vibration forces through the deformation of its core 28, made of absorptive material such as lead, after pressure is imposed from vertical direction. To assure no-sliding between the core material and the frame such as top pad 10 or bottom pad 12 or the middle pad 20, various designs of the interface geometry 11 are introduced by the drawings on the right.
• Figure 5 A prior art (US4187573): a structural bearing that uses elastomer to damp lateral and vertical vibration while carry the weight of the superstructure.
• Figure 6 A prior art, WO2008/004475, which can be considered as the further development of the art in Figure 5, whereby the key component is the composite block that is made of the laminar structure by elastomer 2b and reinforce plate 2c.
• the block contains a center core 3, made of high plasticity material, e.g. Lead, to reinforce lateral deformation resistance while improve the capacity of damping.
• FIG 7 prior art (US6021992), termed friction pendulum sliding bearing (FPS), which belongs a group of dozen US patents and tens in other countries which are based on the principal of the pendulum depicted on the right-hand side of the figure, utilizing the carried superstructure's weight as a natural force to resist horizontal inertia caused by ground motion. Once such a spectrum of ground motion passed, the gravity restores the bearing back to its original position.
• Figure 8 A prior art (US5669189), termed anti-seismic connector (ANSC). It is actually an assembly of a laminated elastomeric bearing 3 plus the tie-bars (or ropes) 6 that are fastened to the connected super and substructure by the rotate-able fastener 21.
• ANSC anti-seismic connector
• Figure 9 The embodiment of the V-shaped contact surface-pair base bearing for seismic isolation.
• Figure 10 How gravity is utilized to resist horizontal ground acceleration-induced vibration by the V- shape contact surface-pair; for simplification, it is assumed friction coefficient vanishing in the figure.
• Figure 11 The embodiment of the V-shaped contact surface-pair base bearing with sliding-pin.
• Figure 12 (a) prototype of V-shape Elastic Bearing with sliding-pin in Fig. 11 with vertically-laid dissipation pin (VDP); (b) a prototype of V-shape Elastic Bearing in Fig. 10 but with multiple V-shapes in a contact surface-pair and with additional vertical reinforcement pin (VRP).
• VDP vertically-laid dissipation pin
• VRP vertical reinforcement pin
• Figure 13 (a) A prototype of VEB with double orthogonally overlaid V-shape contact surface-pairs to accommodate the vibrations along any direction within a horizontal plane, (b) A prototype of VEB with U-shape contact surface-pair overlaid above V-shape contact surface-pairs to accommodate
• Figure 14 Top: a design example of UVEB, by which the mate sheets 2 and 4 have specially designed contact areas to control the friction coefficient. The two sliding positions in lower part of the figure show how the longitudal stopper works.
• Figure 15 A prototype of MVEB, a sub-class of the invented apparatuses, by which the V-shaped contact surface compromises more than three facets. Between the top or bottom pot contact surfaces is an elastomeric mate block that contains at least one metal or high- strength composite mate plates.
• Figure 16 Design examples of 360°VEB: (a)5-fold; (b)4-fold; (c) ⁇ -fold UV and the mate sheets with designed contact-surface areas.
• Figure 17 Design example of a "one-way VEBSP", which is able to accommodate vibration-induced lateral relative-separation within the plane of the V-geometry while the sliding along the direction perpendicular to the V-shape is restrained by the cover-plates fixed to top pad.
• Figure 18 Design example of a 360° VEBSP that is able to accommodate vibration-induced lateral relative-separations along all horizontal directions while keep the connected super and substructure's integrity.
• Figure 19 Design examples of sliding pins and side stoppers for VEBSP.
• Figure 20 Two prototypes of VEBSP with damping mechanisms.
• Figure 21 An illustration how the damping mechanism works for the prototype given by Figure 20(a), in top; and design of the device.
• Figure 22 The embodiment of "vertical reinforced elastomeric bearing (VREB)" with reinforce-pins, chart of problem-solution.
• VREB vertical reinforced elastomeric bearing
• Figure 23 Two design examples of V-shape base VREB: (a) without post tension; (b) with post tension.
• Figure 24 Two design examples of flat contact- surface VREB: (a) without post tension; (b) with post tension.
• FIG. 25 Two design examples of VREB with damping core: (a) V-shape contact-surface design; (b) flat contact-surface design.
• the first embodiment is based on the concept of "V-sliding" in Fig. 9, which employs at least one pair of V-shape sliding-contact surfaces to establish the connection between super- and sub-structure of a large-scaled civil engineering structural system, allowing a temporally relative sliding when one of sub or superstructure is struck by single or a spectrum of external impacts, so as to protect another part from the inertia force flow induced by the impacts.
• VEB V-shape Elastic Bearing
• the angle a of the ⁇ -shape is the key design parameter, which determines the threshold of the lateral force that causes sliding-separation.
• This force denoted as Q, results in corresponding stress distribution over both super and substructure, by which the peak value of the stress ratio,
• ⁇ ⁇ should be limited to an allowable level that will not cause damage, i.e. ⁇ peak iO) ⁇ aalllloowwaabbllee
• ⁇ ⁇ is the yielding strength of the material element with the stress a peak (Q) under the lateral force
• the second key design-parameter is the maximum allowable sliding distance /, which is quantitatively determined by applying the second Newton's law.
• Figs. 1 and 2 provide the prediction of horizontal PGA (peak ground acceleration) at any location where a building or a bridge is built.
• the time t s can be solved by the first equation of (9) when F s a e is known, which should be determined based on the allowable stress of the bearing; then using the second equation to determine l VEBSP ; or verse versa.
• V(t E ) 0 and S(t E ) ⁇ l VEB (10)
• Fig. 13 illustrates two design prototypes of VEB: the one on left has orthogonally overlaid double V-shape contact surface-pairs that is able to damp vibrations along any direction within a horizontal plane, which is termed "V-VEB". The one on right utilizes U-shape contact surface-pair overlaid above V-shape contact surface-pairs to accommodate superstructure's rotation, which can be termed "U-VEB”.
• Fig.14 is the design example of an U-VEB design, which includes another embodiment that is to adjust the friction coefficient between mate sheet and bearing pads through adjusting contact area.
• a problem to be solved in practice is to minimize the risk of tension instability for this class of materials.
• M-VEB Multi-V Elastomeric Bearing
• a design of MVEB is given in Fig. 20.
• a V-shape contact surface-pair when relative sliding occurs between a facet-pair while separations take place between other pairs of facets, such a separation stretches contained elastomer layer and may cause tension instability. Therefore, in the design of Fig.
• the waive-like, multi-facet, V-contact geometry redistributes the single space caused by the separation between non-sliding side single facet-pair into the cavities of multi-V facet-pairs, by which the key-embodiment of VEB and associated beneficial properties remain.
• This benefit in conjunction with the favorable properties of elastomer material, make this class of bearing to be a candidate to the structures in the region with moderate seismic risk.
• Fig. 16 introduces the design examples with the embodiment to utilize single prism-shape contact surface-pair to damp the vibrations along any direction within a horizontal plane based on the concept of VEB, by which a prism contact surface comprises N facets where N is an integer that is greater than 2; there facets may have the same or different inclined angles to horizontal plane.
• the sliding may either occur within one contact facet-pair that has the inclined angle a F or along two adjacent facet- pairs with the motion along the edge between the two adjacent facets.
• the edge has an inclined angle a E to horizontal plane, determined by the following equation:
• a E is generally smaller than the angles of adjacent facets.
• This subclass of VEB is termed "360°VEB".
• the design examples in Fig. 16 are, respectively, 3-fold, 4-fold, and 4-fold UV type 360° VEB.
• Fig. 17 is a design example of VEB with sliding-pin, which is able to accommodate vibration- induced lateral relative-separation within the plane of the V-geometry, guided by the sliding-pins that preserve super and substructure as an integrated structure through mounted top and bottom pads. Along the direction perpendicular to the V-shape the sliding is restrained by the cover-plates that are fixed onto top pad.
• This subclass of V-sliding concept base bearing is termed "one-way VEBSP”.
• Fig. 18 is a design example of "360° VEBSP" that is able to accommodate vibration-induced lateral relative- separations along all horizontal directions while keep the connected super and substructure's integrity.
• the sliding-pins can slide freely within the grooves on top pad but guided by the slits on the sider stoppers that are screwed onto bottom pad. There is no essential difference if sider stoppers are fixed to top pad while the sliding-pin grooves are cut from bottom pad.
• Fig.19 presents various design-examples of sliding pins and sider stoppers of VEBSP.
• the cylinder rod-pin has lower contact friction but strict requirements to material's strength and wear- resistance.
• the sider stopper with straight slot provides tied vertical constraint to the relative movement between top and bottom pads but needs more careful maintenance for the contact surfaces on the pins and on the stoppers' slits to avoid friction-locking; it also requires certain distance between the pins' groove and the V-shape contact surface.
• a VEB (or VEBSP) bearing for example, that in Fig 11, during the transition of the sliding between one pair of facets to another facet-pair that was separated, the sliding movement changes direction.
• the device in (b) employs a deformable ring containing a damping core. The ring is fixed onto the ends of two opposite sliding-pins, stretched and compressed when sliding occurs, which results in the core's plastic deformation.
• the core is made of deformation-inert material, for example, Lead.
• a design of this device is given in Fig. 21.
• the device in Fig. 20(b) is similar to that in (a) but with two deformable rings and contained cores.
• Elastomer the traditional material for bridges' and building's bearings, can also be used as the mate sheet material between the V-shape contact surface-pair, for examples, the prototype in Fig. 15. Due to its high friction coefficient, the sliding-separation mechanism in other material-mated VEB or VEBSP may not happen when elastomer mate sheet is employed.
• elastomer is often attached to metal surface in bearings' application; sliding between metal surface and elastomer may cause local tension instability that will cause the latter's failure.
• the lateral resistance provided by elastomer's shear modulus is limited. Therefore, this class of bearing lacks sufficient driving force for self-restoration when struck by strong ground motions. Also, when environmental temperature drops below frozen point, elastomer becomes brittle with lower friction resistance.
• VREB vertical reinforcement-reinforced elastomeric bearing
• top pad is mounted onto superstructure while the bottom pad is mounted onto substructure, so these vertically-laid pins essentially hold the two parts as integrated structure.
• both ends of such a pin are respectively fastened tightly by upper and bottom pads, no free rotation is allowed for the pin around its tied ends, which introduce addition resistance against horizontally dislocated motion between the pads while provide intrinsic elasticity force to drive the system back to original position after the dislocations.
• the simplicity in its geometry implies the convenience for manufacturing with enhanced cost-effectiveness.
• the embedded vertical pins and horizontal metal sheet make the elastomeric like a rubber-composite with desired stiffness and damping capacity.
• the embedded pins may also provide additional structural functions such as to process post-tension. As illustrated in Fig.
• VREB is lighted by the superior properties of human's hair. Such a hair's strength is actually higher than mild steel. Its super tenderness and flexibility is due to the small diameter, which inspires the idea to employ multiple high-strength, small diameter, reinforce bars into elastomeric blocks for the desired dual ( isolation and reinforcement) properties. 6 Design examples of VREB are given in Figs. 23-25
• Non Patent Literatures [I] Federal Emergency Management Agency (FEMA), Reports 350-353, 2000

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• Engineering & Computer Science (AREA)
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• Buildings Adapted To Withstand Abnormal External Influences (AREA)
• Vibration Prevention Devices (AREA)
• Bridges Or Land Bridges (AREA)

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• 2012
  • 2012-11-02 EA EA201491066A patent/EA201491066A1/ru unknown
  • 2012-11-02 JP JP2014544741A patent/JP2015507106A/ja active Pending
  • 2012-11-02 EP EP12853643.0A patent/EP2785922A4/de not_active Ceased
  • 2012-11-02 CN CN201280059205.6A patent/CN104254650B/zh active Active
  • 2012-11-02 WO PCT/US2012/063127 patent/WO2013081769A2/en active Application Filing
  • 2012-11-02 CN CN201711135802.3A patent/CN107882403B/zh active Active

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