JP2017106273A - Reinforcement method of existing tubular wall made of reinforced concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for reinforcing an existing cylindrical wall made of reinforced concrete, which can effectively enhance earthquake resistance. SOLUTION: This is a method of reinforcing an existing tubular wall 50 made of reinforced concrete having an internal space open upward, and the existing concrete 54 of the outer surface 52 of the existing tubular wall 50 is replaced with an existing reinforcing bar 56. A new outer reinforcing bar 4 having a larger amount of reinforcing bars and / or higher strength than the existing reinforcing bars 56 at a portion where the existing reinforcing bars 56 are scraped and the existing concrete 54 is scraped. A method for reinforcing an existing tubular wall made of reinforced concrete, which comprises arranging reinforcing bars and placing a new outer concrete 5 on the new outer reinforcing bar 4 to form a tubular wall reinforcing structure 1. I will provide a. [Selection diagram] Fig. 1

Description

  The present invention relates to a method for reinforcing an existing cylindrical wall made of reinforced concrete.

  Walls made of reinforced concrete are often used as wall surfaces of building structures. Various methods for seismically reinforcing such reinforced concrete walls are generally used.

  For example, Patent Document 1 discloses a structure 30 in which a concrete wall as shown in FIG. In this structure 30, an existing concrete wall 31 includes a filling layer 32 made of a filler such as mortar, a reinforcing steel plate 33 fixed to the concrete wall 31 with a horizontal anchor via the filling layer 32, and The reinforcing steel plate 33 is reinforced by the structure of the exterior layer 34 formed by applying a finishing agent to the outside.

  Non-Patent Document 1 describes “reinforcement by increasing the number of existing seismic walls” in which existing reinforced concrete walls are seismically reinforced by striking concrete. FIG. 4 shows this type of reinforcement method. FIG. 4A is a side sectional view of an existing reinforced concrete wall 40. In the present example, the existing reinforced concrete wall 40 includes a concrete 41 and a grid-like bar arrangement 42 composed of vertical bars 42a and horizontal bars 42b.

  First, as shown in FIG. 4B, the surface 43 of the existing reinforced concrete wall 40 is partially roughened. Further, a shear connector, an anchor 44 and the like are provided on the roughened surface 43.

  Thereafter, as shown in FIG. 4 (c), a new lattice-shaped bar arrangement 45 composed of vertical bars 45a and horizontal bars 45b is placed on the roughened surface 43 and tied to the anchor 44, After the mold frame is installed so that the surface 43 and the mold frame sandwich the reinforcing bar 45, the concrete 46 is struck between the surface 43 and the mold frame.

  Such a reinforcing method is often used for general building structures. The wall of a general building structure is surrounded by surrounding frames such as columns and beams on the top, bottom, left and right. The new bar arrangement 45 installed in the portion where the concrete 46 is struck is fixed to the peripheral frame via a post-construction anchor (not shown). As described above, the wall formed by the additional hitting of the concrete 46 by the anchor 44 or the post-construction anchor is integrated with the existing wall 40 or the peripheral frame.

  In general, the thickness of the concrete 46 that has been struck is equal to or greater than the thickness of the existing reinforced concrete wall 40.

JP 2001-329699 A

Japan Architectural Disaster Prevention Association, “Guidelines for Seismic Retrofit Design of Existing Reinforced Concrete Buildings and Explanation”, revised 2001, pages 93-97

  In the existing reinforced concrete wall reinforcement structure and method described in Patent Document 1 and Non-Patent Document 1, the seismic strength increases by increasing the wall, while the weight of the wall also increases. Only increase. If it is a general building structure, the upper, lower, left and right sides of the wall are surrounded by the peripheral frame as described above, and the increased weight is fixed to the peripheral frame by fixing the part that has been struck to the peripheral frame with an anchor or the like. It is also possible to bear it. Therefore, since the increase in the seismic strength exceeds the weight of the wall, that is, the increase in the required seismic strength, the conventional structure and method as described above can sufficiently improve the seismic resistance. However, for example, a reinforced concrete cylindrical wall 50 having an internal space 51 as shown in FIG. 5 is not surrounded by a peripheral frame such as a column or a beam, and thus only supports the weight of the wall. Thus, even if the conventional reinforcement is applied, the increase in seismic strength and the dead weight of the wall, that is, the increase in necessary seismic strength, cancel each other, resulting in a problem that it is difficult to obtain the effect of seismic reinforcement.

  In addition, since the wall such as the cylindrical wall 50 is not surrounded by the peripheral frame such as a column or a beam as described above, the reinforcing bars added in the reinforcement by the conventional additional hitting are used as the existing frame. Cannot be established effectively. Even in such factors, the conventional structure and method are difficult to obtain the effect of seismic reinforcement on the wall such as the cylindrical wall 50 described above.

  In addition, a wall such as the cylindrical wall 50 described above may be used in a nuclear power plant to store a nuclear reactor in the internal space 51 and prevent leakage of radiation emitted by the nuclear reactor to the outside. In order to further improve the radiation shielding property with respect to such a cylindrical wall 50, a roof slab made of reinforced concrete may be newly constructed on the upper part of the cylindrical wall 50 to block the internal space 51. The seismic force acting on the structure has a higher acceleration as the height from the ground is higher. Therefore, when the roof slab is installed, the weight that is increased by the roof slab increases the seismic force acting on the legs of the cylindrical wall 50. . When the seismic reinforcement associated with the installation of the roof slab is performed by the conventional method as described above, the weight of the portion where the wall is struck is further added to the cylindrical wall 50 in addition to the weight of the roof slab. Moreover, the center of gravity of the entire structure becomes higher than before construction due to the installation of the roof slab and the reinforcement of the walls. Due to these factors, there is an increased risk of breakage or collapse of the cylindrical wall 50 or a fall due to the legs of the cylindrical wall 50 being lifted during an earthquake.

  Moreover, when power generation equipment such as a nuclear reactor and a reactor containment vessel is installed in the internal space 51 of the cylindrical wall 50, the temperature of the internal space 51 becomes higher than the outside air. Due to the temperature difference between the inside and outside of the cylindrical wall 50, a temperature gradient is generated in the casing of the cylindrical wall 50. However, since the cylindrical wall 50 has a cross-sectional shape closed in the circumferential direction, the deformation is restrained. As shown in FIG. 6, temperature stress as shown in FIG. 6 is generated inside the casing of the cylindrical wall 50 according to the linear expansion coefficient of concrete. According to FIG. 6, except for the vicinity of the leg portion of the cylindrical wall 50, compressive stress is applied to the inner surface side of the cylindrical wall 50 having a high temperature in both the circumferential direction and the radial direction of the cylindrical wall 50. Tensile stress is generated in. On the other hand, in the vicinity of the legs of the cylindrical wall 50, since the foundation is fixed, tensile stress is generated on the inner surface side and compressive stress is generated on the outer surface side with respect to the radial axis. In the reinforcement method for a general building as described above, the seismic performance in a state where such temperature stress is always acting cannot be effectively improved.

  The subject of this invention is providing the reinforcement method of the existing cylindrical wall made from a reinforced concrete which can raise earthquake resistance effectively.

The present invention employs the following means in order to solve the above problems. That is, the present invention is a method for reinforcing an existing cylindrical wall made of reinforced concrete having an internal space opened upward, and the existing concrete on the outer surface of the existing cylindrical wall is deeper than the existing reinforcing bar. Scraping, removing the existing rebar, placing a new outer rebar with a larger amount of rebar and / or higher strength than the existing rebar in the site where the existing concrete is beaten, A method for reinforcing an existing cylindrical wall made of reinforced concrete is provided, which includes placing a new outer concrete on a new outer reinforcing bar to form a cylindrical wall reinforcing structure.
According to the above configuration, after the existing concrete on the outer surface of the existing cylindrical wall is deeper than the existing rebar and the existing rebar is removed, the amount of rebar is larger than the existing rebar and / or the strength is increased. Since the new outer reinforcing bar is arranged, the cylindrical wall can be reinforced while reducing the increase in weight. Thereby, it is possible to effectively prevent the cylindrical wall reinforcing structure from being damaged, collapsed, or toppled at the time of an earthquake and to improve the earthquake resistance.
Moreover, according to the above structure, in the site | part reinforced, the external surface is in the state where concrete was beaten and roughened over the whole surface. That is, compared with the conventional method, the area of the roughening surface and the degree of unevenness are increased, and the adhesion strength of the joining surface is increased, so the number of anchors installed per unit area and the diameter of the anchor can be reduced. Is possible. Thereby, construction cost can be reduced more.

The turning of the existing concrete and the removal of the existing reinforcing bar are performed over the entire circumference of the existing cylindrical wall, the new outer reinforcing bar includes a horizontal reinforcing bar, The bars may be continuously arranged over the entire circumference of the cylindrical wall.
According to the configuration as described above, since the seismic resistance can be improved without fixing the lateral bars of the new outer reinforcing bar to the existing frame, it is possible to effectively increase the seismic resistance even without the peripheral frame. it can.
Moreover, in order to reinforce the outer side of the existing cylindrical wall by arranging a reinforcing bar that can resist tensile stress over the entire circumference, this reinforcing bar occurs in a state where the temperature inside the cylindrical wall is higher than the outside temperature. It acts as a tag that restrains expansion of the cylindrical wall in the circumferential direction due to the above-described temperature stress, thereby preventing cracks in the concrete that occur on the outer surface of the cylindrical wall reinforcing structure.

For the outer surface on the upper side of the existing cylindrical wall, the existing concrete is wound and the existing reinforcing bar is removed, and the new outer reinforcing bar includes an outer vertical bar, and the lower side of the existing cylindrical wall is A new inner vertical bar is arranged on the inner surface, and the inner concrete is further beaten on the inner surface, and the lower end of the outer vertical bar and the upper end of the inner vertical bar overlap in the vertical direction. May be further included.
According to the above configuration, since the reinforcing section in which the lower end of the outer vertical bar and the upper end of the inner vertical bar overlap in the vertical direction is provided, the outer flange on the upper part of the cylindrical wall is provided. It is possible to continuously reinforce from the rear striking reinforcement portion to the inner reinforcement reinforcement portion at the lower part of the cylindrical wall, and it is possible to effectively improve the earthquake resistance even without a peripheral frame.
Further, with respect to the above-described temperature stress generated in a state where the temperature inside the cylindrical wall is higher than the temperature outside, the amount of the reinforcing bar on the outer side where the tensile stress acts is large on the upper side of the cylindrical wall, and / or Or it is reinforced so as to increase the strength, and further, on the lower side of the cylindrical wall, for example, in the vicinity of the legs, the inner concrete is reinforced and the inner reinforcing bars are additionally arranged. Thereby, in each part of the cylindrical wall, it is possible to arrange reinforcing bars effective for tensile resistance on the tensile stress side of the acting bending moment, and the reinforcement against the temperature stress can be effectively performed.
In addition, the weight on the lower side of the cylindrical wall increases and becomes heavier by punching reinforcement, so the weight on the upper side of the cylindrical wall is relatively lighter than the weight on the lower side, and the weight distribution on the upper and lower sides is changed. Therefore, the seismic response of the cylindrical wall reinforcing structure can be further reduced, and the resistance to lifting of the foundation and pulling out from the foundation at the time of the earthquake can be increased, thereby preventing falling. Furthermore, when a roof slab is installed on the upper part of the cylindrical wall, the increase in weight due to the installation of the roof slab also increases the shear force during earthquakes that acts on the legs of the cylindrical wall reinforcement structure. It is also possible to increase the horizontal shear strength of the legs of the wall reinforcement structure.

 ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the reinforcement method of the existing cylindrical wall made from a reinforced concrete which can raise earthquake resistance effectively.

  In a preferred mode, it is possible to reduce the cost for construction.

It is the elements on larger scale which show the reinforcement method of the existing cylindrical wall made from reinforced concrete shown as embodiment of this invention. The reinforcement structure reinforced by the reinforcement method of the existing cylindrical wall made of reinforced concrete shown as an embodiment of the present invention, (a) is a perspective view, (b) is a partially omitted AA of FIG. 2 (a). 'Is a cross-sectional view. It is sectional drawing of the conventional reinforcement structure. It is the elements on larger scale which show the conventional reinforcement method. It is a perspective view of the cylindrical wall used as reinforcement object in the reinforcement method of the existing cylindrical wall made from reinforced concrete shown as embodiment of this invention. It is a temperature stress distribution figure of a cylindrical wall at the time of installing a nuclear reactor in internal space.

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

  FIG. 5 is a perspective view of an existing cylindrical wall 50 to be reinforced in the method for reinforcing an existing cylindrical wall made of reinforced concrete shown as an embodiment of the present invention.

  The existing cylindrical wall 50 is a cylindrical reinforced concrete wall and has an internal space 51 that is open upward. The existing cylindrical wall 50 includes an outer surface 52 that is a surface facing the outside air, and an inner surface 53 that is a surface facing the inner space 51. Such an existing cylindrical wall 50 may be used as a blocking wall for storing a nuclear reactor in the internal space 51 and blocking radiation from the nuclear reactor, for example, in a nuclear power plant. In this case, the existing cylindrical wall 50 has, for example, a height of about 50 m and a thickness of about 1 m.

  Such an existing cylindrical wall 50 is basically sufficient if it has sufficient strength to support its own weight, and therefore often does not have a frame surrounding a beam or column.

  FIG. 1A is a partially enlarged view of a cross section of an existing cylindrical wall 50.

  In the existing cylindrical wall 50 shown in FIG. 1A, the surface on the right side in the paper direction is the outer surface 52, and the left surface is the inner surface 53. The existing cylindrical wall 50 includes an existing concrete 54 and an inner reinforcing bar 55 and an outer reinforcing bar 56 that are arranged inside the existing concrete 54. The inner reinforcing bar 55 is a grid-like reinforcing bar composed of vertical bars 55 a and horizontal bars 55 b, and is disposed closer to the inner surface 53 in the thickness direction of the existing cylindrical wall 50. The outer reinforcing bar 56 is a grid-like reinforcing bar composed of vertical bars 56 a and horizontal bars 56 b, and is disposed closer to the outer surface 52 in the thickness direction of the existing cylindrical wall 50.

  Next, a method for constructing the reinforcing structure 1 of the existing cylindrical wall made of reinforced concrete will be described.

  First, the upper surface of the existing cylindrical wall 50, that is, the outer surface 52 in the range of more than half the height of the existing cylindrical wall 50 from the upper end of the existing cylindrical wall 50, FIGS. Use this to carry out post-rolling reinforcement as described below.

  In the post-rolling reinforcement, as shown in FIG. 1 (b), the existing concrete 54 on the outer surface 52 of the existing cylindrical wall 50 is beaten deeper than the existing outer rebar 56, and the outer rebar 56 is removed. The turning of the existing concrete 54 and the removal of the existing outer rebar 56 are performed over the entire circumference of the existing cylindrical wall 50. On the curled surface 2 that is the outer surface of the site where the existing concrete 54 has been beaten, the entire surface is unevenly formed by the curling of the existing concrete 54.

  The existing concrete 54 is ground deeper than the existing outer rebar 56, preferably less than half the thickness of the existing cylindrical wall 50.

  Then, the post-construction anchor 3 is installed on the turning surface 2 so that one end thereof is buried in the existing concrete 54 left by the turning. The other end of the post-construction anchor 3 is short and vertically bent to form a hook 3a, and the post-construction anchor 3 is installed so that the hook 3a faces upward.

  Further, as shown in FIG. 1C, a new outer reinforcing bar 4 in a lattice shape having vertical bars (outer vertical bars) 4 a and horizontal bars 4 b is arranged on the turning surface 2. The new outer reinforcing bar 4 is a reinforcing bar having a larger amount of reinforcing bars and / or higher strength than the removed outer reinforcing bar 56. That is, the pitch between the reinforcing bars is narrower than that of the existing outer reinforcing bars 56, and the thickness of the reinforcing bars is thicker than that of the existing outer reinforcing bars 56. The vertical bars 4a of the new outer reinforcing bar 4 are arranged so as to extend over the upper side of the existing cylindrical wall 50, that is, over the range of more than half the height of the existing cylindrical wall 50 from the upper end of the existing cylindrical wall 50. . The lateral bars 4b of the new outer reinforcing bar 4 are arranged so as to be continuous on the turning surface 2 over the entire circumference of the existing cylindrical wall 50. The new outer reinforcing bar 4 is arranged so that a part of the horizontal bars 4b are placed on the post-construction anchor 3 and in contact with the inner surface of the hook 3a. The reinforcing bars 4 are bound.

  After that, the mold frame is installed so that the flange surface 2 and the mold frame sandwich the new outer rebar 4, and then a new outer concrete 5 is placed between the flange surface 2 and the mold frame. After the outer concrete 5 is placed, the outer concrete 5 is cured and demolded.

  Next, additional reinforcement is performed on the lower surface of the existing cylindrical wall 50, that is, the inner surface 53 in a range of more than half the height of the existing cylindrical wall 50 from the lower end of the existing cylindrical wall 50. That is, on the inner side of the lower side of the existing cylindrical wall 50, as shown in FIG. 1 (b), the deepening of the existing concrete 54 and the removal of the existing inner reinforcing bar 55 are not performed, and the inner surface 53 is removed. Add new reinforcement and concrete on top.

  Specifically, first, on the inner surface 53, a new lattice-shaped inner vertical streak having vertical and horizontal streaks is arranged. The vertical bars of the new inner reinforcing bar are arranged so as to extend from the lower side of the existing cylindrical wall 50, that is, from the lower end of the existing cylindrical wall 50 over a range of more than half the height of the existing cylindrical wall 50. . As a result, the upper end of the vertical bars of the new inner reinforcing bar 4 is higher than the lower ends of the vertical bars 4a of the new outer reinforcing bar 4 installed on the upper side of the existing cylindrical wall 50, and the lower end and the upper end of each of the vertical bars It overlaps vertically.

  Then, after installing the mold so as to surround the new inner reinforcing bar, new inner concrete is placed between the inner surface 53 and the mold, and demolded after curing.

  2A is a perspective view, and FIG. 2B is a perspective view of the reinforcing structure 1 of the existing cylindrical wall 50 made of reinforced concrete, in which the existing cylindrical wall 50 shown in FIG. 5 is reinforced by the method described above. FIG. 3 is a cross-sectional view taken along the line AA ′ in FIG. FIG. 2A shows a building structure in which a roof slab 10 is installed and an internal space 51 is closed with respect to the reinforcing structure 1 in which the existing cylindrical wall 50 is reinforced by the above-described method.

  The reinforcing structure 1 includes an existing portion 11, an outer roll-up after-strike reinforcement portion 12, and an inward-strike reinforcement portion 13.

  The existing part 11 is formed by removing a part of the structure of the existing cylindrical wall 50. Specifically, the existing part 11 has an existing concrete 54 on the outer surface 52 deeper than the existing outer reinforcing bar 56, as shown in FIG. It is beaten at a depth of less than half the thickness of the existing cylindrical wall 50, and is formed by removing the existing outer rebar 56.

  The outer side punching reinforcement portion 12 is formed on the upper side of the existing cylindrical wall 50 at a site where the existing concrete 54 is beaten and the existing outer rebar 56 is removed.

  As shown in FIG. 1 (c), the outer side punching reinforcement portion 12 includes a new outer rebar 4 and a new outer concrete 5. As described above, the new outer reinforcing bar 4 is formed so as to have a larger amount of reinforcing bars and / or higher strength than the existing outer reinforcing bar 56 that has been removed. That is, the pitch between the reinforcing bars is narrower than that of the existing outer reinforcing bars 56, and the thickness of the reinforcing bars is thicker than that of the existing outer reinforcing bars 56.

  The curling of the existing concrete 54 and the removal of the existing outer reinforcing bars 56 on the upper side of the existing cylindrical wall 50 are performed over the entire circumference of the existing cylindrical wall 50, and as a result, the outer curling post-strike reinforcement portion 12. As shown in FIG. 2 (a), it is formed over the entire circumference on the upper side of the reinforcing structure 1. The lateral reinforcing bars 4b of the new outer reinforcing bars 4 in the outer beaten post-strengthening reinforcement part 12 are arranged so as to be continuous over the entire circumference of the existing part 11 where the existing concrete 54 is beaten.

  As shown in FIG. 1 (c), the new outer concrete 5 is placed so as to bury a new outer rebar 4.

  Further, as shown in FIG. 1 (c), the post-construction anchor 3 is installed so as to fasten the existing portion 11 and the outer-turning post-strike reinforcement portion 12. The new outer reinforcing bar 4 is fixed to the existing portion 11 by being placed and bound on the post-construction anchor 3 provided with the hook 3a.

  As shown in FIG. 2 (b), the inward side reinforcement member 13 is located on the lower side of the existing part 11, that is, in the range of more than half the height of the existing part 11 from the lower end of the existing part 11. Is formed on the inner surface 53 of the existing cylindrical wall 50. Unlike the outer side punching reinforcement part 12, the inner side reinforcement part 13 is formed on the inner surface 53 without the existing inner bar 55 being removed by deeply winding the existing concrete 54 with the installation. Has been.

  The inner side reinforcement hitting portion 13 includes a new inner vertical bar not shown and a new inner concrete. The new inner reinforcing bar is arranged on the inner surface 53. The inner side additional striking reinforcement portion 13 is produced by further striking the inner concrete on the new inner rebar.

  As shown in FIG. 2 (b), the lower end of the outer punching reinforcement portion 12 is located at a lower height than the upper end of the inner reinforcement portion 13. As a result, the vertical bars 4a of the new outer reinforcing bar 4 arranged in the outer beaten post-strike reinforcing portion 12 and the new inner reinforcing bars arranged in the inner additional reinforcing member 13 are arranged. The streaks are installed such that their lower and upper ends overlap in the vertical direction.

  The leg portion 13a, which is the lower end of the inwardly-increasing reinforcing portion 13, is formed in a tapered shape so that the thickness of the wall gradually increases from the upper side toward the lower side in contact with the foundation.

  Next, the operation and effect of the reinforcing structure 1 will be described.

  In the reinforcing structure 1 as described above, as shown in FIG. 1, the existing concrete 54 on the outer surface 52 of the existing cylindrical wall 50 is placed on the existing outer side in the outer side beat-up post-reinforcement portion 12 on the upper side of the reinforcing structure 1. After striking deeper than the reinforcing bar 56 and removing the existing outer reinforcing bar 56, a new outer reinforcing bar 4 is arranged. The new outer reinforcing bar 4 has a larger amount of reinforcing bars and / or higher strength than the existing outer reinforcing bar 56.

  In some cases, it is possible to make the thickness of the upper wall of the reinforcing structure 1 after carrying out post-rolling reinforcement thinner than the existing cylindrical wall 50. Thereby, the reinforcement which reduces an increase in weight is attained, the damage, collapse, and fall of a cylindrical wall at the time of an earthquake can be prevented effectively, and earthquake resistance can be improved.

  In addition, in the lower inner side reinforcement portion 13 on the lower side of the reinforcing structure 1, the lower inner surface 53 of the existing cylindrical wall 50 is deeply wound with concrete like the outer side punching reinforcement portion 12. It is formed by installing new inner vertical bars and new inner concrete on the inner surface 53 without removing the reinforcing bars. Thus, the weight on the lower side of the reinforcing structure 1 is increased and becomes heavier by the hitting reinforcement, so that the weight on the upper side of the reinforcing structure 1 is relatively lighter than the weight on the lower side, and the height of the center of gravity is low. As the weight distribution on the upper and lower sides is changed, the seismic response of the reinforced structure 1 is further reduced, and the resistance to lifting and pulling of the foundation during an earthquake is increased, thereby preventing a fall. can do.

  Moreover, the leg part 13a which is the lower end of the inner side additional reinforcement part 13 is formed in a taper shape so that the thickness of the wall gradually increases from the upper side toward the lower side in contact with the foundation. Thereby, it is possible to prevent the fall more effectively and to improve the earthquake resistance.

  Further, the reinforcing structure 1 has a lower center of gravity than the existing cylindrical wall 50 as described above. Therefore, it is possible to install the roof slab 10 without impairing the earthquake resistance. Furthermore, the shear rigidity in the horizontal direction of the inward additional reinforcement portion 13 is increased by additional reinforcement, and in the seismic response analysis, the natural period of the entire structure in which the roof slab 10 is installed is reinforced without the roof slab 10. It is possible to further effectively improve the earthquake resistance by keeping the natural period of the previous existing cylindrical wall 50 equal to that of the previous cylindrical wall 50 and also setting the response displacement at the top of the reinforcing structure 1 to the same level as before the reinforcement.

  Further, regarding the above-described temperature stress generated in a state where the temperature of the internal space 51 is higher than the external temperature, in the above-described reinforcing structure 1, the new outer reinforcing bar 4 on which tensile stress acts is formed above the reinforcing structure 1. The reinforcement is reinforced so that the amount of reinforcing bars is large and / or the strength is high. Further, on the lower side of the reinforcing structure 1, the inner concrete is struck repeatedly, and the inner reinforcing bars are additionally arranged. Thereby, in each part of the reinforcing structure 1, it becomes possible to arrange reinforcing bars effective for tensile resistance on the tensile stress side of the acting bending moment, so that reinforcement against temperature stress can be effectively performed.

  In addition, in the outer beaten post-strengthening reinforcement portion 12, the lateral reinforcement 4 b of the new outer reinforcement 4 is arranged continuously over the entire circumference of the existing portion 11 where the existing concrete is beaten. Thereby, it is possible to improve the earthquake resistance without fixing the horizontal bars 4b of the new outer reinforcing bars 4 to the existing frame. Further, a new vertical reinforcing bar 4a of the outer reinforcing bar 4 that is arranged in the outer beaten reinforcement portion 12 and a new inner reinforcing bar that is arranged in the inner reinforcing reinforcement portion 13 are arranged. Since the lower end and the upper end of each of them are installed so as to overlap in the vertical direction, the lower inner side of the reinforcing structure 1 and the inner inner side of the reinforcing structure 1 are further increased from the outer punching and reinforcing part 12 on the upper side of the reinforcing structure 1. Continuous reinforcement to the reinforcing portion 13 is possible. Due to these factors, even if there is no surrounding frame, it is possible to effectively improve the earthquake resistance.

  Further, the horizontal bar 4b of the new outer reinforcing bar 4 acts as a tag that restrains the expansion of the reinforcing structure 1 in the circumferential direction due to the above-described temperature stress generated when the temperature of the internal space 51 is higher than the external temperature. Thus, cracks in the concrete that occur on the outer surface of the reinforcing structure 1 can be prevented.

  In addition, when the nuclear reactor is installed in the internal space 51 in order to thicken the lower wall of the existing cylindrical wall 50 by additional reinforcement, in the active area of the worker who performs work outside the cylindrical wall It becomes possible to further improve the shielding property of radiation to the vicinity of a certain ground surface.

  In the method shown in FIG. 4, the surface of the wall 40 is partially roughened. On the other hand, according to the reinforcing structure 1 as described above, The part to be reinforced is in a state in which concrete is crushed and roughened over the entire surface. That is, compared to the conventional method, the area of the roughening surface and the degree of unevenness are increased, and the adhesion strength of the joining surface is increased. Therefore, the number of anchors 3 installed per unit area on the turning surface 2 and the anchor 3 It is possible to reduce the diameter. Thereby, construction cost can be reduced more.

  In the above-described embodiment, the lateral reinforcement 4b of the new outer reinforcing bar 4 of the outer rolling post-strike reinforcement section 12 is arranged so as to be continuous over the entire circumference of the existing section 11 where the existing concrete is beaten. However, the horizontal bars 4b do not have to be a single reinforcing bar continuous over the entire circumference. For example, a plurality of reinforcing bars may be joined by a lap joint or the like.

  In the above embodiment, the existing cylindrical wall 50 has a cylindrical shape. However, this shape may be any shape as long as the horizontal cross-sectional shape is closed, and therefore, a rectangular shape, a hexagonal shape, an octagonal shape, etc. It may be a polygon.

  Moreover, in said embodiment, when constructing the reinforcement structure 1, although the outer side roll after-strike reinforcement part 12 was constructed in front of the inner striking reinforcement part 13, it is not restricted to this. For example, the inward-strike reinforcement portion 13 may be constructed in front of the outer roll-up after-strike reinforcement portion 12, or may be constructed simultaneously.

  The preferred embodiments of the present invention have been described in detail above. However, those skilled in the art will understand that various modifications and equivalent embodiments are possible from this. .

  Therefore, the scope of rights of the present invention is not limited to this, and various modifications and improvements of those skilled in the art using the basic concept of the present invention described in the claims are also included in the present invention.

1 Reinforced structure of existing tubular wall made of reinforced concrete 2 Ridge surface 3 Post-construction anchor 4 New outer reinforcement 4a Longitudinal reinforcement (outer longitudinal reinforcement)
4b Lateral Reinforcement 5 New Outer Concrete 10 Roof Slab 11 Existing Part 12 Outer Rolling Post-Strike Reinforcement Part 13 Inner Additional Strike Reinforcement Part 50 Existing Cylindrical Wall 51 Inner Space 52 Outer Surface 53 Inner Surface 54 Existing Concrete 55 Existing Inner Reinforcement 56 Existing outer rebar

Claims (3)

A method of reinforcing an existing cylindrical wall made of reinforced concrete, having an internal space that is open upward,
Rolling the existing concrete on the outer surface of the existing cylindrical wall deeper than the existing rebar, removing the existing rebar,
Arranging a new outer reinforcing bar with a larger amount of reinforcing bars and / or higher strength than the existing reinforcing bars in the site where the existing concrete is beaten,
Placing a new outer concrete on the new outer reinforcing bar to form a cylindrical wall reinforcing structure;
A method for reinforcing an existing tubular wall made of reinforced concrete. The turning of the existing concrete and the removal of the existing reinforcing bars are performed over the entire circumference of the existing cylindrical wall,
The existing outer reinforcing bar made of reinforced concrete according to claim 1, wherein the new outer reinforcing bar includes a horizontal reinforcing bar, and the horizontal reinforcing bar is continuously arranged over the entire circumference of the existing cylindrical wall in which the existing concrete is beaten. A method of reinforcing a cylindrical wall. For the outer surface on the upper side of the existing tubular wall, the existing concrete is removed and the existing rebar is removed, and the new outer rebar includes an outer vertical rebar,
A new inner vertical bar is arranged on the inner surface of the lower side of the existing cylindrical wall, and the inner concrete is further beaten on the inner vertical bar, and the lower end of the outer vertical bar and the upper end of the inner vertical bar are , Overlapping vertically,
The method for reinforcing an existing tubular wall made of reinforced concrete according to claim 1 or 2, further comprising:

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