JP4264095B2 - Manhole reinforcement structure - Google Patents

Description

  The present invention relates to a reinforcing structure for manholes, which are concrete structures embedded in the ground, and in particular, can be reinforced in a short time by a simple method, and against a wheel load from a vehicle traveling on a road. The present invention relates to a manhole reinforcement structure capable of improving the proof stress.

  Conventionally, for example, in order to secure a space for branching communication cables buried in the ground, accommodating a connection portion, and a space for an operator to enter the mine and construct and maintain the cable, (Human hole) is buried in the ground.

  The capacity and shape of the manhole are determined by the number of pipelines on the route, the number of cables to be accommodated, or the branch direction, and a plurality of types having different capacities are standardized according to the number of applicable pipelines. Each manhole has the following basic configuration.

  As shown in FIG. 14, the manhole 1 includes an upper floor slab 2 a, a side wall (longitudinal side wall) 2 b along the longitudinal direction, and a side wall (short side) along the lateral direction (direction perpendicular to the longitudinal direction) of the box 2. The opening neck 3 was connected to the upper floor slab 2a of the reinforced concrete box 2 in which a rectangular inner space was formed by the direction side wall 2c and the lower floor slab 2d. The opening neck 3 has a cylindrical shape having an opening 4 communicating with the box 2 and has a lid 5 at the top.

  A duct sleeve 6 is formed on a side wall (short side wall) 2 c of the box 2, and a conduit 7 is connected thereto. A communication cable or the like is laid through the pipeline 7.

  The dimensions shown in FIG. 14 are based on the standard of straight line No. 3, and are merely examples.

  The manhole 1 is disposed in the ground by a spot casting method in which unreinforced concrete or reinforced concrete is cast at the site, or a block method in which precast products are transported and installed on the site. Although it is designed to withstand strength, deterioration due to wheel load (increase in road design load) due to traffic of vehicles or the like occurs in relation to earth covering. In addition, deterioration due to aging of concrete is observed in many manholes 1. When actually observing from the inside of the manhole 1, cracks (cracks) of the concrete and exposure of the reinforcing bars (explosion) are observed. For this reason, repair and reinforcement are necessary.

  Conventionally, the repair of the manhole 1 has been done only by repairing the cross section after rust-proofing by removing the deteriorated part such as the part where the reinforcing steel corrodes and expands and the cover concrete part is peeled off, Such a repair method takes time for construction, and the reinforcing effect is limited.

  On the other hand, FIG. 15 schematically shows the stress distribution (bending moment) for the horizontal unit cross section 1S and the vertical unit cross section 2S of the box 2 in the ground of the manhole 1 having the opening neck 3 as an entrance. . The unit cross section 1S is rectangular, and due to earth pressure applied to the side wall, a horizontal stress or a partial pressure of the stress has a minus (−) bending moment at the corner and a plus (+) at the left and right side walls. The bending moment of As for the unit cross section 2S, this unit cross section has a narrow gate shape, and a negative (−) bend is applied to the corner portion due to a vertical stress due to a load on the ground or a partial pressure of the stress as a partial pressure. A positive (+) bending moment is generated on the upper and lower and left and right side walls. For this reason, it is particularly necessary to reinforce the corner 8.

  Also, the manhole 1 has a small internal width, and communication cables are bundled there and congested, so that the repair work needs to be performed under adverse conditions with only a narrow space that is extremely small. There is.

Regarding the reinforcement of such manholes, there are the following patent documents, especially repair and reinforcement methods for narrow manholes for the purpose of reinforcing the corners and wall surfaces thereof.
JP-A-2005-155273 (Repair / reinforcement method for narrow manholes)

  As shown in FIG. 16, the construction method of Patent Document 1 drives anchor bolts 9 into two adjacent surfaces closest to the corner 8 and at appropriate intervals in the depth direction. The reinforcing bar 10 is reinforced by attaching the deformed reinforcing bars 10 at appropriate intervals in the same depth direction through the slabs, placing the resin mortar 11 by hand so that these members are impregnated, and performing the plastering finish. It is.

  Moreover, after applying a ground treatment to the upper and lower wall surfaces and / or the left and right wall surfaces, the carbon fiber sheet 12 is attached using an impregnating adhesive, and the surface is finished to reinforce the concrete wall.

  However, in this Patent Document 1, it takes time and labor to dispose atypical reinforcing bars or to place a resin mortar by hand packing to perform plastering. When the construction takes time, the manhole 1 is buried in the ground below the road, so there is a problem that traffic regulation is long and repair / reinforcement work is difficult.

  Furthermore, regarding the affixing of the carbon fiber sheet using the impregnated adhesive, as shown in FIG. Since many steps such as fiber sheet adhesion treatment (resin impregnation and curing) with 16a, carbon fiber 17, and impregnating adhesive (overcoating) 16b are required, construction takes time.

  An object of the present invention is to eliminate the disadvantages of the conventional example, and to improve the resistance to wheel loads from vehicles traveling on the road through manholes buried in the ground in a short time and efficiently. It is to provide a manhole reinforcement structure that can be used.

In order to achieve the above object, the present invention according to claim 1 is characterized in that a longitudinal side wall and a short side wall of a manhole in which an opening neck is connected to an upper floor slab of a box comprising a lower floor slab, a side wall, and an upper floor slab. The trapezoidal resin concrete haunch blocks are stacked side by side in the corners on the inner space side, that is, in four corners, arranged in columns, fixed by adhesion, and the load against vertical compression and the surrounding area of the box Resin concrete haunch blocks are received at the corners on the inner space side of the box formed by the lower surface of the upper floor slab and the side walls in the longitudinal direction. Are arranged side by side, resin concrete haunch blocks are arranged side by side at the corner of the inner space side of the box formed by the upper surface of the lower floor slab and the longitudinal side wall, and the lower floor slab, side wall, On the side of the box on the upper floor It is an Abstract that it has Yibin bonding the fiber-reinforced plastic strip reinforcement.

  According to the first aspect of the present invention, first, the reinforcement of the corners at the four corners of the side wall of the manhole is effected in a short time by arranging the haunch blocks which are easy to handle and easy to mount in a column shape. Can be done automatically. The haunch block is segmented in consideration of workability, the mass per segment is lightweight, and lifting can be done manually. In the structural calculation, the haunch block can be calculated as a solid cement concrete haunch of the same size. In addition, since the pillars by the haunch block are replenished to the corners of the side walls, the load on the vertical compression of the box and the horizontal load around the box are received by the trapezoidal haunch blocks arranged in columns at the corners of the side walls. The upper floor slab and the side wall can be reinforced by stacking the haunch blocks.

Further , by arranging the haunch blocks side by side, including the corners other than the four corners of the manhole side wall, the corner portions can be reinforced in a short time and effectively. In addition, it further reinforces the lower floor slab, side wall, and upper floor slab, and acts on the lower floor slab, side wall, and upper floor slab by bonding a fiber-reinforced plastic strip reinforcement to the side of the box. The strip-shaped reinforcing material can share the stress against the tensile stress to be generated, and a strong reinforcement can be obtained by the synergistic effect of the reinforcement of the corner portion.

  In addition, the manhole can be reinforced with good workability by carrying a band-shaped reinforcing material made of fiber reinforced plastic that has already been cured into the manhole and affixing it to a predetermined location. Therefore, the manhole reinforcement work can be performed efficiently in a short time. In particular, the work can be completed in a very short time by using a fast-curing adhesive resin as the primer and adhesive resin. Furthermore, since the strength and rigidity per unit width are higher than those of the carbon fiber sheet, it is not necessary to stick the entire surface of the repaired portion, and it is possible to perform construction with a gap.

  The haunch block can be easily installed by fixing by bonding.

The haunch block is made of resin concrete and has a compressive strength 5 to 7 times that of cement concrete. Thus, the haunch block has a greater compression performance than the solid cement concrete haunch. In particular, it can be easily installed by fixing by adhesion. In particular, since the haunch block is made of resin concrete, a concrete box can be fixed by bonding, and can be integrated by adhesive bonding with an existing manhole, so that a high reinforcing effect can be obtained. The quality of the haunch block is constant because it is factory processed.

The gist of the present invention described in claim 2 is that the haunch blocks are boxed out and connected to each other with bolts.

According to the second aspect of the present invention, the haunch block is box-opened and semi-hollow in order to easily realize mechanical connectivity. Further, by connecting with each other with bolts, stability at the time of fixing by adhesion can be enhanced, and the strength of the beam-like or columnar shape connected and fixed can be further increased.

The gist of the present invention described in claim 3 is that the haunch block is a fire type in which the corner portion is not in contact with the box corner portion.

According to the third aspect of the present invention, there are several hunch blocks located in the center, with the corners being in non-contact with the corners, so that the top plate and the side wall of the box can be heated. The load on the lower floor slab and the side wall can be distributed, and the support reinforcement can be made without difficulty.

The gist of the present invention described in claim 4 is that the haunch block is formed by stacking the end portions of the band-shaped reinforcing material made of fiber reinforced plastic on top of each other and pressing it down from above.

According to the present invention described in claim 4, it is possible to use the haunch block as a presser for bonding the belt-like reinforcing material made of fiber reinforced plastic, and to apply the belt-like reinforcing material without any other presser. Is possible.

The gist of the present invention described in claim 5 is that the belt-like reinforcing material made of fiber reinforced plastic has a linear shape and is arranged orthogonal to a lattice shape.

According to the present invention described in claim 5, the belt-like reinforcing material made of fiber reinforced plastic has a linear shape, and can be reinforced in the vertical and horizontal directions by being arranged orthogonal to the lattice shape. A sufficient reinforcing effect can be obtained.

  As described above, the manhole reinforcing structure of the present invention can reinforce the manhole efficiently in a short time. Furthermore, according to the present invention, it is possible to provide a reinforced manhole with improved resistance to wheel loads from vehicles traveling on the road.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a longitudinal front view showing an embodiment of a manhole reinforcement structure according to the present invention, FIG. 2 is a view taken along the line AA in FIG. 1, FIG. 3 is a view taken along the line BB in FIG. Is a vertical sectional side view, and FIG. 5 is a perspective view of the main part.

  The manhole 1 to which the present invention is applied in the present embodiment has a box 2 which is a rectangular casing (concrete box), a cylindrical neck 3 and a lid 5 as described in FIG. . The box 2 includes an upper floor slab 2 a, a side wall (longitudinal side wall) 2 b along the longitudinal direction of the box 2, and a side wall (short side wall) along the short direction (direction perpendicular to the longitudinal direction) of the box 2. ) 2c and the lower floor slab 2d form a rectangular internal space. The neck 3 has an opening 4 that is connected to the upper floor slab 2 a and communicates with the internal space of the box 2. Further, a duct sleeve 6 is formed on the lateral side wall 2c of the box 2 and a pipe line 7 is connected thereto.

  The manhole 1 is made of an RC precast manhole as a large-division type, in which the upper floor slab 2a and the upper half of the side wall are manufactured as one piece, or in-situ concrete.

  In such a manhole 1, the structural calculation is performed with the upper floor slab 2a as a simple support (lid) and the side walls as horizontal ramen, so when a wheel load is applied from the neck 3 to the upper floor slab 2a, At the junction between the longitudinal side wall 2c and the upper floor slab 2a, a tensile stress acts on the upper surface of the upper floor slab 2a. Concrete is strong in compressive force and weak in tensile force. Further, in order to perform the reinforcement work for the manhole 1 in a short time with high efficiency, it is required to reinforce the upper surface of the upper floor slab 2a from the internal space of the box 2.

  Further, when a horizontal force is applied to the side wall (longitudinal side wall) 2b and the side wall (short side wall) 2c, a tensile force is generated on the outer side of the corner and the inner side of the side wall. Further, reinforcement is required due to an increase in wheel load and deterioration of the side wall.

  2 is strong against the upper surface of the upper floor slab 2a of the joint between the longitudinal side wall 2b and the upper floor slab 2a in the range of about 1.5 times the diameter of the opening 4 around the longitudinal center line XX shown in FIG. Tensile stress is generated.

  Therefore, in the present invention, trapezoidal haunch blocks 19 are stacked side by side in a columnar shape at the corner 8 on the inner space side formed by the longitudinal side wall 2b and the side wall (short side wall) 2c, that is, at the four corners. Set up.

  Further, haunch blocks 19 and 20 are arranged side by side at the corner 8 on the inner space side of the box 2 formed by the lower surface of the upper floor slab 2a and the longitudinal side wall 2b, and the upper surface and the longitudinal side wall of the lower floor slab 2d are arranged. The haunch blocks 20 are arranged side by side at the corner 8 on the inner space side of the box 2 formed by 2b.

  A haunch block 19 is disposed around the opening of the corner 8 on the inner space side of the box 2 formed by the lower surface of the upper floor slab 2a and the longitudinal side wall 2b. Since the corner portions 8 of the box 2 have a haunch shape, the haunch blocks 19 and 20 have a trapezoidal shape corresponding to this, but the haunch block 19 is formed by the lower surface of the upper floor slab 2a and the longitudinal side wall 2b. In the corner 8 on the inner space side of the box 2 formed by the inner space side of the box 2 and the upper surface of the lower floor slab 2d and the longitudinal side wall 2b, the block located at the center of the side by side, the haunch block 20 is It is a block located on the left and right. In addition, the haunch blocks 19 are stacked in the vertical direction at the corner 8 on the inner space side formed by the long side wall 2b and the side wall (short side wall) 2c.

  As shown in FIGS. 9 to 11, the haunch block 20 matches the haunch shape of the corner portion 8, and has a top end surface 20 a joined to the inclined surface 8 a of the haunch, and a side surface continuous from the top end surface 20 a. 20b and 20c are surfaces joined to the upper floor slab 2a and the side wall 2b.

  As shown in FIGS. 6 to 8, the haunch block 19 has a top end surface 19 a that is not joined to the inclined surface 8 a of the haunch of the corner 8, and the corner is a corner on the inner space side when installed. It is assumed that the gap α (see FIG. 5) is secured without contact with the portion 8. Sides 19b and 19c continuous from the top end surface 19a are the same as the haunch block 20 in that they are surfaces joined to the upper floor slab 2a and the side wall 2b.

  Both the haunch blocks 19 and 20 are unboxed, provided with bolt through holes 22 and connected to each other with bolts 23 (and nuts). In addition, anchor bolt through holes 24 penetrating the top end surfaces 19a and 20a were formed, and embedded nuts 25 for attaching the handle were embedded in the boxed inner surface opposite to the side surfaces 19b, 20b, 19c and 20c. The through holes 24 for anchor bolts need not be provided in all the hunch blocks 19 and 20, and those provided and those not provided may coexist. Although not shown in the figure for the embedded nut 25 for attaching the handle, a plate body provided at the base of the U-shaped handle is fixed to the embedded nut 25 with a butterfly bolt. If it does in this way, a U-shaped handle can be provided in the back side right and left of the haunch blocks 19 and 20, and it can support at the time of insertion.

  The material constituting the haunch blocks 19 and 20 is preferably resin concrete that is made of an unsaturated polyester resin, vinyl ester resin, epoxy resin, etc. that is resistant to acid instead of cement, and is mixed and molded with aggregate and filler. In addition, resin concrete as a material has a compressive strength 5 to 7 times that of cement concrete, and can be reduced in weight.

  Resin concrete exhibits excellent corrosion resistance against various chemicals, and in particular, exhibits excellent strength against corrosion by hydrogen sulfide. Since not only the resin but also the aggregate and filler are made of a material with high wear resistance, they have a great resistance to wear action and are excellent in durability. Water absorption is very small and there is no strength deterioration due to freezing and thawing. In addition, the surface is smooth and has excellent hydraulic properties.

The haunch blocks 19 and 20 have the physical properties shown in Table 1 below as an example of resin concrete.

  The material constituting the haunch blocks 19 and 20 in addition to the resin concrete is not particularly limited, such as concrete or a casting such as aluminum die-cast.

Resin concrete-made haunch blocks 19 and 20 are fixed by adhesion, and the standards for the adhesive shown in Table 2 can be used.

  In the present invention, an upper floor slab 2a, a side wall (longitudinal side wall) 2b along the longitudinal direction of the box 2, and a belt-like reinforcing material 18 made of fiber reinforced plastic on the side of the box inside the lower floor slab 2d using an adhesive resin. Glued.

  The belt-like reinforcing member 18 has a linear shape, and the upper floor slab 2a and the lower floor slab 2d are arranged orthogonally in a lattice shape. Further, the side wall (longitudinal side wall) 2b may be crossed in a plurality of steps or in a cross shape and crossed in a lattice shape.

  Further, on the lower surface a of the upper floor slab 2a around the opening 4, an arc-shaped fiber reinforced plastic (FRP) reinforcing material (hereinafter referred to as "arc-shaped reinforcing material") 18 'is bonded with an adhesive resin. And adhered.

  A carbon fiber reinforced (CFRP) plate obtained by impregnating a carbon fiber in a unidirectional arrangement with a thermosetting resin and molding and curing it in a plate shape. Is used, it is affixed to the concrete surface with a special epoxy resin or the like.

The features of the CFRP plate are as follows.
(1) Since the CFRP plate is higher in strength and rigidity per unit width than the carbon fiber sheet, it is not necessary to stick it on the entire surface of the repaired part, and it is possible to perform construction with a gap.
(2) One CFRP plate is equivalent to six carbon fiber sheets, and a large reinforcing effect is obtained. Therefore, there is no need to affix multiple layers, and the amount of work is greatly reduced.
(3) Since a high-strength carbon fiber is used, the reinforcing effect is high.
(4) Since no impregnation / adhesive for impregnation is used at the construction site, it is possible to reduce the burden and curing of the worker in the upward construction. Furthermore, construction in a short time is possible.
(5) Since it is lightweight, it can be easily constructed by hand and can be reinforced in a narrow space.
(6) It is a construction method that reinforces only by bonding, and can be reinforced without damaging the concrete frame.
(7) Reinforced with carbon fiber FRP and epoxy resin adhesive, with no rust and corrosion concerns and excellent durability.
(8) Since the arc-shaped reinforcing member 18 ′ has the carbon fibers oriented in the circumferential direction, the arc-shaped reinforcing member 18 ′ has a high restraining effect on cracks that radially enter the circular hole portion.

  The arc-shaped reinforcing member 18 ′ is a semicircular shape of ± 90 ° with respect to the center line XX in the longitudinal direction of the manhole 1 passing through the opening 4 as a reference (0 °), and the two are combined into a circular shape. To do.

These band-shaped reinforcing member 18 and arc-shaped reinforcing member 18 ′ have the standards shown in Tables 3 and 4 below as an example.

  The height of the neck 3 of the manhole 1 is usually 50 cm to 1 m, and the inner diameter of the opening 4 is 60 to 90 cm. The band-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ′ having a predetermined width that have already been hardened are of a size that can be carried into the box 2 through the opening 4 of the neck 3.

  As shown in FIG. 12, the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 ′ have a layer of reinforcing fibers f1 (hereinafter referred to as “unidirectional fiber layer”) F1 which is a continuous fiber aligned in one direction. It is preferable to have. Then, the reinforcing fibers f1 are formed by impregnating the matrix resin and curing.

  Reinforcing fiber f1 arranged in one direction is a strand produced by bundling a large number of filaments in parallel or loosely, or a strand obtained by bundling multiple strands in parallel or loosely. (Roving, yarn). As a result, the unidirectional fiber layer F1 of the band-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ′ has a unidirectionally arranged fiber structure bonded with the matrix resin in a state where the filaments are laminated in a plurality of layers and oriented in one direction. Will have.

  As the reinforcing fiber f1, in addition to the carbon fiber (CFRP), inorganic fiber including glass fiber, ceramic fiber, boron fiber; metal fiber including titanium and steel; aramid, polyester, polyethylene, nylon, vinylon, polyacetal, Any fiber selected from organic fibers including PBO (polyparaphenylene benzbisoxazole) and high-strength polypropylene, or a hybrid fiber in which a plurality of these fibers are mixed can be used.

  As the unidirectional fiber layer F1 constituting the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 ′, a unidirectionally arranged reinforcing fiber sheet in which the reinforcing fibers f1 are arranged substantially uniformly in one direction may be used. Note that the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 ′ may have a plurality of unidirectional fiber layers F1 substantially composed of the same or different kinds of reinforcing fibers f1.

  In addition to the unidirectional fiber layer F1, an auxiliary layer may be provided on the first surface (front surface) and / or the second surface (back surface) of the unidirectional fiber layer F1.

  Further, as shown in FIG. 13, the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 ′ have a layer of conductive reinforcing fibers f1 as a unidirectional fiber layer F1 at the center of the cross section. Further, the band-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ′ are formed on the outer side of the unidirectional fiber layer F1, here, on the first surface (front surface) and the second surface (back surface) of the unidirectional fiber layer F1. It can also have a cross-sectional structure (sandwich structure) in which layers (auxiliary layers) F2 of reinforcing fibers f2 having electrical insulating properties are laminated.

  Preferably, when a carbon fiber, which is a conductive fiber, is used as the reinforcing fiber f1 of the unidirectional fiber layer F1, a glass fiber can be suitably used as the reinforcing fiber f2 having electrical insulation of the auxiliary layer F2. Further, as the structure of the auxiliary layer F2 made of the glass fiber f2, a mat can be suitably employed.

  As described above, when the reinforcing fiber f1 constituting the unidirectional fiber layer F1 is a conductive fiber, at least one surface thereof (the side facing the internal space of the box 2 when applied to a manhole) is electrically insulated. By arranging the reinforcing fiber f2 that is provided, there is an effect of improving the safety against an electrical leakage in the manhole 1.

  Further, the volume content of the reinforcing fibers of the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 ′ is usually 20 to 70% by volume so that a desired tensile strength can be obtained and the resin impregnation property is good. It is said.

As shown in FIG. 13, when the auxiliary layer F2 made of a glass fiber mat is provided outside the belt-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ', the fiber basis weight of the glass fiber mat is 300 to 2,000 g / m. Can be ^two . Accordingly, the thickness t of the band-shaped reinforcing material 18 and the arc-shaped reinforcing material 18 ′ (including the unidirectional fiber layer F1 and the auxiliary layer F2) after being impregnated with the matrix resin and cured is 0.5 to 20 mm. It is said.

  Next, a step of attaching the belt-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ′ to the side wall (longitudinal side wall) 2b along the longitudinal direction of the box 2 and the side of the box of the lower floor slab 2d, the hunch block 19, The installation of 20 will be further described. The step of attaching the band-shaped reinforcing member 18 and the arc-shaped reinforcing member 18 ′ according to the present invention includes all or any combination of the following steps.

(Preparation)
The area to be reinforced is cleaned, dried and inked, and the inked area is sanded with a sander.

(Upper floor slab reinforcement)
A primer is applied to the surface of the ground surface, and a portion to be reinforced by the belt-shaped reinforcing material 18 is coated with an adhesive on each of the concrete surface and the belt-shaped reinforcing material 18, and the belt-shaped reinforcing material 18 is bonded. Do the same for the points to be reinforced.
The haunch block 19 is temporarily aligned with the center of the longitudinal corner, drilled with a concrete drill, a hole-in anchor is driven, and a bolt is attached.
Apply adhesive to the reinforcement area.
Adhesive is also applied to the back of the haunch block 19, a bolt is passed through the bolt hole, and the haunch block 19 is tightened with a washer and a hexagon nut. At this time, since the end of the arc-shaped reinforcing member 18 'is also fixed, the position is sufficiently confirmed.
The above operation is repeated on the basis of the haunch block 19 bonded to the center of the longitudinal surface, and three blocks are bonded side by side. The haunch blocks 20 are bonded to the left and right in order. Also, the blocks are bonded in the same procedure for the corners on the opposite longitudinal surface.

(Side wall reinforcement)
The portion of the side wall 2b that is reinforced with the belt-shaped reinforcing material 18 is similarly performed.
The haunch block 19 is bonded to the lower surface of the corner of the side wall as described above. At this time, the height of the haunch block is adjusted by sandwiching a plate or the like between the lower floor board and the haunch block so as not to hit the lower haunch.
Based on the haunch block 19 as a reference, the blocks are sequentially bonded upward. At this time, the haunch blocks 19 are also coated with an adhesive and connected with bolts.
In the same manner, the haunch blocks are bonded in order for the remaining three corners.

(Lower floor plate reinforcement)
Apply primer to the clean surface.
The part reinforced with the belt-shaped reinforcing material 18 is performed in the same manner.
From the center of the corner of the longitudinal surface of the lower floor board 2d, the blocks are bonded side by side in the manner described above. At this time, the haunch blocks 20 are also coated with an adhesive and connected with bolts.
Glue the block in the opposite direction.
Similarly, the block is bonded to the opposite surface of the corner portion of the longitudinal surface of the lower floor slab 2d.
Finally, when the level difference of the belt-shaped reinforcing material 18 adhered to the lower floor slab 2d is significant, the level difference is eliminated with a resin-based mortar.

  As explained above, the most important point for repair and reinforcement of the existing concrete manhole is to properly repair and reinforce the bending tension that occurs on the back side of the opening of the upper floor slab and on the front side of the corner. The manhole 1 thus formed is arranged around the opening 4 by appropriately selecting the belt-like reinforcing member 18 and the arc-shaped reinforcing member 18 'and the haunch block 19 or 20 according to the degree of repair required, and attaching them to predetermined positions. Both the tensile stress acting on the lower surface of the upper floor slab 2a and the tensile stress acting on the end of the upper surface of the upper floor slab 2a, that is, the main stress generated in the manhole 1 by the wheel load acting on the box 2 via the neck 3 Therefore, it is possible to efficiently reinforce the tensile stress from the inside of the manhole 1 in a short time.

  In the above embodiment, the concrete structure is described as a manhole used as a branch space for a communication cable, but the present invention is not limited to this. The present invention works extremely effectively in the manhole, but includes a casing portion and a cylindrical neck portion having an opening connected to the upper floor slab of the casing portion and communicating with the internal space of the casing portion. It is equally applicable to any concrete structure that is embedded and used in the ground.

It is a vertical front view which shows one Embodiment of the reinforcement structure of the manhole of this invention. It is an AA arrow line view of FIG. It is a BB line arrow directional view of FIG. It is a vertical side view which shows one Embodiment of the reinforcement structure of the manhole of this invention. It is a perspective view of the important section showing one embodiment of the manhole reinforcement structure of the present invention. It is a bottom view which shows the 1st example of a haunch block. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is a bottom view which shows the 2nd example of a haunch block. FIG. 10 is a sectional view taken along line AA in FIG. 9. FIG. 10 is a sectional view taken along line B-B in FIG. 9. It is a perspective view of one Example of a strip | belt-shaped reinforcement material and an arc-shaped reinforcement material. It is sectional drawing of the other Example of a strip | belt-shaped reinforcement material and an arc-shaped reinforcement material. It is a schematic diagram of an example of a manhole. It is explanatory drawing which shows the relationship of the stress distribution (bending moment) of a manhole. It is sectional drawing of the principal part which shows a prior art example. It is explanatory drawing which shows another prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Manhole 2 ... Box 2a ... Upper floor slab 2b, 2c ... Side wall 2d ... Lower floor slab 3 ... Neck 4 ... Opening 5 ... Lid 6 ... Duct sleeve 7 ... Pipe line 8 ... Corner 8a ... Inclined surface 9 ... Anchor bolt 10 ... Atypical rebar 11 ... Resin mortar 12 ... Carbon fiber sheet 13 ... Base kerren 14 ... Primer 15 ... Non-land surface correction material 16a, 16b ... Impregnating adhesive 17 ... Carbon fiber 18 ... Strip-shaped reinforcing material 18 '... Arc shape Reinforcing material 19, 20 ... Haunch block 19a, 20a ... Top end face 19b, 19c, 20b, 20c ... Side face
22 ... Bolt through hole 23 ... Bolt 24 ... Anchor bolt through hole 25 ... Embedded nut

Claims (5)

A manhole with an opening neck connected to the upper floor of the box consisting of the lower floor, side walls, and upper floor
The corners on the inner space side formed by the longitudinal side walls and the short side walls, that is, the trapezoidal resin concrete haunch blocks are stacked side by side in the four corners, arranged in columns, fixed by bonding, The load against compression and the horizontal load around the box are received, and the upper floor slab and side walls are reinforced by stacking this haunch block,
Resin concrete haunch blocks are arranged side by side at the corner on the inner space side of the box composed of the lower surface of the upper floor slab and the longitudinal side wall, and the interior of the box composed of the upper surface of the lower floor slab and the longitudinal side wall Resin concrete haunch blocks are placed side by side in the corners on the space side,
A reinforcing structure for manholes, wherein a belt-shaped reinforcing material made of fiber reinforced plastic is appropriately bonded to the side surfaces of the lower floor slab, side walls, and upper floor slab .   2. The manhole reinforcement structure according to claim 1, wherein the haunch blocks are boxed out and connected to each other with bolts.   The reinforcing structure for a manhole according to claim 1 or 2, wherein the haunch block is of a fire type in which a corner portion is not in contact with a box corner portion.   4. The manhole reinforcement structure according to claim 1, wherein the haunch block has a band-shaped reinforcing member made of fiber reinforced plastic, with the end portions thereof stacked on top of each other and pressed down from above.   The reinforcing structure for manholes according to any one of claims 1 to 4, wherein the fiber-reinforced plastic band-shaped reinforcing material has a linear shape and is arranged perpendicular to a lattice shape.

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