JP4399606B2 - Sliding dowel bar - Google Patents

Description

  The present invention is, for example, on-site concrete pavement such as airport pavement and road pavement constructed on a roadbed by arranging side end surfaces of a plurality of concrete pavement plates adjacent to each other, expansion contraction due to temperature change, external stress, etc. The present invention relates to an improvement of a dowel bar as a load transmission means used for eliminating a problem that a step is generated due to relative displacement of a positional relationship between concrete paving plates.

Concrete structures such as airport runways, taxiways, aprons, roads, etc., or large concrete structures such as buildings, such as paving slabs with the required shape, are constructed by on-site concrete pavement. It is constructed by connecting multiple pieces on the roadbed and ground. By arranging these large structures adjacent to each other through joints, it is possible to cope with external factors that the structure receives, such as expansion and contraction due to temperature changes, changes in the ground, and the like.
For example, when building a runway at an airport, a plurality of PC paving plates having a width of 7.5 m, a length of 100 m, and a predetermined thickness (for example, 35 mm) are adjacent to the base layer portion (roadbed etc.) on the site. Work to arrange. That is, a plurality of paving plates are formed by sequentially performing a paving plate manufacturing process for each paving plate after placing a rectangular formwork on the base layer at the site and filling the formwork with a material such as concrete. A large structure (runway) with adjacent plates is completed.
Structures such as individual paving slabs constituting these large structures are connected end faces of adjacent structures due to expansion and contraction due to temperature changes, external stress applied by passing heavy objects such as aircraft and vehicles, etc. Misalignment and displacement are likely to occur between them. If misalignment or the like that occurs between the connecting end faces occurs in the vertical direction, a step in the vertical direction occurs at the top of the connection between the structures, and the step is easily damaged by aircraft, vehicles, etc. that pass on the paving slab. Or accidents caused by the presence of steps may occur.

  For this reason, conventionally, at the joint between the paving plate and the paving plate, a metal bar having a function of load transmission is penetrated so as to be orthogonal to both connection end faces and embedded in each paving plate. Such a metal bar is called a dowel bar and is embedded and fixed across both pavement plates so as to penetrate through the connection end surfaces of two adjacent pavement plates, whereby the connection end surfaces of the two pavement plates are in the vertical direction. By transmitting the load generated by one relative displacement to the other via the dowel bar, the two paving slabs are displaced in the vertical direction by the same distance in the same direction. Yes. The conventional dowel bar can also follow the displacement of the paving plate in the longitudinal direction of the dowel bar to some extent. A plurality of dowel bars are arranged in a predetermined arrangement along the lateral direction of the joint surface.

In addition, the conventional dowel bar is not only a type composed of a single metal rod as described above, but also, for example, a female screw portion and a male screw portion at each end of two metal rods in consideration of convenience during construction. Various types have been proposed, such as a type in which a connecting portion made of each of them is provided so that a single metal rod is formed at the time of connection (for example, Patent Documents 1 to 4). However, the conventional dowel bar is intended to prevent a step formed on the upper surfaces of two adjacent pavement plates. However, the dowel bar is also used when there is a displacement due to expansion or contraction in the plate length lateral direction. Tries to exert its load transfer function (try to generate restraint stress). This caused damage to the concrete part in which the dowel bar was embedded.
In order to solve such a problem, in Patent Document 5, a connection member made of precast concrete having an oval cross section that is long in the joint direction is embedded across both connection end surfaces of two pavement plates, thereby generating on the connection end surface. A load transmission means has been proposed that allows the pavement plates to slide relative to each other during the expansion and contraction in the transverse direction of the plate while exhibiting the load transmission function between the pavement plates in the longitudinal direction. Yes.

However, since the connecting member having an oval cross section is made of concrete, it is difficult to maintain durability for a long period of time, and it is easy to break. If the connecting member is broken, the load transmission function may be lost. In addition, even when a relative displacement in the plate length (lateral) direction between the paving plates occurs, the connecting member cannot smoothly slide between both connection end faces, and the paving plate slides with the connecting member. There was a possibility that the portion deteriorated with time and was damaged. If this connection member is made of metal, there is a risk that a problem may occur due to the difference in rigidity from the concrete paving plate.
In order to solve such a problem, in Patent Document 6, a metal member is used as a main component, maintaining mechanical strength and durability, and having a compact shape, the structure can be displaced in the lateral direction. There has been proposed a sliding dowel bar that can ensure a large amount of movement. However, this slide type dowel bar has a drawback that the number of parts is increased and the number of assembling steps is increased and the cost is increased.
Japanese Patent Laid-Open No. 2001-182008 JP-A-10-195810 Japanese Patent No. 3160839 JP 2001-159103 A JP 63-217011 A JP 2004-278242 A

  The problem to be solved by the present invention is, for example, when a plurality of concrete paving plates are arranged on a roadbed with end surfaces facing each other in order to construct a runway of an airfield, for example, a paving plate caused by a temperature change or the like In the dowel bar which prevents the occurrence of a vertical step between the connection end faces between the paving plates due to relative displacement of the positional relationship between the concrete paving plates due to expansion and contraction, external stress such as load, etc. An object of the present invention is to provide a slide type dowel bar that can absorb and eliminate the displacement in the plate length (lateral) direction between the paving plates.

In particular, according to the sliding dowel bar of the present invention, the surface is not limited to a concrete structure such as a concrete paving slab, but exerts a load transmission function for a longitudinal displacement between two structures having a large weight. On the other hand, it is possible to prevent the structural body from being damaged by not exhibiting the load transmission function (generating restraint stress) against the lateral displacement.
Furthermore, according to the slide type dowel bar of the present invention, a small amount of parts and a compact shape can ensure a large movable amount when the structure is displaced in the lateral direction, and the cost can be reduced.

In order to solve the above-mentioned problems, the present invention provides a dowel bar as a load transmitting means between two concrete structures that are installed adjacent to each other on the roadbed and in which the connection end faces are relatively displaced. A first embedded unit horizontally embedded and fixed from the connection end surface to the inside of the structure, and a second embedded unit horizontally embedded and fixed from the connection end surface of the other structure to the inside, The first embedded unit is embedded and fixed in an exposed state on the connection end surface of one structure, and has a hollow support portion therein and a horizontally long guide hole on the front surface, and a back surface of the guide member And a steel bar that is integrally protruded from and fixed to the inside of the one structure, and the second embedded unit extends from the connection end surface of the other structure to the inside. A steel bar that is fixedly installed and the front part is inserted into the hollow support part of the guide member through the guide hole, and is fixed to the front end part of the steel bar and fitted into the hollow support part of the guide member to be transverse A fitting piece that is supported so as to be able to move forward and backward, and the guide member is configured to move relative to the lateral direction of the second embedded unit when the connecting end surfaces of both structures are relatively displaced in the plane direction. It has a structure that transmits the load in the vertical direction while prohibiting relative movement in the vertical direction along the surface direction of the connection end surface while allowing the movement and generating no restraining stress in the horizontal direction. Features.

Further, in the present invention, the guide member constituting the first burying unit has a recessed portion which is embedded and fixed on the connection end surface of the one structure body and which forms the hollow support portion on the front surface, and the steel bar on the back surface. A metal base member projecting integrally, and a metal lid member fixed to the front surface of the metal base and penetrating through a laterally extending guide hole that communicates with the recess. In a state where the fitting piece constituting the embedded unit is supported in the hollow support portion inside the guide member so as to be able to advance and retreat in the lateral direction, the steel bar protruding from the fitting piece is hollow supported from the guide hole provided in the metal lid member It protrudes to the outside of the part.

The present invention also Oite to claim 1, on the front surface of the metal lid member constituting the guide member fixed to the one end face of the structure, the second as well as sealing the guide holes A low resistance sheet having an insertion hole that is in close contact with the outer periphery of the steel bar of the embedded unit is slidably disposed on the front surface of the metal lid member.

  According to the present invention, for example, when constructing a concrete structure such as an airfield runway, a road or the like, the end surfaces of a plurality of concrete paving plates face each other and are arranged on the roadbed, so that the pavement is caused by a temperature change or the like. Prevents relative displacement in the vertical (vertical) direction due to expansion and contraction of the plates and external stresses such as load, etc., connecting surfaces (joints) of adjacent concrete pavement plates The dowel bar as a load transmission means by not only eliminating the problem of the formation of a step in the vertical direction but also allowing the positional relationship between the two paving plates to be displaced relatively in the plate length (lateral) direction. This can eliminate the problem of damage to concrete and concrete.

The dowel bar of the present invention is not limited to a concrete structure such as a concrete paving plate, and can be used for a dowel bar as a load transmitting means embedded between two structures.
Further, the dowel bar of the present invention is compact and has a simple shape and structure with a small number of parts, but flexibly responds to the horizontal (lateral) displacement of the structure, and the horizontal (lateral) displacement of the two structures. Therefore, the structure can be reliably protected.
In addition, since the size, shape, and number of used dowel bars can be changed in accordance with the size of the structure, it can be applied to all types of structures to generate steps due to relative displacement between structures. It is possible to effectively prevent damage to the structure due to stress generated between the structures.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
Before detailing the structure of the sliding dowel bar of the present invention, the procedure for embedding the dowel bar of the present invention across the connecting end faces of two concrete paving plates arranged adjacent to each other will be described with reference to FIGS. .
First, FIG. 1 (a) (b) has shown the manufacture (installation) procedure at the time of newly installing a pavement plate, and the bottom part of the formwork 6 whose planar shape is a rectangular frame on the base layer part 1 of a roadbed etc. Is fixed with bolts 10 and the sliding dowel bar 20 of the present invention is used in advance by using bolts 11 or the like inside the side plate 6a of the mold 6 that covers the connection end face (joint) 2A with another adjacent paving plate. To fix. The required number of dowel bars 20 is arranged on the connecting end face 2A near the both ends in the longitudinal direction of the pavement plate 2 formed by filling the mold 6 with concrete. The reason why the dowel bars 20 are arranged at positions closer to both ends in the longitudinal direction of the pavement plate 2 is that this portion of the connection end surface of the pavement plate is the place where the expansion and contraction is most likely to occur due to temperature change or the like. The dimensions of this paving plate are, for example, about 7.5 m wide, 100 m long, and 35 cm thick.

  After the dowel bar 20 is fixed to the required position of the side plate 6a of the mold 6 and the concrete is filled into the mold 6 and solidified, the bolt 11 is removed from the side plate 6a, and the bolt 10 is removed from the mold. The first pavement plate 2-1 is completed by removing the mold 6 from the base layer 1 after removing from the skirt. In this state, one steel bar 32 of the dowel bar 20 is embedded and fixed in the pavement plate, and the other steel bar 61 protrudes in the horizontal direction perpendicular to the connection end surface 2A.

  Next, FIG. 2 explains a procedure for constructing other paving plates in order after the first paving plate 2-1 is completed on the base layer portion 1, and the first paving plate 2-1 is completed. After that, prior to the construction of the adjacent second paving plate 2-2, the third paving plate 2-3 is constructed in the same procedure as described in FIG. A dowel bar 20 is embedded in 2B. At this time, the bar 61 of the dowel bar 20 protrudes from the connection end surface 2B of the third paving plate 2-3. Next, an operation for constructing the second pavement plate 2-2 is performed. At this time, the right connection end surface 2A of the first pavement plate 2-1 and the left connection end surface 2B of the third pavement plate 2-3 are molded. Since it can be used in place of the long side plate 6a of the frame, only the front and rear side surfaces where no pavement plate is present are closed by plate members not shown, respectively, and then both pavement plates 2-1 and 2-3 and the front and rear 2 A second pavement plate 2-2 is constructed by filling concrete into a space surrounded by a sheet of plate material. Prior to filling the concrete for constructing the second pavement plate 2-2, the work of inserting a low resistance sheet 75 or the like to be described later into the bar steel 61 of each dowel bar 20 is completed.

If a new pavement plate is to be connected to the existing pavement plate for widening the airport or road, a hole extending inward is drilled in the connection end face of the existing pavement plate. After the steel bar 61 of the dowel bar 20 is inserted and fixed in the hole, concrete is filled into the space formed by the side surface of the existing paving plate and the formwork and solidified.
The structure to which the sliding dowel bar of the present invention is applied is not limited to a concrete paving plate, but includes a concrete structure.

  Next, the sliding dowel bar of the present invention will be described in detail with reference to FIG. 3 (a), (b), (c) and (d) are an external perspective view of an example of a sliding dowel bar of the present invention, a partially exploded perspective view thereof, an exploded perspective view of all components, and a first embedded unit. FIGS. 4A, 4B, and 4C are a cross-sectional plan view, a front vertical cross-sectional view, and a side view of FIG. 4A showing a state in which the dowel bar is assembled to the structure.

The sliding dowel bar (hereinafter referred to as the dowel bar) 20 of the present invention has two adjacent structures, for example, concrete paving plates 2-1 and 2-2 disposed adjacent to the base layer 1 such as a roadbed. When the connection end faces 2A and 2B of both paving plates are displaced relative to each other in the vertical direction (vertical direction) along the surface direction, a step is generated in the vertical direction by transmitting a load from one paving plate to the other paving plate. On the other hand, when relative displacement is caused in the lateral direction (horizontal direction), it acts to allow lateral displacement without performing load transmission. The schematic configuration is as follows.
That is, the dowel bar 20 includes a first embedding unit 30 that is horizontally embedded and fixed from the connection end surface 2A of one pavement plate 2-1 to the inside, and a horizontal connection from the connection end surface of the other pavement plate 2-2 to the inside. And a second embedded unit 60 that is fixedly embedded and supported by the first embedded unit 30 so as to be displaceable in the lateral direction along the surface direction of the connection end surface.

The first embedding unit 30 is embedded and fixed in a state where the front surface is exposed to the connection end surface 2A of one pavement plate 2-1, and has a hollow support portion 36 therein and a horizontally long guide hole 41 on the front surface. And a steel bar 32 that is integrally protruded from the back surface of the guide member 31 and is embedded and fixed inside the one structure.
The second embedding unit 60 is embedded and fixed from the connection end surface 2B of the other pavement plate 2-2 to the inside and is a bar steel that allows the front portion 61a to enter the hollow support portion 36 of the guide member through the guide hole 41. 61 and a fitting piece 62 that is fixed to the front end portion of the steel bar 61 and is fitted in the hollow support portion 36 of the guide member 31 so as to be movable in the lateral direction. The steel bar 61 has a male screw part 61 b in the front part 61 a, and the male screw part 61 b is screwed and fixed in a screw hole 62 a provided in the fitting piece 62. The diameter of the screw hole 62a is set so as to be equal to or smaller than the vertical width of the guide hole 41, so that the screw hole 62a of the fitting piece 62 positioned inside the guide hole 41 is set. The screw portion 61b of the steel bar 61 can be screwed from the outside. In addition, in the state where the threaded portion 61 b of the steel bar 61 is screwed into the screw hole 62 a of the fitting piece 62, the outer diameter of the tip end of the steel bar 61 can be moved in the lateral direction along the guide hole 41. And the vertical width of the guide hole 41 are set.

The fitting piece 62 made of metal such as iron has, for example, a front end surface that is rectangular and flat, and has a generally bowl shape. The fitting piece 62 is in close contact with the inner wall of the hollow support portion 36 by its curved outer peripheral surface. The flat front end surface is configured to slide in the lateral direction while being in close contact with the inner side surface of the metal lid member 40. The screw hole 62a is open at the center of the front end surface, and terminates before reaching the back surface of the fitting piece 62 in this example. The screw hole 62 a may be penetrated to the back surface of the fitting piece 62.
The guide member 31 allows the relative movement of the second embedded unit 60 in the lateral direction when the connecting end faces of the both paving plates 2-1 and 2-2 are relatively displaced in the lateral direction, and the lateral direction. While restraint stress is not generated, a function of transmitting load in the vertical direction by prohibiting relative movement in the vertical direction along the surface direction of the connection end surface is provided.

  A detailed configuration for exhibiting such a function is, for example, as shown in FIG. That is, the guide member 31 constituting the first burying unit 30 is embedded and fixed on the connection end surface 2A of one structure 2-1, and has a recessed portion 37 constituting the hollow support portion 36 on the front surface and a steel bar on the back surface. A metal base 35 integrally projecting 32 and a laterally extending guide hole 41 that is detachably fixed to the front surface (outer frame end surface) of the metal base 35 and communicates with the recessed portion 37 are formed. And a metal lid member 40. The outer shape of the metal base 35 is an oval shape, an oval shape, or an oval shape as shown in FIG. 4C, and a planar shape is a curved shape at both ends in the longitudinal direction as shown in FIG. In addition, the front and rear surfaces are flat surfaces, and the front shape is substantially bowl-shaped as shown in FIG. The area (vertical and horizontal dimensions) and shape of the metal lid member 40 are configured as an oval, elliptical, or oval plate shape so as to substantially match the outer peripheral contour shape of the front end surface of the metal base 35.

  The outer frame on the front surface of the metal base 35 and the metal lid member 40 may be integrated by welding, or a plurality of screw holes (not shown) provided on the outer frame on the front surface of the metal base 35 and the metal lid member 40 side. The hollow support portion 36 may be formed by closing the recessed portion 37 with the metal lid member 40 by fastening with a bolt in a state where the corresponding through-hole (screw hole) provided in is connected. When screw holes are formed in the outer frame of the metal lid member 40 and the metal base 35, the metal base 35 is temporarily fixed when the dowel bar 20 is temporarily fixed to the side plate 6a of the mold as shown in FIG. In addition, the screw holes provided in the metal lid member 40 can be used to temporarily fix them with bolts.

  The hollow support part 36 sets the inner wall shape and dimensions so as to prohibit movement in the vertical direction while supporting the fitting piece 62 so as to be able to advance and retreat in the lateral direction. That is, the hollow support portion 36 is slidable in a state in which the outer peripheral surface (excluding both lateral end surfaces) of the substantially bowl-shaped fitting piece 62 is in close contact with the inner surface of the recessed portion 37 and the inner surface of the metal lid member 40. On the other hand, the lateral length (longitudinal direction) length L1 of the hollow support portion 36 is such that the lateral length L2 of the fitting piece 62 allows the movement of the fitting piece 62 in the same direction within a predetermined range. Longer than that. An appropriate amount of non-volatile and water-insoluble oil such as grease is filled between the inner wall of the hollow support portion 36 and the outer surface of the fitting piece 62, and the hollow support portion serves as an airtight space with a smooth sliding state. 36 is configured to continue semi-permanently.

Before the metal lid member 40 is fixed to the front surface of the metal base 35, the fitting piece 62 is fitted into the recessed portion 37, and then the metal lid member 40 is fixed to the front surface of the metal base 35. At this time, since the screw hole 62a of the fitting piece 62 is exposed from the guide hole 41 of the metal lid member 40, the screw portion 61b of the steel bar 61 can be attached to and detached from the screw hole 62a via the guide hole 41. it can.
Thus, by fitting the fitting piece 62 constituting the second embedded unit 60 into the hollow support portion 36 inside the guide member 31, the bar steel 61 protruding outward from the guide hole 41 is laterally formed by the guide hole 41. It is supported so that it can move forward and backward. Of course, grease or the like is applied in advance between the inner wall of the hollow support portion 36 and the outer peripheral surface of the fitting piece 62 to reduce the sliding resistance.

When the screw portion 61b is screwed into the screw hole 62a of the fitting piece, the insertion hole 75a of the low resistance sheet 75 made of a rubber plate, a resin plate or the like is formed on the outer peripheral surface of the steel bar 61 corresponding to the front surface of the metal lid member 40. Is inserted. The low resistance sheet 75 is inserted from the other end of the steel bar 61 until it is in close contact with the front surface of the metal member 40. The low resistance sheet 75 is a flat plate-like closing means that slidably contacts the front surface of the metal lid member 40 and permanently closes the guide hole 41. That is, the low-resistance sheet 75 has a vertical width v sufficient to close the guide hole 41 and a horizontal width h that can keep closing the guide hole 41 even when moved laterally together with the steel bar 61. . The low resistance sheet 75 is, for example, a rubber plate, and the insertion hole 75 a is a circular hole that is in close contact with the outer peripheral surface of the steel bar 61.
In a state where the insertion hole 75a of the low resistance sheet 75 is inserted into the steel bar 61 and brought into contact with the front surface of the metal lid member 40, the center hole of the fixing washer 80 is further inserted into the bar steel 61 and the low resistance sheet 75 is inserted. In a state of being in close contact with the outer side surface, it is locked and fixed to the outer peripheral surface of the steel bar 61 by a claw provided in the central hole of the washer. By locking and fixing the washer 80, the low resistance sheet 75 can maintain a state in which it is slidably adhered to the front surface of the metal lid member 40. Conversely, when removing the low resistance sheet 75, the washer 80 may be removed from the steel bar in advance.

  As described with reference to FIGS. 1 and 2, the dowel bar 20 is embedded in the connecting end surface 2A when the first paving plate 2-1 is newly constructed. In this case, the low resistance sheet 75 and the washer 80 are The steel bar 61 is not inserted. After constructing the first pavement plate 2-1, when the side plate 6 a of the mold 6 is removed, the low resistance sheet 75 is inserted into the steel bar 61 protruding from the connection end surface 2 </ b> A and the front surface of the metal lid member 40. And is fixed by a washer 80. In this state, concrete for constructing the second paving plate 2-2 is filled. And when the 2nd pavement plate 2-2 is completed by hardening of the filled concrete, the steel bar 61 is fixed to the inside of the 2nd pavement plate 2-2, and the low resistance sheet 75 and the connection end surface 2B The washer 80 is fixed.

  As described above, when the dowel bar 20 of the present invention is disposed in the newly installed pavement plate, the first embedded unit 30 side of the dowel bar 20 that has been assembled is embedded in the first pavement plate 2-1. As for the steel bar 61 constituting the second burying unit 60, the low resistance sheet 75 and the washer 80 are assembled in the concrete or when the second pavement plate 2-2 is constructed later. Take the procedure of embedding in the end face.

On the other hand, when connecting a new pavement plate to the side of the existing pavement plate, first, the steel bar 61 of the second embedded unit 60 is inserted and locked to the connection end surface of the existing pavement plate. In the state where the round hole 75a of the low resistance sheet 75 is inserted into the steel bar 61 and fixed by the washer 80, the steel bar 61 is inserted into the insertion hole of the connection end face, and mortar is injected. Fix it. At this time, in this state, the steel bar 32 on the first embedding unit 30 side protrudes in a state orthogonal to the connection end surface of the existing pavement plate. Thereafter, an adjacent new pavement plate is constructed according to the procedure described with reference to FIGS.
The description of the above embodiment mainly relates to a concrete paving slab, but this is only an example, and the sliding dowel bar of the present invention has a structure in which a plurality of structures of any material are arranged adjacent to each other. In the relative movement in the vertical direction, the load transmission function can be exerted so as to move integrally while allowing the lateral displacement movement between the connecting end faces.

Furthermore, although the case where the two connection end surfaces of the two structures are substantially vertical surfaces has been described in the above embodiment, this is merely an example. Therefore, even when the two connecting end surfaces are horizontal or inclined surfaces, the dowel bar of the present invention is applied to perform load transmission in the vertical direction and release the restraining stress in the horizontal direction. Problems caused by relative displacement can be solved.
Further, the connection end face does not necessarily have to be a flat face, and can be applied to two opposing non-flat connection end faces.

(A) And (b) is a figure which shows the manufacturing point order of the pavement plate using the sliding dowel bar of this invention, and principal part sectional drawing. Explanatory drawing which shows the manufacture procedure of a pavement plate, and the assembly procedure of a dowel bar. (A), (b), (c) and (d) are an external perspective view of an example of a sliding dowel bar of the present invention, a partially exploded perspective view thereof, an exploded perspective view of all components, and a rear side of the first embedded unit. Perspective view. (A) (b) And (c) is a plane cross-sectional view showing a state where the dowel bar is assembled to the structure, a front vertical cross-sectional view, and an exploded perspective view of the dowel bar of the present invention which is a side view of (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Base layer part, 2 ... Concrete paving plate, 2A ... Right connection end surface, 2B ... Left connection end surface, 6 ... Formwork, 6a ... Side plate, 10 ... Bolt, 11 ... Bolt, 20 ... Sliding dowel bar, 30 ... Embedded unit 31 ... Guide member, 32 ... Steel bar, 35 ... Metal base, 36 ... Hollow support part, 37 ... Recessed part, 40 ... Metal lid member, 41 ... Guide hole, 60 ... Buried unit, 61 ... Steel bar, 61a ... Front part , 61b ... thread portion, 62 ... fitting piece, 62a ... screw hole, 75 ... low resistance sheet, 75a ... round hole, 80 ... washer, 80 ... fixing washer.

Claims (1)

In the dowel bar as a load transmission means between two concrete structures that are installed adjacent to each other on the roadbed and in which the connection end faces are relatively displaced,
The dowel bar includes a first embedded unit that is horizontally embedded and fixed from the connection end surface of one structure to the inside, and a second embedded unit that is embedded and fixed horizontally from the connection end surface of the other structure to the inside; Have
The first embedded unit is embedded and fixed in an exposed state on the connection end surface of one structure, and has a hollow support portion therein and a horizontally long guide hole on the front surface, except for a flat front end surface. A guide member whose outer surface is curved , and a steel bar that is integrally projected from the back surface of the guide member and is embedded and fixed inside the one structure,
The second embedded unit has a steel bar that is embedded and fixed from the connection end surface to the inside of the other structure and has a threaded portion at the front end , and a screw hole that is screwed to the threaded portion of the steel bar. And a fitting piece that fits into the hollow support portion of the guide member and is supported so as to be able to advance and retreat in the lateral direction.
The guide member allows a relative movement in the lateral direction of the second embedded unit and does not generate a restraining stress in the lateral direction when the connection end surfaces of both structures are relatively displaced in the plane direction. With the configuration to transmit the load in the vertical direction by prohibiting the relative movement in the vertical direction along the surface direction of the connection end surface,
The guide member includes a metal base that is embedded and fixed on a connection end surface of the one structure and has a recessed portion that forms the hollow support portion on the front surface, and the bar steel that protrudes integrally on the back surface, and the metal base A metal lid member that is fixed to the front surface of the metal plate and that extends through a laterally extending guide hole that communicates with the recessed portion.
In a state where the fitting piece is supported in a hollow support part inside the guide member so as to be able to advance and retreat in the lateral direction, a steel bar protruding from the fitting piece is passed through a guide hole provided in the metal lid member to the outside of the hollow support part. Project
The front surface of the metal lid member constituting the guide member fixed to the end surface of the one structure has an insertion hole that seals the guide hole and closely contacts the outer periphery of the steel bar of the second embedded unit. A sliding dowel bar , wherein the low resistance sheet is slidably disposed on the front surface of the metal lid member .

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