Support structure

Abstract

To provide a bearing structure capable of welding and joining a bearing to a lower joined part and suppressing the occurrence of dissimilar metal contact corrosion after joining of the bearing to the lower joined part even when the lower joined part of parts of an upper structure to which the lower joined part is joined is made of anti-corrosion metal more precious than carbon steel.SOLUTION: A bearing structure 10 comprises: a structure having upper and lower structures; and a bearing 12 that is positioned between the upper and lower structures and that transmits a load of the upper structure to the lower structure. The bearing 12 has a sole plate 18 fixed with an upper surface in contact with a lower joined part 62X which is a lower surface part of the upper structure to which the bearing 12 is joined. The upper surface of the sole plate 18 in contact with the lower joined part 62X is made of anti-corrosion metal more precious than carbon steel, and the lower joined part 62X of the upper structure is also made of anti-corrosion metal more precious than the carbon steel.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a support structure, and more particularly to a support structure provided with a corrosion-resistant metal at least in part. In the present application, a support means a member that is located between an upper structure and a lower structure in a structure and transmits the load of the upper structure to the lower structure.

Background Art

[0002] In structures such as bridges, the support is a member that plays an important role in transmitting the load of the upper structure to the lower structure, and since it is a member that is used over a long period of time, long-term durability is required.

[0003] On the other hand, for example, in a bridge, the support is disposed at a position that is liable to be affected by corrosion-promoting substances such as rainwater flowing from the upper structure and salts contained in the rainwater, and is in a disposition state where deterioration due to corrosion is likely to occur.

[0004] A technique described in Patent Document 1 is considered to be a technique that can cope with this point. Patent Document 1 describes a support for a structure that is installed between an upper structure and a lower structure that are vertically divided in a structure, and has at least a steel upper base plate fixed to the upper structure and a steel lower base plate fixed to the lower structure. In this support for a structure, a molten zinc-aluminum alloy plating is applied to the surfaces of the upper base plate and the lower base plate, and then a synthetic resin coating is applied to sustain the corrosion resistance of the molten zinc-aluminum alloy plating and extend its service life (paragraph 0012 of Patent Document 1).

[0005] On the other hand, the lower surface of the upper structure of the bridge, which serves as a passage for moisture to the support, is also a part that is liable to be affected by moisture, and is in an environment where corrosion is likely to occur, similar to the support, and improvement of corrosion resistance is required.

[0006] Therefore, as a measure to improve the corrosion resistance of the underside of the bridge superstructure, it is conceivable to use corrosion-resistant metals such as stainless steel on the underside of the bridge superstructure.

[0007] In the technology described in Patent Document 1, as mentioned above, the surface of the steel upper base plate is plated with a hot-dip zinc-aluminum alloy and then coated with a synthetic resin. However, even if the hot-dip zinc-aluminum alloy plating and the synthetic resin coating are carefully removed with a grinder or the like, it is thought that a small amount of zinc will remain. Therefore, when the steel upper base plate is welded to the superstructure, the remaining zinc will melt due to the welding heat. As a result, if corrosion-resistant metals that may cause zinc embrittlement cracking (specifically, for example, austenitic and duplex stainless steels, nickel alloys) are used at or near the welding location of the superstructure, it is difficult to weld the upper base plate to the superstructure. Furthermore, since titanium cannot be welded to carbon steel, if the welding location of the superstructure to be welded is titanium, it is not possible to weld the steel upper base plate to the superstructure.

[0008] Furthermore, when installing the upper base plate, on-site alignment is necessary, which may cause friction with the superstructure, potentially damaging the synthetic resin coating on the upper base plate, which is coated with a hot-dip zinc-aluminum alloy plating. If the superstructure to which the upper base plate is attached is made of carbon steel, even if moisture penetrates between the superstructure and the upper base plate while the synthetic resin coating is damaged, the sacrificial corrosion protection of the hot-dip zinc-aluminum alloy plating will protect the upper base plate from corrosion. However, if the joints of the superstructure's support structure use clad steel with a corrosion-resistant metal (stainless steel, titanium, etc.) as the cladding material, or if a single material of a corrosion-resistant metal (stainless steel, titanium, etc.) is used, moisture penetrating between the superstructure and the upper base plate may cause the hot-dip zinc-aluminum alloy plating to corrode and disappear prematurely due to galvanic corrosion.

[0009] Furthermore, according to the method described in paragraph 0035 of Patent Document 1, the synthetic resin coating on the upper base plate is applied to the surface of the molten zinc-aluminum alloy plating by immersing the preheated upper base plate, which is the object to be coated, in a container where the powder is suspended in an airflow. According to the method described in paragraph 0036 of Patent Document 1, the synthetic resin powder, which is charged with high voltage, is sprayed onto the grounded upper base plate, which is the object to be coated, using a spray gun to fix it, and then heated and melted to form a coating film, thereby applying it to the surface of the plating layer. Both methods are difficult to implement on-site, and it is also difficult to repair scratches on the synthetic resin coating of the upper base plate on-site.

[0010] Furthermore, the sole plate in this application corresponds to the upper base plate in the technology described in Patent Document 1. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Publication No. 2006-193773 [Overview of the project] [Problems that the invention aims to solve]

[0012] The present invention has been made in view of the above, and aims to provide a bearing structure in which, even if the lower joint portion of the superstructure to which the bearing is joined is made of a corrosion-resistant material nobler than carbon steel, the bearing can be welded to the lower joint portion, and dissimilar metal contact corrosion after the bearing is joined to the lower joint portion is suppressed. [Means for solving the problem]

[0013] The present invention solves the aforementioned problems and is a support structure as follows.

[0014] That is, the first embodiment of the support structure according to the present invention is a support structure comprising a structure having a superstructure and a substructure, and a support located between the superstructure and the substructure for transmitting the load of the superstructure to the substructure, wherein the support has a sole plate fixed with its upper surface in contact with a lower surface joint portion, which is a portion of the lower surface of the superstructure to which the support is joined, the upper surface of the sole plate in contact with the lower surface joint portion is made of a corrosion-resistant metal nobler than carbon steel, and the lower surface joint portion of the superstructure is also made of a corrosion-resistant metal nobler than carbon steel.

[0015] A second embodiment of the support structure according to the present invention is an embodiment in which, in the first embodiment, the sole plate is welded to the lower joint portion of the superstructure.

[0016] A third aspect of the bearing structure according to the present invention is a configuration in which, in the second aspect, the portion of the sole plate and the lower joint portion, which are joined by welding, are both made of stainless steel with a pitting index of 23 or higher.

[0017] A fourth aspect of the support structure according to the present invention is an aspect in which, in any of the first to third aspects, the sole plate is joined to the lower joint portion of the superstructure by a rod-shaped member.

[0018] A fifth aspect of the support structure according to the present invention is a configuration in which, in the fourth aspect, the rod-shaped member is made of metal, and at least a portion of the outer surface of the rod-shaped member is provided with a corrosion-resistant coating.

[0019] A sixth aspect of the support structure according to the present invention is the fifth aspect, wherein the corrosion protection coating is formed of a heat-shrinkable sleeve.

[0020] A seventh aspect of the support structure according to the present invention is the sixth aspect, wherein the thickness of the heat-shrinkable sleeve is 0.3 mm or more.

[0021] The eighth aspect of the support structure according to the present invention is that, in any of the first to seventh aspects, the corrosion-resistant metal forming the upper surface of the sole plate and the corrosion-resistant metal forming the lower surface joining portion of the upper structure are both pure titanium, or stainless steel with a pitting index difference of 6 or less, or a nickel alloy.

[0022] The ninth aspect of the support structure according to the present invention is that, in any of the first to eighth aspects, the corrosion-resistant metal forming the upper surface of the sole plate and the corrosion-resistant metal forming the lower surface joining portion of the upper structure are made of the same corrosion-resistant metal.

[0023] Here, the "same corrosion-resistant metal" when the corrosion-resistant metal is a nickel alloy means using the same nickel alloy among NCF825, NW0276, NCF625, and NW6022.

[0024] The tenth aspect of the support structure according to the present invention is that, in any of the first to ninth aspects, the member including the lower surface joining portion of the upper structure is formed of a single material of stainless steel, titanium, or nickel alloy.

[0025] The eleventh aspect of the support structure according to the present invention is that, in any of the first to ninth aspects, the lower surface joining portion of the upper structure is formed of a clad steel composite material, and the clad steel composite material is formed of a more noble corrosion-resistant metal than the carbon steel that is the base material of the clad steel.

[0026] The twelfth aspect of the support structure according to the present invention is an aspect configured such that, in any one of the first to eleventh aspects, it has a first metal member and a second metal member made of a material different from that of the first metal member, and has an insulating layer between the first metal member and the second metal member.

[0027] The thirteenth aspect of the support structure according to the present invention is an aspect in the twelfth aspect, where the insulating layer is formed by painting.

[0028] The fourteenth aspect of the support structure according to the present invention is an aspect in the twelfth aspect, where the insulating layer is formed of a fluororesin or a fluororesin mixed with a filler.

[0029] The fifteenth aspect of the support structure according to the present invention is an aspect in the fourteenth aspect, where the insulating layer is formed in a sheet shape.

[0030] The sixteenth aspect of the support structure according to the present invention is an aspect configured such that, in any one of the first to fifteenth aspects, the sole plate is formed of clad steel, the upper surface of the sole plate is formed of the facing material of the clad steel, and the facing material of the clad steel is formed of a noble corrosion-resistant metal compared to the carbon steel that is the base material of the clad steel.

[0031] The seventeenth aspect of the support structure according to the present invention is an aspect in the sixteenth aspect, where an anticorrosion coating is provided so as to cover both the facing material and the base material of the clad steel exposed on the thickness-direction surface formed by cutting or machining the clad steel forming the sole plate in the thickness direction so as to cross both the facing material and the base material.

[0032] The eighteenth aspect of the support structure according to the present invention is an aspect in the seventeenth aspect, where the thickness-direction surface is the bevel surface of the sole plate.

[0033] A 19th embodiment of the support structure according to the present invention is, in the 17th embodiment, the surface in the thickness direction is the inner surface of a hole into which a bolt can be inserted.

[0034] A 20th embodiment of the support structure according to the present invention is an embodiment in which, in any of the 16th to 19th embodiments, a corrosion-resistant coating is provided that covers the outer surface in the in-plane direction of the base material of the clad steel forming the sole plate.

[0035] Here, "the outer surface of the base material of the clad steel in the in-plane direction" refers to the surface of the base material of the clad steel that faces outward, and is the surface of the clad steel in the in-plane direction (the surface in a direction substantially parallel to the direction in which the clad steel spreads as a surface material). Similar descriptions in other parts of this application shall be interpreted in the same way.

[0036] A 21st embodiment of the bearing structure according to the present invention is an embodiment in which, in any of the 16th to 20th embodiments, the clad steel forming the sole plate is rolled clad steel.

[0037] A 22nd aspect of the bearing structure according to the present invention is an aspect in which, in any of the first to 15 aspects, the sole plate is formed from a single material, either stainless steel, titanium, or nickel alloy. [Effects of the Invention]

[0038] According to the present invention, even if the lower joint portion of the superstructure to which the bearing is joined is made of a corrosion-resistant material nobler than carbon steel, the bearing can be welded to the lower joint portion, and a bearing structure can be provided in which dissimilar metal contact corrosion occurs after the bearing is joined to the lower joint portion. [Brief explanation of the drawing]

[0039] [Figure 1] A schematic cross-sectional view of a support structure 10 according to the first embodiment of the present invention. [Figure 2] A schematic side view showing a box girder bridge 60 equipped with a bearing structure 10 according to the first embodiment of the present invention, viewed from a direction perpendicular to the bridge axis. [Figure 3] A schematic vertical cross-sectional view showing the box girder 62, which is the superstructure of the box girder bridge 60, as viewed from the bridge axis direction. [Figure 4] A schematic cross-sectional view of a support structure 30 according to a second embodiment of the present invention. [Figure 5] A schematic cross-sectional view of a support structure 40 according to the third embodiment of the present invention. [Figure 6] A schematic cross-sectional view of a support structure 50 according to the fourth embodiment of the present invention. [Figure 7] A schematic vertical cross-sectional view showing the support structure 70 according to the fifth embodiment of the present invention. [Modes for carrying out the invention]

[0040] The embodiments (1st to 5th embodiments) of the bearing structure according to the present invention will be described in detail below with reference to the drawings. As a specific application, each embodiment will be described assuming a bearing structure for a box girder bridge equipped with a steel box girder as the superstructure. However, the application of the present invention is not limited to this, and it can be applied to bearing structures for bridges other than box girder bridges, and furthermore, to bearing structures for structures other than bridges. In addition, in the 1st to 5th embodiments described below, rubber bearings using a rubber body are used as the bearings, but the bearings to which the present invention can be applied are not limited to rubber bearings, and it can also be applied to steel bearings.

[0041] (1) First Embodiment Figure 1 is a schematic side cross-sectional view of the bearing structure 10 according to the first embodiment of the present invention, where the left side of the centerline is a side view viewed from the direction perpendicular to the bridge axis, and the right side of the centerline is a vertical cross-sectional view viewed from the direction perpendicular to the bridge axis. Figure 2 is a schematic side view of the box girder bridge 60 equipped with the bearing structure 10 according to the first embodiment of the present invention viewed from the direction perpendicular to the bridge axis, and Figure 3 is a schematic vertical cross-sectional view of the box girder 62, which is the superstructure of the box girder bridge 60, viewed from the direction in the bridge axis direction. In Figure 2, reference numeral 110 indicates a precast PC slab, reference numeral 120 indicates an expansion joint, in Figure 3, reference numeral 62A1 indicates a bottom plate longitudinal rib that reinforces the bottom plate 62A of the box girder 62, reference numeral 62C indicates a transverse rib, reference numeral 62D indicates an upper flange, reference numeral 62D1 indicates a top flange tip longitudinal rib, reference numeral 62E indicates a vertical stiffener, and reference numeral 112 indicates asphalt pavement. Furthermore, Figure 2 does not depict members located above the top surface of the precast PC floor slab 110.

[0042] As shown in Figures 2 and 3, the bearing structure 10 according to this first embodiment is a bearing structure for a box girder bridge 60.

[0043] As shown in Figures 1 to 3, the support structure 10 comprises a support 12, a box girder 62 which is the superstructure of the box girder bridge 60, and a pier 100 which is the substructure of the box girder bridge 60. The lower joint portion 62X of the box girder 62 is the lower surface portion of the box girder 62 to which the sole plate 18, which is the uppermost member of the support 12, is joined.

[0044] The bearing 12 of the bearing structure 10 is located between the box girder 62, which is the superstructure of the box girder bridge 60, and the pier 100, which is the substructure of the box girder bridge 60, and plays the role of transmitting the load of the box girder 62, which is the superstructure of the box girder bridge 60, to the pier 100, which is the substructure.

[0045] As shown in Figure 1, the support 12 consists of a base plate 14, a support body 16, and a sole plate 18, in that order from bottom to top. The base plate 14 is fixed to the top of the pier 100 by anchors 14A, and the sole plate 18 is attached to the bottom plate 62A of the box girder 62 by sole plate mounting bolts 24 and set bolts 26, such that the upper surface of the sole plate 18 is joined to the bottom joint portion 62X, which is the lower surface of the box girder 62.

[0046] As shown in Figure 1, the bearing body 16 of the bearing 12 has, from bottom to top, a lower shoe 16A, a rubber body 16B, and an upper shoe 16C. The lower surface of the lower shoe 16A is attached and fixed so as to join with the upper surface of the base plate 14, and the upper surface of the upper shoe 16C is attached and fixed so as to join with the lower surface of the sole plate 18. The lower surface of the rubber body 16B is attached and fixed so as to join with the upper surface of the lower shoe 16A, and the upper surface of the rubber body 16B is attached and fixed so as to join with the lower surface of the upper shoe 16C. The bearing body 16 is a commonly used rubber bearing, and the base plate 14 is also a commonly used steel base plate. Specific materials for the steel base plate 14 include rolled steel for welded structures such as SM490A, SM490B, SM490C, SM490YA, SM490YB, or SM520B, SM520C. The rubber body 16B may be constructed by alternately laminating metal plates and rubber layers. Alternatively, the rubber body 16B may be laminated rubber with lead plugs.

[0047] The box girder 62 included in the support structure 10 according to this first embodiment is constructed using clad steel 66 for the bottom plate 62A and web 62B. The clad steel 66 is a member formed by metallizing a clad steel base material 66A, which is a steel base material, with a clad steel cladding material 66B, which is a corrosion-resistant metal. The thickness of the clad steel cladding material 66B is preferably 1.5 mm or more from the viewpoint of corrosion resistance and scratch resistance. In the bottom plate 62A and web 62B of the box girder 62, the clad steel cladding material 66B, which is a corrosion-resistant metal, is located on the outer surface side of the box girder 62, and the clad steel base material 66A, which is a steel base material, is located on the inner surface side of the box girder 62. The clad steel cladding material 66B is made of a corrosion-resistant metal that is nobler than carbon steel. In addition, a corrosion-resistant coating 68 is provided on the inner surface side of the box girder 62 of the clad steel base material 66A. The corrosion protection coating 68 can be any corrosion protection coating commonly used on the inner surface of a steel box girder. Specifically, for example, the C-5 coating, D-5 coating, D-6 coating described in the Steel Road Bridge Painting and Corrosion Protection Handbook, as well as other organic zinc-rich primer + epoxy resin paint, organic zinc-rich primer + modified epoxy resin paint, metal spraying (zinc, aluminum, zinc-aluminum alloy, aluminum-magnesium alloy), and corrosion protection specifications with epoxy resin coating applied over the metal spraying can be used.

[0048] Furthermore, although not shown in the illustration, corrosion-resistant coatings 68 are also provided on the surfaces (the surfaces facing the inside of the box girder 62) of the components located inside the box girder 62, including the bottom plate longitudinal rib 62A1, the transverse rib 62C, the upper flange 62D, the upper flange tip longitudinal rib 62D1, and the vertical stiffener 62E.

[0049] Since a clad steel composite 66B, which is a more noble and corrosion-resistant metal than carbon steel, is arranged on the outer surfaces of the bottom plate 62A and web 62B of the box girder 62, the box girder 62 can be suitably used even in corrosive environments affected by the sea. Furthermore, a corrosion-resistant coating 68 is provided on the inner surface of the clad steel base material 66A of the box girder 62, so it is also suitable for corrosive environments in this respect.

[0050] The sole plate 18 is a plate-shaped member made of clad steel 20, which is formed by metallographically bonding a clad steel composite material 20B, which is a corrosion-resistant metal, to a clad steel base material 20A, which is a steel base material. The thickness of the clad steel composite material 20B is preferably 1.5 mm or more from the viewpoint of corrosion resistance and scratch resistance. The clad steel base material 20A is made of a corrosion-resistant metal that is nobler than carbon steel.

[0051] In the support structure 10 according to this first embodiment, the sole plate 18 is joined to the lower joint portion 62X of the box girder 62, but the upper surface of the sole plate 18 is formed of a clad steel composite material 20B, which is a corrosion-resistant metal. On the other hand, the lower joint portion 62X of the box girder 62 is also formed of a clad steel composite material 66B, which is a corrosion-resistant metal. Therefore, even if the upper surface of the sole plate 18 is joined to the lower joint portion 62X of the box girder 62, dissimilar metal contact corrosion is unlikely to occur.

[0052] The connection between the upper surface of the sole plate 18 and the lower surface joint portion 62X of the box girder 62 is made by sole plate mounting bolts 24 and set bolts 26. As shown in Figure 1, the head of the sole plate mounting bolt 24 is engaged with the upper surface of the larger diameter portion of the through hole 18A in the sole plate 18, its shaft is inserted through the through hole 18A of the sole plate 18 and the through hole 62A2 of the bottom plate 62A of the box girder 62, and the tip of the shaft protrudes into the inside of the box girder 62 and is fastened with a nut. The set bolt 26 has its shaft inserted through the through hole 62A3 of the bottom plate 62A of the box girder 62 and the through hole 18B of the sole plate 18, and the tip of the shaft reaches the hole 16C1 of the upper shoe 16C of the support body 16, is inserted through the through holes 62A3 and 18B and is screwed into the hole 16C1.

[0053] The clad steel composite 20B forming the upper surface of the sole plate 18 and the clad steel composite 66B forming the lower joint portion 62X of the box girder 62 can both be made of any corrosion-resistant metal nobler than carbon steel, without any particular restrictions. For example, austenitic, ferritic, or martensitic stainless steels, pure titanium, or nickel alloys can be used. As stainless steel, for example, SUS410L, SUS410S, SUS430, SUS304, SUS304L, SUS316, SUS316L, SUS317, SUS317L, SUS321, SUS347, SUS310S, SUS329J1L, SUS329J3L, SUS329J4L, SUS312L, SUS836L, NAS354N, JSL310Mo, etc., can be suitably used. As pure titanium, for example, TP270H, TP340H, TP270C, TP340C, etc., can be suitably used. As nickel alloy, NCF825, NW0276, NCF625, NW6022, etc., can be suitably used.

[0054] However, it is preferable to use stainless steel with high corrosion resistance. Since the corrosion resistance of welded parts of stainless steel decreases, it is necessary to use different types of stainless steel depending on whether or not welding is performed. In the support structure 10 according to the first embodiment, the sole plate 18 is attached to the box girder 62, which is the superstructure, with bolts (sole plate mounting bolts 24, set bolts 26) and welding is not used. Therefore, when stainless steel is used for the clad steel composite material 20B of the sole plate 18, a composition with a pitting index of 16 or higher can be used, and preferably a composition with a pitting index of 18 or higher can be used. In the support structure 30 according to the second embodiment described later, welding is used to attach the sole plate 18 to the box girder 62, which is the superstructure. In this case, a composition with a pitting index of 23 or higher can be used, and preferably a composition with a pitting index of 28 or higher can be used. In this application, the pitting index is an index calculated using the content (mass%) of Cr, Mo, and N contained in stainless steel, and is a value (expressed as mass%) calculated by the formula Pitting Index = Cr + 3.3Mo + 16N (where each element symbol in the formula represents the content of that element).

[0055] From the viewpoint of suppressing galvanic corrosion, it is preferable to use the same type of corrosion-resistant metal for the clad steel composite 20B forming the upper surface of the sole plate 18 and the clad steel composite 66B forming the lower surface joint portion 62X of the box girder 62. Here, it means that the clad steel composite 20B and the clad steel composite 66B are the same type of corrosion-resistant metal, meaning that they are either pure titanium, stainless steel with a pitting index difference of 6 or less, or a nickel alloy.

[0056] From the viewpoint of further suppressing galvanic corrosion, it is preferable to use the same corrosion-resistant metal for the clad steel cladding material 20B that forms the upper surface of the sole plate 18 and the clad steel cladding material 66B that forms the lower surface joint portion 62X of the box girder 62.

[0057] In the thickness direction of the sole plate 18, when the sole plate 18 is cut or machined across both the clad steel composite 20B and the clad steel base material 20A, both the clad steel composite 20B and the clad steel base material 20A are exposed, which may lead to galvanic corrosion. Therefore, it is preferable to provide a corrosion-resistant coating that covers the entire surface of the aforementioned thickness direction surface of the sole plate 18.

[0058] Examples of the thickness-direction surfaces of the sole plate 18 include the edge surface 18X, which is the thickness-direction cut surface of the end of the sole plate 18, and the inner surfaces of the through holes used for connecting the sole plates 18 (through holes 18A for the sole plate mounting bolts 24 and through holes 18B for the set bolts 26). It is preferable to provide a corrosion-resistant coating that covers the entire surface of these thickness-direction surfaces (edge ​​surface 18X and the inner surfaces of the through holes 18A and 18B).

[0059] Furthermore, since both the clad steel cladding material 66B and the clad steel base material 66A are exposed on the inner surfaces of the through holes 62A2 and 62A3 in the bottom plate 62A of the box girder 62, it is preferable to provide a corrosion-resistant coating that covers the entire inner surface of the through holes 62A2 and 62A3 in the bottom plate 62A of the box girder 62, from the viewpoint of suppressing galvanic corrosion.

[0060] Furthermore, it is preferable to provide a corrosion-resistant coating on the sole plate mounting bolts 24 and set bolts 26. Examples of corrosion-resistant coatings include paint, fluororesin coating, epoxy resin coating, vinyl ester resin coating, and ceramic coating. However, since galvanic corrosion will occur, metals with sacrificial corrosion protection, such as zinc-aluminum alloy plating, should not be used for the corrosion-resistant coating of the bolts. High-strength stainless steel bolts (made of SUS630) may also be used for the sole plate mounting bolts 24 and set bolts 26.

[0061] Furthermore, it is preferable to provide a corrosion-resistant coating so as to cover the in-plane outer surface 20X of the steel clad steel base material 20A of the sole plate 18. The in-plane outer surface 20X of the clad steel base material 20A is the outward-facing surface of the steel clad steel base material 20A of the sole plate 18, and is the in-plane surface of the clad steel 20 (the surface in a direction substantially parallel to the surface in which the clad steel 20 spreads as a surface material), and is the surface to which the upper surface of the upper shoe 16C is joined.

[0062] For the corrosion protection coating applied to cover the aforementioned thickness-direction surfaces of the sole plate 18 (edge ​​surface 18X, inner surfaces of through holes 18A and 18B), the inner surfaces of the through holes 62A2 and 62A3 of the bottom plate 62A of the box girder 62, and the in-plane outer surface 20X of the steel clad steel base material 20A of the sole plate 18, it is preferable to use a corrosion protection method that can be repaired on-site. This can include paint (solvent-based, solvent-free, water-based, powder) or corrosion protection tape. If thermal spraying is used, paint should be applied on top of the thermal spraying. Since the bearing is usually installed in a location that is not directly exposed to sunlight, the painting specifications for the clad steel sole plate often involve a thick epoxy resin coating on top of an epoxy primer. Polyurethane or fluororesin coating may also be applied on top of that.

[0063] The corrosion-resistant coating on the upper shoe 16C, lower shoe 16A, and base plate 14 is the same as the corrosion-resistant coating on the thickness-direction surfaces of the sole plate 18 (edge ​​surface 18X, inner surfaces of through holes 18A and 18B) as described above. Alternatively, instead of providing a corrosion-resistant coating, a single material of corrosion-resistant metal may be used for the upper shoe 16C, lower shoe 16A, and base plate 14. From the viewpoint of suppressing galvanic corrosion, when a single material of corrosion-resistant metal is used for the upper shoe 16C, lower shoe 16A, and base plate 14, it is preferable to provide an insulating layer between them and the carbon steel members that come into contact with them.

[0064] No zinc-containing paint or zinc plating is used on the clad steel sole plate 18, specifically on the clad steel cladding portion (clad steel cladding 20B) made of corrosion-resistant metal. This is because if corrosion-resistant metals such as stainless steel or titanium are used for the clad steel cladding 20B of the clad steel 20, zinc plating will wear off prematurely in the areas that come into contact with these metals.

[0065] In the support 12 of the support structure 10 according to this first embodiment, displacement restraining members such as lifting force stopping plates and side blocks may be used.

[0066] Furthermore, a support cover may be provided to cover the support 12 of the support structure 10 according to this first embodiment. In the portion where the bolts for attaching the support cover come into contact with the clad steel cladding material 66B of the clad steel 66 of the box girder 62, a rubber sheet may be used for insulation or a coated and corrosion-resistant bolt may be used to suppress the occurrence of galvanic corrosion.

[0067] (2) Second Embodiment Figure 4 is a schematic one-sided cross-sectional view of a support structure 30 according to a second embodiment of the present invention, where the left side of the center line is a side view taken perpendicular to the bridge axis, and the right side of the center line is a vertical cross-sectional view taken perpendicular to the bridge axis.

[0068] In the support structure 10 according to the first embodiment, the sole plate 18 was joined to the lower joint portion 62X of the box girder 62 using sole plate mounting bolts 24 and set bolts 26, thereby attaching the support 12 to the box girder 62. However, in the support structure 30 according to this second embodiment, the clad steel cladding material 20B of the sole plate 18a is joined to the clad steel cladding material 66B of the bottom plate 62A of the box girder 62 by fillet welding 32, and the set bolts 26 are inserted through the through holes 62A3 and 18B and screwed into the hole 16C1, thereby joining the upper surface of the sole plate 18a to the lower joint portion 62X of the box girder 62, and attaching the sole plate 18a to the box girder 62. In all other respects, the support structure 30 according to this second embodiment is the same as the support structure 10 according to the first embodiment, so explanations of similar points will be omitted in principle and replaced with explanations of the first embodiment. Furthermore, the same reference numerals are generally used for members and parts of the support structure 10 according to the first embodiment, and their descriptions are generally omitted.

[0069] As shown in Figure 4, in the support structure 30 according to this second embodiment, the clad steel composite member 20B of the sole plate 18a is joined to the clad steel composite member 66B of the bottom plate 62A of the box girder 62 by fillet welding 32. For this reason, the support structure 30 according to this second embodiment does not use sole plate mounting bolts 24, and the sole plate 18a is not provided with through holes 18A for sole plate mounting bolts 24. In all other respects, the sole plate 18a and the support 12a are the same as the sole plate 18 and the support 12 in the support structure 10 according to the first embodiment, respectively. In the support structure 30 according to this second embodiment, the support 12a is attached to the box girder 62 by fillet welding 32 and set bolts 26.

[0070] As mentioned above, the corrosion resistance of welded stainless steel is reduced, so it is necessary to use different types of stainless steel depending on whether or not welding is performed. In the support structure 30 according to this second embodiment, the clad steel cladding material 20B of the sole plate 18a is joined to the clad steel cladding material 66B of the bottom plate 62A of the box girder 62 by fillet welding 32. Therefore, when stainless steel is used for the clad steel cladding material 20B and the clad steel cladding material 66B, it is preferable to use a composition with a pitting index of 23 or higher, and more preferably a composition with a pitting index of 28 or higher.

[0071] Furthermore, although titanium cannot be welded to carbon steel, titanium can be welded to itself. Therefore, when titanium is used as a clad steel composite material in the support structure 30 according to this second embodiment, it is necessary to use titanium for both the clad steel composite material 20B and the clad steel composite material 66B.

[0072] (3) Third Embodiment Figure 5 is a schematic one-sided cross-sectional view of a support structure 40 according to the third embodiment of the present invention, where the left side of the center line is a side view seen perpendicular to the bridge axis, and the right side of the center line is a vertical cross-sectional view seen perpendicular to the bridge axis.

[0073] In the bearing structure 10 according to the first embodiment, clad steel (clad steel 20, which is formed by metallographically joining a clad steel base material 20A, which is a steel base material, with a clad steel cladding material 20B, which is a corrosion-resistant metal) was used for the sole plate 18. However, in the bearing structure 40 according to this third embodiment, a single material of corrosion-resistant metal is used for the sole plate 44 of the bearing 42 instead of clad steel. In all other respects, the bearing structure 40 according to this third embodiment is the same as the bearing structure 10 according to the first embodiment, so explanations of similar points will be omitted in principle and replaced with explanations of the first embodiment. In addition, members and parts corresponding to members and parts of the bearing structure 10 according to the first embodiment will be denoted by the same reference numerals in principle, and explanations will be omitted in principle.

[0074] In the support structure 40 according to this third embodiment, the sole plate 44 is not welded to the clad steel composite material 66B of the bottom plate 62A of the box girder 62. Instead, the upper surface of the sole plate 44 is joined to the lower joint portion 62X of the box girder 62 using both the sole plate mounting bolts 24 and the set bolts 26, thereby attaching the sole plate 44 to the box girder 62.

[0075] As shown in Figure 5, in the support structure 40 according to this third embodiment, since a single material of corrosion-resistant metal is used for the sole plate 44, carbon steel is not exposed on the edge surface, which is the cross-section in the thickness direction of the end of the sole plate 44, and on the inner surface of the through holes used for connecting the sole plate 44 (through hole 44A for the sole plate mounting bolt 24, through hole 44B for the set bolt 26), and only the corrosion-resistant metal is exposed, so it is not necessary to provide a corrosion-resistant coating on these surfaces. Furthermore, since only the corrosion-resistant metal is exposed on the outer surface of the sole plate 44 in the in-plane direction, it is not necessary to provide a corrosion-resistant coating.

[0076] The corrosion-resistant metal that can be used for the sole plate 44 is the same as the clad steel composite material 20B of the sole plate 18 in the support structure 10 according to the first embodiment.

[0077] From the viewpoint of suppressing galvanic corrosion, an insulating layer may be provided between the sole plate 44, made of corrosion-resistant metal, and the upper shoe 16C. As the insulating layer, any rubber or plastic that can be processed into a sheet and has high electrical resistance can be used, but it is preferable to use a flexible rubber (natural rubber, chloroprene rubber, fluororubber, ethylene propylene rubber, nitrile rubber, acrylonitrile butadiene rubber, urethane rubber, styrene butadiene rubber, MSR rubber) because it is easy to adhere to.

[0078] (4) Fourth Embodiment Figure 6 is a schematic one-sided cross-sectional view of a bearing structure 50 according to the fourth embodiment of the present invention, where the left side of the center line is a side view seen perpendicular to the bridge axis, and the right side of the center line is a vertical cross-sectional view seen perpendicular to the bridge axis.

[0079] In the support structure 40 according to the third embodiment, the sole plate 44 was joined to the lower joint portion 62X of the box girder 62 using sole plate mounting bolts 24 and set bolts 26, thereby attaching the support 42 to the box girder 62. However, in the support structure 50 according to this fourth embodiment, the sole plate 44a is joined to the clad steel composite material 66B of the bottom plate 62A of the box girder 62 by fillet welding 52, and the set bolts 26 are inserted through holes 62A3 and 44B and screwed into holes 16C1 to attach the sole plate 44a to the box girder 62. In all other respects, the support structure 50 according to this fourth embodiment is the same as the support structure 40 according to the third embodiment, so explanations of similar points will be omitted in principle and replaced by explanations of the third embodiment. In addition, members and parts corresponding to members and parts of the support structure 40 according to the third embodiment will be denoted by the same reference numerals in principle, and explanations will be omitted in principle.

[0080] As shown in Figure 6, in the support structure 50 according to this fourth embodiment, the sole plate 44a is joined to the clad steel composite material 66B of the bottom plate 62A of the box girder 62 by fillet welding 52. For this reason, the support structure 50 according to this fourth embodiment does not use sole plate mounting bolts 24, and the sole plate 44a is not provided with through holes 44A for sole plate mounting bolts 24. In all other respects, the sole plate 44a and the support 42a are the same as the sole plate 44 and the support 42 in the support structure 40 according to the third embodiment, respectively. In the support structure 50 according to this fourth embodiment, the upper surface of the sole plate 44a is joined to the lower surface joining portion 62X of the box girder 62 by fillet welding 52 and set bolts 26, thereby attaching the sole plate 44a to the box girder 62.

[0081] As mentioned above, the corrosion resistance of welded stainless steel is reduced, so it is necessary to use different types of stainless steel depending on whether or not welding is performed. In the bearing structure 50 according to this fourth embodiment, the sole plate 44a is joined to the clad steel composite 66B of the bottom plate 62A of the box girder 62 by fillet welding 52. Therefore, when stainless steel is used for the sole plate 44a and the clad steel composite 66B, it is preferable to use a composition with a pitting index of 23 or higher, and more preferably a composition with a pitting index of 28 or higher.

[0082] Furthermore, although titanium cannot be welded to carbon steel, titanium can be welded to itself. Therefore, when titanium is used as the corrosion-resistant metal in the support structure 50 according to this fourth embodiment, it is necessary to use titanium for both the sole plate 44a and the clad steel composite material 66B.

[0083] (5) Fifth embodiment Figure 7 is a schematic vertical cross-sectional view of a support structure 70 according to the fifth embodiment of the present invention, viewed from a direction perpendicular to the bridge axis.

[0084] The fifth embodiment of the present invention, the support structure 70, is an embodiment of the support structure 50 according to the fourth embodiment, in which the upper shoe 16C is made of carbon steel upper shoe 16C0, the sole plate 44a is made of stainless steel sole plate 44a0, the clad steel cladding material 66B of the clad steel 66 used in the bottom plate 62A of the box girder 62 is made of stainless steel clad steel cladding material 66B0, and the clad steel 66 is made of clad steel 66a, and an insulating layer 72 is provided between the carbon steel upper shoe 16C0 and the stainless steel sole plate 44a0. The carbon steel upper shoe 16C0 and the stainless steel sole plate 44a0 are dissimilar metals, but by providing an insulating layer 72 between them, contact between the carbon steel upper shoe 16C0 and the stainless steel sole plate 44a0 is prevented, thereby preventing corrosion of dissimilar metals. Furthermore, in the support structure 70 according to this fifth embodiment, a bolt sleeve 26A is provided on the surface of the cylindrical portion (the unthreaded part) of the shaft of the carbon steel set bolt 26, and a support cover 74 is provided to cover the support body 16a, thereby improving corrosion resistance. Regarding other points, the support structure 70 according to this fifth embodiment is the same as the support structure 50 according to the fourth embodiment, so explanations of similar points will be omitted in principle and replaced by explanations of the fourth embodiment. Also, members and parts corresponding to those of the support structure 50 according to the fourth embodiment will be denoted by the same reference numerals in principle, and explanations will be omitted in principle.

[0085] The bearing 42b of the bearing structure 70 according to this fifth embodiment is located between the box girder 62, which is the superstructure of the box girder bridge 60, and the pier 100, which is the substructure of the box girder bridge 60, and plays the role of transmitting the load of the box girder 62, which is the superstructure of the box girder bridge 60, to the pier 100, which is the substructure.

[0086] As shown in Figure 7, the support 42b consists of, from bottom to top, a base plate 14, a support body 16a, an insulating layer 72, and a sole plate 44a0. The base plate 14 is fixed to the top of the pier 100 by anchors 14A, and the sole plate 44a0 is attached to the bottom plate 62A of the box girder 62 by set bolts 26 and fillet welds 52, such that the upper surface of the sole plate 44a0 is joined to the bottom joint portion 62X, which is the lower surface of the box girder 62.

[0087] As shown in Figure 7, the bearing body 16a of the bearing 42b consists of a lower shoe 16A, a rubber body 16B, and an upper shoe 16C0, in that order from bottom to top. The lower surface of the lower shoe 16A is attached and fixed so as to be joined to the upper surface of the base plate 14, and the upper surface of the carbon steel upper shoe 16C0 is attached and fixed so as to be joined to the lower surface of the stainless steel sole plate 44a0 via an insulating layer 72. The lower surface of the rubber body 16B is attached and fixed so as to be joined to the upper surface of the lower shoe 16A, and the upper surface of the rubber body 16B is attached and fixed so as to the lower surface of the upper shoe 16C0. The bearing body 16a is a commonly used rubber bearing, and the base plate 14 is also a commonly used steel base plate.

[0088] As shown in Figure 7, in the support structure 70 according to this fifth embodiment, the stainless steel sole plate 44a0 is joined to the stainless steel clad steel composite material 66B0 of the bottom plate 62A of the box girder 62 by fillet welding 52. For this reason, in the support structure 70 according to this fifth embodiment, similar to the support structure 50 according to the fourth embodiment, sole plate mounting bolts 24 are not used, and the sole plate 44a0 does not have through holes 44A for sole plate mounting bolts 24. In the support structure 70 according to this fifth embodiment, the upper surface of the sole plate 44a0 is joined to the lower surface joining portion 62X of the box girder 62 by fillet welding 52 and set bolts 26, thereby attaching the sole plate 44a0 to the box girder 62.

[0089] As mentioned above, the corrosion resistance of welded stainless steel is reduced, so it is necessary to use different types of stainless steel depending on whether or not welding is performed. In the support structure 70 according to this fifth embodiment, the stainless steel sole plate 44a0 is joined to the stainless steel clad steel composite material 66B0 of the bottom plate 62A of the box girder 62 by fillet welding 52, similar to the support structure 50 according to the fourth embodiment. Therefore, it is preferable to use stainless steel with a pitting index of 23 or higher for the stainless steel sole plate 44a0 and the stainless steel clad steel composite material 66B0, and more preferably stainless steel with a pitting index of 28 or higher.

[0090] Since the sole plate 44a0 is made of stainless steel and the upper shoe 16C0 is made of carbon steel, in order to prevent corrosion from contact between dissimilar metals, the bearing structure 70 according to this fifth embodiment is provided with an insulating layer 72 between the sole plate 44a0 and the upper shoe 16C0 so that the carbon steel upper shoe 16C0 and the stainless steel sole plate 44a0 do not come into contact.

[0091] As the insulating layer 72, any material that can prevent electrical contact between the stainless steel sole plate 44a0 and the carbon steel upper shoe 16C0 can be used. Specifically, for example, a coating with a predetermined insulating performance can be used. Alternatively, a fluororesin or a fluororesin mixed with a filler can be used.

[0092] Specific examples of coatings that can be used for the insulating layer 72 include coatings formed using epoxy resin paint, polyurethane resin paint, fluororesin paint, and ultra-thick film epoxy resin paint. Furthermore, examples of primers that can be used when forming these coatings include epoxy resin primer, organic zinc-rich primer, and inorganic zinc-rich primer.

[0093] Fluororesin has superior chemical resistance and creep resistance compared to rubber. Furthermore, mixing glass fibers or alumina with fluororesin further improves creep resistance and abrasion resistance.

[0094] Since the insulating layer portion that receives a large load in a direction perpendicular to the layer surface is prone to a decrease in insulating function, it is preferable to use a sheet-shaped fluororesin for such insulating layer portions. The sole plate 44a0 and the upper shoe 16C0 are portions of the support structure 70 that receive a large vertical load, and the insulating layer 72 between the sole plate 44a0 and the upper shoe 16C0 is an insulating layer portion that receives a large load in a direction perpendicular to the sole plate 44a0 and the upper shoe 16C0. Therefore, it is preferable to use a sheet-shaped fluororesin for the insulating layer 72 of the support structure 70 according to this fifth embodiment. Examples of fluororesins that can be formed into a sheet include polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and ethylene-tetrafluoroethylene copolymer (ETFE).

[0095] Furthermore, fluororesin formed in sheet form is particularly effective when components of different materials are arranged above and below, and when used as an insulating layer that transmits horizontal shear force. In the fifth embodiment, the insulating layer 72 of the bearing structure 70 has components of different materials (stainless steel sole plate 44a0 and carbon steel upper shoe 16C0) arranged above and below it, and is an insulating layer that transmits horizontal shear force, so it is preferable to use fluororesin formed in sheet form for the insulating layer 72.

[0096] Furthermore, the set bolts 26 used in the support structure 70 according to this fifth embodiment are made of carbon steel, but may be zinc-plated on their entire surface. The heads of the set bolts 26 are coated with paint (organic zinc-rich paint, inorganic zinc-rich paint, epoxy paint) or thermal spraying (material: Al, Zn, Al-Zn, Al-Mg). The surface of the cylindrical part of the shaft of the set bolt 26 (the part that is not threaded) is also coated with paint (organic zinc-rich paint, inorganic zinc-rich paint, epoxy paint) or thermal spraying (material: Al, Zn, Al-Zn, Al-Mg). However, on the surface of the cylindrical part of the shaft of the set bolt 26, a bolt sleeve 26A is provided on top of the coating to further improve corrosion resistance. The bolt sleeve 26A is a heat-shrinkable sleeve with a thickness of 0.3 mm or more. The tip surface of the shaft portion of the set bolt 26 (the outer circumferential surface of the threaded tip portion and the threaded tip surface) is not fitted with a bolt sleeve 26A, nor is it coated with paint or thermal spraying. The tip portion is screwed into the hole 16C1 of the upper shoe 16C0, which has threads on its inner surface, with the carbon steel exposed. However, since the upper shoe 16C0 and the set bolt 26 are made of the same carbon steel, galvanic corrosion does not occur even if they come into contact.

[0097] Although galvanic corrosion can occur between the clad steel cladding material 66B0 (made of stainless steel) and sole plate 44a0 (made of stainless steel) of the bottom plate 62A (clad steel 66a) of the box girder 62 and the carbon steel set bolts 26, a bolt sleeve 26A is provided on the surface of the cylindrical part (the unthreaded portion) of the shaft of the set bolt 26 that passes through the through holes 62A3 and 44B. This prevents contact between the clad steel cladding material 66B0 (made of stainless steel) and sole plate 44a0 (made of stainless steel) and the carbon steel set bolts 26, providing sufficient insulation and thus preventing galvanic corrosion and achieving sufficient corrosion protection. Furthermore, the corrosion protection can be further improved by applying epoxy resin coating to the inner surfaces of the through holes 62A3 and 44B. Furthermore, the heads of the set bolts 26 may also be coated with at least one of the following paints in addition to the aforementioned paint or metal spray coating: epoxy paint, urethane paint, acrylic silicone resin paint, fluororesin paint, and ultra-thick film epoxy resin paint. In Figure 7, epoxy coating using epoxy paint is shown as a specific example and is illustrated with a dashed line as epoxy coating 80 (illustrated only on the left side of Figure 7, with the description omitted on the right side). This epoxy coating 80 may be applied not only to the heads of the set bolts 26, but also to the entire inner surface of the box girder 62, as shown on the left side of Figure 7, or to the outer surfaces (surfaces exposed to the outside) of the upper shoe 16C0, lower shoe 16A, and base plate 14.

[0098] Furthermore, in the support structure 70 according to this fifth embodiment, a support cover 74 is attached to the support body 16a with fasteners 76 so as to cover the periphery of the support body 16a. However, since the fasteners 76 are made of carbon steel, it is preferable to use fasteners 76 attached to the stainless steel sole plate 44a0 that have their outer surface covered with a corrosion-resistant coating (for example, epoxy coating formed using epoxy resin paint). Also, since the fasteners 76 only serve to fix the support cover 74, it is not necessary to use high-strength carbon steel bolts for the fasteners 76, and bolts made of stainless steel or titanium may be used as fasteners 76 attached to the stainless steel sole plate 44a0.

[0099] When installing a bolt sleeve 26A on the cylindrical part (the unthreaded portion) of the shaft of a set bolt 26, the cylindrical part of the shaft of the set bolt 26 is inserted into the bolt sleeve 26A, and heat is applied to the bolt sleeve 26A to shrink it and make it tightly adhere to the cylindrical part of the shaft of the set bolt 26. Methods of applying heat include hot air, heating by electrical resistance, far-infrared radiation, and a burner. The temperature at which the heat-shrinkable sleeve shrinks is lower than the melting point of the resin. Therefore, unlike powder lining, which involves melting and coating with resin, it is easy to install, does not require special equipment, and can be installed on-site. Also, because it is a pre-molded sleeve, the thickness of the bolt sleeve 26A attached to the cylindrical part of the shaft of the set bolt 26 is uniform, and pinholes are less likely to occur. Suitable materials for the bolt sleeve 26A include polyvinyl chloride, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, and fluororesin (PFA, tetrafluoroethylene-hexafluoropropylene copolymer (FEP)). By mixing these with reinforcing fibers to create a composite material, it is possible to prevent damage penetrating the bolt sleeve 26A during installation. However, even without using reinforcing fibers, it is possible to prevent damage penetrating the bolt sleeve 26A during installation by making the thickness of the bolt sleeve 26A 0.3 mm or more.

[0100] This has been confirmed experimentally, so the details and results of that experiment are described below.

[0101] <Sleeve-covered bolt drop test> A sleeve-coated bolt damage resistance test was conducted to investigate the required thickness of the sleeve covering the cylindrical portion (the unthreaded part) of the shaft of a sleeve-coated bolt.

[0102] A standard M16 hexagonal bolt with zinc plating (cylindrical diameter: φ16mm, underhead length: 100mm, partially threaded) was used, and metal spraying (Al-Mg spraying) was applied to the head and the cylindrical part of the shaft (the part without threads). After the metal spraying, a sleeve was added to the cylindrical part of the shaft with varying film thicknesses.

[0103] A rectangular stainless steel container (630mm x 430mm x 150mm) was filled with 20-30mm crushed stone, and a sleeve-coated M16 bolt was dropped onto the crushed stone from a height of 2m to investigate whether defects (pinholes) occurred.

[0104] The presence or absence of defects (pinholes) was checked visually and using a pinhole detector (manufactured by Sanko Electronics Laboratory Co., Ltd.). The pinhole detector was set to a voltage of 2kV to investigate the presence or absence of defects (pinholes).

[0105] The results are shown in Table 1 below. × indicates that a defect occurred, and ○ indicates that no defect occurred.

[0106] [Table 1]

[0107] As can be seen from Table 1, when the sleeve thickness is 0.3 mm or more, no defects (pinholes) occur. From this, it can be concluded that by making the thickness of the bolt sleeve 26A 0.3 mm or more, it is possible to prevent damage penetrating the bolt sleeve 26A from occurring during installation.

[0108] (6) Supplement When using clad steel (clad steel using corrosion-resistant metal as the cladding material) in carrying out the present invention, it is preferable to use rolled clad steel because it is easy to manufacture large plates and is less expensive than explosive clad steel or build-up clad steel. [Explanation of Symbols]

[0109] 10, 30, 40, 50, 70…Support structure 12, 12a, 42, 42a, 42b...Support 14…Base plate 14A... Anchor 16, 16a...Support body 16A…Lower shoe 16B...Rubber body 16C, 16C0…Kamikutsu 16C1…hole 18, 18a, 44, 44a, 44a0… sole plate 18A, 18B, 44A, 44B, 62A2, 62A3...Through hole 18X... Edge 20, 66, 66a… Clad steel 20A, 66A... Clad steel base material 20B, 66B, 66B0... Clad steel composite materials 20X... Outer surface in the in-plane direction of the clad steel base material 20A 24…Sole plate mounting bolts 26…Set bolts 26A... Bolt sleeve 32, 52... Fillet welds 60…Box girder bridge 62... Box girders 62A…Bottom plate 62A1...Bottom plate vertical ribs 62B...Web 62C...Transverse ribs 62D…Upper flange 62D1… Upper flange tip vertical rib 62E…Vertical stiffener 62X…Bottom surface joint part 68...Corrosion-resistant coating 72…Insulating layer 74...Support cover 76… Fasteners 80... Epoxy coating 100... Bridge piers 110... Precast PC floor slab 112... Asphalt pavement 120…Expansion device

Claims

1. A support structure comprising a structure having a superstructure and a substructure, and a support located between the superstructure and the substructure for transmitting the load of the superstructure to the substructure, The support has a sole plate that is fixed with its upper surface in contact with the lower surface joining portion, which is the lower surface portion of the upper structure to which the support is joined. The upper surface of the sole plate that contacts the lower joint portion is made of a corrosion-resistant metal that is nobler than carbon steel, and the lower joint portion of the superstructure is also made of a corrosion-resistant metal that is nobler than carbon steel. The support structure is characterized in that the sole plate is joined by welding to the lower joint portion of the upper structure.

2. A support structure comprising a structure having a superstructure and a substructure, and a support located between the superstructure and the substructure for transmitting the load of the superstructure to the substructure, The support has a sole plate that is fixed with its upper surface in contact with the lower surface joining portion, which is the lower surface portion of the upper structure to which the support is joined. The upper surface of the sole plate that contacts the lower joint portion is made of a corrosion-resistant metal that is nobler than carbon steel, and the lower joint portion of the superstructure is also made of a corrosion-resistant metal that is nobler than carbon steel. A bearing structure characterized in that the corrosion-resistant metal forming the upper surface of the sole plate and the corrosion-resistant metal forming the lower joint portion of the superstructure are both pure titanium, stainless steel with a pitting index difference of 6 or less, or a nickel alloy.

3. The bearing structure according to claim 1, characterized in that both the portion of the sole plate and the lower surface joining portion, which are joined by the aforementioned welding, are made of stainless steel with a pitting index of 23 or higher.

4. The support structure according to claim 2, characterized in that the sole plate is joined to the lower joint portion of the upper structure by a rod-shaped member.

5. The bearing structure according to claim 4, characterized in that the rod-shaped member is made of metal, and at least a portion of the outer surface of the rod-shaped member is provided with a corrosion-resistant coating.

6. The bearing structure according to claim 5, characterized in that the corrosion-resistant coating is formed of a heat-shrinkable sleeve.

7. The bearing structure according to claim 6, characterized in that the thickness of the heat-shrinkable sleeve is 0.3 mm or more.

8. The bearing structure according to claim 2, characterized in that the member including the lower joint portion of the superstructure is formed of a single material, which is stainless steel, titanium, or nickel alloy.

9. The support structure according to claim 1 or 2, wherein the member including the lower joint portion of the superstructure is made of clad steel, the lower joint portion of the superstructure is made of a clad steel composite, and the clad steel composite is made of a corrosion-resistant metal that is nobler than the carbon steel which is the base material of the clad steel.

10. The support structure according to claim 1 or 2, wherein the lower surface of the sole plate is formed of a first metal member, the portion of the support joined to the lower surface is formed of a second metal member made of a different material from the first metal member, and there is an insulating layer between the first metal member and the second metal member.

11. The bearing structure according to claim 10, characterized in that the insulating layer is formed by painting.

12. The bearing structure according to claim 10, characterized in that the insulating layer is formed of fluororesin or fluororesin mixed with a filler.

13. The bearing structure according to claim 12, characterized in that the insulating layer is formed in a sheet shape.

14. The bearing structure according to claim 1 or 2, characterized in that the sole plate is made of clad steel, the upper surface of the sole plate is made of a clad steel composite, and the clad steel composite is made of a corrosion-resistant metal that is nobler than the carbon steel that is the base material of the clad steel.

15. The bearing structure according to claim 14, characterized in that, on the thickness-direction surface formed by cutting or machining the clad steel forming the sole plate in the thickness direction so as to cross both the clad material and the base material, a corrosion-resistant coating is provided so as to cover both the clad material and the base material of the exposed clad steel.

16. The bearing structure according to claim 15, characterized in that the surface in the thickness direction is the edge surface of the sole plate.

17. The bearing structure according to claim 15, characterized in that the surface in the thickness direction is the inner surface of a hole into which a bolt can be inserted.

18. The bearing structure according to claim 14, characterized in that a corrosion-resistant coating is provided to cover the downward outer surface of the base material of the clad steel that forms the sole plate.

19. The bearing structure according to claim 14, characterized in that the clad steel forming the sole plate is rolled clad steel.

20. The bearing structure according to any one of claims 1 to 8, characterized in that the sole plate is formed from a single material, either stainless steel, titanium, or nickel alloy.

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