JP6247611B2 - Shear reinforcement method - Google Patents

Description

  The present invention relates to a shear reinforcement method, and more particularly to a shear reinforcement method for reinforcing an existing reinforced concrete wall on which a shear load acts.

  For example, box-shaped reinforced concrete structures such as box culverts that form spaces such as underground spaces support earth pressure and water pressure from the ground, for example, by building a reinforced concrete wall surrounding the space. It has a structure. In addition, the reinforced concrete wall around the space such as the underground space has a predetermined cover thickness between these wall surfaces on one wall side and the other wall side across the central portion in the thickness direction, Main reinforcing bars and distributing reinforcing bars are generally arranged in a grid and are installed in concrete.

  On the other hand, in response to the recent Great Hanshin-Awaji Earthquake and the Great East Japan Earthquake, for example, box-shaped concrete structures such as box culverts that form spaces such as underground spaces have undergone seismic reinforcement work to improve earthquake resistance. To be done. For example, in the case of seismic reinforcement of underground structures, it is necessary to perform reinforcement work from the inside of the underground space without digging up the underground structure.For example, after reinforcing reinforcement bars are installed along the wall facing the underground space, When concrete is placed and reinforced by increasing the thickness of the reinforced concrete wall, the underground space becomes narrower. For this reason, a plurality of reinforcing material insertion holes are formed in the reinforced concrete wall, a shear reinforcing material is inserted and installed in the formed reinforcing material insertion hole, and the filler is further solidified by filling. Various methods of shear reinforcement for seismically reinforcing a reinforced concrete wall have been developed by integrating the reinforced concrete wall with the reinforced concrete wall to improve the shear strength of the underground structure without narrowing the underground space (for example, Patent Document 1). reference).

  In particular, when the reinforced concrete wall to be seismically reinforced is a reinforced concrete wall with a reinforcing material insertion hole formed upward from the lower surface, such as a reinforced concrete wall in a ceiling part of a reinforced concrete structure, such as a grout material to be filled It is necessary to prevent the filler from flowing downward from the reinforcing material insertion hole. For this reason, prior to inserting a shear reinforcement (anchor bolt) into the reinforcement insertion hole (anchor hole), for example, a car body that has been filled or adhered with a filler such as a grout material is reinforced. By loading the material into the material insertion hole, the filler is held inside the reinforcing material insertion hole, and then the shearing material is pushed into the reinforcement material insertion hole, so that the filler held by the car body is sheared. There has also been developed a shear reinforcement method in which a reinforcing material is inserted into a space between the reinforcing material insertion holes around the reinforcing material and the space between them is filled with the filling material (see, for example, Patent Document 2).

Japanese Patent No. 3932094 Japanese Patent No. 3054734

  However, in the above conventional reinforced concrete wall shear reinforcement method, the reinforced concrete wall to be seismically reinforced particularly has a reinforcing material insertion hole formed upward from the lower surface, such as a reinforced concrete wall at the ceiling of a reinforced concrete structure. In this case, the adhesive force between the filler that fills the gap between the reinforcing material insertion holes around the shear reinforcing material and the wall surface inside the reinforcing material insertion hole tends to be insufficient. If sufficient adhesion between the filler and the hole wall surface of the reinforcing material insertion hole cannot be secured, the reinforcing effect of the shear reinforcing material cannot be exhibited efficiently.

  The present invention ensures sufficient adhesion between the filler that fills the gap between the reinforcing material insertion holes around the shear reinforcing material and the hole wall surface of the reinforcing material insertion hole, and is reinforced by the shear reinforcing material. It aims at providing the shear reinforcement construction method which can exhibit an effect efficiently.

The present invention is a shear reinforcement method for reinforcing an existing reinforced concrete wall to which a shear load acts, and forms a bottomed reinforcing material insertion hole from one wall surface of the reinforced concrete wall to the other wall surface. A drilling step, a loading step of loading a filler into the formed reinforcing material insertion hole, and a reinforcing material installation step of inserting and installing a shear reinforcing material in the reinforcing material insertion hole loaded with the filler. In the loading step, a filling jig provided with a presser enlarged diameter portion having an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole at the distal end portion of the discharge pipe is used. By inserting the filler into the reinforcing material insertion hole until the presser expanded diameter portion is in contact with or close to the bottom of the distal end hole of the reinforcing material insertion hole, the expanded diameter portion of the presser foot is moved to the bottom of the distal end hole. The presser enlarged diameter part and the front The portion between the bottom of the tip hole and the bottom of the tip hole is loaded by continuously filling the filler while raising the pressure, and the reinforcing material installation step is performed along the outer peripheral surface of the shear reinforcing material. A cylindrical slide packing member that is mounted so as to be slidable in the axial direction and has an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole is inserted into the axial insertion hole and the shear reinforcing material is inserted into the shearing reinforcing material. In the state attached to the tip of the material, the tip of the shear reinforcement is inserted into the reinforcement insertion hole until it is pressed against the rear end of the filler loaded in the reinforcement insertion hole, and the cylindrical shape A tip insertion step in which a filler is filled in a portion between the slide packing member and the bottom of the tip hole, and a tip of the shear reinforcing material to which the cylindrical slide packing member is attached is used as a filler. At the rear edge In this state, the shear reinforcing material is pushed into the filler toward the bottom of the tip end hole of the reinforcing material insertion hole so that the space between the cylindrical slide packing member and the bottom of the tip hole is reduced. The cylindrical slide packing member is slid rearwardly toward the hole opening portion of the reinforcing material insertion hole along the outer peripheral surface of the shear reinforcing material while raising the pressure of the filling material filled in this portion. The above object is achieved by providing a shear reinforcement method including a shear reinforcement push-in step.

  In the shear reinforcement method of the present invention, the reinforcing material insertion hole formed in the drilling step is drilled upward from the lower surface of the reinforced concrete wall, thereby opening to the lower surface of the reinforced concrete wall. It is preferable that the insertion hole is extended in the longitudinal direction having the bottom of the tip hole at the top.

  In the shear reinforcement method of the present invention, it is preferable to use a thixotropic filler as the filler.

  Furthermore, in the shear reinforcement method of the present invention, the distal end portion of the shear reinforcement member to which the cylindrical slide packing member is attached from the cylindrical slide packing member at the distal end insertion step of the reinforcement member installation step. It is preferable to insert the tip of the shear reinforcing material into the reinforcing material insertion hole in a state where the filler is applied to the side portion.

  Still further, in the shear reinforcement method of the present invention, in the shear reinforcement material pushing step of the reinforcement material installation step, the cylindrical slide packing member has a rear end portion of the shear reinforcement material along the outer peripheral surface of the shear reinforcement material. When the slide reinforcement moves to the rear, an auxiliary rod having an outer diameter substantially the same as that of the shear reinforcement is pushed into the axial insertion hole of the cylindrical slide packing member, and the pressure of the filler is raised while the pressure of the filler is raised. It is preferable to embed the whole of the shear reinforcement material in the filler as a single unit by further pushing in.

  Further, in the shear reinforcement method of the present invention, the shear reinforcement material is integrally provided with a diameter-enlarged fixing portion having a larger cross-sectional shape at the tip portion, and a shape having a pointed tip toward the tip side than the diameter-enlarged fixing portion. In the shear reinforcing material pushing step of the reinforcing material installation step, the shear reinforcing material is filled until the tip of the sharpened portion comes into contact with the bottom of the tip of the reinforcing material insertion hole. It is preferable to be pushed into the inside.

  According to the shear reinforcement method of the present invention, sufficient adhesion is ensured between the filler filling the gap between the reinforcing material insertion holes around the shear reinforcing material and the inner wall surface of the reinforcing material insertion hole. And the reinforcement effect by a shear reinforcement can be exhibited efficiently.

1 is a schematic cross-sectional view of a box culvert that is a box-shaped underground structure that is shear-reinforced by a shear reinforcement method according to a preferred embodiment of the present invention. (A)-(c) is a schematic sectional drawing explaining the drilling process of the shear reinforcement construction method which concerns on preferable one Embodiment of this invention. (A)-(c) is a schematic sectional drawing explaining the loading process of the shear reinforcement construction method which concerns on preferable one Embodiment of this invention. (A)-(c) is a schematic sectional drawing explaining a shear reinforcement and a filling jig. (A), (b) is a schematic sectional drawing explaining the reinforcing material installation process of the shear reinforcement construction method which concerns on preferable one Embodiment of this invention. (A), (b) is a schematic sectional drawing explaining the situation which pushes in a shear reinforcement further using an auxiliary bar in the reinforcement installation process of the shear reinforcement construction method which concerns on preferable one Embodiment of this invention. (A), (b) is a schematic sectional drawing explaining the condition which finishes the hole part of a reinforcing material insertion hole, after embedding a shear reinforcement material in a filler. It is a schematic sectional drawing explaining the other method of finishing the hole part of a reinforcing material insertion hole.

  The shear reinforcement method according to a preferred embodiment of the present invention is preferably a box-shaped culvert 10 made of reinforced concrete for an underground tunnel as shown in FIG. 1, for example, as a box-like existing underground structure forming an underground space. It was adopted as a method for improving the shear strength and toughness of the reinforced concrete wall 11 of the ceiling wall, side wall, bottom wall, and partition wall that surrounds the underground space 10a when seismic reinforcement is performed. is there. According to the shear reinforcement method of the present embodiment, it can be easily constructed by work from the underground space 10a inside the box culvert 10, and without increasing the wall thickness and narrowing the inner space of the underground space 10a. The reinforced concrete wall 11 can be effectively shear-reinforced. Further, the shear reinforcement method of the present embodiment includes a filler 14 (see FIGS. 7A and 7B) filled in the reinforcing material insertion hole 12, and a hole wall surface 12 a inside the reinforcing material insertion hole 12. It has the function of improving the reinforcement effect by the shear reinforcement material 13 by increasing the adhesive force between the two.

  In addition, although this embodiment demonstrates the case where the reinforced concrete wall 11 of the ceiling wall part of the box culvert 10 shown in FIG. 1, especially the part shown by the code | symbol A is seismically reinforced, according to the shear reinforcement construction method of this invention, The seismic reinforcement can be similarly applied to the reinforced concrete walls 11 of the side wall portion, the bottom wall portion, and the partition wall portion.

  And the shear reinforcement construction method of this embodiment is a shear reinforcement construction method for reinforcing, for example, the reinforced concrete wall 11 of the ceiling wall portion of the box culvert 10 as an existing reinforced concrete wall on which a shear load acts. 7, a drilling step of drilling a bottomed reinforcing material insertion hole 12 from one wall surface 11 a of the reinforced concrete wall 11 to the other wall surface 1 b (see FIGS. 2A to 2C). Then, a loading step (see FIGS. 3A to 3C) for loading the filler 14 into the formed reinforcing material insertion hole 12, and a shear reinforcing material 13 for the reinforcing material insertion hole 12 loaded with the filler 14. It includes a reinforcing material installation process (see FIGS. 5A and 5B) for insertion.

  In the loading process (see FIGS. 3A to 3C), a filling treatment in which a presser enlarged diameter portion 20b having an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole 12 is provided at the distal end portion of the discharge pipe 20a. The tool 20 is used to insert the filling jig 20 into the reinforcing material insertion hole 12 until the presser enlarged diameter portion 20b comes into contact with or close to the tip hole bottom 12b of the reinforcing material insertion hole 12 (FIG. 3 ( a) see), by feeding the filler 14, pressurizing the portion between the presser enlarged diameter portion 20b and the tip hole bottom portion 12b while separating the presser enlarged diameter portion 20b from the tip hole bottom portion 12b. The filling material 14 is continuously filled (see FIG. 3B).

The reinforcing material installation step (see FIGS. 5A and 5B) is mounted so as to be slidable in the axial direction along the outer peripheral surface of the shear reinforcing material 13, and is substantially the same as the inner diameter of the reinforcing material insertion hole 12. In a state where the cylindrical slide packing member 21 having an outer diameter is attached to the distal end portion of the shear reinforcement member 13 by inserting the shear reinforcement member 13 through the axial insertion hole 21a, the distal end portion of the shear reinforcement member 13 is attached to the reinforcement member. The reinforcing material is inserted into the reinforcing material insertion hole 12 until it is pressed against the rear end portion of the filling material 14 loaded in the insertion hole 12, and the portion between the cylindrical slide packing member 21 and the tip hole bottom portion 12b is filled with the filling material 14. In the state where the tip end insertion step (see FIG. 5A) to be in a state of contact and the tip end portion to which the cylindrical slide packing member 21 of the shear reinforcement member 13 is attached are pressed against the rear end portion of the filler 14 Reinforcement 13 is inserted By toward the front end hole bottom 12b of the bore 12 Yuku pushed inside the filler 14, Tatase pressure of the filling material 14 filled in the portion between the cylindrical slide packing member 21 and the front end hole bottom 12ba On the other hand, a shear reinforcing material pushing step for sliding the cylindrical slide packing member 21 backward (downward) toward the hole portion 12c of the reinforcing material insertion hole 12 along the outer peripheral surface of the shear reinforcing material 13 (FIG. 5 ( b)).

  Further, in the shear reinforcement method of the present embodiment, the cylindrical slide packing member 21 is arranged along the outer peripheral surface of the shear reinforcement member 13 in the shear reinforcement member pushing step of the reinforcement member installation step. After sliding backward (downward) to the lower end portion, as shown in FIGS. 6A and 6B, the axial insertion hole 21a of the cylindrical slide packing member 21 is substantially the same as the shear reinforcement member 13. By pushing the auxiliary rod 22 having a diameter and further pushing the shear reinforcement member 13 while raising the pressure of the filler material 14, the entire shear reinforcement material 13 is embedded in the filler material 14. .

  Furthermore, in the shear reinforcement method of the present embodiment, when the auxiliary rod 22 is pushed into the axial insertion hole 21a of the cylindrical slide packing member 21 so that the entire shear reinforcement 13 is embedded in the filler 14 as an integral unit, As shown in FIGS. 7A and 7B, the cylindrical slide packing material 21 and the auxiliary rod 22 are collected, and the hole portion 12c of the reinforcing material insertion hole 12 is finished.

  2, 3, and 5 to 8, the reinforcing bars arranged on the reinforced concrete wall 11 of the ceiling wall portion of the box culvert 10 are omitted, but actually, the reinforced concrete wall is drawn. 11 and the other wall surface 11b with a predetermined cover thickness between the wall surface 11a and the other wall surface 11b with the central portion in the thickness direction between the main reinforcing bar and the distribution reinforcing bar. Are arranged in a grid and embedded in concrete. Further, the reinforcing material insertion hole 12 into which the shear reinforcing material 13 is inserted is formed in a portion avoiding these bar arrangement positions so as not to interfere with these reinforcing bars.

  In the present embodiment, the drilling step of drilling the bottomed reinforcing material insertion hole 12 from one wall surface 11a to the other wall surface 11b of the reinforced concrete wall 11 is shown in FIGS. 2 (a) and 2 (b). Thus, for example, by using a known drilling machine 30 such as a core drill or a rock drill, the work from the underground space 10a becomes the ceiling surface of the underground space 10a, and is vertically above the one wall surface 11a. This is done by drilling the core toward. Accordingly, a circular shape having an inner diameter of, for example, about 30 to 80 mm, which is larger than the maximum outer diameter of the enlarged diameter fixing portion 13a (see FIG. 4A) using a hexagon nut attached to the distal end portion of the shear reinforcement member 13 described later. The reinforcing material insertion hole 12 having a cross section is formed so as to have the same inner diameter from the hole opening portion 12c having the base end opening to the tip end bottom portion 12b (see FIG. 2C). Further, by this, the reinforcing material insertion hole 12 is drilled upward from the lower surface (ceiling surface) of the reinforced concrete wall 11, thereby opening the lower surface of the reinforced concrete wall 11 and having the tip hole bottom portion 12b at the top. It is formed as an insertion hole extending in the longitudinal direction.

  Here, the reinforcing material insertion holes 12 are preferably arranged in the interior of the reinforced concrete wall 11 in a lattice shape, with the central portion of the grid of the main reinforcing bars and the reinforcing reinforcing bars as the drilling positions. It is formed at a plurality of locations on the one wall surface 11a serving as the ceiling surface at predetermined intervals in the vertical and horizontal directions. The predetermined interval and the number of the reinforcing material insertion holes 12 formed can be appropriately set in view of the seismic strength after reinforcement of the reinforced concrete wall 11, the size and thickness of the box culvert 10, the installation depth, and the like. it can.

  Further, the reinforcing material insertion hole 12 is drilled from the proximal end opening of the hole portion 12c to a depth at which the tip hole bottom portion 12b is disposed close to the main reinforcing bar on the other wall surface 11b side in contact with the natural ground 23. Preferably it is formed. If the depth of the reinforcing material insertion hole 12 is too deep, the concrete on the cover portion on the other wall surface 11b facing the natural ground 23 is likely to be damaged, and if too shallow, the reinforced concrete wall by the shear reinforcing material 13 and the filler 14 11 cannot be fully exerted.

  In the present embodiment, when the reinforcing material insertion hole 12 is formed by drilling to a predetermined depth, the inside of the reinforcing material insertion hole 12 is filled before the filler 14 is filled into the formed reinforcing material insertion hole 12. Clean. As shown in FIG. 2C, the inside of each strong material insertion hole 12 is cleaned using, for example, a high-pressure air cleaning tool 24 to which a cleaning nozzle 24b with a brush having a spout 24a at the tip is attached. It is possible to carry out easily while jetting.

  As shown in FIGS. 3 (a) and 3 (b), the loading step of loading the filler 14 into the formed reinforcing material insertion hole 12 is performed at the tip of the discharge pipe 20a with the inner diameter of the reinforcing material insertion hole 12. By using the filling jig 20 provided with the presser enlarged diameter portion 20b having substantially the same outer diameter, for example, the filler 14 having high fluidity is made to work with the press enlarged diameter portion 20b and the tip by work from the underground space 10a. This is done by continuously filling the portion between the hole bottom 12a and the pressure.

  Here, in the present embodiment, it is preferable to use a filler having thixotropy, which is a property that the viscosity is lowered by stirring and then the viscosity is returned to the original by leaving it agitated. . It is more preferable to use a high fluidity mortar having thixotropy and excellent filling properties. As a high fluidity mortar with thixotropic properties and excellent filling properties, for example, a premix type void filling grout with high thixotropic properties that can be used by adding a predetermined amount of water at the time of use and kneading. As a material, for example, a trade name “Noshital” (manufactured by Newtec Co., Ltd.) can be preferably used.

  By using a filler 14 having thixotropy as the filler 14, even after a predetermined amount of filler 14 is loaded into the reinforcing material insertion hole 12, the filling jig 20 is removed from the reinforcing material insertion hole 12. As shown in FIG. 3 (c), in the reinforcing material installing step described later, the tip of the shear reinforcing material 13 including the cylindrical slide packing member 21 is extended in the longitudinal direction without flowing down until it is pressed from below. It is possible to easily maintain the state in which the filler 14 is loaded on the upper side of the reinforcing material insertion hole 12 to be provided. Further, by using a high fluidity mortar excellent in filling property as the filling material 14, the solidified filling material 14 is effectively used as a stable reinforcing material having higher strength than the concrete of the existing reinforced concrete wall 11. It becomes possible.

  In the loading process, for example, the filler 14 fed through a pressure feeding hose 25 connected to a known mortar pump (not shown) having a hopper having a considerable capacity is shown in FIGS. 3 (a) and 3 (b). As described above, from the filling jig 20 connected to the pressure feeding hose 25, by using the pressure feeding pressure by the mortar pump, the presser enlarged diameter portion 20b at the tip of the filling jig 20 and the tip hole bottom 12a of the reinforcing material insertion hole 12 The press-in expanded pressure portion 20b that is in contact with or close to the tip hole bottom portion 12a is separated from the tip hole bottom portion 12a by this press-fitting pressure, and the pressure is raised between them. The filling material 14 is continuously filled in this portion.

  Here, in this embodiment, the filling jig 20 is connected to the pumping hose 24, for example, a discharge pipe 20a made of vinyl chloride, and a presser expansion made of, for example, rubber sponge fixed to the tip of the discharge pipe 20a. And a diameter portion 20b. The discharge pipe 20 a has an outer diameter similar to the inner diameter of the pressure feeding hose 25. The proximal end portion of the discharge pipe 20a is inserted in close contact with the inside of the distal end portion of the pressure feeding hose 25, and as a joint auxiliary member, for example, a hose band 26 is wound from the outside so that the filling jig 20 is pressure-fed by a mortar pump. It is firmly joined to the tip of the pressure hose 25 so that it does not escape due to pressure.

  The presser enlarged diameter portion 20b is a circular donut-shaped packing member having a through hole having an inner diameter similar to the outer diameter of the discharge pipe 20 at the central portion and having an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole 12. It is. The presser enlarged diameter portion 20b is joined with an adhesive or the like in a state in which the distal end portion of the discharge pipe 20a is fitted in the through hole, and the discharge pipe 20a is opened with the distal end opening thereof opened. It is fixed to the tip of the unit as a single unit. A guide ring that is integrally joined to the outer peripheral surface of the discharge pipe 20a and has an outer diameter slightly smaller than the inner diameter of the reinforcing material insertion hole 12 at an intermediate portion between the presser enlarged diameter portion 20b and the hose band 26. 27 is attached.

  In the present embodiment, in the loading process, the filling jig 20 having the above-described configuration is inserted into the reinforcing material insertion hole 12 until the presser enlarged diameter portion 20b comes into contact with or closes to the tip hole bottom portion 12a of the reinforcing material insertion hole 12. (See FIG. 3 (a)). Thereafter, the filler 14 is pumped from the mortar pump via the pressure feeding hose 25 and the filling jig 20, and the portion between the presser enlarged diameter portion 20b and the tip hole bottom portion 12a from the tip opening of the discharge pipe 20a. The filler 14 fed under pressure is discharged into the reinforcing material insertion hole 12. Due to the discharge pressure at this time, the filling jig 20 is pushed downward from the reinforcing material insertion hole 12 while separating the presser enlarged diameter portion 20b from the tip hole bottom portion 12a, The portion between the tip hole bottom portion 12a is continuously filled with the pumped filler 14. Further, when the filling jig 20 is pushed downward by the filling pressure of the filling material 14 to be filled, for example, the pushing pressure is applied to the outer peripheral surface of the presser enlarged diameter portion 20 and the inner peripheral surface of the reinforcing material insertion hole 12. The presser diameter-enlarging portion 20b and the pressure-increasing portion 20b while maintaining the filling pressure of the filler 14 to be filled in a desired size by supporting the discharge pipe 20a with a hand by appropriately supporting the discharge pipe 20a. It becomes possible to continuously fill the filler 14 into the portion between the tip hole bottom 12a.

  By filling the filler 14 into the portion between the presser enlarged diameter portion 20b and the tip hole bottom portion 12a while increasing the pressure, the filler 14 loaded in the reinforcing material insertion hole 12 is reinforced. It is possible to firmly adhere to the hole wall surface 12a of the material insertion hole 12, and the attachment between the loaded filler 14 and the hole wall surface 12a of the reinforcing material insertion hole 12 after the filler material 14 is solidified. It is possible to effectively increase the wearing power.

  By compressing the filler 14, the filler 14 is continuously filled in the portion between the press-increasing diameter portion 20 b of the filling jig 20 and the tip hole bottom portion 12 b of the reinforcing material insertion hole 12. When a predetermined amount of filler 14 is loaded into the insertion hole 12, as shown in FIG. 3C, the loaded filler 14 is held on the upper side inside the reinforcing material insertion hole 12, The filling jig 20 is taken out from the reinforcing material insertion hole 12 so that the next reinforcing material installation step can be performed. Here, the predetermined amount of the filler 14 loaded in the loading step is such that the volume of the space inside the reinforcing material insertion hole 12 left below the loaded filler 14 is embedded in the filler 14. It is preferable to set the amount to be slightly smaller than the volume of the shear reinforcement member 13 to be installed. This makes it possible to embed the shear reinforcing material 13 inside the filler 14 in a state where the filler 14 is sufficiently spread over the entire reinforcing material insertion hole 12 including the hole portion 12c (FIG. 7). (Refer to (a) and (b)).

  In the present embodiment, the reinforcing material installing step is performed in a state where the cylindrical slide packing member 21 is attached to the tip of the shear reinforcing material 13 as shown in FIGS. 5 (a) and 5 (b). A front end portion inserting step (see FIG. 5A) for pressing the front end portion of 13 to the rear end portion of the filler 14 loaded in the reinforcing material insertion hole 12; The cylindrical slide packing member 21 is pushed into the reinforcing material insertion hole 12 while the pressure of the loaded filling material 14 is raised by pushing the shear reinforcing material 13 into the filling material 14 while being pressed against the end portion. And a shear reinforcing material pushing step (see FIG. 5B) that slides backward (downward) toward the hole portion 12c.

  Here, as shown in FIGS. 4 (a) and 4 (b), the shear reinforcing material 13 is a reinforcing steel bar having a diameter of about 13 to 51 mm, for example, and preferably has a male screw part at the tip part. Reinforcing bar with screws. The shear reinforcement member 13 is integrally provided with a diameter-enlarged fixing portion 13a having a large cross-sectional shape at the tip portion, and has a sharpened portion 13b having a sharp tip on the tip side of the enlarged-diameter fixing portion 13a. Yes.

  In the present embodiment, the shear reinforcement member 13 has a length of about 140 to 4600 mm, for example, obtained by subtracting the cover thickness on both the one wall surface 11a side and the other wall surface 11b side from the thickness of the reinforced concrete wall 11. ing. The enlarged diameter fixing portion 13a is preferably provided integrally with the distal end portion of the shear reinforcement member 13 by screwing a hexagon nut having a maximum outer diameter of, for example, about 23 to 75 mm as a nut member to the male screw portion. It has been. The sharpened portion 13b has a shape in which the tip is pointed at the tip of the diameter-enlarged fixing portion 13a by, for example, obliquely cutting a portion of the shear reinforcement member 13 that protrudes toward the tip side from the diameter-enlarged fixing portion 13a. Is formed.

  In the shear reinforcing material pushing step described later, the shear reinforcing material 13 is pushed into the filler 14 until the tip of the sharpened portion 13b comes into contact with the tip hole bottom 12a of the reinforcing material insertion hole 12 (FIG. 6B). reference). As a result, the shear reinforcement member 13 is positioned inside the reinforcement member insertion hole 12, and the enlarged diameter fixing portion 13 a having a large cross-sectional shape at the tip portion is placed on the other side facing the ground mountain 23 of the reinforced concrete wall 11. It becomes possible to arrange close to the main reinforcing bar arranged on the wall surface 11b side. In addition, this makes it possible to increase the anchoring strength. Therefore, during an earthquake, the load applied to the cover portion of the existing concrete on the ground mountain 23 side of the main rebar is dispersed over a wide range, thereby providing a reinforced concrete wall. 11 can be effectively improved in shear strength and toughness. Further, since the shear reinforcement member 13 is positioned inside the reinforcement member insertion hole 12 with the sharp tip of the sharp portion 13b being brought into contact with the tip hole bottom portion 12a of the reinforcement member insertion hole 12, the shear reinforcement member 13 The filler 14 is also filled between the tip surface around the contact point by the pointed tip and the tip hole bottom 12a, thereby further improving the adhesion force to the hole wall surface of the tip hole bottom 12a. It becomes possible.

  In the present embodiment, the cylindrical slide packing member 21 has an inner diameter that is substantially the same as the outer diameter of the shear reinforcement member 13 and an outer diameter that is substantially the same as the inner diameter of the reinforcing member insertion hole 12, preferably from a rubber sponge. A thick-walled main body portion 21b formed into a substantially cylindrical shape, and a reinforcing ring plate 21c formed into an annular donut shape, preferably made of a plastic plate, respectively joined to the upper and lower end faces of the main body portion 21b. It is configured to include. In the central portion of the cylindrical slide packing member 21, there is formed an axial insertion hole 21a penetrating in the axial direction thereof and opening at the portion of the reinforcing ring plate 21c. For example, the cylindrical slide packing member 21 is inserted into the axial insertion hole 21a until the reinforcing ring 21c on the upper end surface comes into contact with the lower end surface of the enlarged diameter fixing portion 13a. It is attached integrally to the upper end part (tip part) of the shear reinforcement member 13 in a state in which it can slide in the axial direction (vertical direction) along the outer peripheral surface of 13 (see FIGS. 4A and 4B).

  In addition, the shear reinforcement member 13 is inserted into the reinforcement member insertion hole 12 loaded with the filler material 14 in a tip portion insertion step (see FIG. 5A), which will be described later. As shown in FIG. 3, the filler 14 is applied to the distal end portion of the shear reinforcement member 13 to which the diameter-enlarged fixing portion 13a and the cylindrical slide packing member 21 are attached, from the cylindrical slide packing member 21 to the distal end side. It is preferable to keep it. The filler 14 is applied to the distal end portion of the shear reinforcing material 13 from the cylindrical slide packing member 21 to insert the distal end portion of the shear reinforcing material 13 into the reinforcing material insertion hole 12. Thus, it is effective that air biting occurs between the enlarged end fixing portion 13a or the cylindrical slide packing member 21 and the rear end portion of the filler 14 when pressed against the rear end portion of the filler 14. Can be avoided.

  In this embodiment, as shown in FIG. 5 (a), the tip portion insertion step of the reinforcing material installation step is a cylindrical slide packing that is slidably mounted in the axial direction along the outer peripheral surface of the shear reinforcing material 13. In a state where the member 21 is in contact with the lower end surface of the diameter-enlarged fixing portion 13a, the front end portion of the shear reinforcing material 13, preferably the filler material 14 is applied to the front end portion in advance, and then the reinforcing material is applied. The reinforcing material is inserted into the reinforcing material insertion hole 12 until it is pressed against the rear end portion of the filler 14 loaded in the insertion hole 12. As a result, the enlarged fixing portion 13a at the front end of the shear reinforcement member 13 and the cylindrical slide packing member 21 are brought into close contact with each other so as to bite into the rear end portion of the loaded filler 14.

  When the front end of the shear reinforcement 13 is brought into close contact with the rear end of the filler 14 loaded in the reinforcement insertion hole 12, it is shown in FIG. As described above, only the shear reinforcement 13 is pushed further into the filler 14 toward the tip hole bottom 12 b of the reinforcement insertion hole 12. As a result, the portion of the shear reinforcement member 13 below the diameter expansion fixing portion 13a is newly pushed into the filler 14 loaded in the reinforcement member insertion hole 12. Further, the portion of the shear reinforcement material 13 below the diameter-enlarged fixing portion 13a is newly inserted into the filler material 14 so that the volume of the reinforcement material insertion hole 12 is more distal than the cylindrical slide packing member 21. Since it is necessary to add to the hole bottom portion 12a side, the cylindrical slide packing member 21 is formed by the filler 14 when the shear reinforcement member 13 is pushed in to increase the volume of the newly pushed shear reinforcement member 13. While being pressed by the extrusion pressure and sliding along the outer peripheral surface of the shear reinforcement member 13 and the inner peripheral surface of the reinforcement member insertion hole 12, it slides downward toward the hole portion 12c of the reinforcement member insertion hole 12. .

  Further, at this time, the extrusion pressure by the filler 14 is changed to, for example, the frictional force between the outer peripheral surface of the cylindrical slide packing member 21 and the inner peripheral surface of the reinforcing material insertion hole 12, or the inner peripheral surface of the axial insertion hole 21a. The cylindrical slide packing member 21 is supported by the reinforcing material insertion hole 12 while the pressure of the filled material 14 is raised to a desired level by supporting it with a frictional force between the outer circumferential surface of the material and the shear reinforcement material 13. It is possible to slide downward toward the hole portion 12c.

  The shear reinforcement 13 is pushed into the filler 14 loaded in the reinforcement insertion hole 12, and the cylindrical slide packing member 21 is slid toward the hole portion 12c, as shown in FIG. Thus, when the cylindrical slide packing member 21 moves downward to the lower end (rear end) of the shear reinforcement 13 along the outer peripheral surface of the shear reinforcement 13, the lower end of the shear reinforcement 13 slides into the cylindrical slide. It is hidden by the packing member 21 and it becomes difficult to push the shear reinforcement material 13 further. For this reason, in this embodiment, the auxiliary rod 22 made of, for example, round steel having an outer diameter substantially the same as the reinforcing bar diameter of the shear reinforcing material 13 is used, and the tip of the auxiliary rod 22 is shear-reinforced. The material 13 is pushed into the filler 14 together with the shear reinforcement 13 by being inserted into the axial insertion hole 21 a of the cylindrical slide packing member 21 subsequent to the shear reinforcement 13 while being in contact with the rear end portion of the material 13. Go. As a result, as shown in FIG. 6B, the entire shear reinforcement member 13 is reinforced with the sharpened portion 17 in contact with the bottom hole bottom portion 12 a of the reinforcement member insertion hole 12. It is possible to embed as an integral part of the filler 14 filled in the container.

  In the present embodiment, the auxiliary rod 22 is pushed into the axial insertion hole 21 a of the cylindrical slide packing member 21 after the shear reinforcing material 13, and the entire shear reinforcing material 13 is embedded in the filler 14 as a unit. Then, as shown in FIGS. 7A and 7B, the cylindrical slide packing material 21 and the auxiliary rod 22 are collected, and the hole portion 12c of the reinforcing material insertion hole 12 is finished. The finish of the hole portion 12c is repaired by, for example, repairing the portion where the auxiliary rod 22 has been removed by filling it with the surplus filler 14 protruding from the hole portion 12c of the reinforcing material insertion hole 12. The portion of the filler 14 that protrudes from the hole portion 12c of the material insertion hole 12 can be easily cut and removed. In addition, as shown in FIG. 8, the hole portion 12c can be finished by, for example, pressing and fixing a rubber plug 28 into the hole portion 12c. When the rubber plug 28 is pushed in, for example, by forming a through hole 28a having a diameter of about 5 mm at a position shifted from the center of the rubber plug 28, the rubber plug 28 can be pushed in while discharging the surplus filler 14. It becomes possible.

  And according to the shear reinforcement construction method of this embodiment provided with the above-mentioned structure, the filler 14 which fills the clearance gap between the reinforcement material insertion holes 12 around the shear reinforcement material 13, and the inside of the reinforcement material insertion holes 12 It is possible to sufficiently secure the adhesive force between the hole wall surface 12a and efficiently exert the reinforcing effect by the shear reinforcing material 13.

  That is, according to the shear reinforcement method of the present embodiment, a loading step of loading the formed reinforcing material insertion hole 12 with the filler 14, and a shear reinforcing material 13 is inserted into the reinforcing material insertion hole 12 loaded with the filler 14. In the loading step, the filling material 20 is inserted into the reinforcing material insertion hole 12 until the presser enlarged diameter portion 20b comes into contact with or comes close to the bottom end bottom portion 12b of the reinforcing material insertion hole 12. Then, the filler 14 is continuously fed while the pressure is applied to the portion between the presser enlarged diameter portion 20b and the tip hole bottom portion 12b by pumping the filler 14 after the insertion. In the reinforcing material installation step, the shear reinforcing material 13 is inserted into the reinforcing material insertion hole 12 in a state where the tip end portion of the shear reinforcing material 13 to which the cylindrical slide packing member 21 is attached is pressed against the rear end portion of the filler 14. Tip hole bottom 1 The cylindrical slide packing member 21 is slid rearward toward the hole portion 12c of the reinforcing material insertion hole 12 while the pressure of the filler 14 is raised by being pushed into the filler 14 toward b. It is like that.

  Therefore, according to the shear reinforcement construction method of the present embodiment, by raising the pressure of the filler 14 loaded or filled in the reinforcing material insertion hole 12 in both the loading step and the reinforcing material installation step, Since the filler 14 can be firmly adhered to the hole wall surface 12a of the reinforcing material insertion hole 12, the filler material 14 between the loaded filler material 14 and the hole wall surface 12a of the reinforcing material insertion hole 12 can be formed. By effectively increasing the adhesive force after solidification, it is possible to ensure a sufficient adhesive force and efficiently exert the reinforcing effect by the shear reinforcing material 13.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the filler loaded in the reinforcing material insertion hole does not necessarily need to be a thixotropic filler. The shear reinforcing material may be a reinforcing bar with a screw, a reinforcing bar, a steel bar, or the like. In the tip insertion process of the reinforcement installation process, it is necessary to insert the shear reinforcement into the reinforcement insertion hole with the filler applied to the tip of the shear reinforcement to which the cylindrical slide packing member is attached. Is not necessarily. It is not always necessary to provide an enlarged fixing portion or a sharpened portion at the tip of the shear reinforcement material. The enlarged diameter fixing portion does not necessarily need to be a nut member, and may be provided integrally joined to the shear reinforcing material.

  The existing underground structure that is seismically reinforced by the shear reinforcement method of the present invention may be other box-like underground structures such as underground parking lots other than box culverts, and reinforced concrete other than underground structures. For example, it may be a reinforced concrete structure provided with walls. For example, if there is existing equipment on the back side of a reinforced concrete wall, the back side is a waterway, the back side faces a railway or road, or it is difficult to install a scaffold on the back side It is also possible to carry out shear reinforcement of a reinforced concrete structure by performing the shear reinforcement method of the present invention from the front side opposite to the side.

10 Box culvert (box-like underground structure)
DESCRIPTION OF SYMBOLS 10a Underground space 11 Reinforced concrete wall 11a One wall surface 11b The other wall surface 12 Reinforcement material insertion hole 12a Hole wall surface 12b Tip hole bottom portion 12c Hole opening portion 13 Shear reinforcement material 13a Expanding fixing portion 13b Sharpening portion 14 Filler material 20 Discharge pipe 20b Presser enlarged diameter part 21 Cylindrical slide packing member 21a Axial insertion hole 21b Main body part 21c Reinforcement ring 22 Auxiliary bar 23 Ground pile 30 Drilling machine

Claims (6)

A shear reinforcement method for reinforcing an existing reinforced concrete wall on which a shear load acts,
A drilling step of drilling a bottomed reinforcing material insertion hole from one wall surface of the reinforced concrete wall toward the other wall surface, a loading step of loading a filler into the formed reinforcing material insertion hole, and the filling A reinforcing material installation step of inserting and installing a shear reinforcing material in the reinforcing material insertion hole loaded with a material,
In the loading step, a filling jig provided with a presser enlarged diameter portion having an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole at the distal end portion of the discharge pipe is used. The expanded diameter portion is inserted into the reinforcing material insertion hole until the expanded diameter portion comes into contact with or close to the bottom of the tip end hole of the reinforcing material insertion hole, and then the press-enlarged diameter portion is removed from the bottom of the distal end hole by pumping the filler. While being spaced apart, the portion between the presser enlarged diameter portion and the bottom of the tip hole is loaded by continuously filling the filler while raising the pressure,
The reinforcing material installation step is mounted so as to be slidable in the axial direction along the outer peripheral surface of the shear reinforcing material, and a cylindrical slide packing member having an outer diameter substantially the same as the inner diameter of the reinforcing material insertion hole, In a state where the shear reinforcing material is inserted into the axial insertion hole and attached to the distal end portion of the shear reinforcing material, the rear end portion of the filler loaded in the reinforcing material insertion hole is attached to the distal end portion of the shear reinforcing material. Inserting the reinforcing material into the reinforcing material insertion hole until it is pressed against the tip, and inserting the filler into the portion between the cylindrical slide packing member and the bottom of the tip hole, and inserting the shear reinforcing material In a state where the tip end portion to which the cylindrical slide packing member is attached is pressed against the rear end portion of the filler, the shear reinforcement is pushed into the filler toward the bottom of the tip hole of the reinforcement insertion hole. Going More, while standing the pressure of the filling material filled in the portion between said tubular sliding packing member front end hole bottom, the tubular slide packing member along said outer circumferential surface of the shear reinforcement A shear reinforcement construction method including a shear reinforcement material pushing step of sliding backward toward the hole portion of the reinforcement material insertion hole.   The reinforcing material insertion hole formed in the drilling step is formed in a vertically long shape having an opening in the lower surface of the reinforced concrete wall and having the tip hole bottom in the upper portion by drilling upward from the lower surface of the reinforced concrete wall. The shear reinforcement construction method according to claim 1, wherein the insertion hole extends in a direction.   The shear reinforcement construction method according to claim 1 or 2, wherein a filler having thixotropy is used as the filler.   In the distal end insertion step of the reinforcing material installation step, a filler is applied to the distal end portion of the shear reinforcement member to which the cylindrical slide packing member is attached from the cylindrical slide packing member to the distal end side portion. The shear reinforcement construction method according to any one of claims 1 to 3, wherein a tip end portion of the shear reinforcement material is inserted into the reinforcement material insertion hole in a state in which the shear reinforcement material is made to be in the state of being made.   When the cylindrical slide packing member slides back to the rear end portion of the shear reinforcement along the outer peripheral surface of the shear reinforcement in the shear reinforcement push-in step of the reinforcement installation step, the cylindrical slide By pushing an auxiliary rod having an outer diameter substantially the same as that of the shear reinforcement into the axial insertion hole of the packing member, and further pushing the shear reinforcement while raising the pressure of the filler, the shear reinforcement The shear reinforcement construction method according to any one of claims 1 to 4, wherein the whole is embedded in the filler as one body.   The shear reinforcing material is integrally provided with a diameter-enlarged fixing portion having a large cross-sectional shape at a tip portion, and has a sharpened portion with a pointed tip on the tip side with respect to the diameter-enlarged fixing portion, In the shear reinforcement push-in step of the reinforcement installation step, the shear reinforcement is pushed into the filler until the tip of the sharpened portion comes into contact with the bottom of the tip of the reinforcement insert hole. The shear reinforcement construction method according to any one of the above.

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