JP6365948B2 - External mounting method of ribbed split steel sheet - Google Patents

Description

  The present invention relates to a method for attaching a ribbed split steel sheet used in a hyper seismic external reinforcement method.

As a seismic reinforcement method for reinforced concrete columns in existing buildings, laminated steel plates with ribs are placed on the entire circumference or outer surface of existing reinforced concrete columns, and strip-like continuous fiber sheets (hereinafter abbreviated as fiber sheets ) are laminated on these steel plates. A method of forming a seismic reinforcement structure for an existing reinforced concrete column by injecting a grout material into a space provided between the steel plate and the existing reinforced concrete column (hereinafter referred to as a hyper seismic method). It has been proposed (Patent Document 1 and Patent Document 2).

The hyper seismic method is classified into “full-round reinforcement” that reinforces the periphery of the column and “external reinforcement” that reinforces the outer periphery of the column facing the outside of the column and the column with sleeve walls. .
As for external reinforcement, after assembling a newly-arranged bending reinforcement bar, an adhesive anchor and a connection anchor, in order to horizontally restrain the flange part of this thin steel plate, a tie bar is installed in the horizontal direction and its end part The existing concrete column and the reinforcing part are integrated by tightly bonding to a thin steel plate with a nut via a flat plate washer (hereinafter abbreviated as a washer) and filling high fluid mortar between the existing concrete column surface and the thin steel plate. This is a construction method to achieve
(1) Installation of bending reinforcement bars (2) Installation of adhesive anchors (3) Installation of connection anchors (4) Installation of split steel plates with ribs (5) Installation of tie bars (6) Fiber sheet affixing (7) Suppression plate installation (8) High flow mortar placement (9) Mortar finishing, Fig. 1 shows the construction outline.

Japanese Patent Application No. 2011-284347 (Japanese Patent Laid-Open No. 2013-133737) Japanese Patent Application No. 2012-045733 (Japanese Patent Laid-Open No. 2013-181332)

When installing tie bars and connecting anchors on ribbed split steel plates in the hyper seismic external reinforcement method, a method is adopted in which the ends of the tie bars and connecting anchors are projected outside the steel plates and fastened to the ribbed split steel plates with washers and nuts. ing. However, in the affixing operation of the fiber sheet, the protruding portion is a negative factor with respect to workability and reinforcement.
The purpose of attaching the fiber sheet to the ribbed divided steel sheet is to improve the horizontal restraining effect. In order to obtain the effect, it is important that the fiber sheet is applied evenly and parallel to the steel sheet without being cut.

  When affixing fiber sheets, there are protrusions at the ends of tie bars and connection anchors on the outside of the ribbed split steel sheet. The fiber sheet is cut and pasted at any of the above portions, and pasting is performed by either method. However, in any of the methods, the fiber sheet loses uniformity in the tensile strength at the projection portion, so that the reinforcing property is lowered and it is difficult to ensure the strength of the fiber sheet.

The connection anchor used for the hyper seismic external reinforcement method is generally an M12 anchor bolt, and the tie bar is a deformed steel bar defined in JIS G3112 (steel bar for reinforced concrete), with a rebar of nominal diameter D16 to D25. Yes. The size of the ribbed split steel is generally height 400 mm, 2 locations in connection anchor as shown in Figure 1 with respect to one of the ribbed split steel sheet in this aspect, there are four points projections in tie bar The reinforcing property of the fiber sheet having a minimum width of 44 mm (12 + 16 × 2) and a maximum width of 62 mm (12 + 25 × 2) is lowered. When this is converted, the reinforcing effect of the fiber sheet is reduced by a minimum of 11% (44/400 = 0.11) and a maximum of 15.5% (62/400 = 0.155). Affixing multiple pieces of the same fiber sheet from the upper part of the cut fiber sheet makes it possible to repair that part, but it is difficult to repair the bolt part and it is still unreinforced is there.

As a feature of the hyper seismic method, when the seismic force is applied, the rib portions attached to each other slide relative to each other and exhibit a damping effect . Although This is different damping effect on the magnitude of the earthquake force, even if a small earthquake has occurred, occurs sliding of the rib comrades of adjacent ribs with split steel plate, damping effect is exhibited. This vibration control effect is the biggest feature of the hyper seismic method. In order to obtain the vibration damping effect to the maximum, it is important to obtain friction between the ribs of the ribbed divided steel sheet, and for that purpose, it is better not to constrain with bolts or the like.

In the case of Hyper External Seismic Reinforcement, there are ribs facing each other in the horizontal direction of the split steel plate with ribs, and a seismic force damping effect is expected, but there are no ribs facing each other in the vertical direction. The rib portion does not slide. Further, the reinforcement der Ru Textile sheet the fiber structure, ribbed split steel for horizontal seismic forces, grout, although effective together with reinforcement, vertical force no vertical restraining force on the textiles sheets for, if the interior of the grout material is destroyed by an earthquake, adhesion rebar is lost, when ribbed split steel sheet each slide apart worst There is a fear of collapse.

As an adhesive for the fiber sheet, an epoxy adhesive is generally used. The standard curing temperature of the epoxy adhesive is 5 ° C or higher, more preferably 10 ° C or higher. It is said that when the temperature is 5 ° C. or lower, the curing is poor and there is a problem in adhesion. Therefore, the construction time in cold regions is limited, making it difficult for construction in winter.
Since the epoxy adhesive is two-component, first, mixing and stirring work is performed in a container. Next, the container is transported to the work place and applied to the ribbed divided steel sheet with a brush. The fiber sheet is applied to a ribbed divided steel plate coated with an epoxy adhesive, and the fiber sheet is lined by a hand pressing roller brush, defoaming roller or the like from above. Epoxy adhesives can cause skin contact and swelling when in direct contact with the skin. The work site of the external seismic construction method is outdoor work, and the work place is narrow and work in high places, so it is difficult to thoroughly apply coating and handling, and it is a human work, so it is more than an epoxy resin agent Even workers who are familiar with the handling of sprays may come in direct contact with the adhesive due to splashing at the time of application or carelessness, and there may be a history of epoxy adhesives. In the worst case, it will be impossible to secure workers, which will hinder construction.

In the case of the hyper seismic external mounting method, since there are no ribs facing each other in the vertical direction, it is best to fasten the ribs in the horizontal direction with bolts. However, the horizontal direction is important that the effective vibration control by that rib portion is mutually sliding is exhibited, it is required a method of connecting a working range in the horizontal direction bolts for this purpose.

The present invention has been made to solve these problems, so as not to protrude protrusions on the surface of the ribbed split steel, as well as providing a method of mounting the ribbed split steel with no need to cut the fiber sheet, The purpose is to reduce health problems and history due to adhesives to workers by connecting ribbed divided steel sheets and attaching fiber sheets in factories.

  The present invention is a method of externally attaching a ribbed divided steel plate to a concrete pillar of an existing building, wherein the grooved steel plate is attached to the concrete column, the strip is attached to the groove leg inside the grooved steel plate, and the strip After temporarily placing the assembled tie bar, attach the ribbed split steel plate to the outer groove legs of the channel steel plate, and connect the temporarily placed tie bar to the ribbed split steel plate to project protrusions on the ribbed split steel plate surface It adjusts so that it may not let it be.

  The grooved steel plate means a thin steel plate processed into a groove shape, the groove leg of the grooved steel plate means the part standing on both sides of the bottom of the groove shape, and the outer groove leg is in contact with the ribbed divided steel plate A groove leg on the side, and the inner groove leg is a groove leg in the divided steel plate with ribs facing the outer groove leg.

The present invention is characterized by a method of attaching a tie bar as a shear reinforcement which is indispensable when attaching a ribbed divided steel plate to a concrete column of an existing building. When attaching the tie bar to the ribbed split steel plate, the grooved steel plate is attached to the concrete pillar of the existing building, and the strip is attached to the groove leg inside the grooved steel plate. Temporarily place the assembled tie bar on this strip. By inserting the ribbed divided steel sheet into the predetermined position from the front, both ends of the tie bar are stored in the storage box attached to the ribbed divided steel sheet. Then, by rotating one of the data Iba, by緊桔mutual ribbed split steel plate and tie bars is adjusted so as not to protrude protrusions on the surface of the ribbed split steel.

As a method of preventing protrusions from protruding on the surface of the ribbed divided steel plate, a fixed end bolt as a fixed end is attached to the inner side of the ribbed divided steel plate, and a position adjusting steel plate jig as a free end is attached to the tip of the connection anchor. It is preferable to adopt a method in which the mounting, fixed end bolts and the position adjusting steel plate jig are positioned at the inside of the steel plate of the ribbed divided steel plate and adjusted so as not to project the protrusions on the surface of the ribbed split steel plate.

Install the ribbed split steel concrete pillars of the existing building, when connecting the ribbed split steel plates positioned vertically, ribbed dividing the vibration damping effect by that rib portions are mutually slid exerted The connection method between steel plates is preferred. The size of the bolt that connects the rib portions of the ribbed divided steel plate is M12. FIG. 7 is a schematic diagram in which one of the opposing rib portions is fastened with M12 bolts having a φ14 mm round hole G30 and the other rib portion having a long hole H31 of 14 mm × 25 mm. Accordingly, even if a force is applied in the horizontal direction by the earthquake, while some operating range damping effect is exerted, vertically collapse ribbed split steel sheet because it is attached with a bolt are those prevented .

  The method of externally attaching a ribbed divided steel sheet to the concrete pillar according to the present invention is preferably carried out on site after a necessary number of fiber sheets are pasted on the steel plate surface portion of the ribbed divided steel sheet in advance.

According to the present invention, there are no protrusions such as bolts on the outside of the ribbed divided steel sheet, and the fiber sheet can be attached without cutting, so that the work efficiency is improved and the strength of the attached fiber sheet is maintained. Can do. When bolts are protruding, it is necessary to cut or cut the fiber sheet according to the dimensions of the bolt. However, because the fiber sheet is made of super fiber, it cannot be easily cut with commercially available scissors or cutters. Therefore, a special tool was used, and much effort and labor were required for the cutting. By eliminating these operations, work efficiency was greatly improved in the fiber sheet pasting operation.
By eliminating protrusions on the surface of the ribbed split steel sheet, fiber sheets can be pasted in factories with environmental management (fire management, temperature management, exhaust management, protective equipment management). As a result, there is less direct contact with the epoxy resin with bare hands, the impact on the human body is insignificant, and there is no sticking of fiber sheets on site, leading to reduction in construction cost and shortening of the construction period. . FIG. 8 is a schematic diagram of attaching a fiber sheet.

Schematic diagram of hyper seismic external mounting method Schematic diagram of tie bar installation Tie bar fixed end A steel plate storage box schematic diagram Tie bar free end B steel plate storage box schematic diagram Schematic diagram of thin steel plate for temporary placement of tie bars Schematic diagram of connecting anchor installation, steel plate jig schematic diagram for position adjustment Bolt schematic diagram Fiber sheet pasting diagram

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 shows the installation of bending reinforcement 1 in the conventional hyper seismic external method, the installation of adhesive anchor 2, the installation of connection anchor 3, the installation of ribbed divided steel plate 4, the installation of tie bar 5, the application of fiber sheet 6 The schematic diagram (cross-sectional view) of the hyper seismic external reinforcement structure of the reinforced concrete column of the existing building constructed by installing the holding plate 7, placing the high-fluid mortar 8 and finishing with the finishing mortar 9 is shown. As the connection anchor 3, a concrete anchor, a chemical anchor, or the like is used, and is fixed to an existing concrete surface. Next, a method is adopted in which the connection anchor 3 is passed through the opening hole of the connection anchor opened in the ribbed divided steel plate 4 and connected with a washer and a bolt from the outside.

  The standard height of the ribbed divided steel sheet is 400 mm. The attachment position of the tie bar is 100 mm from the surface of the existing concrete column and 100 mm or 300 mm deep from the upper surface, and the work place is narrow. In addition, the bending reinforcement reinforcing bar 1 is installed on the front of the tie bar, and the adhesive anchor 2 and the connection anchor 3 are attached to the existing concrete pillars. It was necessary to install a tie bar. Positioning, assembling, installation and the like took a lot of time for the tie bar installation work.

FIG. 2 is a schematic diagram of tie bar attachment. In the present invention, when the tie bar is attached to the ribbed divided steel plate, the grooved steel plate 14 is attached to the existing concrete column as shown in FIG. 2, and the tie bar temporary placing strip is attached to the inner groove leg of the grooved plate steel plate 14. 15 is attached.
A D22 rebar with an inner dimension L- (minus) of 100 mm with ribs is prepared, and this is designated as a tie bar 5. A 50 mm × 50 mm fixed-end steel plate 16 is attached to one side of the tie bar 5, and the other tip is machined with M20 thread. A steel plate storage box 17 for storing the fixed end steel plate 16 is attached to the inside of the ribbed divided steel plate, and this is shown as a fixed end A in FIG. A steel plate 19 for free end having a diameter of 50 mm is attached to a length of 75 mm. A nut 21 corresponding to the thread processing 20 of the tie bar is attached to the other end. A storage box 22 for storing the steel plate 19 is attached to the other inner side of the ribbed divided steel plate, and this is shown as a free end B in FIG. The tie bar is assembled by inserting the nut 21 of the D22 rebar 18 into the threaded portion 20 of the tie bar 5 and rotating the D22 rebar 18 to assemble them. The assembled tie bar (abbreviated as tie bar X) is placed on the tie bar temporary placement strip 15. In consideration of the case where the band plate 15 for temporary placement intersects with the positions of the adhesive anchor 2 and the connection anchor 3, the band plate 15 can be operated up and down 15 mm.

The tie bar X assembled to the thin steel plate 15 is left and temporarily placed at a position avoiding the adhesive anchor 2 and the connection anchor 3, and the ribbed divided steel plate 4 is pushed in from the entire surface and set to a predetermined installation. At this time, the fixed-end steel plate 16 and the free-end steel plate 19 can be stored in the storage boxes 17 and 22. Thereafter, the D22 rebar 18 of the temporarily placed tie bar X is rotated to bring the ribbed divided steel plate and the tie bar together. In other words, positioning of the tie bar X in advance makes it possible to easily attach the tie bar, and there is no protrusion on the surface of the ribbed split steel sheet, ensuring the design strength of the fiber sheet and shortening the fiber sheet attaching time. This leads to shortening of the process.
The tie bar temporary placing strip 15 is shown in FIG.

In the present invention, as shown in FIG. 1, the connection anchor 3 is driven and fixed to the existing concrete surface 50. The bolt (connection anchor bolt 11) used for the connection anchor 3 is M12, and the length thereof is a ribbed divided steel plate W- (minus) 60 mm.
FIG. 6 is a schematic diagram of the connection anchor bolt 11 . A fixed end bolt 12 shown in FIG. 6 is attached to the inner surface of the ribbed divided steel plate 4, and this is used as a fixed end C. The steel plate jig 13 for position adjustment which processed the steel plate is temporarily fixed to the fixed end bolt 12. A connecting portion between the connection anchor bolt 11 and the steel plate jig 13 for position adjustment that has been processed by a steel plate is a free end D. Fixed Tambo belt 12 is attached to the design position determined by the steel sheet processing plant. On the other hand, the connection anchor bolt 11 is positioned and fixed and driven by human power.

What is important when attaching the connection anchor in the field is that the positions of the fixed end C and the free end D are on the same line. If it is on a straight line, it can be installed and installed without any problem, but it may be an on-site construction and there may be a construction error, and it is not always on the same line, and there is a need for position adjustment when fixing. When it is necessary to adjust the fixed end bolt 12 and the connection anchor bolt 11 , the problem of construction error can be solved by using a steel plate jig 13 for position adjustment that has been processed by a steel plate . The steel plate jig 13 for adjusting the position of the processed steel plate has a long hole 23 on one surface and a long hole 24 on the other surface, and can be adjusted 15 mm in the vertical and horizontal directions. The fixed end C and the free end Of course, when the position of D is on the same line, there is a sufficient adjustment allowance even when there is some variation in the vertical and horizontal directions.
The steel plate jig 13 for position adjustment is shown in FIG.

1 Bending reinforcement 2 Adhesive anchor 3 Connection anchor 4 Ribbed split steel plate 5 Tie bar (D22 rebar)
6 Fiber sheet 7 Restraining plate 8 High flow mortar 9 Finishing mortar 11 Connection anchor bolt 12 Fixed end bolt 13 Steel plate jig for position adjustment 14 Grooved steel plate 15 Strip plate for tie bar temporary placement 16 Steel plate for fixed end 17 Steel plate storage box for fixed end 18 D22 rebar 19 Steel plate for free end 20 Tie bar screw processing 21 Nut corresponding to tie bar screw part 22 Steel plate storage box for free end 23 Slot E
24 Long hole F
30 round hole G30
31 Slotted hole H31
50 Existing concrete surface

Claims (4)

This is a method of attaching a ribbed split steel plate to a concrete pillar of an existing building, attaching a grooved steel plate to the concrete column, attaching a strip to the groove leg inside the grooved steel plate, and assembling the tie bar to that strip After the temporary mounting, attach the ribbed divided steel plate to the outer groove leg of the channel steel plate, and tighten the temporarily placed tie bar and the ribbed divided steel plate so that the protrusions do not protrude from the surface of the ribbed divided steel plate. A method for externally attaching a ribbed divided steel sheet.
A fixed-end bolt is attached to the inside of the ribbed split steel plate, a connection anchor bolt is fixed to the existing concrete surface, and these are connected via a steel plate jig for position adjustment. The method for externally attaching a ribbed divided steel sheet according to claim 1, wherein the rib is not protruded.
The method for externally attaching a ribbed divided steel sheet according to claim 1 or 2, wherein a movable area in the horizontal direction is provided when connecting the divided steel sheets with ribs located above and below, but no movable area is provided in the vertical direction.
The method for externally attaching a ribbed divided steel sheet according to any one of claims 1 to 3, wherein a fiber sheet is attached in advance to the steel plate surface portion of the ribbed divided steel sheet and then conveyed to the site.

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