JP2017115371A - Steel pipe reinforcement structure and reinforcement method of steel pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel pipe reinforcement structure and a reinforcement method of steel pipe capable of increasing buckling proof and axial strength of the steel pipe, and capable of easily working.SOLUTION: A steel pipe reinforcement structure 1 provided to an existing structure and reinforcing a steel pipe 2 constituting the structure includes: a block member 3 which is disposed out of a range 16 to be reinforced in the steel pipe 2 to block the inside of the steel pipe 2; and a reinforcement filler 4 which is filled in the block member 3 in the range 16 to be reinforced inside the steel pipe 2. The block member 3 has a bag body 31 and a filler 32 for a block member which is filled in the bag body 31.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a steel pipe reinforcing structure that is provided in an existing structure and forms a structure, and a steel pipe reinforcing method.

Conventionally, whether the steel pipe truss beams installed in existing structures are sufficiently resistant to external forces during earthquakes and snowfalls is determined by the buckling strength of the steel pipe that is the compression material of the steel pipe truss beams and axial compression. Often done based on intensity values. When performing seismic reinforcement of a steel pipe truss beam, reinforcement is often performed to increase the buckling strength and axial strength (axial compression strength) of the steel pipe truss beam.
As a method for buckling reinforcement of a steel pipe serving as a compression material for a steel pipe truss beam, a cross-sectional reinforcement method for a steel pipe by welding is known. However, such a method has a risk of fire occurrence due to welding, and it is difficult to perform a welding operation at a high place. Therefore, a buckling reinforcement method for a steel pipe that does not require welding has been proposed.

  For example, a steel pipe is sandwiched from both sides with a reinforcing member formed by vertically dividing a new steel pipe, and the reinforcing member is fixed to the steel pipe with a band material, or a steel pipe is sandwiched from both sides by a reinforcing member obtained by dividing a new steel pipe vertically A method has been proposed in which these reinforcing members are fixed to each other with a fixing tool such as a bolt and the reinforcing member is fixed to the steel pipe.

Patent Document 1 discloses a method in which a concrete-filled steel pipe in which a steel tube is filled with a high-toughness fiber-reinforced cement composite material is adopted as a steel pipe truss beam.
Further, Patent Document 2 discloses a method of reinforcing a steel pipe by forming a hole in the steel pipe and filling a cement-based solidified material into the steel pipe from the hole.

JP 2000-170323 A JP 2009-174173 A

However, the method of fixing the reinforcing member to the steel pipe needs to integrate the reinforcing member with the steel pipe, so that high dimensional accuracy is required for processing the reinforcing member, and there is a problem that it takes time to process the reinforcing member. If the dimensional accuracy of the reinforcing member is low, the reinforcing member and the steel pipe are not integrated, and the reinforcing effect by the reinforcing member may not be sufficiently obtained. In addition, there is a problem in that the cross-sectional shape of the member is increased and the appearance is changed by fixing the reinforcing member to the steel pipe.
The method disclosed in Patent Document 1 has a problem that it takes time and effort to fill the steel pipe with a high-toughness fiber-reinforced cement composite material. Moreover, since the method is based on the premise of a new structure, there is a problem that it cannot be applied immediately to an existing structure.
Moreover, since the method disclosed in Patent Document 2 is insulated without integrating the steel pipe and the cement-based solidified product, the axial strength of the steel pipe cannot be increased and is not suitable for reinforcing the axial strength.

  Therefore, an object of the present invention is to provide a steel pipe reinforcing structure and a steel pipe reinforcing method that can increase the buckling strength and axial strength of the steel pipe and can be easily constructed.

  In order to achieve the above object, a steel pipe reinforcement structure according to the present invention is provided in an existing structure, and is disposed outside the reinforcement target range inside the steel pipe in the steel pipe reinforcement structure that reinforces the steel pipe constituting the structure. A sealing member for closing the inside of the steel pipe, and a reinforcing filler filled in a reinforcing target range inside the steel pipe, the sealing member being filled in the bag body and the bag body And a filler for a closing member.

  The steel pipe reinforcing method according to the present invention is a steel pipe reinforcing method provided in an existing structure for reinforcing a steel pipe constituting a structure, wherein the steel pipe communicates outside and inside the reinforcing target range of the steel pipe. From the 1st hole formation process which forms the 1st hole part, the 2nd hole formation process which forms the 2nd hole part which makes the inside and outside of the steel pipe connect within the reinforcement object range of the steel pipe, from the 1st hole part A closing member forming step of inserting a bag body into the steel pipe, filling the inside of the bag body with a filler for a closing member, and forming a closing member for closing the inside of the steel pipe; and the closing member forming step And a reinforcing filler filling step of filling the reinforcing filler from the second hole within the reinforcing target range inside the steel pipe.

In the present invention, the steel pipe is filled with the reinforcing filler, so that the buckling strength of the steel pipe can be increased, and the reinforcing filler is integrated with the steel pipe to thereby reduce the axial strength of the steel pipe. Can be increased.
In addition, by installing a closing member outside the reinforcement target range inside the steel pipe and then filling the reinforcing filler within the reinforcement target range, the reinforcing filler can be easily added within the reinforcement target range inside the steel pipe. Can be filled.
Since the closing member has a configuration in which the inside of the bag body inserted into the steel pipe is filled with the filler for closing member, the closing member can be easily installed.

In the steel pipe reinforcing structure according to the present invention, it is preferable that the reinforcing filler is a non-shrinkable cement-based solidified material.
By setting it as such a structure, since the reinforcing filler with which the inside of the steel pipe was filled hardly shrink | contracts, the axial strength of a steel pipe can be increased by adhesion with a reinforcing filler and a steel pipe.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to increase the buckling strength and axial strength of a steel pipe, it can construct easily.

It is a figure which shows an example of the steel pipe truss beam which employ | adopted the reinforcement structure of the steel pipe by embodiment of this invention. It is a longitudinal cross-sectional view of FIG. (A) is the sectional view on the AA line of FIG. 2, (b) is the sectional view on the BB line of FIG. FIG. 3 is an enlarged view of part C of FIG. 2. (A) is a figure explaining the 1st hole formation process and the 2nd hole formation process, and is the figure which looked at the steel pipe of the lower chord material from the upper part, and (b) is a DD line sectional view of (a). It is a figure explaining a blocking member formation process. It is a figure explaining the closing member formation process following FIG. It is a figure explaining the filler filling process for a reinforcement. It is a figure explaining the filler filling process for a reinforcement following FIG.

Hereinafter, a steel pipe reinforcing structure and a steel pipe reinforcing method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9.
As shown in FIGS. 1 and 2, the steel pipe reinforcing structure 1 according to the present embodiment is used when reinforcing a steel pipe truss beam 12 of an existing structure 11. The steel pipe truss beam 12 includes an upper chord member 13 and a lower chord member 14 extending in the horizontal direction, and a plurality of diagonal members 15, 15... Provided between the upper chord member 13 and the lower chord member 14.
The upper chord member 13, the lower chord member 14, and the plurality of diagonal members 15, 15,... The plurality of diagonal members 15, 15... Are joined to the upper chord member 13 and the lower chord member 14, respectively, by welding or the like.
In the present embodiment, a predetermined length range of the lower chord member (structure) 14 is set as a reinforcement target range 16, and the steel pipe reinforcement structure 1 is applied to the reinforcement target range 16.

  As shown in FIG. 2, the reinforced lower chord material 14 includes a steel pipe 2 extending in the horizontal direction and a pair of blocking members 3 provided on both outer sides in the length direction of the reinforcement target range 16 inside the steel pipe 2. 3 and a reinforcing filler 4 filled between the pair of closing members 3, 3. The steel pipe 2 is an existing one, and a pair of closing members 3 and 3 and a reinforcing filler 4 are newly provided inside the steel pipe 2 in order to reinforce the lower chord material 14. As shown in FIG. 3A, the reinforced lower chord material 14 is not filled with the reinforcing filler 4 inside the steel pipe 2 outside the reinforcement target range 16, as shown in FIG. 3B. In addition, in the reinforcing object range 16, the reinforcing filler 4 is filled in the steel pipe 2.

As shown in FIG. 4, the pair of closing members 3, 3 are arranged at intervals in the length direction, and each divides the inside of the steel pipe 2 into one side and the other side in the length direction. Each of the pair of closing members 3, 3 has a stretchable bag 31 made of synthetic resin, and a filler 32 for a closing member such as a cement-based solidified material filled in the bag 31. . The bag 31 is configured to be inflated by being filled with a filler 32 for a closing member, so that the inside of the steel pipe 2 can be closed so that one side and the other side in the length direction do not communicate with each other.
For the reinforcing filler 4, for example, a non-shrinkable cement-based solidified material is used. The reinforcing filler 4 is hardened and integrated with the steel pipe 2.

Before the steel pipe 2 is provided with the pair of closing members 3, 3 and the reinforcing filler 4 inside the steel pipe 2, the bag body 31 and the closing member of each of the pair of closing members 3, 3 outside the reinforcement target range 16. Two sealing member holes 21 and 21 (first hole) into which the filler 32 for insertion can be inserted, and a reinforcing hole (second hole) serving as a filling hole for filling the reinforcing filler 4 into the reinforcing object range 16. (Hole part) 22 and a confirmation hole part 23 for confirming the state of the reinforcing filler 4 filled in the steel pipe 2 are formed.
These holes 21 to 23 are each closed by a sealing material 24 and the like after a pair of closing members 3 and 3 and a reinforcing filler 4 are provided inside the steel pipe 2.

Next, a method for reinforcing the lower chord material 14 (a method for reinforcing a steel pipe) will be described.
First, as shown in FIG. 5, a pair of closing members for forming a pair of closing members 3 and 3 (see FIG. 4) on both outer sides in the length direction of the reinforcement target range 16 of the steel pipe 2 of the lower chord member 14. The member holes 21 and 21 are formed (first hole forming step).
In the present embodiment, a pair of blocking member holes 21 and 21 are formed on the upper side of the steel pipe 2. The inner diameter of each of the pair of blocking member holes 21 and 21 is about 30 mm.

A reinforcing hole 22 for filling (press-fitting) the reinforcing filler 4 (see FIG. 4) into the reinforcing object range 16 of the steel pipe 2, and a confirmation hole for checking the filled reinforcing filler 4 Part 23 is formed (second hole forming step).
In the present embodiment, the reinforcing hole 22 is formed on the lower side of the steel pipe 2, and the confirmation hole 23 is formed on the upper side of the steel pipe 2. The inner diameter of the reinforcing hole 22 and the inner diameter of the confirmation hole 23 are about 30 mm.

Subsequently, as shown in FIGS. 6 and 7, a pair of blocking members 3 and 3 (see FIG. 7) are formed inside the steel pipe 2 (blocking member forming step).
As shown in FIG. 6, the bag body 31 in a contracted state is inserted into the steel pipe 2 through the hole 21 for the closing member. The filling port 31 a of the bag body 31 inserted into the steel pipe 2 is disposed in the vicinity of the closing member hole 21.
The inside of the bag body 31 is filled with the filler 32 for the closing member from the filling port 31a of the bag body 31 inserted into the steel pipe 2.
As shown in FIG. 7, the bag body 31 expands and expands by being filled with the closing member filler 32. The inside of the bag body 31 is filled with the closing member filler 32 until the bag body 31 is large enough to close the steel pipe 2.
When the bag body 31 and the closing member filler 32 are large enough to block the steel pipe 2, the filling of the closing member filler 32 into the bag body 31 is terminated, and the filling port 31a of the bag body 31 is closed.

Subsequently, as shown in FIG. 8, the reinforcing filler 4 is filled into the reinforcing target range 16 inside the steel pipe 2 (reinforcing filler filling step).
The reinforcing filler 4 is filled into the steel pipe 2 from the reinforcing hole 22. At this time, the state of the reinforcing filler 4 injected into the steel pipe 2 is confirmed from the confirmation hole 23.
The pair of closing members 3, 3 become a form of the reinforcing filler 4, and even if the reinforcing filler 4 reaches the pair of closing members 3, 3, the reinforcing filler 4 flows out of the reinforcement target range 16. To prevent it.
As shown in FIG. 9, when the reinforcing filler 4 is filled into the reinforcing object range 16, the closing member holes 21, 21, the reinforcing hole 22, and the confirmation hole 23 are closed with a sealing material 24 or the like.
In this way, the lower chord material 14 is reinforced.

Next, the reinforcement design of the steel pipe will be described.
When the buckling strength of the steel pipe 2 is insufficient, the reinforcement design of the buckling strength is performed, and when the axial strength of the steel pipe 2 is insufficient, the reinforcement design of the shaft strength is performed. In addition, the buckling strength and axial strength of the steel pipe 2 after reinforcement shall conform to a concrete filling steel pipe structure design and construction guideline (Architectural Institute of Japan, published in October 2008).
The buckling strength of the steel pipe 2 after reinforcement is a cumulative buckling strength obtained by accumulating the buckling strength of the steel pipe 2 and the buckling strength of the reinforcing filler 4 (concrete portion) filled in the reinforcing object range 16. The buckling strength of the steel pipe 2 after reinforcement, the buckling strength of the concrete portion, and the buckling strength of the steel pipe 2 are shown below.

  Each value is set so that the buckling strength of the steel pipe 2 after reinforcement is equal to or greater than the target buckling strength.

  The axial strength of the steel pipe 2 after reinforcement is calculated by adding the axial strength transmitted from the steel pipe 2 to the concrete portion due to adhesion between the steel pipe 2 and the concrete portion to the axial strength of the steel pipe 2. The axial force transmitted from the steel pipe 2 to the concrete part due to the adhesion between the steel pipe 2 and the concrete part is shown below.

Next, operations and effects of the steel pipe reinforcing structure 1 and the steel pipe reinforcing method according to the above-described embodiment will be described.
In the steel pipe reinforcing structure 1 and the steel pipe reinforcing method according to the above-described embodiment, the steel pipe 2 is filled with the reinforcing filler 4 so that the buckling strength of the steel pipe 2 can be increased. By integrating the filler 4 for use with the steel pipe 2, the axial strength of the steel pipe 2 can be increased.

Also, a pair of blocking members 3 and 3 are installed outside the reinforcement target range 16 inside the steel pipe 2, and the reinforcing filler 4 is filled in the reinforcement target range 16 so as to reach the pair of blocking members 3 and 3, respectively. Thus, the reinforcing filler 4 can be easily filled in the reinforcing target range 16 inside the steel pipe 2.
By adjusting the positions where the pair of blocking members 3 and 3 are provided, the desired length range of the steel pipe 2 can be set as the reinforcement target range 16, and the entire interior of the steel pipe 2 is filled with the reinforcing filler 4. As compared with, the weight of the lower chord material 14 can be reduced.
Since the pair of blocking members 3 and 3 are configured such that the inside of the bag 31 inserted into the steel pipe 2 is filled with the filler 32 for the blocking member, the pair of blocking members 3 and 3 can be easily installed. Can do.

Moreover, in this embodiment, it can reinforce, without changing the cross-sectional shape and external appearance of the lower chord material 14 compared with the method of newly fixing a reinforcement member on the outer side of the steel pipe 2. FIG.
Further, by employing a non-shrinkage type cement-based solidified material for the reinforcing filler 4, the reinforcing filler 4 filled in the steel pipe 2 can be reliably integrated with the steel pipe 2.

As mentioned above, although embodiment of the reinforcement structure of the steel pipe by this invention and the reinforcement method of a steel pipe was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, in the above-described embodiment, the lower chord member 14 of the steel pipe truss beam 12 is reinforced, but the steel pipe reinforcing structure 1 and the steel pipe reinforcing method according to the present embodiment may be adopted for reinforcing the upper chord member and the diagonal member. Good. The form of the steel pipe truss beam 12 may be other than the above.
Further, in the above embodiment, the closing members 3 and 3 are provided on both outer sides in the length direction of the reinforcement target range 16 inside the steel pipe 2, but either one of the length directions of the reinforcement target range 16 is provided. When the side is closed, the closing member 3 may be provided only on the other side.
Further, in the above embodiment, the bag body 31 of the closing member 3 is configured to be extendable and retractable. However, if the inside of the steel pipe 2 can be closed together with the closing member filling material 32 filled therein. It is not necessary to expand and contract.

DESCRIPTION OF SYMBOLS 1 Steel pipe reinforcement structure 2 Steel pipe 3 Closing member 4 Reinforcing filler 11 Existing structure 14 Lower chord material (structure)
16 Reinforcement target range 21 Closing member hole (first hole)
22 Reinforcing hole (second hole)
23 Confirmation hole (second hole)
31 Bag body 32 Filling material for closing member

Claims (3)

In a steel pipe reinforcement structure that is provided in an existing structure and reinforces a steel pipe that forms the structure,
A sealing member disposed outside the reinforcement target range inside the steel pipe, and closing the inside of the steel pipe;
A reinforcing filler filled in a reinforcing object range inside the steel pipe,
The said sealing member has a bag body and the filler for fillers with which the said bag body was filled, The reinforcement structure of the steel pipe characterized by the above-mentioned.   The reinforcing structure for a steel pipe according to claim 1, wherein the reinforcing filler is a non-shrinkable cement-based solidified material. In a steel pipe reinforcing method for reinforcing a steel pipe that is provided in an existing structure and forms the structure,
A first hole forming step for forming a first hole for communicating the inside and outside of the steel pipe outside the reinforcement target range of the steel pipe;
A second hole forming step for forming a second hole for communicating the inside and the outside of the steel pipe within the reinforcement target range of the steel pipe;
Inserting a bag body into the steel pipe from the first hole, filling the bag body with a filler for a closing member, and forming a closing member for closing the inside of the steel pipe; and
A reinforcing filler filling step of filling the reinforcing filler from the second hole in the reinforcing target range inside the steel pipe after the closing member forming step; Method.

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