JP2008138460A - Method of reinforcing column standing in water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing method for reinforcing even a column standing in water, in a manner easily bringing materials in the field at a low cost and in a short construction period, without carrying out underwater construction or large-scale cutoff works, and without providing a special construction machine. <P>SOLUTION: The reinforcing method is provided for reinforcing the column standing in water, specifically a reinforcement target portion which is partly located in water, and characterized by carrying out the following (A), (B), (C), and (D) steps. In the step (A), a reinforcing layer is formed on the periphery of the column at a height higher than a water level. In the step (B), a water cutoff material for preventing infiltration of water into a gap between the reinforcing layer and the column, is set at a lower portion of the reinforcing layer. In the step (C), the reinforcing layer and the water cutoff material are lowered to the reinforcement target portion. In the step (D), a filler for connecting the reinforcing layer and the column together in one body, is filled in the gap between the reinforcing layer and the column. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention mainly relates to a novel column reinforcing method for compensating for a lack of proof strength of an existing pier that stands in water and improving its strength.

  Since the Great Hanshin Earthquake, lack of strength of pillar members such as bridge piers has been pointed out in various places, and the reinforcement method of covering the outer periphery with concrete, steel plate or fiber reinforced plastic is used.

  However, in the case of pillars and piers that stand in water, the current situation is that reinforcement work is not progressing due to various problems such as legal restrictions and technical and cost problems. For example, reinforcement by reinforced concrete winding increases the thickness of the reinforced concrete to about 25 cm. In particular, in the case of rivers, there are many cases where river managers such as ministries and local governments managing rivers do not permit in consideration of a decrease in river flow capacity.

  In other words, river managers set the rate of hindrance for bridge piers in order to prevent problems such as flooding and breakage due to river flow inhibition, and it is difficult to approve any reinforcement beyond that. However, many of the existing piers have already been constructed with the structural dimensions that are just below the established river volume inhibition rate, and there is no room for reinforcement with reinforced concrete.

  Reinforcing steel plates does not require the same thickness as concrete, so the problem of the river volume inhibition rate does not occur so much. However, in order to prevent corrosion of the iron plate, it is necessary to recoat the surface with a rust-preventive paint and a weather-resistant paint that protects it, but the coating films of both paints may peel off over the course of use. When left in a peeled state, there is a concern that the steel sheet will corrode and the reinforcing effect will be significantly reduced, so it is necessary to periodically inspect and repaint. Furthermore, there is a problem that repainting in water is not easy and the cost of repainting is high. Therefore, the current situation is that the reinforcement by winding the steel plate is hardly adopted in the pier that stands in water.

  Reinforcement by continuous fiber reinforced plastic winding can be reinforced thinner than steel sheet winding, and there is almost no problem of the river volume inhibition rate. Furthermore, since the material does not corrode, the maintenance work is less than that of the steel sheet winding reinforcement, which is equivalent to the reinforced concrete winding reinforcement. However, since the continuous fiber reinforced plastic impregnates a continuous fiber sheet with a matrix resin to form a continuous fiber reinforced plastic reinforcing layer, the matrix resin weak against moisture cannot be cured and a reinforcing layer cannot be formed. There are also resins that cure in water, but so far the reinforcing effect of the continuous fiber reinforced plastic winding formed with this resin has not been confirmed and has not been publicly recognized. Furthermore, the cost is much higher than that of generally used epoxy resins. Therefore, under the present circumstances, reinforcement by continuous fiber reinforced plastic winding is hardly employed in bridge piers standing in water.

  In view of this, a method for reinforcing a pier that stands in existing water without causing a problem of a river volume inhibition rate has been proposed (see, for example, Patent Documents 1 and 2).

  Patent Document 1 discloses a continuous fiber reinforced plastic in which a continuous fiber sheet is wound around the pier outer periphery by underwater work, and further surrounded by an outer frame that also serves as a mold, and after dehydration, a curable resin is injected and impregnated and cured. A method of forming a reinforcing layer is disclosed. Although the outer frame is made of steel, the outer frame encloses the pier having a diameter of several meters, so the weight is heavy, and heavy equipment is required for installing the outer frame. Furthermore, since the outer frame is produced upon receipt of order, the versatility of the material is low and the material cost is high compared to steel-winding reinforcement. Moreover, because it is installed underwater, the outer frame is towed in by a tugboat or the like, and a special construction machine such as a water crane is required, or only a pier with a land nearby is limited reinforcement. Furthermore, since it is an underwater work, a diver is required for construction, not a general worker. Especially in the construction of the river flow situation, the river flow is applied as resistance to the continuous fiber sheet, and the winding work is not easy. Therefore, there are problems such as limitation of construction methods, extension of construction period, and increase of construction costs.

  Patent Document 2 is a method in which a rigid member such as a square steel pipe is installed on a surface orthogonal to the river flow direction in a river pier that is set as a paragraph, and an anchor is used for fixing the rigid member and an existing pier. . For joining anchor anchors in the water, a deadline is implemented and either the worker enters after dehydration or construction is performed underwater using a diver. Moreover, since the steel material is used as a rigid member and the dimension of a reinforcing material is also the same level as a bridge pier cross section, it becomes a considerable weight. This rigid member is brought into the construction site by assembling it at a temporary factory or construction site on the land. Construction equipment is required, or limited reinforcement for bridge piers with land nearby. Therefore, there are problems that the construction method is restricted and the construction period is long, and the construction cost is high.

In other words, the proposed reinforcement method does not cause the problem of river blockage rate, but specially prepares the reinforcement material, it is not easy to carry in the reinforcement material, and a special machine is required for the construction. There is still a problem that it takes a lot of construction costs, which is the construction of the period.
JP 2006-9336 A (Claim 1, FIG. 3) JP 2005-30119 A (Claim 1, FIG. 1)

  The present invention has been made in view of the above-described problems, and does not require any special material even if it is a pillar that stands in existing water, and can easily carry in the material and can be reinforced. It is an object of the present invention to provide a method for reinforcing a pillar that is erected in water, which does not require a special construction machine, does not cause a problem of river blockage rate, and can be reinforced in a short period of time.

In order to solve the above problems, the present invention employs the following configuration. That is,
(1) A reinforcement method in which a part of a reinforcing part of a column that stands in water includes an underwater part, and is subjected to the following steps (A), (B), (C), and (D) Column reinforcement method.
(A) forming a reinforcing layer around the pillar at a position higher than the water surface;
(B) a step of installing a water stop material for preventing water from entering between the columns at the bottom of the reinforcing layer;
(C) a step of lowering the reinforcing layer and the water stop material to the reinforcing portion of the column,
(D) A step of filling a gap between the reinforcing layer and the column with a filler for integrating the reinforcing layer and the column.

  (2) The method for reinforcing a column according to (1), wherein the reinforcing layer is made of continuous fiber reinforced plastic or a metal material.

  (3) In the step (A), after the mold is installed in advance on the outer periphery of the column and the reinforcing layer is formed on the outer periphery of the mold, the process until the reinforcing layer is moved in the step (C) The column reinforcing method according to (1) or (2) above, wherein the formwork is removed.

  (4) The column reinforcing method according to any one of (1) to (3), wherein the mold has a release layer on a surface in contact with the reinforcing layer.

  (5) The column reinforcing method according to any one of (1) to (4), wherein in the step (D), a filler is injected from above into the gap between the column and the reinforcing layer.

  According to the reinforcing method of the present invention, it is possible to easily reinforce a pillar that does not need a special construction machine, does not need a special construction machine, stands in water, and a part of the reinforcing portion includes an underwater part. . Moreover, since the material used is also light, it is easy to carry in the material from above the structure located at the upper part of the column by manpower or a light truck with a crane. Furthermore, since there is no need to carry out large-scale cut-off work or carrying-in work that causes problems in terms of construction period or construction cost, it is possible to reinforce the pillars that stand in water in a short time.

  Moreover, by having a mold release layer on the mold surface in contact with the reinforcing layer, the mold release can be facilitated, and the construction time for the mold release frame can be shortened.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings of one example.

  According to the present invention, a step of forming a reinforcing layer around the pillar at a position higher than the water surface with respect to an existing pillar that is standing in water and a part of the reinforcing portion includes the underwater part, and a lower part of the reinforcing layer A step of installing a water-stopping material between the existing pillars, a step of lowering the reinforcing layer and the water-stopping material to the reinforcing part of the column, and a step of filling the gap between the reinforcing layer and the column with a curable material It is a reinforcement method.

  FIG. 1 is a cross-sectional view showing an embodiment of a method for reinforcing an existing pillar that is standing in water and includes a portion of the underwater part that is underwater according to the present invention, and includes a reinforcing part (AA and A′-A). An embodiment in which a continuous fiber reinforced plastic reinforcement layer 2 is formed on a construction scaffold located at a position higher than the water surface with respect to the existing pillar 1 located at a position across the water surface (BB). It is sectional drawing shown. FIG. 2 is a cross-sectional view showing an embodiment in which the continuous fiber reinforced plastic reinforcing layer 2 is moved to the reinforcing part of the existing pillar 1 in which a part of the reinforcing part includes an underwater part. FIG. 3 is a cross-sectional view showing an embodiment in a state where a reinforcing layer is fixed to a reinforcing portion of the existing pillar 1. FIG. 4 is a cross-sectional view of the lower part of the formwork. FIG. 5 is a sectional view of the mold 3 having a film and the continuous fiber reinforced plastic reinforcing layer 2.

  As shown in FIG. 1, (A) a step of forming a reinforcing layer 2 around the existing pillar 1 at a position higher than the water surface is performed.

  Construction scaffolding so as to surround the outer peripheral surface of the existing pillar 1 in a space that first stands in water and a part of the reinforcement part protrudes above the water surface (BB) with respect to the existing pillar 1 including the underwater part. 5 is installed. Examples of the construction scaffold 5 include a temporary pier with a simple pillar on the water, a ship, and a gondola type scaffold suspended from the upper structure 8, but the construction scaffold 5 is easy to set up and the construction scaffold installation cost is high. It is preferable to use a gondola type because of its low cost.

  Next, on the construction scaffold 5, as shown in FIG. 4, a mold 3 for forming a reinforcing layer on the outer peripheral surface of the existing pillar 1 is installed.

  Examples of the reinforcing layer 2 include a continuous fiber reinforced plastic or a metal material as a material for obtaining the reinforcing effect of the existing columns.

In the case of continuous fiber reinforced plastic, the continuous fiber sheet used as the reinforcing material is selected from the group consisting of carbon fiber sheet, aramid fiber sheet, glass fiber sheet, polyparaphenylene benzoxazole (PBO) fiber sheet, and high-strength polyethylene fiber sheet. At least one continuous fiber is preferred. Among these it is preferable that the tensile modulus of elasticity using a carbon fiber sheet in the range of ^{245kN / mm 2 ~440kN / mm 2} . Although a carbon fiber sheet is expensive, it is preferable among continuous fiber sheets because of its excellent strength and elastic modulus.

  Examples of the impregnated adhesive resin used as the base material of the continuous fiber reinforced plastic reinforcing layer 2 include various curable resin-based impregnated adhesives such as epoxy, acrylic, urethane, vinyl ester, and polyester. However, an acrylic resin-based impregnated adhesive is preferable in consideration of early curing in an environment on the water surface of a river.

  In the case of a metal material, structural steel material, cast iron material, stainless steel material, titanium material, aluminum alloy material, or the like may be used. Among these, it is preferable to use a general structural rolled steel, a welded structural rolled steel or a welded weathering hot rolled steel generally used in construction materials. In addition, when using a metal material, since it is processed and carried in the field by the shape and dimension matched with the pillar for reinforcement in a factory etc., the normal formwork 3 is unnecessary.

  In addition, we compare continuous fiber reinforced plastics with metal materials. Considering that a part of the reinforcing part in the present invention is in the underwater part, the reinforcing layer formed of a metal material (hereinafter referred to as a metal material reinforcing layer) is concerned about corrosion, and some measures against corrosion are necessary. It becomes. Further, since the metal material reinforcing layer is higher in density than the reinforcing layer formed of continuous fiber reinforced plastic (hereinafter referred to as continuous fiber reinforced plastic reinforcing layer), the reinforcing layer itself becomes heavier. The equipment to be fixed or suspended becomes larger. Therefore, it is even more preferable to use a continuous fiber reinforced plastic.

  The reinforcement part (range between AA and A'-A ') is calculated based on the reinforcement design of existing piers described in, for example, “Japan Road Public Corporation Design Guidelines Vol. 2 Bridges, Retaining Walls, and Calverts”. Range.

  In the case of the continuous fiber reinforced plastic reinforcing layer 2, the formwork 3 is installed in order to build the shape of the reinforcing layer locally. The range of the mold 3 is most preferably the same as the reinforcing part (the range between AA and A′-A ′) of the existing pillar 1 from the viewpoint of economy, but the continuous fiber reinforced plastic reinforcement performed next is performed. In consideration of the workability of the layer 2, it may be wide up to 50 cm in the ceiling direction. Further, the shape of the mold 3 is preferably 5 mm to 10 mm in order to make the river inhibition rate as small as possible and leave a width where the filler 7 can be injected.

  Next, in order to form the continuous fiber reinforced plastic reinforcement layer 2 around the mold 3, an impregnated adhesive resin is applied, and a continuous fiber sheet having a reinforcement amount calculated by the reinforcement calculation is pasted thereon. Thereafter, the continuous fiber sheet is impregnated with an adhesive resin to form the continuous fiber reinforced plastic reinforcing layer 2.

  Further, in the present invention, for the purpose of easy demolding after the continuous fiber reinforced plastic reinforcing layer 2 is formed, a release layer 6 is interposed between the mold 3 and the continuous fiber reinforced plastic reinforcing layer 2 as shown in FIG. And a method of simply integrating with the mold 3 is proposed. The release layer 6 includes oils and fats and films, but it is preferable to use a film because of compatibility with the continuous fiber reinforced plastic reinforcement layer 2. The film material of the release layer 6 is preferably polyester, polypropylene, polyphenylene sulfide (PPS), polycarbonate, polyethylene, fluorine, or silicon, but a polyester film (for example, “Lumirror”) manufactured by Toray Industries, Inc. (Registered trademark)) is preferably used. For joining the formwork 3 and the film, an adhesive or double-sided tape that has an adhesive strength that can be easily peeled off by human hands, so that the film and the continuous fiber reinforced plastic reinforcing layer 2 cannot be peeled off by their own weight. Adhesion is preferred.

  Next, as shown in FIG. 4, a process of installing a water blocking material 4 that fills the gap between the reinforcing layer 2 and the existing pillar 1, which is a process (B), is performed.

  The water blocking material 4 is installed to prevent water from entering between the existing pillar 1 and the reinforcing layer 2 when the water blocking material 4 is lowered below the water surface in (C) described later. In the case of the continuous fiber reinforced plastic reinforcing layer 2, after the mold 3 is installed or after the continuous fiber reinforced plastic reinforcing layer 2 is installed, it is installed under the continuous fiber reinforced plastic reinforcing layer 2 or the mold 3. It is preferable to install after installation. In the case of the metal material reinforcing layer, the formwork 3 is not required, and therefore, after the metal material reinforcing layer is installed, a water stop material 4 that is buried between the existing pillars 1 is installed below the reinforcing layer, or in advance a factory However, since it is possible to save work work at the construction site, it is preferable to install it below the metal material reinforcement layer in advance at a factory or processing site.

  As a material of the water blocking material 4 filling the space between the reinforcing layer 2 and the existing pillar 1, rubber or plastic resin may be used. Among these, it is preferable to use a rubber having flexibility.

  Next, as shown in FIG. 2, the step (C) of lowering the reinforcing layer 2 to the reinforcing portion of the existing pillar 1 (the range between AA and A′-A ′) is performed.

  In the case of the continuous fiber reinforced plastic reinforcing layer 2, the continuous fiber reinforced plastic reinforcing layer 2 and the formwork 3 are separated, and a space is provided between the existing pillar 1 and the continuous fiber reinforced plastic reinforcing layer 2. The continuous fiber reinforced plastic reinforcing layer 2 is suspended by using the upper structure 8 or a pulley so that the continuous fiber reinforced plastic reinforcing layer 2 does not slide down after the demolding frame. In addition, it is confirmed that the water stop material 4 and the existing pillar 1 at the lower part of the continuous fiber reinforced plastic reinforcing layer 2 are in close contact with each other, and gradually the reinforcing portions (AA and A′-A ′) of the existing pillar 1 To the range between).

  In the case of a metal material reinforcement layer, it is confirmed that the water stop material 4 and the existing pillar 1 at the lower part of the metal material reinforcement layer are completely in close contact with each other, and gradually the reinforcement part of the existing pillar 1 (AA and A′− (Range between A ').

  Finally, as shown in FIG. 3, the step (D) of filling the gap between the reinforcing layer 2 and the existing pillar 1 with a filler is performed.

  In order to completely fix the reinforcing layer and the existing pillar 1, the gap formed between the existing pillar 1 and the reinforcing layer 2 is filled with the filler 7 and integrated with the existing pillar 1.

  In the case of the continuous fiber reinforced plastic reinforcing layer 2, in order to integrate the continuous fiber reinforced plastic reinforcing layer 2 and the existing pillar 1, a filler 7 such as a curable material is filled in a gap therebetween. As the curable material, for example, a material mainly composed of a curable resin such as an epoxy resin, or cement, concrete, mortar, expandable concrete, expandable mortar, or the like may be used. Considering familiarity, cost, and filling capacity, it is preferable to use expandable concrete or expandable mortar.

  In the case of a metal material reinforcing layer, a hole is made in the metal material reinforcing layer and fixed to the existing pillar 1 using an anchor bolt, and then the anchor bolt and the metal material reinforcing layer are fixed by welding, The gap between the existing pillars 1 is filled with a filler 7 such as a curable material. As the curable material, for example, a material mainly composed of a curable resin such as an epoxy resin, or cement, concrete, mortar, expandable concrete, expandable mortar, or the like may be used. In consideration of familiarity, cost, and filling capacity, it is preferable to use expandable concrete or expandable mortar.

It is sectional drawing which formed the continuous fiber reinforced plastic reinforcement layer on the construction scaffold in the position higher than the water surface of an existing pillar. It is sectional drawing which descended the continuous fiber reinforced plastic reinforcement layer to the reinforcement site | part of the existing pillar in which one reinforcement site | part contains an underwater part. It is sectional drawing which fixed the continuous fiber reinforced plastic reinforcement layer to the existing pillar which stands in water. It is sectional drawing of a mold frame lower surface. It is sectional drawing of a formwork and a continuous fiber reinforced plastic reinforcement layer which have a film.

Explanation of symbols

1: Existing column 2: Reinforcement layer 3: Formwork 4: Water-stopping material 5: Construction scaffold 6: Release layer 7: Curable filler 8: Upper structure AA: Upper end position A′- of the reinforcement part A ′: Lower end position of the reinforcing part BB: Water surface position

Claims (5)

A column of a pillar that stands in water is a reinforcement method in which a part of the reinforcement part includes an underwater part, and the column is characterized by undergoing the following steps (A), (B), (C), and (D) Reinforcement method.
(A) forming a reinforcing layer around the pillar at a position higher than the water surface;
(B) a step of installing a water stop material for preventing water from entering between the columns at the bottom of the reinforcing layer;
(C) a step of lowering the reinforcing layer and the water stop material to the reinforcing portion of the column,
(D) A step of filling a gap between the reinforcing layer and the column with a filler for integrating the reinforcing layer and the column. The column reinforcing method according to claim 1, wherein the reinforcing layer is made of a continuous fiber reinforced plastic or a metal material. In the step (A), after the mold is set in advance on the outer periphery of the column and the reinforcing layer is formed on the outer periphery of the mold, the mold is moved until the reinforcing layer is moved in the step (C). The column reinforcing method according to claim 1, wherein the column reinforcing method is removed. The column reinforcing method according to claim 1, wherein the mold has a release layer on a surface in contact with the reinforcing layer. 5. The column reinforcing method according to claim 1, wherein, in the step (D), a filler is injected from above into a gap between the column and the reinforcing layer.

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