JP2010059717A - Joint structure of structural body and anchoring member for shear force transmission used in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance, when a new concrete-structural body adjacent to an existing concrete-structural body is constructed, shear force transmission efficiency between the two structures. <P>SOLUTION: In a joint structure wherein an anchoring member 3 is arranged over an old structure 1 and a new structure 2 adjacent to each other and a shear force caused when the new structure 2 is relatively displaced to the old structure 1 is transmitted to the old structure 1 via the anchoring member 3, a groove 1a is formed in the old structure 1 from the front face side, and the anchoring member 3 is formed of a flat-plate shaped body 31 superposed on a boundary face between the old structure 1 and the new structure 2 and an annular protrusion 32 formed on the rear face of the body 31 and fitted in the groove 1a. While at least a part of the body 31 in the thickness direction is positioned inside the new structure 2 and at least a part of the protrusion 32 in the thickness direction is positioned inside the old structure 1, the anchoring member 3 is embedded in the old structure 1 and the new structure 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, for example, an existing concrete structure and a new concrete structure constructed in contact with the structure are sheared between the two structures when relative displacement (displacement deformation) is about to occur between the two structures. The present invention relates to a joining structure of structures that are joined so that force is transmitted, and a shear force transmitting fixing member used in the joining structure.

  When constructing a new concrete structure in contact with the surface of an existing concrete structure, the existing structure (new structure) is installed so that shear force is transferred between the two structures. It is necessary to join to (old structure). For example, if the new structure is a slab and is joined to the old structure at its end face, the new structure is integrated into the old structure for the purpose of reinforcing the old structure against horizontal forces during an earthquake. Therefore, it is necessary to join the old structure so that the horizontal shearing force is transmitted between the two structures.

  In such a case, the shearing force transmission member fixed to the old structure by an anchor such as an anchor bolt is usually fixed to the surface of the old structure in a state of protruding into the new structure (patent) References 1 and 2).

  只, Patent Documents 1 and 2 are examples where a new structure is planned to be spliced at the time of construction of the old structure, and the shear force transmission member can be embedded in advance at the time of construction of the old structure. When the old structure is completed, it is possible to embed a shear force transmission member in a portion near the surface of the old structure. On the other hand, when the new structure is not planned to be joined to the surface of the old structure, there is no necessity to embed a shear force transmission member near the surface of the old structure. It is necessary to embed a force transmission member.

  Therefore, when it is necessary to newly fix the shearing force transmitting member on the surface of the old structure completed as described above, the methods of Patent Documents 1 and 2 cannot be applied. After all, when joining a new structure to an existing structure, it depends on the method of joining the new structure to the old structure by embedding anchor bolts in the existing structure. Inevitably (see Patent Document 3).

JP-A-7-180352 (Claim 1, paragraphs 0017 to 0024, FIGS. 3 to 5) Japanese Patent Laid-Open No. 7-180353 (paragraphs 0010 to 0017, FIGS. 1 to 3) Japanese Unexamined Patent Publication No. 7-91060 (Claim 1, paragraphs 0008 to 0012, FIGS. 1 to 4)

  However, since the transmission efficiency of shear force at the joint surface of old and new concrete is determined by the projected area of the shear transmission member in the direction of the acting shear force, if the transmission of the acting shear force is dependent on anchor bolts, the number of burials is increased. There is a need to. As a result, it is assumed that the shearing force transmission member cannot fit in the end surface of the slab, or the concrete filling property is hindered.

  In view of the above background, the present invention mainly uses a joint structure with good shear force transmission efficiency between two structures when a new concrete structure is constructed in contact with an existing concrete structure. A fixing member for transmitting shear force is proposed.

When the fixing member is arranged between the old structure and the new structure that are in contact with each other, and the new structure is about to be displaced relative to the old structure It is a joint structure of the structure that transmits the shear force of the old structure to the old structure through the fixing member
Grooves are formed from the surface side of the old structure,
The fixing member has a flat plate-like main body portion that overlaps a boundary surface between the old structure and the new structure, and an annular convex portion that is formed on the back surface of the main body portion and fits into the groove portion, and has at least a thickness of the main body portion. It is embedded in the old structure and the new structure with a part in the vertical direction located in the new structure and at least a part in the thickness direction of the convex part located in the old structure. This is a configuration requirement.

  “Overlap” of “overlap with boundary surface” includes a case where the fixing member directly overlaps the boundary surface and a case where the fixing member overlaps with a gap. In the latter case, the gap is filled with a filler such as an adhesive to prevent the fixing member from sliding relative to the old structure.

  The relative displacement of the new structure with respect to the old structure is also the relative displacement of the old structure with respect to the new structure, and mainly refers to the relative displacement (displacement deformation) that is caused by the shear force parallel to the boundary surface between the two structures. . The relative displacement in the direction in which both structures are separated (separated) in the opposing direction can cause an axial force to act on the anchor when the anchor is connected to the fixing member, but the boundary between the old structure and the new structure In the present invention, since it becomes a problem to prevent the displacement deformation from the relative displacement in the directions to be separated from each other, the present invention does not assume the relative displacement in the direction to be separated.

  The structure is mainly a part of a reinforced concrete structure, but may be unreinforced concrete or mortar. The old structure refers to, for example, an existing concrete structure, and the new structure refers to a concrete structure constructed in contact with the surface of an existing concrete structure. The structure includes both building structures and civil engineering structures, and includes bridge girders, bridge piers, footings, etc. in addition to building columns, beams, slabs, foundations, and the like.

  The joint part of the old structure and the new structure is not limited. For example, the old and new slabs, beams (girder), columns, foundations, or any combination of these according to the construction position of the new structure Become. When the new structure has a role of seismic reinforcement for the old structure, the new structure is constructed with the slab or beam of the new structure in contact with the surface of any part of the old structure.

  Regardless of the time of construction of the new structure with respect to the old structure, the construction of the old structure is performed in addition to the construction of the new structure immediately after the construction of the old structure, such as the joining of the old structure and the new structure. Is completed, and there is a need to reinforce the old structure during use.

  At the boundary surface between the old structure and the new structure, relative contact (displacement deformation) tends to occur while the contact surfaces of both sides remain parallel during an earthquake as described above. Trying to receive shear force from the old and new structures. Of the entire thickness of the fixing member, at least a part (part) embedded in the new structure which is a part in the thickness direction receives shearing force from the new structure, and at least a part of the convex part in the thickness direction. A section (portion) embedded in a certain old structure transmits the shearing force from the new structure to the old structure and bears the reaction force.

  The fixing member used in the joining structure according to claim 1 is a flat main body and, as described in claim 2, protrudes from the periphery of the main body or from a position close to the periphery to the back side, and the surface of the old structure. And an annular convex portion that fits into the groove portion. The new structure of the main body part is used by using at least a part of the main body part in the thickness direction in the new structure and at least a part of the convex part in the thickness direction in the old structure. A part near the body bears a shearing force from the new structure, and a part near the old structure of the convex part transmits the shearing force to the old structure.

  Regardless of the formation position and shape of the convex part in the main body part, the annular convex part that fits into the groove part of the old structure is formed on the outer periphery of the main body part, and is formed at a position closer to the inner side than the outer periphery of the main body part. The In the former case, the outer peripheral surface of the convex portion is continuous with the outer peripheral surface of the main body portion, and in the latter case, the outer peripheral surface of the convex portion is located on the inner peripheral side from the outer peripheral surface of the main body portion. The convex portion is fitted over the entire circumference in a groove portion formed in an annular shape or a planar shape corresponding to the shape. In the groove part, the whole convex part may be inserted in the depth direction, or a partial section may be inserted.

  When the whole convex part fits into a groove part, the outer peripheral surface of a main-body part contacts a new structure. When a partial section of the convex part is fitted into the groove part, the outer peripheral surface of the main body part and a part of the convex part are in contact with the new structure. In either case, as will be described later, the outer peripheral surface of the main body bears the shearing force from the new structure, and the shearing force is transmitted from the outer peripheral surface and the inner peripheral surface of the convex portion to the old structure.

  A plurality of convex portions may be concentrically formed in the radial direction (radial direction) of the main body portion. The main body of the fixing member is basically formed in a disk shape having no directionality, but may be formed in a polygonal shape, an elliptical shape, or the like.

  When the convex portion of the fixing member is fitted into the groove portion of the old structure, as described above, the shear force from the new structure is transmitted from the convex portion to the old structure, but the shear force from the new structure is received. The main body portion has a function of ensuring the rigidity of the convex portion so that the convex portion is not deformed by a reaction force from the old structure when transmitting from the convex portion to the old structure.

  For example, if the fixing member is composed only of an annular convex part and there is no main body part connecting the convex part, the fixing member has the same shape as a steel pipe (Japanese Patent No. 3384992). It is assumed that the convex portion is deformed in the radial direction when receiving the reaction force of the shearing force from the old structure. That is, when a steel pipe without a main body straddles the old structure and the new structure and is embedded in both grooves, the steel pipe bears a shearing force in a direction perpendicular to the axis from the new structure, and the old structure When subjected to a reaction force, the bending force is easily deformed by a radial force, so that the ability to transmit shear force to the old structure is low.

  On the other hand, the fixing member is disc-shaped or the like, and the plate-like main body portion is positioned on the inner periphery of the annular convex portion, so that the convex portion is restrained in the radial direction (radial direction). Since the main body portion is in a state of transmitting a shearing force to the convex portion by an in-plane force, the convex portion has a large bending rigidity in the radial direction, and the convex portion is less likely to be deformed in that direction. Therefore, when the convex portion transmits the shearing force to the old structure, since the resistance force against the reaction force from the old structure is high, the shearing force received by the convex portion can be transmitted to the entire fixing member. .

  When a convex part is formed on the outer periphery of the fixing member main body part, at least a part of the main body part is positioned in the new structure, and at least a part of the convex part is fitted into the groove part of the old structure, so that the new structure The outer peripheral surface of the main body is in contact with the body, and the outer peripheral surface of the convex portion is in contact with the old structure. For this reason, the shearing force from the new structure is transmitted from the outer peripheral surface of the main body to the main body, and from the convex portion to the old structure. Since the convex portion of the fixing member is fitted into a groove portion formed in an annular shape or the like, shear force is transmitted to the old structure from the outer peripheral surface and the inner peripheral surface of the convex portion.

  As shown in FIGS. 2A and 2B, when a rightward shearing force is applied to the fixing member from the new structure, the shearing force is received by the outer peripheral surface of the fixing member main body facing the direction of the action. . The shear force from the new structure is received by the projected area in the shearing force acting direction in the outer peripheral surface of the main body. In FIG. 2 (a) and (b), the surface which receives a shear force is shown by the thick line.

  The shearing force received by the outer peripheral surface of the main body is transmitted to the old structure from the outer peripheral surface and inner peripheral surface of the convex portion facing the outer surface. As shown in FIG. 2B, the convex portion also transmits the shearing force to the old structure by the projected area corresponding to the direction in which the shearing force acts. The shear force from the new structure received by the outer peripheral surface of the main body is the outer peripheral surface of the convex portion located on the side facing the outer peripheral surface of the main body portion, and the inner periphery of the convex portion located on the same side as the outer peripheral surface of the main body portion. It is transmitted from the surface to the old structure. Shear force acting on the old structure is transferred to the new structure in the reverse path. Hereinafter, a case where shear force is transmitted from the new structure to the old structure will be described.

  In this way, the shear force from the new structure acts from the outer peripheral surface of the main body and is transmitted to the old structure from the outer peripheral surface and inner peripheral surface of the convex portion. The shearing force transmission capability of is determined by the projected area in the direction in which the shearing force is applied, and this capability is exhibited by the fact that the convex portion has rigidity that is not deformed by the shearing force.

  For example, when the convex part is not formed in the main body part, the shearing force is transmitted only from the outer peripheral surface of the main body part in the section of the main body part embedded in the old structure to the old structure, By having the convex portion, the shearing force can be transmitted also from the inner peripheral surface of the convex portion. Therefore, the fixing member has a convex portion, and in contrast to the case where there is no convex portion, the shear stress is reduced by the bearing pressure area received by the inner peripheral surface of the convex portion, and the shearing force from the convex portion to the old structure is reduced. Increased certainty of transmission.

  In the case of FIG. 2, the convex part is a part that transmits the shearing force received by the main body part to the old structure. Therefore, in order to increase the bearing area for transmitting the shearing force, around the main body part (outer periphery) Advantageously formed. However, as described above, it is not always necessary, and it may be formed at a position closer to the inner peripheral side than the periphery of the main body.

  When the shearing force received by the main body is transmitted from the convex part to the old structure, the fixing member has the main body part, so that the shearing force is transmitted to the convex part by the in-plane force of the main body part. There is no bending moment by force. Therefore, the main body portion is in a form in which bending deformation is unlikely to occur due to the shearing force from the new structure, so that the shearing force can be transmitted to the old structure without loss.

  The groove portion of the old structure into which the convex portion of the fixing member is fitted is formed by rolling the old structure from the surface side. At this time, if there is a gap between the convex portion and the groove portion, the groove portion is filled with an adhesive or a filler such as (non-shrink) mortar for the purpose of stabilizing the convex portion. The filler may be filled between the back surface of the fixing member main body and the old structure. Since the filler transmits the shearing force received by the fixing member to the old structure by the frictional force, the filler serves to supplement the transmission of the shearing force by the fixing member.

  For example, when anchor bolts are fixed to an old structure, it is necessary to form a drilling hole having a depth sufficient for fixing using a core drill or the like on the old structure. The vibration and noise applied to can be a problem. On the other hand, in the method of forming a groove in the old structure as in the present invention, it is sufficient to form a groove having a depth enough to roughen the surface by shot blasting from the surface side of the old structure. The effect on the body is reduced.

  As described above, the fixing member has a main body portion and a convex portion so that the shearing force received by the main body portion can be transmitted to the old structure without loss. Possess the ability.

  In particular, since the convex portion can resist the shearing force on the outer peripheral surface and the inner peripheral surface, the shearing resistance force per fixed member can be earned more than when using the anchor bolt. As a result, it is possible to reduce the number of fixing members arranged on the boundary surface between the old structure and the new structure, and to arrange the shear resistance elements on the boundary surface in an overcrowded state as in the case of depending on the anchor bolt. The situation is avoided, and filling of the hardened material having fluidity such as concrete constituting the new structure is not hindered.

  An anchor may be connected to the fixing member in the thickness direction of the main body as described in claim 6. The anchor in this case mainly functions as a resistance element against a shearing force in a direction perpendicular to the axis, not as a resistance element against the pulling force in the axial direction. Accordingly, the resistance force corresponding to the projected area of the anchor in the shearing force acting direction is added to the shearing resistance force of the convex portion. The anchor is given a diameter (thickness) and length corresponding to the shear resistance that should be expected. The anchor is connected to the main body portion of the fixing member by screwing into an insertion hole formed in the fixing member or simply passing through the insertion hole and filling the insertion hole with an adhesive or mortar. .

  The anchor may be connected from the front surface (new structure) side of the main body portion or may be connected from the back surface (old structure) side, and may penetrate the main body portion in the thickness direction. “Connection” may be performed by screwing or by insertion and filling with an adhesive or the like.

  When the anchor is connected from the back side of the main body, the anchor is embedded in the old structure, but the embedded depth is set to such an extent that the anchoring length to the old structure does not become excessive. The When the anchor is connected from the back side of the main body, the anchor is connected to a protrusion described later by rotating the fixing member relative to the anchor or dropping in the axial direction.

  When the anchor is connected to the front side of the main body, the anchor bears the shearing force from the new structure, and when it is connected to the back side, the shearing force from the new structure is transmitted to the old structure. Have a role to do. When penetrating the main body, it has a role of bearing a shearing force from the new structure and a role of transmitting to the old structure. The anchor is connected to the surface side of the main body, and functions to integrate the new structure and the fixing member when embedded in the new structure.

  If the main body of the fixing member is embedded in the new structure partly in the thickness direction, and has a thickness that can bear the shearing force from the new structure, the main part of the fixing member will change from the convex part to the old structure. Shear force can be transmitted. Therefore, the cross-sectional shape when the main body is cut in the axial direction is not limited, and for example, additional portions may be continuously formed on the flat main body.

  Specifically, as described in claim 3, a cylindrical projecting portion that projects to at least one of the front surface side and the back surface side may be formed on the main body portion of the fixing member.

  The projecting part is formed so as to project from the main body part to at least one of the front surface side (new structure side) and the back surface side (old structure side), thereby bearing the shearing force from the new structure together with the main body part. Or, it functions to transmit the shearing force from the new structure to the old structure together with the convex portions. When the protrusion is formed on the surface side of the main body, it bears the shearing force from the new structure, and when it is formed on the back side, it transmits the shearing force to the old structure. The protrusion may be continuously formed on the front side and the back side of the main body.

  Since the formation of the protrusion on the main body changes the cross-sectional shape of the main body, the protrusion functions to improve the cross-sectional performance (second moment of cross-section) of the main body. That is, when the anchor is connected to the protrusion, and the bending moment acting on the main body due to the shearing force received by the anchor cannot be ignored, the protrusion increases the bending rigidity of the main body and increases the resistance to the bending moment. It also has the role of ensuring stability.

  The protrusion may be a solid cross section, but may be formed with a hollow cross section. When the insertion hole is formed in the thickness direction of the main body as described in claim 5, the insertion hole is formed in the protrusion, so the protrusion is formed with a hollow cross section, and the anchor is It connects with the insertion hole of a protrusion part. When the insertion hole is formed in the protrusion, the protrusion corresponds to the formation position of the insertion hole and is formed in the central part of the main body part, etc. A plurality may be formed.

  When an insertion hole is formed in the main body and the fixing member is used without an anchor connected to the insertion hole, the insertion hole is filled with a hardened material such as concrete or mortar of the new structure. Thus, the bearing pressure from the concrete can be received on the inner peripheral surface of the insertion hole. In this case, since the hardening material of the new structure is filled in the insertion hole, the shearing force for this hardening material is added, so that the shearing force transmission capability of the fixing member is improved.

  For this reason, even if an anchor is not connected to the insertion hole, the fixing member having the insertion hole can ensure a resistance against a certain shearing force. By filling the insertion hole with a hardening material, the shear force from the new structure is transmitted to the fixing member also from the inside of the insertion hole, and the shear force is the projected area of the inner peripheral surface of the insertion hole in the shearing force acting direction. Therefore, it becomes possible to receive a shearing force from the new structure equivalent to that when the anchor is connected.

  On the other hand, when the insertion hole is formed in the main body portion, and the anchor is connected to the insertion hole, as described above, the anchor receives a shearing force from the new structure, and the anchor is not connected. In contrast, since the shearing force for the anchor is added, there is an advantage that the shearing force transmission effect of the fixing member is improved.

  The fixing member functions as a shearing force transmission member that transmits the shearing force from the new structure acting in the direction orthogonal to the axial direction (thickness direction) to the old structure, and resists the pulling force in the axial direction. Since it is not necessary, adhesion between the old structure and the new structure is not expected.

  For example, if an external thread is formed on the protruding portion in order to expect adhesion at the protruding portion, a bending moment may be applied to the fixing member due to the adhesive force with the new structure. As a result, it becomes difficult to obtain a state in which the fixing member purely resists the shearing force. Therefore, it is reasonable not to form a male screw on the protruding portion in terms of the function of the fixing member. Therefore, when a protrusion is formed on the main body, it is not necessary to form a male screw on the outer periphery of the protrusion.

  The fixing member is manufactured mainly by casting, forging, or cutting from a form having a main body portion and a convex portion. For example, when the fixing member is manufactured by cutting, if a male screw is formed on the protruding portion, the amount of steel material lost by the cutting for forming the male screw is large, and the steel material is wasted. In the case of manufacturing by casting or forging, forming the male screw at the projecting portion has many inconveniences in manufacturing, for example, the die cannot be removed due to the presence of the male screw (thread) at the time of demolding.

  As described above, as long as the fixing member has a main body portion and a convex portion, it is possible to transmit a shearing force between the new structure and the old structure. The main body has the freedom to form additional portions continuously. In addition to the protruding portion, the main body portion may be formed with a frame portion that protrudes from the periphery of the main body portion to the surface side, for example, and the fixing member may be formed in an H-shaped cross-sectional shape.

  Like the convex portion, the frame portion may be formed continuously on the outer peripheral surface of the main body portion or may be formed inside the outer peripheral surface, and may be formed in a plurality of concentric shapes. When the convex part is formed inside the outer peripheral surface of the main body part and the frame part is also formed inside the outer peripheral surface of the main body part, the cross section of the fixing member has a crown shape (FIG. 4- (b)).

  Whether the frame portion is continuous with the outer peripheral surface of the main body portion or located on the inner peripheral side thereof, the working area of the shearing force from the new structure is increased, so that the fixing member can be received from the new structure (load) Since the shearing force increases, it is possible to reduce the number of fixing members to be arranged on the boundary surface between the old structure and the new structure, compared to the case where there is no frame portion. Since the shearing force from the new structure is received by the surface of the frame part facing the direction of the action, when the shearing force acts on the right side as shown in FIG. 4, it is located on the left side in the frame part in the figure. The outer peripheral surface of the portion and the inner peripheral surface of the portion located on the right side receive a shearing force.

  Further, the fixing member has an H-shaped cross-sectional shape by forming a convex portion on the back surface around the main body portion and a frame portion on the surface, but the main body portion is present as described above due to the presence of the main body portion. Since this works to increase the rigidity of the convex portion and the frame portion, bending deformation of the annular convex portion and the frame portion is difficult to occur. Accordingly, the fixing member having an H-shaped cross-sectional shape and the like ensures the effect of bearing the shear force from the new structure at the frame portion and the effect of transmitting the shear force from the convex portion to the old structure.

  The fixing member may be used as a set with an anchor connected to the insertion hole as described in claim 6. In this case, since the anchor also receives the shearing force from the new structure as a support pressure corresponding to the projected area in the direction of action, the fixing member bears the shearing force that can be transmitted to the old structure. As described above, the anchor penetrates the main body of the fixing member and is embedded in the old structure. In this case, the anchor functions to transmit a shearing force to the old structure.

  In order to fit the convex part on the outer periphery of the fixing member main body into the groove formed from the surface side of the old structure, the shearing force from the new structure is transmitted from the outer peripheral surface of the main body part to the fixing member, Can be transmitted to the structure. In particular, since the fixing member has the main body portion, the shearing force can be transmitted to the convex portion by the in-plane force of the main body portion, so that the shearing force can be transmitted to the old structure without loss.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  1A shows a shearing force when the fixing member 3 is disposed between the old structure 1 and the new structure 2 that are in contact with each other, and the new structure 2 is about to be displaced relative to the old structure 1. An example of a joining structure of a structure that transmits the current to the old structure 1 through the fixing member 3 is shown.

  In the old structure 1, a groove 1a is formed from the surface side. The fixing member 3 has a flat plate-like main body 31 that overlaps the boundary surface between the old structure 1 and the new structure 2, and an annular convex portion 32 that is formed on the back surface of the main body 31 and fits into the groove 1a. In the state where at least a part of the main body part 31 in the thickness direction is located in the new structure 2 and at least a part of the convex part 32 is located in the old structure 1, It is embedded in the new structure 2. The groove portion 1 a is formed in a ring shape corresponding to the shape of the convex portion 32, or a plate shape such as a disk shape including an annular shape surrounding the convex portion 32.

  FIG. 1A shows an example of the most basic shape of the fixing member 3. The fixing member 3 shown here has a flat plate-like main body portion 31 and a convex portion that protrudes from the periphery of the main body portion 31 or a position close to the periphery to the back side and fits into a groove portion 1 a formed on the surface of the old structure 1. 32 and is formed in a plate shape as a whole. The planar shape of the main body 31 is not limited and is formed in a circular shape, an elliptical shape, a polygonal shape, or the like. The fixing member 3 is mainly formed of a metal material such as a steel material, but the material of the fixing member 3 is not limited, and the fixing member 3 is also formed of a fiber reinforced plastic or the like.

  The fixing member 3 is arranged on the boundary surface with the surface of the old structure 1, that is, the boundary surface with the new structure 2, or with a slight clearance secured. 1- (a) shows an example in which the main body 31 is simply plate-shaped (there is no insertion hole 31a), FIG. 1- (b) shows one insertion hole in the center of the main body 31. The example at the time of forming 31a is shown. The insertion hole 31a is used not only for filling the constituent material (curing material) of the new structure 2, but also for connecting the anchor 4. In FIG. 1- (b), the internal thread is not cut on the inner periphery of the insertion hole 31a, but the internal thread may be cut as shown in FIG.

  1B and 1C, the inner diameter of the insertion hole 31a is made larger than the diameter of the anchor 4 to secure a clearance between the anchor 4 and the insertion hole 31a. The case where the anchor 4 is connected to the fixing member 3 by filling a filler 6 such as an adhesive or mortar filled with the old structure 1 is shown. FIG. 1- (c) gives the shaft 4 of the anchor 4 a length sufficient to be fixed in the old structure 1, and the integrity of the fixing member 3, the old structure 1, and the new structure 2 is improved. An example in the case of raising is shown. In the case of (c), a drilling hole into which the shaft portion of the anchor 4 is inserted is formed in the old structure 1, the insertion hole 31a is inserted, the anchor 4 is inserted into the drilling hole, and the filler 6 is filled into the drilling hole. By doing so, the anchor 4 is fixed to the old structure 1. In the example of FIGS. 1- (b) and (c), an internal thread may be cut into the insertion hole 31a, and the anchor 4 may be screwed into the insertion hole 31a.

  FIG. 2A shows a state in which the shearing force indicated by the arrow from the new structure 2 acts on the fixing member 3 and the fixing member 3 receives the reaction force of the shearing force from the old structure 1. . FIG. 2B shows the back surface of the fixing member 3 shown in FIG. In the fixing member 3, a part of the main body 31 near the new structure 2 bears a shearing force from the new structure 2, and a part of the outer peripheral surface of the convex portion 32 near the old structure 1 is old. It is placed in a state of bearing a shearing force from the structure 1.

  When forming the insertion hole 31a, the insertion hole 31a penetrates the main body 31 in the thickness direction or is formed in a section from one of the front side and the back side to the middle. Even if the insertion hole 31a is formed, the anchor 4 is not connected to the insertion hole 31a, and the constituent material of the new structure 2 may enter.

  In the drawing, the convex portion 32 is formed at a position continuous with the outer peripheral surface of the main body portion 31, and the outer peripheral surface of the main body portion 31 and the outer peripheral surface of the convex portion 32 are the same. It may be formed closer to the inner periphery. Moreover, the convex part 32 may be formed in multiple in the radial direction (radial direction) of the main-body part 31. FIG.

  In the state where the convex portion 32 of the fixing member 3 is fitted into the groove portion 1a of the old structure 1, the groove portion 1a is filled with the filler 6 as shown in FIG. The movement of the (fixing member 3) relative to the old structure 1 is restricted. By filling the groove 6a with the filler 6 or by inserting the convex portion 32 into the groove 1a filled with the filler 6, the filler 6 is attached to the back surface of the main body 31 of the fixing member 3 as shown in FIG. And the stability of the entire fixing member 3 with respect to the shearing force, that is, the integrity of the fixing member 3 with the old structure 1 can be increased.

  When the convex portion 32 of the fixing member 3 is fitted into the groove portion 1 a of the old structure 1 and is restrained by the filler 6, the shearing force from the new structure 2 passes through the main body portion 31 and the convex portion 32 of the fixing member 3. It is transmitted to the old structure 1. When the filler 6 is also passed between the main body 31 of the fixing member 3 and the old structure 1, slippage between the back of the main body 31 and the surface of the old structure 1 is prevented. Shear force is transmitted between the main body 31 and the surface of the old structure 1.

  When the insertion hole 31a is formed in the main body 31, the new structure 1 is basically combined with the fixing member 3 as shown in FIG. 3 in order to increase the load capacity of the shearing force from the new structure 2 in the insertion hole 31a. An anchor 4 that bears a shearing force is connected. However, since concrete or the like flows into the insertion hole 31a, the inner peripheral surface of the insertion hole 31a can be used to receive a shearing force, so that the insertion hole 31a is not connected to the insertion hole 31a. The concrete which comprises the new structure 2 may be filled in 31a.

  The anchor 4 is directly screwed into a female screw formed on the inner peripheral surface of the insertion hole 31a as shown in FIG. 3 (a), and is simply inserted as shown in FIG. 3 (b), on both sides of the insertion hole 31a. The nut 5 is connected to the main body 31 by screwing or by filling the insertion hole 31a with a filler 6 such as an adhesive or mortar.

  The anchor 4 bears the shearing force from the new structure 2 on the side surface corresponding to the projected area in the direction in which the shearing force acts, and transmits the shearing force to the fixing member 3. In the drawing, a bolt having a head is used as the anchor 4, but the form of the anchor 4 is not limited to a rod shape but may be a block shape. The anchor 4 only needs to have a bending rigidity that does not cause bending deformation due to the shearing force from the new structure 2.

  FIG. 3 also shows that a cylindrical protrusion 33 that protrudes to at least one of the front side and the rear side of the main body 31 a is formed at a position where the insertion hole 31 a of the main body 31 is formed. The case where the insertion hole 31a is formed is shown. 3A and 3B show the case where the protrusions 33 are formed on the front surface side of the main body 31, and FIG. 4A shows the case where the protrusions 33 are formed on the front surface side and the back surface side of the main body portion 33.

  When the anchor 4 is connected to the projecting portion 33 by screwing as shown in FIG. 3- (a), an internal thread is formed on the inner peripheral surface thereof, but as shown in FIG. When connecting with the nut 5 on both sides in the axial direction, it is not always necessary to form a female thread.

  In the case of FIG. 3B, the tip of the anchor 4 and the nut 5 screwed to the anchor 4 protrude from the back surface of the main body 31, so that the old structure 1 is formed with a countersunk portion 1b for the portion to enter. Is done. In this case, there is an advantage that the shearing force from the main body portion 31 can be transmitted to the old structure 1 through the anchor 4 or the nut 5 entering the counterboring portion 1b by forming the counterboring portion 1b. As in (a), the filling material 6 is filled in the spot digging portion 1b, the gap between the nut 5 and the inner peripheral surface of the digging portion 1b is closed, and the shearing force from the fixing member 3 is It is transmitted from the inner peripheral surface of the part 1b to the old structure 1.

  The shearing force acting on the fixing member 3 from the new structure 2 and the reaction force received from the old structure 1 constitute a couple, and a moment acts on the fixing member 3. Therefore, in the case where the moment acting on the fixing member 3 is excessive due to the arrangement state of the fixing member 3, for example, the depth of insertion of the convex portion 32 into the old structure 1, the chain line in FIG. As shown in FIG. 4, the anchor 4 is given a length for receiving a resistance force from the new structure 2, or the old structure 1 and the new structure 2, which can cause the anchor 4 to resist the moment.

  When the projecting portion 33 is formed in the main body portion 31, the projecting portion 33 has a function of compensating for a decrease in rigidity due to the formation of the insertion hole 31 a in the main body portion 31. When the protrusion 33 is formed on the front surface side of the main body 31, the shear force from the new structure 2 is shared. When the protrusion 33 is formed on the back surface, the shear force from the new structure 2 is shared. Is also transmitted to the old structure 1.

  FIG. 4- (a) shows a case where the protrusions 33 are formed continuously on the front side and the back side of the main body 31 as described above. In this case, the protrusions 33 are formed on both surfaces of the main body 31 to improve the effect of increasing the rigidity of the main body 31, and the main body 31 receives the same as in the example of FIG. The effect of transmitting the shearing force to the old structure 1 is also enhanced. When the anchor 4 is not connected to the insertion hole 31a of the protrusion 33, the load capacity of the shearing force received from the new structure 2 is improved in comparison with the case where the protrusion 33 is not formed on the back surface. Also in the example of FIG. 4, when the anchor 4 is connected, the anchor 4 is screwed into the insertion hole 31 a or connected to the insertion hole 31 a and the filler 6.

  FIG. 4- (a) also shows a case where a frame portion 34 protruding to the surface side is formed around the main body portion 31. In this case, since the main body portion 31 includes the frame portion 34, the contact area between the main body portion 31 and the new structure 2 is increased, so that the shearing force that the fixing member 3 receives from the new structure 2 is increased, and the fixing is performed. There is an advantage that the number of installed members 3 can be reduced. Similarly to the convex portion 32, the frame portion 34 may be formed at a position closer to the inside than the outer periphery of the main body portion 31, or may be formed in multiple in the radial direction of the main body portion 31. FIG. 4B shows a case where the convex part 32 and the frame part 34 are formed on the inner peripheral side from the outer periphery of the main body part 31.

  FIG. 5- (a) shows the depth of the bottom surface of the projecting portion 33 projecting to the back side particularly when the projecting portion 33 continuous to the front surface side and the back surface side of the main body portion 31 is formed as in FIG. 4- (a). An example in which the height is made larger than the depth of the bottom surface of the convex portion 32 and the protruding portion 33 is fitted into the old structure 1 is shown. In this case, the old structure 1 is formed with a spot digging portion 1b into which the protrusion 33 on the back side of the main body 31 is fitted, but shearing from the fixing member 3 through the inner peripheral surface of the digging portion 1b. Since the force is transmitted to the old structure 1, there is an advantage that the transmission effect of the shearing force from the fixing member 3 is improved.

  In FIG. 5, the main body 31 itself is increased in thickness, and the height (depth) of the protrusion 32 from the back surface of the main body 31 is relatively reduced, so that the main body 31 itself has a new structure. 2 shows an example of manufacturing the fixing member 3 in the case where both the function of bearing the shearing force from 2 and the function of transmitting the shearing force to the old structure 1 are provided.

  In FIG. 5, since the width of the convex portion 32 is reduced, about half of the thickness of the main body portion 31 enters the old structure 1 together with the convex portion 1a, so that the groove portion 1a into which the convex portion 32 is fitted is formed. It is formed as a disk-like groove into which the main body 31 is inserted. In this case, the groove part 1a for inserting the convex part 32 has an area where the whole main body part 31 is inserted and a depth at which about half the thickness of the main body part 31 is inserted. In the example of FIG. 5, the spot digging portion 1b having a depth larger than the depth of the convex portion 32 is formed, so that the shearing force transmitted through the projecting portion 33 and the inner peripheral surface of the digging portion 1b are inserted into the pocket digging portion 1b. There are increasing benefits.

  In the case where the thickness of the main body 31 of the fixing member 3 is increased and the fixing member 3 is disposed between the two structures 1 and 2 so that the main body 31 extends over the old structure 1 and the new structure 2 equally. The main body 31 bears the shearing force from the new structure 2 as a force in the in-plane direction and transmits it to the old structure 1 as it is. The main body 31 is a plate having a large in-plane rigidity, and thus has the ability to effectively transmit the shearing force from the new structure 2 received in the in-plane direction to the old structure 1.

  In FIG. 5, an insertion hole 31 a penetrating the entire length of the projecting portion 33 formed above and below the main body 31 is formed, and an anchor 4 having a male screw formed on the peripheral surface is screwed to the entire length of the insertion hole 31 a. I am allowed to enter. A nut 5 for increasing the surface area is screwed to the tip of the anchor 4 on the new structure 2 side. A nut 5 is fastened to the connecting portion of the anchor 4 with the protruding portion 33 on the new structure 2 side in order to ensure the rigidity of the anchor 4 exposed from the protruding portion 33. Also in the example of FIG. 5, the anchor 4 may be connected to the insertion hole 31 a and the filler 6.

  FIG. 6 shows a construction example when the old structure 1 is constructed in a state in which the new structure 2 is in contact with the old structure 1 and the old structure 1 is seismically reinforced. Specifically, the slab 8 as the new structure 2 is abutted and joined to the beam 7 on the outdoor side of the existing structure of the reinforced concrete structure as the old structure 1, so that the shearing force from the existing beam passes through the slab 8. It is made to flow into the earthquake-proof reinforcement frame 9 connected to the end. The seismic strengthening frame 9 includes a column 91 connected to the end of the slab 8, a beam 92 laid between the columns 91 and 91, and a brace 93 laid between the column / beam junction.

  The fixing member 3 is disposed on the boundary surface between the side surface of the beam 7 as the old structure 1 and the end face of the slab 8 as the new structure 2, and the anchor 4 protrudes from the new structure 2 side of the fixing member 3, It is embedded in the new structure 2.

  The details of FIG. 6 are shown in FIG. 7- (a) and the surface portion (dashed line circle portion) of the old structure 1 is shown in FIG. 7 (b). 6 and 7, the fixing member 3 to which the anchor 4 is connected is arranged at an appropriate interval in the axial direction of the beam 7 as shown in FIG. 7- (b). A plurality of stages may be arranged in the forming direction of the beam 7 (the thickness direction of the slab 8). In particular, FIG. 7 shows a state where the shaft portion of the anchor 4 is inserted into a drilling hole formed in the old structure 1. In this case, a clearance is secured between the peripheral surface of the anchor 4 and the inner peripheral surface of the insertion hole 31 a of the fixing member 3.

FIG. 8- (a) is overlapped so that the boundary surface between the old structure 1 and the new structure 2 is a horizontal plane, and the fixing member 3 indicated by the solid line in FIG. The load (shear force) Q (kN) applied to the new structure 2 and the old structure when an alternating load (shear force) is applied horizontally to the new structure 2 with the old structure 1 fixed The relationship with relative displacement δ (mm) with respect to 1 is shown. An adhesive as a filler 6 is filled between the fixing member 3 and the old structure 1. (B) is for comparison, and only an adhesive anchor in which a drilling hole formed in the old structure 1 is filled with an adhesive and an anchor is inserted is interposed between the old structure and the new structure as a shear force resistance member. The relationship between the load Q and the relative displacement δ is shown. The compressive strength Fc of the concrete constituting the old structure 1 and the new structure 2 is 16 N / mm ² .

  If the performance of the fixing member 3 is evaluated in a range where the relative displacement is 0 to 2 mm, when the fixing member 3 is absent ((b)), the shearing force Q that can be transmitted at the boundary surface remains at about 60 kN. On the other hand, when the fixing member 3 is interposed ((a)), it can be seen that the fixing member 3 bears a high shearing force Q exceeding 180 kN.

  When the fixing member 3 is absent, the magnitude of the shearing force depends only on the frictional force at the boundary surface, whereas when the fixing member 3 is present, the fixing member 3 bears and transmits the shearing force. By exhibiting the above, a shearing force that is nearly three times as large as when relying only on the frictional force is obtained.

  When the fixing member 3 is not present, the relative displacement exceeds 2 mm and the shearing force is maintained at about 60 kN in the range up to about 10 mm, whereas when the fixing member 3 is interposed, the relative displacement is 8 mm. It can be seen that the shearing force tends to decrease gradually to a level exceeding. However, even when the relative displacement is 8 mm, the shear force is maintained at about 100 kN, which is higher than that in the absence.

  When the fixing member 3 is interposed, the shearing force tends to gradually decrease as the relative displacement increases after the shearing force reaches the maximum when the relative displacement is about 2 mm. it is conceivable that.

  When the shearing force starts to act, a filler 6 such as an adhesive filled between the fixing member 3 and the old structure 1 adheres to ensure the integrity of the fixing member 3 and the old structure 1. The fixing member 3 has a high rigidity against the shearing force. For this reason, it is considered that the shear rigidity of the fixing member 3 itself is exhibited as long as the filler 6 is adhered. It is considered that as the adhesion with the old structure 1 is cut and the integrity is lowered, the fixing member 3 exerts a shear resistance force while causing a relative movement with respect to the old structure 1.

  If the envelope of the shear force-deformation curve shown in FIGS. 8A and 8B is drawn, it will be as shown in FIGS. 9A and 9B. In the absence of the fixing member 3, as the relative displacement increases, the shear force draws a range until reaching the maximum value and then a gentle slope curve, and the maximum value remains at about 100 kN (FIG. 9- (b)). .

  On the other hand, when the fixing member 3 is interposed, the shearing force increases with the occurrence of the relative displacement, and even after reaching the maximum value, the shearing force tends to decrease without extremely decreasing, and the shearing force is 100 kN. The numerical value exceeding this is maintained (FIG. 9- (a)). From the comparison of (a) and (b), it can be seen that the range in which the numerical value in which the shearing force exceeds 100 kN is maintained is the effect of the interposition of the fixing member 3. In FIG. 9A, the curve shown in FIG. 9B is indicated by a broken line, but the difference (shearing force) between the solid line and the broken line is the effect of the fixing member 3 interposed.

(A) is a longitudinal sectional view showing the basic shape of the fixing member of the present invention and how shear force is transmitted from the new structure to the old structure, and (b) and (c) are (a) the fixing member main body. It is the longitudinal cross-sectional view which showed a mode that the penetration hole was formed in the part and the anchor was penetrated to the penetration hole. (A) is a longitudinal sectional view showing a basic shape of a fixing member having an insertion hole and a state of transmission of shearing force from the new structure to the old structure, and (b) is a rear view of (a). (A) is a longitudinal sectional view showing a state in which a protrusion is formed on the fixing member shown in FIG. 2 and an anchor is connected to the protrusion, and (b) is a nut screwed to the anchor protruding on both sides of the main body. It is the longitudinal cross-sectional view which showed the mode. (A) is the longitudinal cross-sectional view which showed a mode that the convex part and the frame part were formed in the circumference | surroundings of the fixing member main-body part, (b) is the perspective view which showed the mode that the convex part and the frame part were formed inside the circumference | surroundings. is there. (A) is the longitudinal cross-sectional view which showed a mode that the depth of the protrusion part of a main-body part back surface was enlarged, and formed the countersink part in the old structure, (b) is a rear view of (a). It is the longitudinal cross-sectional view which showed the usage example when the fixing member is interposed in the interface of an old structure (existing structure) and a new structure (new structure). (A) is the perspective view which expanded and showed a part of FIG. 6, (b) is the perspective view which showed the mode before construction of the new structure in (a). (A) is a graph showing a shearing force-deformation relationship when the fixing member of the present invention is interposed at the boundary surface between the old structure and the new structure and a shearing force is applied to the new structure, (b) 6 is a graph showing a shearing force-deformation relationship when no fixing member is interposed. (A) is the envelope of FIG. 8- (a), (b) is the envelope of FIG. 8- (b).

Explanation of symbols

1 ... Old structure, 1a ... Groove, 1b ... Cutter, 2 ... New structure,
3... Fixing member, 31... Body portion, 31 a .. insertion hole, 32... Convex portion, 33.
4 ... Anchor, 5 ... Nut, 6 ... Filler,
7 ... Existing beams, 8 ... New slabs,
9: Seismic retrofit frame, 91 ... Column, 92 ... Beam, 93 ... Brace.

Claims (6)

A fixing member is disposed across the old structure and the new structure that are in contact with each other, and shear force when the new structure is about to be displaced relative to the old structure is applied to the old structure through the fixing member. It is the joint structure of the structure to be transmitted,
Grooves are formed from the surface side of the old structure,
The fixing member has a flat plate-like main body portion that overlaps a boundary surface between the old structure and the new structure, and an annular convex portion that is formed on the back surface of the main body portion and fits into the groove portion. At least a part of the main body in the thickness direction is located in the new structure, and at least a part of the convex part in the thickness direction is located in the old structure, the old structure and the new structure A structure joining structure characterized by being embedded in a structure. A fixing member used for the structure joining structure according to claim 1,
It has a flat plate-like main body part, and an annular convex part that protrudes from the periphery of the main body part, or a position close to the periphery to the back side, and fits into the groove part formed on the surface of the old structure,
At least a part of the main body part in the thickness direction is located in the new structure, and at least a part of the convex part in the thickness direction is used in a state of being located in the old structure,
A part of the main body near the new structure bears a shearing force from the new structure, and a part of the convex part near the old structure transmits the shearing force to the old structure. A fixing member for transmitting a shearing force characterized by the above.   The shearing force transmitting fixing member according to claim 2, wherein the main body portion is formed with a cylindrical protruding portion that protrudes to at least one of a front surface side and a back surface side thereof.   The shearing force transmitting fixing member according to claim 2, wherein a frame portion that protrudes from the periphery of the main body portion to the surface side is formed.   The shearing force transmitting fixing member according to claim 2, wherein an insertion hole is formed in a thickness direction of the main body portion. The fixing member for shear force transmission according to claim 5, wherein an anchor is connected to the insertion hole of the main body.

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