JP2020060012A - Method for repairing reinforced concrete vertical wall of tunnel watchman passage - Google Patents

Abstract

To provide a method for repairing a reinforced concrete vertical wall of a tunnel watchman passage, which can reduce labor and shorten a construction period.SOLUTION: The method for repairing a reinforced concrete vertical wall of a tunnel watchman passage includes: a first step of removing concrete of a top end portion of a reinforced concrete vertical wall; a second step of chipping one side covering surface of the reinforced concrete vertical wall; a third step of arranging a plurality of UFC panels that also serve as a formwork so as to be adjacent to each other at a predetermined distance from a chipped surface; and a fourth step of injecting rust prevention agent-containing non-shrink mortar in a gap between each UFC panel that also serves as the formwork and the chipped surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method of repairing a reinforced concrete vertical wall of a tunnel guard passage.

  The reinforced concrete vertical wall of the tunnel observer passage is exposed to a bad environment due to exhaust gas of various vehicles passing through the tunnel, and therefore tends to deteriorate rapidly. Further, the water containing the salt contained in the antifreezing agent is splashed up as the vehicle travels, and the salt damage further facilitates the deterioration of the vertical wall made of reinforced concrete. If such deterioration progresses, concrete debris may fall onto the road surface and cause a serious traffic accident.To prevent the accident, it is necessary to repair the deteriorated reinforced concrete vertical wall promptly. There is.

  Conventionally, as a method for repairing a deteriorated reinforced concrete vertical wall, for example, a rod is fixed to an anchor placed in a deep portion of a base wall surface, a tile panel is penetrated through the rod, and a tile is kept at a predetermined distance from the base wall surface. After fixing the panel, a method of filling a mortar slurry having a specific property into the space between the tile panel and the base wall surface and hardening it to form a lightweight cellular concrete layer (Patent Document 1), a damaged portion of the tiled wall surface or a fragile portion After peeling off the part, and adjusting the unevenness with anchor bolts attached to the wall surface, while installing the tile panel that also serves as the formwork at a predetermined interval from the wall surface, prevent the tile panel from bulging when filling the mortar. Meanwhile, a method (Patent Document 2) for filling a fluid mortar between the tile panel and the wall surface has been proposed.

JP, 2014-148825, A Japanese Patent No. 5761701

However, in the conventional repair method, it is necessary to mount an anchor on the side surface of the vertical wall to fix the panel, and when the deteriorated portion of the vertical wall is peeled and removed, not only the deteriorated portion but also the healthy portion is removed. Since it needs to be removed, a major problem is that repair work requires a great deal of labor and time.
An object of the present invention is to provide a method for repairing a reinforced concrete vertical wall of a tunnel observer passage, which can reduce labor and shorten a construction period.

  As a result of various investigations by the present inventors, the concrete at the top end of the vertical wall made of reinforced concrete was removed, then the vertical wall was covered with a cover, and then a specific panel also serving as a formwork was provided on the surface with a predetermined interval. It was found that the vertical wall made of reinforced concrete in the tunnel observer passage can be repaired in a short construction period without much labor by injecting a specific mortar into the gap between the panel and the hanging surface.

That is, the present invention is a method for repairing a reinforced concrete vertical wall of a tunnel observer passage,
A first step of removing the concrete at the top of the reinforced concrete vertical wall,
The second step of covering the side wall of the reinforced concrete vertical wall,
A third step of arranging a plurality of UFC panels that also serve as formwork so as to be adjacent to each other with a predetermined distance from the flapping surface;
It is intended to provide a repair method including a fourth step of injecting a non-shrink mortar-containing non-shrink mortar into a gap between a UFC panel that also serves as a formwork and a flapping surface.

  According to the present invention, the vertical wall made of reinforced concrete of the tunnel observer passage can be repaired in a short construction period without requiring much labor.

It is a schematic diagram which shows an example of the tunnel to which the repair method of this invention is applied. It is a figure which shows the vertical wall part made from reinforced concrete of the tunnel guard passage of FIG. It is a figure which shows typically an example of the repair method of this invention. It is a figure which shows an example of a UFC panel also used as a formwork.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. Further, for convenience of illustration, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a schematic diagram showing an example of a tunnel to which the repair method of the present invention is applied. FIG. 2 (a) is a diagram showing a reinforced concrete vertical wall portion of a tunnel guard passage, and FIG. 2 (b) is a reinforced concrete vertical wall portion viewed from the roadway side.

  As shown in FIG. 1, the observer passage 1 includes a reinforced concrete vertical wall 2 that is erected vertically along the tunnel on one end side of a roadway 3 in the tunnel, and a lateral direction from the upper end of the vertical wall 2. And a passage portion 1a extended to the. In addition, in this specification, as shown in FIG. 2 (a), “the top end of the reinforced concrete vertical wall” refers to the end portion 2 a that is the farthest from the bottom surface of the reinforced concrete vertical wall 2, and also “the reinforced concrete The “vertical wall side surface” refers to a vertical surface 2b facing the side of the road 3 as shown in FIG. 2 (a).

  On the upper surface of the vertical wall 2 made of reinforced concrete, as shown in FIG. 2 (b), a plurality of handrail columns 4 a are installed at predetermined intervals. As shown in FIG. 2C, each of the columns 4a is fixed by a post-construction anchor 4c, and is erected upward from the upper surface of the vertical wall 2 made of reinforced concrete. Further, the upper ends of the adjacent columns 4a are bridged by a handrail rod 4b, and the handrail 4 is formed by the column 4a and the handrail rod 4b.

  The object of application of the present invention is the vertical wall 2 made of reinforced concrete, and the degree of deterioration is from "I (incubation period)" to "III-2 (late acceleration period)" in appearance grade shown in Table 1 below. And the corrosion grade of the reinforcing bar shown in Table 2 below is from "I (no rust adhered to the concrete surface)" to "III (no cross-section defect)" enjoys the effect of the present invention. It is preferable because it is easy. That is, the repairing method of the present invention can be suitably applied to those in which the reinforcing bars in the vertical wall concrete are not replaced or added.

  Next, the repair method of the present invention will be described. The repair method of the present invention includes a first step, a second step, a third step and a fourth step. Hereinafter, each step will be described in detail with reference to the drawings.

<First step>
The first step is a step of removing the concrete on the top end 2a of the vertical wall 2 made of reinforced concrete.
Prior to this step, the construction anchor 4c is cut and removed after the handrail support 4a. Next, as shown in FIG. 3, the concrete of the top end portion 2a is removed together with a part of the post-construction anchor 4c embedded in the concrete. The amount of concrete removed from the top end portion 2a can be appropriately set according to the deterioration state of the concrete, but since the concrete at the top end portion 2a is deteriorated due to rust or the like of the post-installed anchor 4c, the vertical wall 2 top It is preferable to remove the concrete up to about 200 mm from the edge. The concrete removing work can be performed by a general method, and for example, a wall saw or the like can be used.

  Further, in the present invention, after removing the concrete of the top end portion 2a, as shown in FIG. 3, a step of placing anchors 6 at predetermined intervals in the concrete removing portion may be included. The anchor 6 may be placed before the third step, and in order to further increase the strength, the deformed bar may be arranged laterally with respect to the longitudinal bar of the anchor 6. By placing the anchor 6 in this manner, the upper end of the UFC panel can be fixed to the anchor 6 when the UFC panel is arranged in the third step described later, which facilitates the alignment and allows the adjacent UFC panels to be aligned. It is possible to suppress the unevenness. The anchor 6 may be set at an appropriate interval depending on the size of the UFC panel, but is usually about 250 mm.

<Second step>
The second step is a step of covering the side surface 2b of the vertical wall 2 made of reinforced concrete. In the chipping step, the deteriorated portion of concrete may be removed from the upper surface of the side surface 2b of the vertical wall 2.
The amount of chipping can be appropriately set according to the deterioration state of the concrete, as long as the vertical wall 2 made of reinforced concrete after chipping has a thickness capable of withstanding the back surface earth pressure, but is usually 30 to 50 mm. The chipping work can be performed by a general method, and for example, an electric hammer or an air pick can be used.

Further, in this step, as shown in FIG. 3, there may be a step of providing the groove 8 in the lower end portion of the covering surface, that is, in the base portion of the vertical wall 2 made of reinforced concrete. By providing the groove 8 in this way, the lower end of the UFC panel can be dropped into the groove 8 when arranging the UFC panel in the third step, which will be described later, so that the alignment becomes easy and the adjacent UFC panels can be aligned. It is possible to suppress the unevenness with the panel. The groove 8 can be formed not only before or after the chipping step but also together with the chipping step.
The depth of the groove 8 can be appropriately set as long as the lower end of the UFC panel can be buried, but it is usually about 50 mm. Further, the depth of the groove 8 can be appropriately set in consideration of the distance from the fishing surface when the UFC panel is arranged in the third step described later. The groove 8 can be formed by a general method, and for example, an electric hammer or an air pick can be used.

<Third step>
First, the UFC panel used in the present invention will be described.
In the present invention, the "UFC panel" is formed by molding Ultra High Strength Fiber Reinforced Concrete into a panel shape. ) ”(Hereinafter referred to as UFC guideline), or super high strength fiber reinforced concrete with the same super high strength as physical properties (air permeability coefficient, chloride ion diffusion coefficient) related to mass transfer shown in UFC guideline. It can be manufactured using fiber reinforced concrete. By using ultra high-strength fiber reinforced concrete in this way, it is possible to reduce the weight of the panel, and as a result, it is easy for a small number of people to carry and install, reducing labor and shortening the construction period. You can

  In the present invention, since the UFC panel is also used as a mold, characteristics such as high strength, high toughness and high durability are required. For example, it is preferable to use a UFC panel having the characteristics shown in Table 3 below.

The size of the UFC panel can be appropriately set according to the size of the vertical wall made of reinforced concrete, but the height is usually 800 to 1200 mm, preferably about 1000 mm, and the width is usually 500 to 1500 mm, preferably Is 750 to 1200 mm, and the thickness is usually 10 to 50 mm, preferably 15 to 30 mm.
Further, the shape of the UFC panel is not particularly limited as long as it can be installed in the horizontal direction with respect to the vertical wall made of reinforced concrete, and an example thereof is shown in FIG. The UFC panel 5 shown in FIG. 4A has a protrusion 5a on a part of a rectangular flat plate, and the protrusion 5a is provided with an opening 5b. In addition, FIG. 4B shows a cross-sectional view of the UFC panel 5 shown in FIG. The UFC panel 5 shown in FIG. 4 (a) is provided with a protrusion 5a having an opening 5b for embedding a handrail in a part of a rectangular flat plate. For example, the lower surface of the opening 5b shown in FIG. 4 (c). The handrail support can be easily installed by attaching the insert anchor 5c to the. The sizes of the protrusion 5a and the opening 5b can be appropriately set according to the handrail support. For example, the thickness of the protrusion 5a is 10 to 30 mm, preferably 15 to 25 mm. Further, the number of openings 5b provided in the protrusion 5a can be appropriately set depending on the installation situation of the handrail, and the UFC panel shown in FIG. 4A has two openings 5b. Further, the end portion of the opening 5b may be an open end as shown in FIG. 4B, or may be a closed end as long as a handrail can be erected.
Further, the surface of the UFC panel 5 on the side to be filled with mortar, which will be described later, may be provided with irregularities or protrusions in order to improve adhesion with the mortar.

Next, the third step will be described.
The third step is a step of arranging a plurality of UFC panels 5 so as to be adjacent to each other at a predetermined distance from the flapping surface.
The UFC panels 5 are arranged so as to be adjacent to each other with the side surfaces of the UFC panels 5 in contact with each other at a predetermined distance from the flapping surface. As shown in FIG. The top end position can be determined by inserting it into each hole 5e provided in the matching UFC panel 5. The connecting pin is, for example, a rod-shaped member made of resin, and usually has a diameter of 8 to 12 mm and a length of 80 to 100 mm.
As shown in FIG. 3, when the anchor 6 is placed on the top end 2a of the vertical wall 2 made of reinforced concrete, the upper end of the UFC panel 5 is fixed to the metal fitting connected to the anchor 6. May be. For example, the bolt 7a may be fixed to the anchor 6 with a reinforcing bar clamp, the UFC panel 5 may be passed through the bolt, and the UFC panel 5 may be fixed by fitting the end of the bolt with lip groove type steel 7b.
Further, as shown in FIG. 3, when the groove 8 is provided at the lower end of the vertical wall 2 made of reinforced concrete, the lower end of the UFC panel 5 is dropped into the groove 8 with a predetermined distance from the flapping surface, The side surfaces of the UFC panel 5 may be brought into contact with each other and arranged so as to be adjacent to each other. In this case, the lower end of the UFC panel 5 may be fixed at predetermined intervals via a metal fitting. For example, the roadway-side exposed surface of the lower end of the UFC panel 5 and the roadway surface may be fixed by the L-shaped metal fitting 9.

  Further, the UFC panel 5 may be arranged after the resin tape is attached to the side surface and / or the bottom surface of the UFC panel 5. Thereby, in the fourth step, it is possible to prevent the mortar from leaking between the UFC panels 5 and from the bottom of the UFC panels 5. Examples of the resin tape include a gap tape in which an adhesive layer is formed on one surface of a sponge-like material.

  The distance from the flapping surface to the UFC panel 5 can be appropriately set depending on the flapping amount, but is usually 10 to 80 mm, preferably 15 to 65 mm. When the UFC panel 5 has the protrusions 5a, it suffices that the portion other than the protrusions 5a secures the above-mentioned interval.

<Fourth step>
The fourth step is a step of injecting a non-shrink mortar-containing non-shrink mortar into the gap 10 between the UFC panel 5 and the flapping surface.
As the non-shrink mortar, various non-shrink mortars known as materials for civil engineering and construction can be used.
Examples of the rust preventive agent include amines such as tertiary amines; nitrites such as calcium nitrite and lithium nitrite; phosphates; chromates; organic phosphate esters; ester salts; organic acids; sulfonic acids; Alkylphenol; mercaptans; nitro compounds and the like can be mentioned. Two or more kinds of rust preventives may be used in combination. The rust preventive may be added when kneading the non-shrink mortar, and the amount of the rust preventive added is usually 0.1 to 0.5% by mass, preferably 0.2 in the non-shrink mortar. Is 0.4 mass%.

The rust preventive-containing non-shrink mortar can be injected by a general method, and for example, a squeeze pump or the like can be used.
Further, the injection of the non-shrink mortar containing the rust preventive agent is preferably performed in plural times from the viewpoints of reliability of mortar filling and improvement of work efficiency. For example, after inserting an injection hose into the gap 10 at the upper end of the UFC panel 5 and injecting a rust preventive-containing non-shrinkable mortar from the bottom to the middle of the reinforced concrete vertical wall 2 to form a first mortar layer, Cure for about 6 hours. Next, a non-shrink mortar-containing non-shrink mortar is injected up to the upper end of the chipping surface to form a second mortar layer, followed by curing for about 4 to 6 hours. Next, concrete is poured up to the upper surface of the UFC panel 5 to form the top end 2a of the vertical wall 2 made of reinforced concrete. An expansive material may be added when pouring concrete, and examples of the expansive material include lime expansive materials suitable for JIS A 6202 expansive material for concrete. The amount of the expanding agent added is usually 10 to 30 kg per 1 m ^{3 of} concrete.

  After confirming that the concrete of the top end 2a of the reinforced concrete vertical wall 2 has hardened, a handrail is installed on the upper surface of the reinforced concrete vertical wall 2. To install the handrail, for example, after fixing the handrail mounting jig to the upper surface of the vertical wall 2 made of reinforced concrete with bolts, the handrail supporting jig is erected on the handrail mounting jig and the handrail rod is installed on the handrail supporting pillar. .

  Further, among the metal fittings used for fixing the UFC panel 5 in the third step, the metal fittings protruding toward the roadway 3 side can be removed. In this case, the trace hole after removing the metal fitting can be filled with non-shrink mortar.

<Fifth step>
After the fourth step, there may be a fifth step of filling the joint between the UFC panels 5 with the filler. Thereby, the deterioration of concrete can be prevented further. Examples of the filler include mortar and resin. The filling of the filler can be performed by a general method.

  The present invention has been described in detail above based on the embodiments. However, the present invention is not limited to the above embodiment. The present invention can be variously modified without departing from the gist thereof. For example, in the above embodiment, the UFC panel having the protrusion shown in FIG. 4 (a) is used, but the rectangular flat plate UFC panel shown in FIG. 4 (e) can also be used. In this case, when installing the handrail, after the fourth step, if a post-installation anchor for fixing the handrail post to the top end surface of the vertical wall 2 made of reinforced concrete is installed, and after installing the handrail post, the handrail rod is installed. Good.

1 Observatory passage 2 Vertical wall made of reinforced concrete 3 Roadway 4 Handrail 5 UFC panel 6 Anchor 7a, 7b, 9 Metal fittings 8 Groove 10 Gap

Claims (7)

A method for repairing a reinforced concrete vertical wall of a tunnel observer's passage,
A first step of removing the concrete at the top of the reinforced concrete vertical wall,
The second step of covering the side wall of the reinforced concrete vertical wall,
A third step of arranging a plurality of UFC panels that also serve as formwork so as to be adjacent to each other with a predetermined distance from the flapping surface;
A repair method including a fourth step of injecting a non-shrink mortar-containing non-shrink mortar into a gap between a UFC panel that also serves as a formwork and a flapping surface. In the second step, the method further includes the step of providing a groove at the lower end of the flapping surface,
In the third step, a plurality of UFC panels that also serve as molds are arranged such that the lower ends of the UFC panels that serve also as molds are dropped into the grooves and are spaced from each other by a predetermined distance so as to be adjacent to each other.
The repair method according to claim 1.   In the third step, after the resin tape is attached to the side surface and / or the bottom surface of the UFC panel that also serves as the formwork, a plurality of UFC panels that also serve as the formwork are adjacent to each other with a predetermined distance from the mounting surface. The repair method according to claim 1 or 2, wherein the UFC panels are arranged and the connecting pins are inserted into the holes on the side surfaces of the adjacent UFC panels to determine the top end position of the UFC panels. After the first step and before the third step, the method further includes a step of placing anchors at predetermined intervals on the concrete-removed portion of the top end portion,
After the third step and before the fourth step, a step of fixing the upper end of the UFC panel that also serves as the frame to the metal fitting connected to the anchor is included.
The repair method according to claim 1.   5. The method according to claim 1, further comprising a step of fixing the lower end portion of the UFC panel that also serves as the formwork at a predetermined interval after the third step and before the fourth step, via a connecting fitting. Repair method.   The repair method according to any one of claims 1 to 5, wherein the UFC panel that also serves as the mold has an opening at the upper end.   The repair method according to any one of claims 1 to 6, including a fifth step of filling the joint between the UFC panels that also serve as the formwork with a filler after the fourth step.

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