JP2006045917A - Reinforcing method of concrete structure buried in ground and reinforced concrete structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing method capable of efficiently reinforcing a concrete structure buried in the ground such as a manhole in a short time; and the reinforced concrete structure. <P>SOLUTION: This reinforcing method of the concrete structure buried in the ground, comprises a skeleton part 101 and a cylindrical neck part 102 connected to a top board 111 of the skeleton part 101 and having an opening part 121 communicating with an inside space of the skeleton part 101; and is constituted for adhering a fiber reinforced plastic circular arc-shaped reinforcing material 1 ranging over a range of 30° or more on both sides to the the longitudinal directional center line A passing through the center of the opening part 121 in the longitudinal direction of the skeleton part 101 on an inside space side surface 111a of the top board 111 around the opening part 121 by using an adhesive resin 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for reinforcing a concrete structure buried in the ground such as a manhole and a reinforced concrete structure, and more particularly, a concrete buried in the ground such as a manhole in a short time by a simple method. The present invention relates to a reinforcing method for reinforcing a structure, and a reinforced concrete structure having improved resistance to a wheel load from a vehicle traveling on a road.

  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 branching direction. Usually, manholes are selected from standards, but the shape and structure are specially designed as necessary. Manhole standards include straight, branched L, branched T, and branched cross. Further, for each shape, a plurality of types having different capacities are standardized according to the number of applied pipelines. Each manhole has the following basic configuration.

  As shown in FIG. 14, the manhole 100 includes a rectangular casing portion (concrete box) 101, a cylindrical neck portion 102 having an opening 121 communicating with the casing portion 101, and a lid 103. In addition, a duct 104 is formed on the side portion of the housing portion 101, and a pipe line 200 is connected thereto. A communication cable or the like is laid through the pipeline 200. The manhole 100 is made of reinforced concrete (cement concrete, resin concrete, etc.), and initially has a strength design that can withstand lateral earth pressure, road load, and the like. Further, the manhole 100 is disposed in the ground by a spot casting method in which reinforced concrete is cast on site or a block method in which a precast product is transported and installed on the spot.

  The conventional manhole 100 as described above has the following problems. That is, since the manhole 100 is normally buried under the road 300 at a position where the soil cover h is about 50 cm to 1 m, the manhole 100 is deteriorated due to the wheel load caused by the passage of the vehicle 400 on the road 300. In addition, deterioration due to aging is observed in many manholes 100. When actually observing from the inside of the manhole 100, cracks (cracks) of the concrete and exposure (explosion) of the reinforcing bars are observed. For this reason, repair and reinforcement of the manhole 100 are necessary.

  Conventionally, the repair of the manhole 100 has only been carried out by repairing the cross section after rust-proofing by removing a deteriorated part such as a part where the reinforcing bar corrodes and expands and the cover concrete part is peeled off. However, such a repair method takes time for construction, and the reinforcing effect is limited.

  On the other hand, in recent years, there has been proposed a method for reinforcing a concrete structure by impregnating a reinforcing fiber sheet made of carbon fiber, aramid fiber or the like with a resin material and bonding the resin material (for example, Patent Document 1). However, in such a reinforcing method, it takes time to perform the construction because it requires several steps such as a background cleansing process, a primer process, a non-land surface correction process, and a fiber sheet adhesion process (resin impregnation and curing). In the reinforcing fiber sheet, the reinforcing fibers are straight and it is difficult to efficiently reinforce the periphery of the neck portion 102 of the manhole 100. Further, as will be described in detail later, such a construction method cannot reinforce the tensile force generated at the upper surface end portion of the top plate 111 of the casing portion 101.

  And if construction takes time as mentioned above, since the manhole 100 is embed | buried under the road, there exists a problem that a traffic regulation is long and repair and reinforcement construction are difficult.

  As described above, there is a need for a method for reinforcing a concrete structure embedded in the ground such as a manhole efficiently in a short time. To the best knowledge of the inventor, no method has yet been proposed for such purposes.

There is also a need for a reinforced concrete structure with improved proof strength against wheel loads from vehicles traveling on the road.
JP-A-7-97460

  An object of the present invention is to provide a reinforcing method and a reinforced concrete structure capable of reinforcing a concrete structure embedded in the ground such as a manhole efficiently in a short time.

  Another object of the present invention is to provide a reinforcing method that can be easily applied to a concrete structure embedded in the ground such as a manhole.

  Still another object of the present invention is to provide a reinforced concrete structure with improved resistance to wheel loads from vehicles traveling on the road.

  The above object can be achieved by a method for reinforcing a manhole embedded in the ground and a reinforced manhole according to the present invention. In summary, the present invention relates to a concrete embedded in the ground having a housing portion and a cylindrical neck portion having an opening connected to a top plate of the housing portion and communicating with an internal space of the housing portion. A method of reinforcing a structure, on both sides of a longitudinal center line passing through the center of the opening along the longitudinal direction of the housing portion on the inner space side surface of the top plate around the opening An arc-shaped reinforcing material made of fiber reinforced plastic over a range of 30 ° or more is bonded using an adhesive resin, which is a method for reinforcing a manhole embedded in the ground.

  According to one embodiment of the present invention, the method of reinforcing a manhole embedded in the ground further includes the case portion of the corner portion on the inner space side formed by the longitudinal side plate of the case portion and the top plate. 30 ° or more and 60 ° or less from the top plate in a range of 1.5 times the diameter of the opening centering on the center line in the short direction passing through the center of the opening along the short direction perpendicular to the longitudinal direction The diagonal member is fixed with an anchor bolt between the top plate and the longitudinal direction side plate at an angle of. According to a preferred embodiment, the arc-shaped reinforcing material has reinforcing fibers arranged in at least one direction along the arc shape. The diagonal member can be fixed using a putty-like adhesive in addition to or instead of the anchor bolt. According to one embodiment of the present invention, as the arc-shaped reinforcing material, a fiber reinforced plastic layer including a fiber reinforced plastic layer containing carbon fiber as a reinforcing fiber at the center and a reinforcing fiber having electrical insulation on the outside thereof. Those having a cross-sectional structure in which a plastic layer or an electrically insulating resin layer is disposed can be used. Glass fiber can be used as the reinforcing fiber having insulating properties. According to a preferred embodiment of the present invention, the adhesive resin is a fast-curing radical polymerization resin.

  According to another aspect of the present invention, there is provided a housing portion, and a cylindrical neck portion having an opening portion connected to a top plate of the housing portion and communicating with an internal space of the housing portion. An arc made of fiber reinforced plastic covering a range of 30 ° or more on both sides with respect to a longitudinal center line passing through the center of the opening along the longitudinal direction of the casing portion on the surface on the inner space side of the surrounding top plate A reinforced concrete structure is provided in which the shape reinforcement is bonded using an adhesive resin. According to an embodiment of the present invention, the reinforced concrete structure further includes a longitudinal portion of the corner portion on the inner space side formed by the longitudinal side plate of the housing portion and the top plate, and the longitudinal direction of the housing portion. In the range of 1.5 times the diameter of the opening centering on the short direction center line passing through the center of the opening along the perpendicular direction, the angle from the top plate is 30 ° or more and 60 ° or less. A diagonal member is fixed between the top plate and the longitudinal side plate using anchor bolts. According to a preferred embodiment, the arc-shaped reinforcing material has reinforcing fibers arranged in at least one direction along the arc shape. According to an embodiment of the present invention, the diagonal member is fixed using a putty-like adhesive in addition to or instead of the anchor bolt.

  According to the present invention, a concrete structure embedded in the ground such as a manhole can be reinforced efficiently in a short time. The method for reinforcing a concrete structure embedded in the ground of the present invention can be easily applied to a concrete structure embedded in the ground such as a manhole. Furthermore, according to the present invention, it is possible to provide a reinforced concrete structure with improved resistance to wheel loads from vehicles traveling on the road.

  Hereinafter, the reinforcing method of a concrete structure embedded in the ground according to the present invention and the reinforced concrete structure will be described in more detail with reference to the drawings.

Example 1
In view of the above-described conventional problems, the present inventor is in a state of damage (concrete cracks, exposed reinforcing bars) seen in a manhole which is a concrete structure embedded in the ground, and the manhole. We studied diligently about power.

  First, a manhole 100 as a concrete structure to which the present invention is applied in the present embodiment will be described with reference to FIG. The manhole 100 includes a rectangular casing portion (concrete box) 101, a cylindrical neck portion 102, and a lid 103. The casing portion 101 is along the top plate 111, the side plate (longitudinal side plate) 112 along the longitudinal direction of the casing portion 101, the bottom plate 113, and the short direction (direction orthogonal to the longitudinal direction) of the casing portion 101. A rectangular internal space is formed by the side plate (short side plate) 114. The neck portion 102 is connected to the top plate 111 and has an opening 121 that communicates with the internal space of the housing portion 101. In addition, a duct 104 is formed in the short side plate 114 of the casing portion 101, and the pipe line 200 is connected thereto.

  As a main thing of the wheel load to the manhole 100 embed | buried under the ground from the vehicle etc. which pass along a road, what is transmitted to the top plate 101 through the lid | cover 103 and the neck part 102 is mentioned. Therefore, the present inventor uses the FEM (finite element method) as the lower surface of the top plate 111 when the wheel load of the vehicle is applied to the manhole 100 buried in the ground. (Inside space side) 111a and upper surface (road side) 111b were analyzed.

Here, as an example, the analysis was performed by modeling the top plate 111 of a linear No. 3 manhole (standard). The size of No. 3 manhole is as follows.
Longitudinal length (length) L (internal dimensions): 2.3 m
Length in the short direction (width) W (internal dimensions): 1.3 m
Height H (internal dimensions): 1.5m
Plate thickness: 150mm
Opening diameter d: 900 mm

  Then, as shown in FIG. 2, FEM analysis was performed on the assumption that the wheel load acts directly on the top plate 111 of the manhole 100. 2 shows an axis line (hereinafter referred to as “longitudinal center line”) A along the longitudinal direction of the casing portion 101 and the center of the opening portion 121 along the short direction of the casing portion 101. A top plate 111 of a quarter size cut by an axis B passing through (hereinafter referred to as a “center line in the short direction”) B is shown.

  In the drawing, an arc-shaped portion with an arrow is a connecting portion of the neck 102, and a wheel load in the direction of the arrow is applied to this portion. The FEM analysis was performed under the following conditions. In other words, concrete was modeled as a three-dimensional solid element as an isotropic material. Two peripheral sides (sides opposite to the center lines in the longitudinal direction and the short direction in FIGS. 2 and 3) were completely constrained, and the center lines in the longitudinal direction and the short direction were set as symmetrical boundary conditions. The analysis was elastic analysis.

  The results are shown in FIGS. FIG. 3 shows a distribution of stress acting on the surface of the top plate 111 (hereinafter referred to as “top plate bottom surface”) 111a on the inner space side of the housing portion 101. 4 shows the distribution of stress acting on the surface of the top plate 111 (hereinafter referred to as “top plate top surface”) 111b outside the casing portion 101. FIG. FIGS. 3 and 4 show the results of the quarter size top plate 111 cut along the center line A in the longitudinal direction and the center line B in the short direction. However, the analysis results are the same for the other quarter size parts. That is, the stress of the top plate 111 appeared substantially symmetrically with respect to the longitudinal centerline A and the transverse centerline B.

If the stress value (unit: N / mm ² ) written in the pattern legend shown in FIGS. 3 and 4 is negative, it indicates that compressive stress is applied, and if it is positive, tensile stress is applied. Moreover, the arrow shown in FIG.3 and FIG.4 has shown the action direction of stress.

[Attaching fiber-reinforced plastic arc-shaped reinforcements]
From the results shown in FIG. 3, it can be seen that when a ring load from the neck 102 is applied to the top plate 111, a tensile stress acts around the opening 121 of the top plate lower surface 111a. Concrete is strong in compressive force and weak in tensile force.

  This will be further described with reference to FIG. According to the study of the present inventor, the top plate lower surface 111a has a range of ± 60 ° around the opening 121 and a longitudinal centerline A as a reference (0 °), more specifically a range of ± 45 °. In particular, a strong tensile stress is generated in the range of ± 30 °.

  Therefore, according to one embodiment of the present invention, as shown in FIG. 5, the reinforcing method of the manhole 100 embedded in the ground is formed in an arc-shaped fiber reinforced plastic on the top plate lower surface 111a around the opening 121. It includes bonding a reinforcing material (hereinafter referred to as “arc-shaped reinforcing material”) 1 made of (FRP) using an adhesive resin.

  The arc-shaped reinforcing material 1 has a range of ± 30 ° or more (that is, 30 ° or more on both sides with respect to the longitudinal centerline A) with respect to the longitudinal centerline A of the manhole 100 passing through the opening 121 as a reference (0 °). More preferably, it is a continuous arc shape over a range of ± 45 ° or more (that is, 45 ° or more on both sides with respect to the longitudinal center line A).

  Since the arc-shaped reinforcing member 1 is formed so as to have a predetermined width and is arranged around the opening 121 as described above, the curvature radius of the innermost circumference in the width direction is naturally the radius of the opening 121. More than the radius of curvature. The arc-shaped reinforcing member 1 is preferably attached closer to the circumference of the opening 121. However, the arc-shaped reinforcing material 1 can be attached at a predetermined distance g from the circumference of the opening 121 according to the condition of the concrete surface of the top plate lower surface 111a. The distance g is preferably 100 mm or less from the viewpoint of the reinforcing effect against the tensile stress acting around the opening 121. More preferably, it is 50 mm or less. On the other hand, the distance g is normally 5 mm or more.

  In addition, when the manhole 100 is not a straight shape, for example, when the manhole 100 is a branched L shape, a branched T shape, or a branched cross shape, the basic casing provided with the neck portion 102 excluding the branched portion is assumed to be rectangular and imitated. Then, it is sufficient to think in the same way as above.

  From the viewpoint of reinforcing against the tensile stress acting on the top plate lower surface 111a, the arc-shaped reinforcing material 1 is not limited to what angle it is continuous in the range of 30 ° or more on both sides with respect to the longitudinal center line A. It is not limited. However, the height h of the neck 102 of the manhole 100 is usually 50 cm to 1 m, and the inner diameter of the opening 121 is 60 to 90 cm. Then, the already-cured arc-shaped reinforcing member 1 having a predetermined width is carried into the casing portion 101 through the opening 121 of the neck portion 102. In consideration of these matters, the arc-shaped reinforcing member 1 usually has a range of ± 90 ° (that is, within 90 ° on both sides with respect to the longitudinal center line A) with respect to the longitudinal center line A as a reference (0 °). It shall be continuous. Further, as can be seen from the results shown in FIG. 3, the arc shape is continuous over a range of ± 60 ° (that is, within 60 ° on both sides with respect to the longitudinal center line A) with the longitudinal center line A as a reference (0 °). If the reinforcing material 1 is used, a practically sufficient reinforcing effect can be obtained, and in this case, workability is also good. Therefore, preferably, two arc-shaped reinforcing members 1 ranging from ± 30 ° to ± 60 °, more preferably ± 45 ° to ± 60 ° with respect to the longitudinal center line A as a reference (0 °) are shown in FIG. Thus, it provides symmetrically around the opening 121.

  FIG. 6 shows an embodiment of an arc-shaped reinforcement 1 that can be used in the present invention. The arc-shaped reinforcing material 1 is a continuous fiber that is at least aligned in one direction along the arc shape of the arc-shaped reinforcing material 1 (that is, arranged in the circumferential direction of the arc-shaped reinforcing material 1). It is preferable to have a layer (hereinafter referred to as “arc-shaped unidirectional fiber layer”) F1 of reinforcing fibers f1. The reinforcing fiber f1 is impregnated with a matrix resin and cured to form the arc-shaped reinforcing material 1.

  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). Thus, the arc-shaped unidirectional fiber layer F1 of the arc-shaped reinforcing member 1 has a unidirectionally arranged fiber structure in which filaments are laminated in a plurality of layers and bonded in one direction with a matrix resin. .

  As the reinforcing fiber f1, inorganic fibers including carbon fiber, glass fiber, ceramic fiber and boron fiber; metal fiber including titanium and steel; aramid, polyester, polyethylene, nylon, vinylon, polyacetal, PBO (polyparaphenylene benzbisoxazole) ), An organic fiber containing high-strength polypropylene, or a hybrid type fiber in which a plurality of these fibers are mixed.

The reinforcing fiber f1 can be selected from the above fibers depending on the desired reinforcing strength and the like, but typically, carbon fibers can be preferably used. The carbon fiber may be PAN-based, pitch-based, or any other type of carbon fiber. Preferably, a material having a high strength and a high elastic modulus with a tensile strength of 100 kgf / mm ² (980 N / mm ² ) or more and a tensile elastic modulus of 10 Tof / mm ² (98,000 N / mm ² ) or more is used.

  As the arc-shaped unidirectional fiber layer F1 constituting the arc-shaped reinforcing material 1, a unidirectionally arranged reinforcing fiber sheet in which the reinforcing fibers f1 are arranged substantially uniformly in one direction may be used. The arc-shaped reinforcing material 1 may have a plurality of substantially arc-shaped unidirectional fiber layers F1 made of the same or different types of reinforcing fibers f1.

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

  For example, as an auxiliary layer, a mat, cloth or knit layer (hereinafter referred to as “auxiliary layer”) made of reinforcing fibers of the same or different type as the reinforcing fibers f1 constituting the arc-shaped unidirectional fiber layer F1 is referred to as an arc-shaped unidirectional. A single layer or a plurality of layers can be stacked on the first surface (front surface) and / or the second surface (back surface) of the fiber layer F1. Thereby, the cross-sectional rigidity of the arc-shaped reinforcing material 1 can be improved or a desired surface property can be given as desired.

  Alternatively, as the auxiliary layer, the reinforcing fibers arranged in the direction intersecting with the reinforcing fibers f1 of the arc-shaped unidirectional fiber layer F1 made of the same or different types of reinforcing fibers f1 constituting the arc-shaped unidirectional fiber layer F1. A layer of fibers (typically, a layer of reinforcing fibers arranged in an arc-shaped radial direction) is arranged on the first surface (front surface) and / or the second surface (back surface) of the arc-shaped unidirectional fiber layer F1. In addition, a single layer or a plurality of layers can be stacked. Thereby, in addition to the circular tensile strength in the circumferential direction, the arc-shaped reinforcing member 1 can be given strength in a direction intersecting the arc-shaped reinforcing material (for example, the orthogonal direction).

  As the reinforcing fibers constituting the auxiliary layer, those selected from the above group can be used in the same manner as the reinforcing fibers f1 constituting the arc-shaped unidirectional fiber layer F1. The arc-shaped reinforcing material 1 may have a configuration in which arc-shaped unidirectional fiber layers F1 and auxiliary layers are alternately stacked. Further, the arc-shaped reinforcing material 1 may be provided by combining a plurality of the same or different auxiliary layers with respect to the arc-shaped unidirectional fiber layer F1.

  Here, the mat may be an arbitrary non-woven fabric produced without weaving, for example, a chopped strand obtained by cutting the cut strands in a non-direction to a substantially uniform thickness and solidifying with a binder. Examples thereof include a mat and a continuous strand mat in which continuous strands are stacked in a non-directional and substantially uniform thickness and hardened with a binder. The cloth is a woven fabric produced by weaving having an arbitrary woven structure such as plain weaving or satin weaving, and may be a roving cloth. The knit may have a knitted structure of either warp knitting or weft knitting.

  Further, when a reinforcing fiber layer (cross fiber layer) aligned in a direction intersecting with the reinforcing fiber f1 of the arc-shaped unidirectional fiber layer F1 is provided as the auxiliary layer, the reinforcing fiber f1 of the arc-shaped unidirectional fiber layer F1. The reinforcing fibers can be arranged in more directions by providing two or more cross fiber layers in combination.

  FIG. 7 shows a cross-sectional configuration of an embodiment of the arc-shaped reinforcing member 1 in which an auxiliary layer is provided in addition to the arc-shaped unidirectional fiber layer F1. The arc-shaped reinforcing material 1 shown in FIG. 7 has a layer of reinforcing fibers f1 having conductivity as an arc-shaped unidirectional fiber layer F1 at the center of the cross section. Further, the arc-shaped reinforcing member 1 is electrically insulated on the outer side of the arc-shaped unidirectional fiber layer F1, here, the first surface (front surface) and the second surface (back surface) of the arc-shaped unidirectional fiber layer F1. It has a cross-sectional structure (sandwich structure) in which layers (auxiliary layers) F2 of reinforcing fibers f2 having properties are laminated.

  Preferably, when a carbon fiber that is a conductive fiber is used as the reinforcing fiber f1 of the arc-shaped unidirectional fiber layer F1, a glass fiber is preferably used as the reinforcing fiber f2 having electrical insulation of the auxiliary layer F2. it can. 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 arc-shaped unidirectional fiber layer F1 is a conductive fiber, it is electrically insulated on at least one surface thereof (the side facing the internal space of the casing portion 101 when applied to a manhole). By arranging the reinforcing fiber f2 having the property, there is an effect of improving safety against an emergency electric leakage in the manhole 100.

  For the purpose of providing an insulating layer on the surface of the arc-shaped reinforcing material 1 when using conductive fibers such as carbon fibers as the arc-shaped unidirectional fiber layer F1, reinforcing fibers are used as auxiliary layers. The arc-shaped reinforcing material 1 may be provided with an electrically insulating resin layer that does not contain.

  As matrix resin, polyamide resin, room temperature curable epoxy resin, thermosetting epoxy resin, polycarbonate resin, urethane resin, acrylic resin (MMA (methyl methacrylate) resin, etc.), vinyl ester resin, unsaturated polyester resin, etc. What contains at least 1 or more types of radical reaction system resin (radical polymerization resin) can be used.

  Further, the volume content of the reinforcing fiber of the arc-shaped reinforcing material 1 is usually 20 to 70% by volume so that a desired tensile strength can be obtained and the resin impregnation property is good.

  The production method of the arc-shaped reinforcing material 1 is not particularly limited, and any available molding method can be adopted. From the viewpoint of productivity and stability of dimensional accuracy of the product, the pultrusion method is preferable. The pultrusion method is well known to those skilled in the art, and the reinforcing fiber f1 constituting the arc-shaped unidirectional fiber layer F1 (in some cases, the reinforcing fiber f2 constituting the auxiliary layer F2 such as mat, cloth, knit). ), Impregnation with a matrix resin, shaping / curing with a mold, pulling, cutting, and the like can be performed continuously.

The cross-sectional configuration of the arc-shaped reinforcing member 1 can be appropriately changed according to the required performance. Usually, those having a tensile strength of 1,900 to 5,000 N / mm ² and a tensile modulus of 0.6 × 10 ^{5 to} 6.5 × 10 ⁵ N / mm ² are preferably used.

  The design thickness t of the arc-shaped reinforcing material 1 and the width of the arc-shaped reinforcing material 1 (the length in the direction substantially perpendicular to the orientation direction of the reinforcing fibers f1) w are the dimensions of the manhole 100 to be reinforced and the reinforcing fibers f1. It is determined appropriately according to the type of the item. Usually, the arc-shaped reinforcing member 1 has a thickness t of 2 to 5 mm and a width w of 20 to 100 mm.

For example, when carbon fiber is used as the reinforcing fiber f constituting the arc-shaped unidirectional fiber layer F1 of the arc-shaped reinforcing material 1, for example, roving obtained by bundling 50 pieces of 7 μmφ monofilaments, for example, about 24,000 bundling strands That is, the reinforcing fiber f1 can be used. The reinforcing fibers f1 can be evenly aligned at a fiber basis weight of 300 to 5,000 g / m ² and densely arranged in one direction. Thereby, for example, as shown in FIG. 6, when the arc-shaped reinforcing material 1 is composed only of the arc-shaped unidirectional fiber layer F1, the thickness t after impregnating and curing the matrix resin is 0.5 to 15 mm.

For example, as shown in FIG. 7, when the auxiliary layer F2 made of a glass fiber mat is provided outside the arc-shaped reinforcing material 1, the fiber basis weight of the glass fiber mat is set to 300 to 2,000 g / m ^2. Can do. Accordingly, the thickness t of the arc-shaped reinforcing material 1 (including the arc-shaped unidirectional fiber layer F1 and the auxiliary layer F2) after being impregnated and cured with the matrix resin is set to 1 to 20 mm.

  Next, the process of sticking the arc-shaped reinforcing material 1 to the top plate lower surface 111a will be further described. The attaching process of the arc-shaped reinforcing material 1 according to the present invention includes all or any combination of the following processes. 8A to 8D show schematic cross sections of the top plate lower surface 111a at the portion where the arc-shaped reinforcing material 1 is attached.

(1) Keren processing step As shown in FIG. 8A, the base concrete of the portion where the arc-shaped reinforcing material 1 is pasted on the bottom surface 111a of the top plate is kelen-treated. Keren treatment can be performed by any means such as a disk sander or sandblast.

(2) Primer Application Step Next, as shown in FIG. 8B, the primer 3 is applied to the top plate lower surface 111a subjected to the keren treatment, and the base treatment is performed. The primer 3 improves the familiarity between the arc-shaped reinforcing material 1 and the concrete surface which are then bonded with an adhesive resin. As the primer 3, any primer that has good affinity with the adhesive resin 2 to be applied next and is allowed to be used together with the arc-shaped reinforcing material 1 can be used. As the primer 3, a room temperature curable resin such as an epoxy resin or a urethane resin, or a radical reaction resin (radical polymerization resin) such as an acrylic resin, an unsaturated polyester resin, or a vinyl ester resin can be used. The primer 3 is particularly preferably a fast-curing radical reaction resin, such as an acrylic resin, which is quickly cured. More specifically, as a fast-curing acrylic resin, FP-M manufactured by Nippon Steel Composite Co., Ltd. can be suitably used. The application amount of the primer 3 is preferably 0.1 to 0.4 kg / m ² per surface area of the arc-shaped reinforcing material 1.

(3) Adhesive resin application process Next, as shown in FIG.8 (c), the adhesive resin 2 is apply | coated to the concrete surface (when primer 3 is applied, primer application surface) of the top-plate lower surface 111a. As the adhesive resin 2, any resin that can be used together with the arc-shaped reinforcing material 1 can be used. As the adhesive resin 2, a room temperature curable resin such as an epoxy resin or a urethane resin, or a radical reaction resin (radical polymerization resin) such as an acrylic resin, a vinyl ester resin, or an unsaturated polyester resin can be used. In particular, a fast-curing radical reaction system resin, such as an acrylic resin, is preferred. More specifically, as the fast-curing acrylic resin, FR-MIP manufactured by Nippon Steel Composite Co., Ltd. can be suitably used. The application amount of the adhesive resin 2 is preferably 0.5 to 5.0 kg / m ² per surface area of the arc-shaped reinforcing material 1.

(4) Arc-shaped reinforcing material adhering step Next, as shown in FIG. 8 (d), the arc-shaped reinforcing material 1 is passed through an adhesive resin 2 (or primer 3 if primer 3 is applied). It adheres to the top plate lower surface 111a. Thereafter, the application of the arc-shaped reinforcing material 1 to the manhole 100 is completed when the adhesive resin 2 is cured.

  In addition, when using the arc-shaped reinforcing material 1 using an epoxy resin as a matrix resin, it is preferable to adhere with an epoxy resin adhesive. Further, when the arc-shaped reinforcing material 1 using an acrylic resin as the matrix resin is used, it is preferable to bond with an acrylic resin adhesive.

  According to a preferred embodiment of the present invention, the step of attaching the arc-shaped reinforcing material 1 to the top plate lower surface 111a includes all of the above steps (1) to (4). However, the primer application step in the step (2) and the kelen treatment step in the step (1) can be omitted depending on circumstances. Further, in the adhesive resin application step (3), the adhesive resin 2 may be applied to the surface of the arc-shaped reinforcing material 1. Moreover, those skilled in the art will easily understand that, in addition to the above steps (1) to (4), arbitrary steps such as a known concrete crack repairing step may be added as appropriate.

  As shown in FIG. 9, for example, a linear reinforcing material 4 made of unidirectional fiber reinforced plastic can be attached to an arbitrary position of the top plate lower surface 111a in an arbitrary orientation as necessary. The additional reinforcing material 4 can be configured in the same manner as the above-mentioned arc-shaped reinforcing material 1 except that the unidirectional reinforcing fibers are not arranged in an arc shape. Further, the step of attaching the top plate lower surface 111 a to the top plate lower surface 111 a can be the same as that of the arc-shaped reinforcing material 1. Preferably, the additional reinforcing member 4 is attached to the portion where the tensile stress is applied on the top plate lower surface 111a so that the unidirectional continuous reinforcing fibers are oriented along the direction in which the tensile stress is applied.

  As described above, by attaching the arc-shaped reinforcing material 1 to the top plate lower surface 111 a, the arc-shaped reinforcing material 1 against the tensile stress (FIG. 3) acting on the top plate lower surface 111 a around the opening 121. Can share stress, and the structure of the manhole 100 can be reinforced. Further, the manhole 100 can be reinforced with good workability by carrying the already hardened arc-shaped reinforcing material 1 into the manhole 100 and affixing it to a predetermined location. Therefore, the reinforcement work of the manhole 100 can be performed with high efficiency in a short time. In particular, by using a fast-curing adhesive resin as the primer 3 and the adhesive resin 2, the reinforcement work can be completed in a very short time. Thereby, the traffic regulation time for the reinforcement work of the manhole 100 buried in the ground can be shortened.

[Installation of diagonal materials]
As described above, the tensile stress acting around the opening 121 of the top plate lower surface 111 a can be reinforced by attaching the arc-shaped reinforcing material 1 from the internal space of the housing portion 101.

  Further, as can be seen from the results shown in FIGS. 3 and 4, in the manhole 100, when a ring load is applied to the top plate 111 from the neck portion 102, a joint portion between the longitudinal side plate 112 near the neck portion 102 and the top plate 111. In FIG. 2, a tensile stress acts on the top plate upper surface 111b. Concrete is strong in compressive force and weak in tensile force. Further, in order to perform the reinforcement work for the manhole 100 in a short time with high efficiency, it is required to reinforce the top plate upper surface 111b from the internal space of the casing portion 101.

  Further description will be made with reference to FIG. 10 as well, in the range of about 1.5 times the diameter of the opening 121 centering on the short direction center line B, the joint of the longitudinal side plate 112 and the top plate 111. A strong tensile stress is generated on the top plate upper surface 111b.

  Therefore, according to another embodiment of the present invention, the reinforcing method of the manhole 10 embedded in the ground is further provided as shown in FIG. 11 with the housing portion 101 formed by the top plate lower surface 111a and the longitudinal side plate 112. The internal space of the top plate lower surface 111a and the longitudinal side plate body portion 101 is within a range R of the corner portion on the internal space side, which is 1.5 times the diameter d of the opening 121 centered on the short direction center line B. Including a diagonal member (strut, support member) 5 fixed to a side surface (hereinafter referred to as “longitudinal side plate inner surface”) 112a. In other words, the reinforcing method of the manhole 10 buried in the ground extends symmetrically to both end sides of the projected portion of the opening 121 on the axis of the corner formed by the longitudinal side plate 112 and the top plate 111. Including a diagonal member (strut, support member) 5 fixed to the top plate lower surface 111a and the longitudinal side plate inner surface 112a within a range of 1.5 times the length of the projection portion.

  The diagonal member 5 is provided at an angle θ from 30 ° to 60 ° from the top plate 111 (top plate lower surface 111a). If the angle θ formed by the axis of the diagonal member 5 with the top plate lower surface 111a is less than 30 ° or exceeds 60 °, the transmission of force when a bending stress is generated becomes inefficient. Most preferably, the angle θ formed between the axis of the diagonal member 5 and the top plate lower surface 111a is 45 °. Although FIG. 11 shows only one corner formed by the top plate lower surface 111a and the longitudinal side plate 112, the diagonal member 5 is usually provided in the same manner on the opposite corner.

  As the diagonal member 5, as shown in FIGS. 12 (a) and 12 (b), a bar member and a plate member can be preferably used. The material of the diagonal member 5 is preferably a metal such as stainless steel or steel from the viewpoint of compressive strength or compressive rigidity.

  More specifically, the diagonal member 5 is provided at an oblique member portion 53 disposed obliquely between the top plate lower surface 111a and the longitudinal side plate inner surface 112a, and at both ends of the diagonal member portion 53 in the axial (length) direction. A fixing portion 51 for fixing the diagonal member 5 to the top plate lower surface 111a and the longitudinal side plate inner surface 112a. The fixing portion 51 is provided with a bolt hole (anchor hole) 52. Thus, the diagonal member 5 can be fixed to the top plate lower surface 111a and the longitudinal side plate inner surface 112a by the anchor bolt 6 using the bolt holes 52.

  When a bar as shown in FIG. 12A is used as the diagonal member 5, typically, at a predetermined interval (usually at regular intervals) within the predetermined range R according to the required reinforcement strength. Install several. The configuration of the diagonal member 5 can be appropriately set according to the reinforcement strength required as a whole, the number of bars to be attached (that is, the reinforcement strength required for one diagonal member 5), and the like. Further, when a plate material as shown in FIG. 12 (b) is used as the diagonal member 5, typically, one plate material continuous within the predetermined range R is used. You may attach the several board | plate material divided | segmented into the said range by the predetermined space | interval (usually equal space | interval).

  The cross-sectional configuration of the diagonal member 5 can be appropriately changed according to the required performance. In the case of a bar, for example, the following can be suitably used. 4.5 mm (thickness) x 120 mm (width: cross section length) x 740 mm (length) steel material (SS400) in the axial direction (length direction) center 500 mm portion (cross section perpendicular to the axial direction) ) Processed into a U-shape to form the diagonal member 53. Then, 120 mm portions at both ends in the axial direction of the diagonal member 53 are bent at an angle of 45 ° with respect to the diagonal member 53 to form the fixing portion 51. In this case, the corrosion resistance is preferably improved by hot dip galvanizing.

  Moreover, in the case of a board | plate material, the following can be used suitably, for example. A diagonal portion 53 is a 500 mm portion at the center in the length direction of a stainless steel material (SUS304) of 4.5 mm (thickness) × 500 mm (width) × 740 mm (length). The fixing portion 51 is formed by bending 120 mm portions at both ends in the length direction of the diagonal member 53 at an angle of 45 ° with respect to the diagonal member 53.

  As described above, the diagonal member 5 can be fixed to the top plate lower surface 111 a and the longitudinal side plate inner surface 112 a by the anchor bolt 6 in the fixing portion 51. In addition to this, as shown in FIG. 13 (a), by using a putty-like adhesive 7 between the fixing portion 51 and the concrete surface of the top plate lower surface 111a and the longitudinal side plate inner surface 112a, the diagonal material 5 Can be fixed to the top plate lower surface 111a and the longitudinal side plate inner surface 112a. In this case, the bolt hole 52 (FIG. 11) is not necessary. As the putty-like adhesive 7, an epoxy resin putty material can be used. More specifically, as the putty-like adhesive material 7, FE-Z manufactured by Nippon Steel Composite Co., Ltd. can be suitably used. Further, as shown in FIG. 13B, putty-like adhesive 7 and anchor bolt 6 may be used in combination.

  In other words, the step of attaching the diagonal member 5 is a step of adapting the diagonal member 5 to a predetermined position in the internal space of the housing portion 100, and the diagonal member 5 using the anchor bolt 6 and / or the putty-like adhesive. A fixing step.

  It should be readily understood by those skilled in the art that known arbitrary processes such as the pretreatment of the concrete surface where the fixing portion 51 of the diagonal member 5 is fixed and the anchor fixing hole processing may be appropriately added. Like.

  As described above, against the tensile stress (FIG. 4) acting on the end of the top plate upper surface 111b, the diagonal member 5 fixed to the top plate lower surface 111a and the longitudinal side plate inner surface 112a in the predetermined range R is applied. By providing, stress can be relieved. Further, the manhole 100 is reinforced with good workability by carrying out the diagonal member 5 made of, for example, a metal rod into the manhole 100 and fixing it to a predetermined position with an anchor bolt or the like. Can do. Therefore, the reinforcement work can be performed with high efficiency in a short time. Thereby, the traffic regulation time for the reinforcement work of the manhole 100 buried in the ground can be shortened.

  As described above, the manhole 100 buried in the ground most preferably attaches both the arc-shaped reinforcing member 1 and the diagonal member 5 to predetermined positions. As a result, both the tensile stress acting on the top plate lower surface 111a around the opening 121 (FIG. 3) and the tensile stress acting on the end of the top plate upper surface 111b (FIG. 4), that is, the casing portion via the neck 102. The main tensile stress generated in the manhole 100 due to the wheel load acting on 101 can be efficiently reinforced in a short time from the inside of the manhole 100.

  In addition, according to the present invention, a manhole 100 reinforced by the above-described reinforcing method is provided. In other words, according to one embodiment, the reinforced manhole 100 according to the present invention has the arc-shaped reinforcing material 1 attached to a predetermined portion around the opening 121. According to another embodiment, the reinforced manhole 100 is further fixed to the top plate lower surface 111a and the longitudinal side plate 112 at a predetermined portion of the corner formed by the top plate lower surface 111a and the longitudinal side plate 112. An oblique member 5 is provided. Most preferably, the reinforced manhole 100 according to the present invention has both arcuate reinforcement 1 and diagonal 5. Thereby, both the tensile stress acting on the top plate lower surface 111a around the opening 121 (FIG. 3) and the tensile stress acting on the end of the top plate upper surface 111b (FIG. 4), that is, the casing portion via the neck portion 102. It is possible to provide the manhole 100 with improved proof strength against the main tensile stress generated in the manhole 100 due to the wheel load acting on 101.

  Next, a specific example according to the present invention will be described. In this example, the arc-shaped reinforcing material 1 and the diagonal material 5 are applied to the linear No. 3 manhole (standard).

-Arc-shaped reinforcing material Reinforcing fiber: High-strength carbon fiber Matrix resin: Acrylic resin [FR-MIP manufactured by Nippon Steel Composite Co., Ltd.]
shape:
Width w 50mm
Thickness t 5mm
Inner circumference radius of curvature 460mm
Arc shape over ± 60 ° with respect to the longitudinal center line Mechanical properties of the reinforcing fibers used:
Tensile strength: 4900 N / mm ² (carbon fiber cross-sectional area base)
Tensile modulus: 2.39 × 10 ⁵ N / mm ² (based on carbon fiber cross-sectional area)
The arc-shaped reinforcing material 1 was adhered to the position where the distance g from the circumference of the opening 121 was 10 mm using the following primer 3 and adhesive resin 2 after the top plate lower surface 111a was subjected to the cleansing treatment.
Primer: Fast-curing acrylic resin [FR-M manufactured by Nippon Steel Composite Co., Ltd.]
Adhesive resin: Fast-curing acrylic resin [FR-MIP manufactured by Nippon Steel Composite Co., Ltd.]

-Diagonal material: Steel (SS400 galvanized)
Shape: Bar (diagonal part is U-shaped in cross section)
Dimensions: diagonal part length 50 cm / diagonal part section length 12 cm / fixed part length 12 cm /
Anchor hole 8.2 mmφ x 2 Number (interval): 7 (22.5 cm interval)
Anchor bolt: M8 expanded anchor Adhesive: Epoxy resin putty material
[FE-Z (4 kg / m ² ) manufactured by Nippon Steel Composite Co., Ltd.]
The diagonal member 5 was fixed to the top plate lower surface 111a and the longitudinal side plate inner surface 112a with anchor bolts. The diameter of the opening 121 was 900 mm, and the diagonal member 5 attachment range R was a range of 1.35 m centering on the short direction center line B.

  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. Although the present invention works extremely effectively in the manhole, a cylindrical neck portion comprising a housing portion and an opening connected to the top plate of the housing portion and communicating with the internal space of the housing portion; And can be equally applied to any concrete structure used by being buried in the ground.

It is a schematic perspective view of the manhole which can apply this invention. It is a figure which shows the computer output of the load conditions of FEM analysis. It is a figure which shows the computer output of the stress distribution of the top plate lower surface by FEM analysis. It is a figure which shows the computer output of the stress distribution of the top plate surface by FEM analysis. It is a schematic diagram of the top plate lower surface for demonstrating the application range of an arc-shaped reinforcement. It is a perspective view of one Example of an arc-shaped reinforcement. It is sectional drawing of the other Example of an arc-shaped reinforcement. It is a schematic diagram for demonstrating the sticking process of an arc-shaped reinforcement material. It is a schematic diagram of the top plate lower surface which shows the other example of application of an arc-shaped reinforcement. It is a schematic diagram of the lower surface of a top plate for demonstrating the application range of a diagonal material. It is a fragmentary sectional view of the manhole for demonstrating the attachment method of a diagonal. It is a perspective view of one Example of (a) rod-shaped diagonal material and (b) plate-shaped diagonal material. (A), (b) Attachment of diagonal material It is a fragmentary sectional view of the manhole for demonstrating other attachment methods. It is a schematic diagram of an example of a manhole.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Arc-shaped reinforcing material 2 Adhesive resin 3 Primer 5 Diagonal material 100 Manhole 101 Body part 102 Neck part 111 Top plate 111a Top plate lower surface 111b Top plate upper surface 112 Longitudinal side plate 112a Longitudinal side plate inner surface

Claims (11)

  A method for reinforcing a concrete structure embedded in the ground, comprising: a housing portion; and a cylindrical neck portion having an opening connected to a top plate of the housing portion and communicating with an internal space of the housing portion. Fiber reinforced over a range of 30 ° or more on both sides with respect to a longitudinal centerline passing through the center of the opening along the longitudinal direction of the housing portion on the surface of the top plate around the opening on the inner space side A method of reinforcing a manhole embedded in the ground, wherein a plastic arc-shaped reinforcing material is bonded using an adhesive resin.   Further, a short side that passes through the center of the opening along the short direction perpendicular to the longitudinal direction of the housing part at the corner portion on the internal space side formed by the longitudinal side plate of the housing part and the top plate. An oblique bolt is fixed between the top plate and the longitudinal side plate at an angle of 30 ° or more and 60 ° or less from the top plate within a range of 1.5 times the diameter of the opening centering on the direction center line. The method for reinforcing a manhole according to claim 1, wherein:   3. The manhole reinforcing method according to claim 1, wherein the arc-shaped reinforcing material has reinforcing fibers arranged in at least one direction along the arc shape.   4. The manhole reinforcement method according to claim 2, wherein the diagonal member is fixed using a putty-like adhesive in addition to or instead of the anchor bolt.   The arc-shaped reinforcing material has a fiber reinforced plastic layer containing carbon fiber as a reinforcing fiber at the center and a fiber reinforced plastic layer containing a reinforcing fiber having electrical insulation on the outside or a resin layer having electrical insulation. The method for reinforcing a manhole according to any one of claims 1 to 4, wherein the manhole has a cross-sectional structure.   6. The manhole reinforcing method according to claim 5, wherein the insulating reinforcing fiber is a glass fiber.   The manhole reinforcing method according to claim 1, wherein the adhesive resin is a fast-curing radical polymerization resin.   A cylindrical neck having an enclosure portion and an opening connected to the top plate of the enclosure portion and communicating with the internal space of the enclosure portion, and the internal space of the top plate around the opening An arc-shaped reinforcing material made of fiber reinforced plastic over a range of 30 ° or more on both sides with respect to the longitudinal center line passing through the center of the opening along the longitudinal direction of the housing portion on the side surface uses an adhesive resin. Reinforced concrete structures characterized by being bonded together.   Further, a short side that passes through the center of the opening along the short direction perpendicular to the longitudinal direction of the housing part at the corner portion on the internal space side formed by the longitudinal side plate of the housing part and the top plate. A diagonal member is anchor bolt between the top plate and the longitudinal side plate at an angle of 30 ° or more and 60 ° or less from the top plate within a range of 1.5 times the diameter of the opening centering on the direction center line. The reinforced concrete structure according to claim 8, wherein the reinforced concrete structure is fixed using   The concrete structure according to claim 8 or 9, wherein the arc-shaped reinforcing material has reinforcing fibers arranged in at least one direction along the arc shape.   11. The manhole reinforcement method according to claim 9, wherein the diagonal member is fixed by using a putty-like adhesive in addition to or instead of the anchor bolt.

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