JP6482123B2 - Reinforcing structure and reinforcing method for existing columns - Google Patents

Description

  The present invention relates to a reinforcing structure and a reinforcing method for an existing pillar.

  The RC hoisting method to reinforce the existing pillar is to arrange a plurality of bar-shaped reinforcing bars extending in the axial direction of the existing pillar along the outer periphery of the existing pillar, and to the outside along the outer periphery of the existing pillar. This is a construction method in which extending frame-shaped reinforcing bars (hoop bars) are arranged side by side along the axial direction of the existing columns, and these grid-shaped reinforcing bars are covered with concrete to reinforce the existing columns. In the case of this construction method, it takes time to arrange the hoop bars one by one, weld the joints, and then sequentially fix them along the axial direction of the existing columns, making construction and quality control difficult. On the other hand, as another construction method for reinforcing the existing pillar, there is a construction method in which a spiral hoop line is wound around the outer circumference of the existing pillar (see, for example, Patent Documents 1 to 4).

JP 9-158494 A Japanese Patent Laid-Open No. 10-148038 JP 2000-64630 A JP-A-8-326215

  By the way, in the reinforcement of the existing pillars, there are cases where the applicable reinforcement method is limited depending on the location conditions where the existing pillars are installed. For example, when a pier is adjacent to a side road on a viaduct or when there are restrictions on building limits, it is not possible to apply a reinforcement method that increases the width (cross-sectional area) of an existing column due to reinforcement. . For this reason, in reinforcing existing pillars, in order to expand the application range of the reinforcement method, it is an important issue how to reduce the cross-sectional area intersecting the axial direction of the existing pillars after reinforcement.

  The present invention has been made from the above technical background, and an object of the present invention is to provide a reinforcing technique capable of reducing the area of a cross section that intersects the axial direction of an existing pillar after reinforcement. And

In order to solve the above-mentioned problem, the reinforcing structure for an existing column according to the first aspect of the present invention is a reinforcing structure for an existing column in which a cross-sectional shape intersecting the axial direction is formed in a circular shape, and the existing column In a state of extending in the axial direction, a plurality of metal axial streaks arranged side by side along the outer periphery of the existing pillar, and the inner diameter of the loop is smaller than the diameter of the existing pillar Provided on the outer periphery of the existing column so as to cover the metal circumferential stripes spirally wound along the outer circumference of the existing pillar in a plastically deformed state, and the axial and circumferential stripes. A mortar section, wherein the axial streak connects the plurality of axial streak bars and the plurality of axial streak bars, and the axial positions adjacent to each other are at a height position in the axial direction. It comprises a first joint member which is arranged offset in the axial direction of the muscle, and the circumferential direction It is characterized in that it comprises a plurality of circumferential muscle bar, and a second joint member for connecting said plurality of circumferential muscle bar, a.

  According to a second aspect of the present invention, in the first aspect of the present invention, the lower end portion of the axial streak is anchored to the base portion of the existing column.

  Moreover, the present invention according to claim 3 is the invention according to claim 1 or 2, wherein the axial direction bars, the circumferential direction bars, or both are small-diameter deformed PC steel bars or high-strength reinforced concrete bars. It is configured.

  Further, the present invention according to claim 4 is the invention according to claim 1 or 2, wherein the axial bars and the circumferential bars are formed of a combination of a small-diameter deformed PC steel bar and a high-strength reinforced concrete bar. It is characterized by being.

According to a fifth aspect of the present invention, there is provided a method of reinforcing an existing column according to the present invention, wherein the cross-sectional shape intersecting the axial direction is formed in a circular shape, and extends in the axial direction of the existing column. a plurality of metallic axial muscle of standing, the step of placing side by side along the outer periphery of the existing columns, the inner loop diameter the existing pillar diameter plastically deformed metal in a smaller diameter than the A step of spirally winding a circumferential streak around the outer periphery of the existing column, and a step of forming a mortar portion on the outer periphery of the existing column so as to cover the axial streak and the circumferential streak. In the directional bar installation step, the plurality of axial bars are connected by the first joint member along the axial direction of the existing column, and the axial bars adjacent to each other include the first joint member. the height position arranged offset in the axial direction of the axial muscles It has a degree, in the winding process of the circumferential muscle comprises the step of connecting the second joint member along a plurality of circumferential muscle bar in a circumferential direction of the existing columns, characterized in that.

  According to a sixth aspect of the present invention, there is provided the method for reinforcing an existing column according to the fifth aspect of the invention, wherein the axial streak installation step includes a step of forming an anchor hole in a base portion of the existing column. And a step of inserting and fixing the lower end portion of the axial streak into the anchor hole.

  According to invention of Claim 1, it becomes possible to reduce the area of the cross section which cross | intersects the axial direction of the existing pillar containing a reinforcement structure.

  According to the invention described in claim 2, it is possible to improve the mechanical strength of the axial streak.

  According to invention of Claim 3, it becomes possible to reduce the area of the cross section which cross | intersects the axial direction of the existing pillar containing a reinforcement structure.

  According to invention of Claim 4, it becomes possible to reduce the area of the cross section which cross | intersects the axial direction of the existing pillar containing a reinforcement structure.

  According to invention of Claim 5, it becomes possible to reduce the area of the cross section which cross | intersects the axial direction of the existing pillar containing a reinforcement structure.

  According to the invention described in claim 6, it is possible to improve the mechanical strength of the axial streak.

It is a principal part perspective view of the bridge which has a pier part to which the reinforcement structure which concerns on one embodiment of this invention was applied. It is the principal part perspective view which removed the surface mortar part of the reinforcement structure part which reinforces the pier part of the bridge of FIG. 1, and showed the reinforcement reinforcing bar part in a reinforcement structure part. It is principal part sectional drawing of the bridge of FIG. It is a principal part expanded sectional view of the lower part side of the pier part of the bridge of FIG. It is a principal part expanded sectional view of the upper part side of the pier part of the bridge of FIG. It is sectional drawing which cross | intersects the axial direction of the pier part of the bridge of FIG. It is a principal part expanded sectional view of the pier part of FIG. It is principal part sectional drawing of the modification of the bridge of FIG. It is a principal part expanded sectional view of the lower part side of the bridge of FIG. It is a principal part expanded sectional view of the upper part side of the bridge of FIG. (A) is the principal part perspective view of the bridge in a reinforcement process, (b) is the principal part expansion perspective view of the bridge of FIG. 11 (a). (A) is a principal part perspective view of the bridge in the reinforcement process following FIG. 11, (b) is a principal part enlarged perspective view of the bridge of FIG. 12 (a). (A) is a principal part perspective view of the bridge in the reinforcement process following FIG. 12, (b) is a principal part enlarged perspective view of the bridge of FIG. 13 (a). (A) is a principal part perspective view of the bridge in the reinforcement process following FIG. 13, (b) is a principal part enlarged perspective view of the bridge of FIG. 14 (a). (A) is a principal part perspective view of the bridge in the reinforcement process following FIG. 14, (b) is a principal part enlarged perspective view of the bridge of FIG. 15 (a). Reinforcing bar strength, distance between existing structure and axial streak, axial streak diameter, circumference when reinforcing bar material (axial and circumferential bars) of the reinforcing structure constituting the bridge in Fig. 1 is changed It is explanatory drawing which showed the measurement result of the diameter of a direction stripe, cover thickness, and reinforcement thickness. It is a principal part expanded sectional view of the surface which cross | intersects the axial direction of the pier part of FIG.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a perspective view of a main part of a bridge having a pier portion to which the reinforcing structure according to the present embodiment is applied, and FIG. 2 is a diagram in which a mortar portion on the surface layer of the reinforcing structure portion for reinforcing the pier portion of the bridge in FIG. It is the principal part perspective view which showed the reinforcing bar part in a reinforcement structure part.

  The bridge 1 is an aerial structure that passes, for example, a road, a railroad, or a waterway, and includes a foundation 2 installed on the ground, a pier (existing pillar) 3 erected on the foundation 2, and a pier And an upper structure portion 4 supported by the portion 3.

  The pier 3 of the bridge 1 is made of, for example, columnar concrete having a circular cross section that intersects in the axial direction, and a reinforcing structure 5 that reinforces the pier 3 is formed on the outer periphery of the pier 3. It is provided so as to cover almost the entire outer peripheral surface. In addition, although it does not specifically limit, the diameter of the pier part 3 is about 400-2000 mm, for example. Moreover, the shape of the cross section which crosses the axial direction of the pier part 3 applied is, for example, an elliptical shape or a rounded rectangular shape (a shape in which two parallel lines of equal length and two semicircles are combined) ).

  The reinforcing structure 5 includes a plurality of main reinforcing bars (axial reinforcing bars) 5a erected along the axial direction of the pier 3 and a helical hoop that is spirally wound around the outside of the plurality of main reinforcing bars 5a ( Circumferential reinforcement) 5b and a mortar portion (covering material) 5c provided on the outer periphery of the pier 3 in a state of covering these reinforcing reinforcing bars.

  Next, the structure of the reinforcement structure part 5 is demonstrated with reference to FIGS. 3 is a cross-sectional view of the main part of the bridge of FIG. 1, FIG. 4 is an enlarged cross-sectional view of the main part of the bridge pier of FIG. 3, and FIG. 5 is an enlarged main part of the upper part of the pier of the bridge of FIG. 6 is a cross-sectional view crossing the axial direction of the pier part of the bridge of FIG. 1, and FIG. 7 is an enlarged cross-sectional view of the main part of the pier part of FIG.

  As shown in FIG. 3, the main reinforcing bar 5 a is made of, for example, a rod-like high-tensile reinforcing bar (SBPD 1275/1420: small-diameter deformed PC steel bar (JIS 3137: 2008) or the like), and is erected along the axial direction of the pier 3. In this state, a plurality of them are installed along the outer periphery of the pier 3. Since the bending strength of the pier 3 can be improved by providing the plurality of main bars 5a on the outer periphery of the pier 3 in this way, the application range of the reinforcing structure 5 can be expanded. Moreover, since the cross-sectional area of the main reinforcing bar 5a can be reduced by forming the main reinforcing bar 5a with a high-strength reinforcing bar, the thickness of the reinforcing structure part 5 can be reduced, and the bridge pier part 3 including the reinforcing structure part 5 can be reduced. It is possible to reduce the area of the cross section intersecting with the axial direction. For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded.

  As shown in FIG. 4, the lower end portion of the main muscle 5 a is inserted into an anchor hole 2 a vertically drilled in the upper part of the base portion 2 and anchored. Thereby, since the plurality of main muscles 5a can be fixed, the mechanical strength of the plurality of main muscles 5a can be improved. A mechanical joint such as a coupler 6a is screwed to the lower end portion of the main bar 5a. Thereby, since the diameter of the lower end part of the main reinforcing bar 5a can be relatively enlarged by the amount of the coupler 6a, the fixing effect of the lower end part of the main reinforcing bar 5a can be improved. Grooves 2b and 2b extending along the circumferential direction of the anchor hole 2a are formed on the inner wall surface of the anchor hole 2a.

  Further, as shown in FIG. 5, the upper end portion of the main bar 5 a is inserted and fixed in a fixing hole 4 a that is vertically drilled in the lower portion of the upper structure portion 4. Similar to the lower end of the main bar 5a, a mechanical joint such as a coupler 6b is screwed to the upper end of the main bar 5a. Thereby, the fixing effect of the upper end part of the main reinforcement 5a can be improved similarly to the lower end part of the main reinforcement 5a. Grooves 4b and 4b extending along the circumferential direction of the fixed hole 4a are formed on the inner wall surface of the fixed hole 4a.

  As shown in FIGS. 3 to 5, each main reinforcing bar 5 a is formed by connecting at least two reinforcing bars (axial reinforcing bar) with a mechanical joint such as a coupler (first joint member) 6 c. It is configured. This can reduce or eliminate variations in product strength due to differences in local conditions and skill levels. Further, when each main bar 5a is installed, the main bar 5a can be easily connected to the anchor hole 2a and the fixed hole 4a by inserting the reinforcing bars for constituting the main bar 5a into the anchor hole 2a and the fixed hole 4a and then connecting them with the coupler 6c. Can be inserted. Further, as shown in FIG. 3, the height positions of the couplers 6c, 6c of the main bars 5a, 5a adjacent to each other along the outer periphery of the pier 3 are shifted in the axial direction of the main bar 5a. Thereby, compared with the case where the height positions of the couplers 6c, 6c of the main bars 5a, 5a adjacent to each other along the outer periphery of the pier part 3 are matched, the overall bending strength of the plurality of main bars 5a is improved. Can do. The coupler 6c can be, for example, an end threaded joint, a steel pipe crimp joint, a mortar filling joint, or a combination of these joints. The end threaded joint is a joint in which a threaded part is friction-welded to a deformed reinforcing bar or a threaded end of a deformed reinforcing bar is joined with a coupler, and is tightened and fixed with a nut. The steel pipe crimp joint is a joint that covers a joint between a deformed reinforcing bar and a deformed reinforcing bar, crimps it with a jack, and bites the sleeve into a node of the deformed reinforcing bar to fix it. Furthermore, the mortar filling type joint is a joint that is fixed by filling a non-shrink mortar between the deformed reinforcing bar and the sleeve.

  On the other hand, as shown in FIGS. 3 to 6, the spiral hoop bar 5b is made of, for example, a rod-like high-tensile reinforcing bar (SBPD1275 / 1420: small-diameter deformed PC steel bar (JIS 3137: 2008) or the like), and a plurality of main bars 5a. Is wound spirally along the outer periphery of the pier 3. By providing such a spiral hoop muscle 5b, the shear strength of the pier 3 can be improved. Further, by forming the helical hoop bar 5b with a high-strength reinforcing bar, it can be bent back and can be wound locally. Furthermore, since the cross-sectional area of the spiral hoop bar 5b can be reduced by forming the spiral hoop bar 5b with a high-strength reinforcing bar, the thickness of the reinforcing structure 5 can be reduced, and the bridge pier 3 (reinforcement). It is possible to reduce the area of the cross section that intersects the axial direction of (including the structure portion 5). For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded.

  The spiral hoop muscle 5b is connected to the main muscle 5a by a binding line (not shown) in a state where the axial interval of the pier 3 is adjusted. The spiral hoop muscle 5b is wound around the outer periphery of the pier 3 in a state of being plastically deformed so that the inner diameter (loop inner diameter) of the loop is smaller than the diameter of the pier 3. Thereby, since the spiral hoop muscle 5b can be wound in a state of being in close contact with the pier part 3, the thickness of the reinforcing structure part 5 can be reduced, and the axis of the pier part 3 including the reinforcing structure part 5 can be reduced. The area of the cross section that intersects the direction can be reduced. For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded. Moreover, since the helical hoop muscle 5b can be tightly wound around the pier part 3, the reinforcement strength of the pier part 3 can be improved. Although not particularly limited, the spiral hoop muscle 5b has a loop inner diameter reduced, for example, by about 5% of the diameter of the pier 3.

Further, the helical hoop bar 5b is configured by connecting at least two reinforcing bars ( circumferential bars ) with a mechanical joint such as a coupler (second joint member) 6d. This can reduce or eliminate variations in product strength due to differences in local conditions and skill levels. Further, when the helical hoop muscle 5b is installed, a reinforcing bar for constituting the helical hoop muscle 5b is inserted into the anchor hole 2a and the fixing hole 4a and then connected by the coupler 6d, whereby the helical hoop muscle 5b is connected to the anchor hole 2a and the fixing hole. 4a can be easily inserted. Further, as described above, the loop inner diameter of the spiral hoop bar 5b is plastically deformed so as to be smaller than the diameter of the pier part 3. Therefore, when the spiral hoop bar 5b is constituted by a single reinforcing bar, the spiral hoop bar As a result of large stress applied to the muscle 5b and distortion, the spiral hoop muscle 5b is deteriorated. On the other hand, in the present embodiment, the spiral hoop muscle 5b is composed of a plurality of reinforcing bars, so that the stress generated in the spiral hoop muscle 5b can be dispersed and the distortion can be reduced. Can be suppressed or prevented. The coupler 6d used in the spiral hoop line 5b is the same as the coupler 6c used in the main line 5a.

  The mortar part 5c is a member that covers and protects a grid-like reinforcing reinforcing bar part composed of a plurality of main reinforcing bars 5a and helical hoop bars 5b. When mortar is used, the filling property is good and the adhesiveness with existing concrete (pier pier 3) is excellent. Moreover, since the thickness of the reinforcement structure part 5 can be made thin compared with the case where concrete is used, the area of the cross section which cross | intersects the axial direction of the bridge pier part 3 containing the reinforcement structure part 5 can be made small. For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded. Moreover, since the weight of the reinforcement structure part 5 can be reduced, the burden to the base part 2 can be reduced.

  Here, in the above description, the case where the coupler is connected to the upper and lower ends of the main bar 5a for fixing the main bar 5a has been described. However, the present invention is not limited to this and can be variously changed. 8 is a cross-sectional view of a main part of a modification of the bridge of FIG. 1, FIG. 9 is an enlarged cross-sectional view of a main part on the lower side of the bridge in FIG. 8, and FIG. is there. Here, a case where the flange portions 5af are integrally formed at the upper and lower ends of the main bar 5a and the upper and lower ends of the main bar 5a are partially large in diameter is illustrated. By providing the flange portions 5af at the upper and lower ends of the main bar 5a, the fixing effect of the main bar 5a can be improved. In addition, since the couplers connected to the upper and lower ends of the main bar 5a become unnecessary, the cost can be reduced.

  Next, an example of the reinforcement method of this Embodiment is demonstrated with reference to FIGS. (A) of FIGS. 11-15 is a principal part perspective view of the bridge in a reinforcement process, (b) is a principal part expansion perspective view of (a) of FIGS. 11-15.

  First, as shown in FIG. 11, after deposits and fragile portions on the surface of the pier 3 are removed by a disk grinder or a water jet, a plurality of pieces are formed on the upper surface of the foundation 2 along the outer periphery of the pier 3 of the bridge 1. The anchor holes 2a are drilled vertically, and a plurality of fixing holes 4a (see FIG. 3 and the like) are drilled in the ceiling surface of the upper structure portion 4.

  Then, as shown in FIG. 12, after inserting a reinforcing bar (axial bar) 5au constituting the main reinforcing bar 5a into each anchor hole 2a or each fixing hole 4a, as shown in FIG. 13, the reinforcing bar 5au. One main reinforcing bar 5a is formed by connecting another reinforcing bar 5au to the extending end of each of them by a coupler 6c, and a plurality of main reinforcing bars 5a are erected along the outer periphery of the pier 3. This can reduce or eliminate variations in product strength due to differences in local conditions and skill levels. Moreover, each main muscle 5a can be installed easily.

  Subsequently, as shown in FIG. 14, the spiral hoop muscle 5 b is wound around the outer periphery of the pier 3 so as to surround the plurality of main bars 5 a on the outer periphery of the pier 3. At this time, the spiral hoop muscle 5b is wound around the outer periphery of the bridge pier 3 in a state of being plastically deformed so that the inner diameter of the loop is smaller than the diameter of the surface intersecting the axial direction of the pier 3. Thereby, since the spiral hoop muscle 5b can be wound in a state of being in close contact with the pier part 3, the thickness of the reinforcing structure part 5 can be reduced, and the axis of the pier part 3 including the reinforcing structure part 5 can be reduced. The area of the cross section that intersects the direction can be reduced. For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded. Moreover, since the helical hoop muscle 5b can be tightly wound around the pier part 3, the reinforcement strength of the pier part 3 can be improved. Further, also in this case, by forming a single hoop hoop 5b by connecting a plurality of reinforcing bars with the coupler 6d, the stress generated in the hoop hoop 5b can be dispersed and the distortion can be reduced. Deterioration of the hoop muscle 5b can be suppressed or prevented.

  Then, after adjusting the space | interval of the spiral hoop muscle 5b part adjacent to the axial direction of the pier part 3, the spiral hoop muscle 5b is tied with the main muscle 5a by a binding line in several places. At this time, it is not necessary to externally fit the hoops one by one and weld the seam, so that it does not take time and can facilitate construction and quality control. Moreover, since the spiral hoop muscle 5b can be wound around the outer periphery of the bridge pier part 3 by an existing technique without adopting a new construction method, the winding work of the spiral hoop muscle 5b can be easily performed.

  Thereafter, as shown in FIG. 15, the mortar part 5c is formed by blowing and solidifying the mortar over the entire outer peripheral surface of the pier part 3 so as to cover the reinforcing reinforcing bar part composed of the main reinforcing bars 5a and the helical hoop bars 5b. . At this time, by forming the mortar portion 5c by spraying, it is possible to improve the construction efficiency as compared with the case of using a temporary frame for mortar filling, so the construction time of the reinforcing structure portion 5 can be shortened. The construction period can be shortened. Moreover, since the thickness of the reinforcement structure part 5 can be made thin by using mortar compared with concrete, the axis | shaft of the pier part 3 (including the reinforcement structure part 5 (refer FIG.1 and FIG.2 etc.)) The area of the cross section that intersects the direction can be reduced. For this reason, since a building limit can be expanded, the application range of the reinforcement structure part 5 can be expanded. Moreover, since the weight of the reinforcement structure part 5 can be reduced, the burden to the base part 2 can be reduced.

  FIG. 16 shows the strength of the reinforcing bars, the separation between the existing structure and the axial bars, and the axial bars when the material of the reinforcing bars (axial bars and circumferential bars) of the reinforcing structure constituting the bridge of FIG. 1 is changed. FIG. 17 is an enlarged cross-sectional view of the main part of the surface intersecting the axial direction of the pier part of FIG. 1.

  Here, the axial bars (main bars 5a) are arranged such that the product of the reinforcing bar diameter and the tensile strength exceeds the standard method. Further, the circumferential streaks (spiral hoops 5b) are arranged with 25 × σy as the upper limit. Further, in FIG. 16, reference signs A and B exemplify the material of the reinforcing reinforcing bar, the reference sign A indicates the above-described small-diameter deformed PC steel bar, and the reference sign B indicates a high-strength reinforcing bar (for example, USD685: high strength). Steel bars for reinforced concrete (certified by the Minister of Land, Infrastructure, Transport and Tourism, certification number MSRB-0081) are shown. In addition, as illustrated in FIG. 17, the cover thickness is a distance (length) t <b> 1 from the outermost edge of the steel material (rebar, etc.) of the reinforcing structure 5 to the surface of the reinforcing structure 5. The reinforcing thickness is the thickness t2 of the reinforcing structure 5 provided around the pier 3. Moreover, the empty t3 between the reinforcing bars is a distance between the adjacent main bars 5a and the main bars 5a.

First, the left column (1) of FIG. 16 assumes standard reinforcement of the pier structure, and the axial reinforcement (main reinforcement 5a) and the circumferential reinforcement (spiral hoop reinforcement 5b) of the reinforcement structure 5 are provided. The measurement result in the case of being composed of ordinary reinforcing bars is shown. The normal rebar here means a rebar of the type (strength, diameter, etc.) used in a normal reinforced concrete structure, for example, yield strength 235 N / mm ^{2 to} 490 N defined in JIS G3112: 2010. / Mm ² , which means a reinforcing bar with a reinforcing bar diameter of 4.3 mm (D4) to 50.8 mm (D51).

Among these, the 1st line has shown the measurement result in case the reinforcement structure part 5 is comprised by the concrete winding method, for example. In the concrete winding method, concrete is used as a covering material on the outer periphery of the reinforcing structure 5. The 2nd line has shown the measurement result in case the reinforcement structure part 5 is comprised by the spraying mortar construction method, for example. In the spray mortar method, mortar is used as a covering material for the outer periphery of the reinforcing structure 5. In any case, the strength of each of the axial and circumferential streaks is, for example, 345 N / mm ² . Further, the diameter of the axial streak is, for example, 35 mm, and the diameter of the circumferential streak is, for example, 25 mm.

  However, the separation between the existing structure and the axial streak is, for example, 100 mm or more when concrete is used as the covering material, whereas in the case of mortar as the covering material, the filling property during construction is improved. Therefore, it is 0 mm, for example. That is, in the concrete standard specifications, etc., it is stipulated that a space is provided around the reinforcing bar, and the size is assumed to secure 4/3 or more of the maximum aggregate size of the concrete (or mortar) to be driven. (The maximum aggregate size of the concrete is set to 3/4 or less of the space t3 between the reinforcing bars (see FIG. 17)). For this reason, in concrete used for general purposes, the maximum aggregate size is 20 mm or 25 mm, and it is necessary to secure a space of 27% or 33 mm or more of 4/3 thereof. On the other hand, when mortar was used as the covering material, it was confirmed that seismic performance was exhibited even when no space was provided between the pier 3 and the axial reinforcement (main reinforcement 5a). As shown in FIG. 17 and the like, the space between the existing structure (pier pier 3) and the axial reinforcement (main reinforcement 5a) could be reduced to 0 mm beyond the specified range. Further, the “cover thickness” of the covering material is, for example, 70 mm or more when using concrete as the covering material, whereas when mortar is used as the covering material, the durability is improved. For example, 30 mm. The reinforcing thickness is, for example, 250 mm when using concrete as a covering material, whereas it can be set to, for example, 90 mm when using mortar, and concrete is used as a covering material. It was possible to make it thinner than half of the case.

  Next, the left column (2) of FIG. 16 shows the case where the axial reinforcement (main reinforcement 5a), the circumferential reinforcement (spiral hoop reinforcement 5b), or both, are composed of the above-described small-diameter deformed PC steel bars. The measurement results are shown.

Among these, the 1st line in the left column (2) has shown the measurement result in case both the axial direction reinforcement and the circumferential direction reinforcement are comprised with the small diameter deformed PC steel rod. In this case, the strength of each of the axial streak and the circumferential streak is, for example, 1275 N / mm ² . Further, the diameter of the axial streak is, for example, 19 mm, and the diameter of the circumferential streak is, for example, 15 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. And the reinforcement thickness could be made into 64 mm, for example, and could be made the thinnest.

The second line in the left column (2) shows the measurement results when the axial direction bars are composed of, for example, small-diameter deformed PC steel bars and the circumferential direction bars are composed of the above-described ordinary reinforcing bars. ing. In this case, the strength of the axial streak is, for example, 1275 N / mm ² , and the strength of the circumferential streak is, for example, 345 N / mm ² . Further, the diameter of the axial streak is, for example, 19 mm, and the diameter of the circumferential streak is, for example, 25 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. And the reinforcement thickness could be made into 74 mm, for example, and could be made thinner than the case of the standard spraying mortar construction method (the 2nd line in the left column (1)).

The third row in the left column (2) is the reverse of the second row in the same column, and the axial reinforcement is composed of, for example, the above-mentioned ordinary reinforcing bars, and the circumferential reinforcement is a small-diameter deformed PC steel rod. The measurement result when configured is shown. In this case, the strength of the axial streak is, for example, 345 N / mm ² , and the strength of the circumferential streak is, for example, 1275 N / mm ² . Further, the diameter of the axial streak is, for example, 35 mm, and the diameter of the circumferential streak is, for example, 15 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. The reinforcing thickness can be, for example, 80 mm, and can be made thinner than in the case of the standard spraying mortar method (second line in the left column (1)).

  Next, the left column (3) of FIG. 16 shows the measurement in the case where the axial reinforcement (main reinforcement 5a), the circumferential reinforcement (spiral hoop reinforcement 5b), or both are made of the above-described high-strength reinforced concrete bars. Results are shown.

Among these, the 1st line in the left column (3) has shown the measurement result in case both the axial direction reinforcement and the circumferential direction reinforcement are comprised with the steel bars for high-strength reinforced concrete. In this case, the strength of each of the axial streak and the circumferential streak is, for example, 685 N / mm ² . In addition, the diameter of the axial streak is, for example, 25 mm, and the diameter of the circumferential streak is, for example, 22 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. The reinforcing thickness could be, for example, 77 mm, which was thinner than in the case of the standard spraying mortar method (second line in the left column (1)).

The second line in the left column (3) shows the measurement results when the axial reinforcement is made of, for example, high-strength reinforced concrete steel bars and the circumferential reinforcement is made of the above-mentioned ordinary reinforcing bars. Yes. In this case, the strength of the axial streak is 685 N / mm ² , for example, and the strength of the circumferential streak is 345 N / mm ² , for example. The diameters of the axial and circumferential streaks are both 25 mm, for example. Further, the “cover thickness” of the covering material is, for example, 30 mm. The reinforcing thickness can be, for example, 80 mm, and can be made thinner than in the case of the standard spraying mortar method (second line in the left column (1)).

The third line in the left column (3) is the reverse of the second line in the same column, and the axial bars are composed of, for example, the above-mentioned ordinary reinforcing bars, and the circumferential bars are composed of high-strength steel bars for reinforced concrete. The measurement results are shown when In this case, the strength of the axial streak is, for example, 345 N / mm ² , and the strength of the circumferential streak is, for example, 685 N / mm ² . Further, the diameter of the axial streak is, for example, 35 mm, and the diameter of the circumferential streak is, for example, 22 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. And the reinforcement thickness could be 87 mm, for example, and could be made thinner than the case of the standard spraying mortar method (the second line in the left column (1)).

  Next, in the left column (4) of FIG. 16, the axial reinforcement (main reinforcement 5a) and the circumferential reinforcement (spiral hoop reinforcement 5b) are composed of a combination of the above-described small-diameter deformed PC steel bar and high-strength reinforced concrete steel bar. The measurement results are shown when

Among these, the 1st line in the left column (4) is a measurement in the case where the axial bars are composed of small-diameter deformed PC steel bars and both the circumferential bars are composed of high-strength reinforced concrete bars. Results are shown. In this case, the strength of the axial streak is, for example, 1275 N / mm ² , and the strength of the circumferential streak is, for example, 685 N / mm ² . Further, the diameter of the axial streak is 19 mm, for example, and the diameter of the circumferential streak is 22 mm, for example. Further, the “cover thickness” of the covering material is, for example, 30 mm. And the reinforcement thickness could be 71 mm, for example, and could be made thinner than the case of the standard spraying mortar method (the 2nd line in the left column (1)).

The second row in the left column (4) is the reverse of the first row in the same column, and the axial bars are made of, for example, high-strength reinforced concrete bars, and the circumferential bars are small-diameter deformed PC steel bars. The measurement result when configured is shown. In this case, the strength of the axial streak is, for example, 685 N / mm ² , and the strength of the circumferential streak is, for example, 1275 N / mm ² . Further, the diameter of the axial streak is, for example, 25 mm, and the diameter of the circumferential streak is, for example, 15 mm. Further, the “cover thickness” of the covering material is, for example, 30 mm. The reinforcing thickness can be, for example, 70 mm, and can be made thinner than in the case of the standard spraying mortar method (second row in the left column (1)).

  As described above, by using a small-diameter deformed PC steel bar or a high-strength reinforced concrete steel bar as the reinforcing bar of the reinforcing structure 5, the strength of the reinforcing bar can be increased and the diameter of the reinforcing bar can be reduced. The reinforcing thickness of the reinforcing structure 5 could be reduced. In particular, when the axial reinforcing bars (main bars 5a) and the circumferential reinforcing bars (spiral hoop bars 5b) are made of small-diameter deformed PC steel bars, the reinforcement thickness can be reduced most. In addition, the reinforcement thickness is reduced in the case where normal reinforcing bars are not used as the material for the axial reinforcement (main reinforcement 5a) and the circumferential reinforcement (spiral hoop reinforcement 5b) compared to the case where normal reinforcement is used. I was able to. Further, by using sprayed mortar instead of concrete as a covering material for reinforcing reinforcing bars of the reinforcing structure 5, the filling property and durability were improved, and the cover thickness of the reinforcing structure 5 could be reduced. .

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. It is not a thing. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  For example, in the above-described embodiment, the case where the mortar portion is formed by spraying has been described. However, the present invention is not limited to this. For example, a temporary frame is assembled on the outer periphery of the reinforcing reinforcing bar portion, and the mortar is placed in the temporary frame. The mortar part may be formed by injecting.

  In the above-described embodiment, the case where the present invention is applied to the reinforcement of a bridge pier has been described. However, the present invention is not limited to this. For example, the reinforcement of other existing columns such as the reinforcement of a pillar of a building. Can be applied to.

DESCRIPTION OF SYMBOLS 1 Bridge 2 Base part 2a Anchor hole 2b Groove 3 Bridge leg part 4 Upper structure part 4a Fixed hole 4b Groove 5 Reinforcement structure part 5a Main reinforcement 5au Reinforcing bar 5af Flange part 5b Spiral hoop reinforcement 5c Mortar part 6a, 6b, 6c Coupler A Small-diameter variant PC steel bar B Steel bar for high-strength reinforced concrete

Claims (6)

It is a reinforcement structure of an existing pillar in which the shape of the cross section intersecting the axial direction is formed in a circular shape,
A plurality of metal axial streaks arranged side by side along the outer periphery of the existing pillar in a state of extending in the axial direction of the existing pillar;
Metal circumferential streaks spirally wound along the outer periphery of the existing column in a state where the inner diameter of the loop is plastically deformed to a diameter smaller than the diameter of the existing column,
A mortar portion provided on the outer periphery of the existing pillar so as to cover the axial streak and the circumferential streak;
With
The axial streak is
A plurality of axial bars,
A first joint member that connects the plurality of axial bars and is disposed so that a height position of the axial bars adjacent to each other is shifted in the axial direction of the axial bars;
With
The circumferential muscle is
A plurality of circumferential bars,
A second joint member for connecting the plurality of circumferential reinforcing bars;
A reinforcing structure for an existing pillar, characterized by comprising:   The reinforcing structure for an existing column according to claim 1, wherein a lower end portion of the axial streak is anchored to a base portion of the existing column.   The reinforcing structure for an existing column according to claim 1 or 2, wherein the axial direction bars, the circumferential direction bars, or both are made of a small-diameter deformed PC steel bar or a high-strength reinforced concrete steel bar.   The reinforcing structure for an existing column according to claim 1 or 2, wherein the axial direction bars and the circumferential direction bars are composed of a combination of a small-diameter deformed PC steel bar and a high-strength reinforced concrete bar. A method of reinforcing an existing pillar in which the shape of a cross section intersecting the axial direction is formed in a circular shape,
Installing a plurality of metal axial streaks extending in the axial direction of the existing columns side by side along the outer periphery of the existing columns;
A step of spirally winding a metal circumferential streak plastically deformed to a diameter smaller than the diameter of the existing column with an inner diameter of the loop around the existing column;
Forming a mortar part on the outer periphery of the existing pillar so as to cover the axial streak and the circumferential streak;
Have
In the axial streak installation step, a plurality of axial stiffeners are connected by a first joint member along the axial direction of the existing pillar, and the first joint is connected to the axial streak adjacent to each other. Having a step of disposing the height position of the member in the axial direction of the axial streak ,
In the winding step of the circumferential bars, a plurality of circumferential bars are connected by a second joint member along the circumferential direction of the existing columns.
A method for reinforcing an existing pillar. The installation process of the axial streaks
Forming an anchor hole in the foundation of the existing pillar;
Inserting and fixing the lower end of the axial streak into the anchor hole;
The method for reinforcing an existing pillar according to claim 5, comprising:

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