JPH09228659A - Form device for reinforcing construction work of existing column structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cover and reinforce an existing column structure firmly with a steel sheet simply and economically. SOLUTION: Face forms A1 -A4 by the combination of horizontal batter materials 1, 1 and vertical batter materials 2, 2 are joined and installed on the outsides of each face plate d1 -d4 of a reinforcing frame D arranged around an existing column B and made of a steel sheet, and these each horizontal batter material 1, 1 is combined 3, 3 mutually by connecting rods 4, 4, etc., at end sections. The horizontal batter materials 1, 1 are mounted so that the nodes 3, 3 of the horizontal batter materials 1, 1 are placed near the sides inner than the ends of the face plates d1 -d4 of the reinforcing frame D by a considerable distance L at that time.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an existing columnar structure,
The present invention relates to a formwork device used in a construction method in which a steel plate is reinforced by coating.

[0002]

2. Description of the Related Art As countermeasures against earthquakes and the like, reinforcement has come to be carried out on aged column structures and column structures which require reinforcement. As the reinforcing work, there are a method of placing concrete with a required thickness around the existing pillar structure and covering it, and a method of covering a reinforcing steel plate around the existing pillar structure. With the former concrete coating, the column structure after reinforcement is considerably thicker than the previous one.Therefore, reinforcement work with steel sheet coating is adopted in construction in places where construction restrictions and appearance are problems. There is.

As shown in FIG. 9, in general, a reinforcing work by coating with a steel plate is provided around an existing pillar structure B (hereinafter referred to as an existing pillar) having a quadrangular cross section with a gap of about 3 to 5 cm from the existing pillar B. Then, the reinforcing frame D made of steel plate is arranged, the mortar C is placed in the gap, and the existing pillar B and the steel plate reinforcing frame D are placed.
And are integrally combined.

In this case, due to the driving pressure of the mortar C, the face plates d _{1 to} d ₄ of the reinforcing frame D are deformed to bulge outward (normal bending), so that this is prevented as much as possible. , Outside the reinforcing frame D, a surface form frame corresponding to each face plate d _{1 to} d ₄
A formwork device in which A _{1 to} A ₄ are combined is installed to suppress the bending of the reinforcing frame D.

The above-mentioned form is usually provided with a large number of vertical flaps 2, 2 laterally spaced inside the horizontal flaps 1, 1 (reinforcing frame D side) arranged vertically at intervals. The surface form frames A _{1 to} A ₄ formed by arranging and connecting the above are connected to each other at the ends of the transverse flap members 1 and 1 using tie bolts (clamping bolts) 9 and 9 as shown in the drawing. , Or by connecting with a pin or the like.

In the above-mentioned reinforcement work, the lateral pressure (placement pressure) when the mortar C is placed between the existing column B and the reinforcement frame D.
Also acts on the face molds A _{1 to} A ₄ of the formwork device through the face plates d _{1 to} d ₄ of the reinforcing frame D. The surface formwork A _{1 to} A ₄ functions to suppress the deflection against the acting lateral pressure.

Since the reinforcing frame D and the formwork device thus constructed cooperate with each other to resist the lateral pressure of the mortar C, it is needless to say that the bending can be suppressed to an allowable degree, but after the mortar C is hardened. When the formwork device is removed from the reinforcing frame D, a part of the reinforcing frame D separates from the hardened mortar C,
As a result of the execution work, it was found that a void was generated there, impairing the integrity of the existing pillar B and the reinforcing frame D, and thus the required strength as the reinforcing pillar could not be obtained.

Even if it is impossible to completely eliminate the gap due to the separation of the reinforcing frame D, I tried replacing the formwork device with a powerful one in order to minimize it, but the result was unsuccessful. . The behavior of the reinforcing frame D is very complicated, and the exact clarification has not yet been made.

[0009]

The present inventor newly created and studied a dedicated calculation system for structural mechanical analysis of a composite structure of a reinforcing frame D and a formwork device which receives the above-mentioned lateral pressure, which is an evenly distributed load. As a result, we have succeeded in clarifying this problem and have been able to explain the behavior of the reinforcing frame as follows.

First, assuming that the mortar is placed without the formwork device, that is, in the form of the reinforcing frame D alone, and if a small lateral pressure is applied, the reinforcing frame D shows a small flexural deformation. Next, when a slightly larger lateral pressure is applied, the amount of flexural deformation increases. Comparing the two, the amount of deflection of the former and the amount of deflection of the latter are proportional to the magnitude of the evenly distributed load called lateral pressure, and the deflection curves of both are similar. Therefore, for a certain reinforcing frame, there is a bending curve that should be called a fixed basic shape, and although the amount of bending differs depending on the magnitude of lateral pressure, if these curved shapes are compared with the basic shape, they are all similar. I think that the relationship of is established. All of the shapes that are similar to the basic shape will be referred to as "inherent bending curves" of the reinforcing frame D.

By the way, in the case of the reinforcing frame alone structure without the aid of this formwork device, the reinforcing frame is deformed by the lateral pressure, and after the mortar is hardened, a void is generated between the mortar and the reinforcing frame. There is absolutely no frame behavior. Therefore,
Mortars that have hardened after removal of the formwork device, even if the formwork device is set, if the flexure curve when subjected to lateral pressure matches the "specific flexure curve" of the reinforcing frame The behavior that the reinforcing frame separates from does not occur.

However, when the conventional formwork apparatus is used for the purpose of reinforcing the reinforcing frame, the bending shape after receiving the lateral pressure is far from the "inherent bending curve" of the reinforcing frame. I will end up. The internal stress of the reinforcing frame formed in the shape of the curve that is not the "inherent bending curve" includes the stress that tends to become the "inherent bending curve". When removed, a free surface that has been unrestrained, that is, a portion that bulges outward, appears,
There is a void there. This will be specifically described below with reference to the drawings.

As shown in FIG. 10, in the case of the reinforcing frame D, the lateral pressure (indicated by the solid line arrow) due to the placement of the mortar is equal to each face plate d ₁
~ D ₄ (hereinafter referred to as d) over the entire surface. Since each face plate d has the property of both ends fixed beam whose ends are constrained by other face plates connected to each other, its peculiar bending curve is middle and high as shown by the chain line in the figure. In contrast, in the mold device D, the horizontal flap members 1,1 Togahobo hinged on each side mold A ₁ to A ₄ of the horizontal flap members 1,1 and other planar frame A ₁ to A ₄ Since it has the characteristics of a simple beam, the lateral pressure due to the bending of each face plate d acts almost at the center as shown by the solid line arrow, so the bending curve due to it is arcuate as shown by the dotted line 1. Becomes

Therefore, when the mortar is actually placed, the face plate d tries to bend as shown by the chain line in FIG. 10, but the vicinity of the central portion is closer to the horizontal flap material 1 than the lateral flap material 1. Since it is pressed by the reaction force a of the face plate d, the face plate d becomes a bend curve of a shape quite different from its "inherent bend curve", and the middle part between the both ends and the center part b, the central part of the face plate d near the b Extra stress (bulging stress) is generated in the face plate d so that (between the portions (b) and (b)) tends to bulge outward, and the mortar C is hardened with the bulging stress included.

After hardening the mortar C, the formwork device is removed. As a result, the pressing of the lateral flap material 1 to the face plate d is released, but in such a case, the face plate d behaves in an attempt to return to the "inherent bending curve" as shown in FIG. That is, it behaves due to the function of the swelling stress contained in the intermediate points b and b. Therefore, the vicinity of the intermediate portion (between (b) and (b)) is separated from the hardened mortar C, and a void portion (c) separated between the two is formed, and the integrity of the existing column B and the reinforcing frame D is improved. Will be damaged.

The present invention has been made in order to solve the problem in the existing column reinforcing work as described above, and the bending shape of the lateral form member of the surface form which suppresses the bending of the reinforcing frame due to the lateral pressure is The structure of the reinforcing frame is similar to the peculiar bending curve due to the lateral pressure of the sole side plate, so that the reinforcing frame, the mortar and the existing columns can be firmly connected, and the economy is improved by using ordinary temporary materials. An object of the present invention is to provide a formwork device which is excellent in workability and workability and is used for reinforcement work of an existing column structure.

[0017]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. A formwork device arranged along the outer surface of each face plate d _{1 to} d ₄ of the reinforcing frame D covered with the surroundings, wherein each face plate d _{1 to} d _{4 is}
Each of the surface form frames A _{1 to} A ₄ to be joined to the outer surface of each of them is connected to each other at the ends of the transverse flap members 1 and 3, and the connection points 3 and 3 are connected to the face plate d ₁ to It is characterized in that it is set at a position closer to the inside than the vicinity of both ends of d ₄ .

The apparatus according to claim 2 is the apparatus according to claim 1, wherein the end portions of the lateral butter members 1, 1 are connected to each other by connecting rods 4, 4.
It is characterized in that they are linked by 4.

The apparatus according to claim 3 is the apparatus according to claim 1, wherein the brackets 6 and 6 are provided at both ends of the lateral flap members 1 and 1, respectively.
Is provided, and the horizontal butter members 1, 1 of the surface form frames A _{1 to} A ₄ are connected to each other by tightening bolts 7, 7 inserted into the brackets 6, 6.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a basic embodiment of the present invention will be described with reference to FIGS. The basis of the idea in the formwork apparatus of the present invention is the surface formwork A ₁ by lateral pressure.
The bending shape of the horizontal flap materials 1, 1 of A ₄ is the face plate d ₁ of the reinforcing frame D ₁ ~
The structure is to be similar to the flexed shape of d ₄ .

FIG. 1 and FIG. 2 show a basic embodiment based on this idea, and are intended for an existing pillar B having a square cross section, and the outer circumference of the existing pillar B and a required gap therebetween. Reinforcing frame D consisting of _four steel face plates d _{1 to} d ₄
Is arranged. Then, on the outer periphery of the reinforcing frame D, the mold apparatus of the present invention in which _four surface molds A _{1 to} A ₄ are combined in a frame shape is installed.

The surface form frames A _{1 to} A ₄ have a plurality of horizontal flap members 1, 1 arranged vertically with a required gap and a required gap in the lateral direction on the inside (reinforcing frame D side) thereof. The vertical flaps 2 and 2 arranged in this manner are formed by being joined to each other. Then, the respective surface form frames A _{1 to} A ₄ are erected so that the vertical butter members 2 and 2 are in contact with the face plates d _{1 to} d ₄ of the reinforcing frame D, and are joined to each other.

The surface form frames A _{1 to} A ₄ are connected to each other by engaging holes 3 provided on the axis O of each end of the transverse flap materials 1, 1.
3, the connecting rods 4, 4 are bridged between them, and connecting pins (not shown) are inserted into the holes 5, 5 of the connecting rods 4, 4 and the engaging holes 3, 3. Then combined. In this case, the positions of the connecting points 3 and 3 are set so as to be located inward by a considerable distance L from the ends of the face plates d _{1 to} d ₄ . Lateral flap material 1 when these connecting points 3 and 3 receive lateral pressure
It serves as a support point for the end of the beam.

In the present invention, as described above, it is important that the connecting points 3 and 3 which are the supporting points of the horizontal flap members 1 and 1 are located inside both ends of the face plate d. Thereby, as shown in FIG. 3, the peculiar bending shape of the lateral flap 1 (shown by the dotted line) is substantially similar to the peculiar bending shape of the face plate d subjected to the lateral pressure (shown by the chain line). become. The connection points 3 and 3 are set at positions having such similar shapes.

By doing so, as shown in FIG.
For the face plate d which is going to bend due to the lateral pressure of the mortar C,
The lateral flap material 1 that tries to suppress the flexure is arranged so as to follow the flexural shape of the face plate d, and suppresses the flexure of the face plate d. Therefore, as shown in FIG. 11 of the related art, extra stress (bulging stress) is not generated in the intermediate portions (b) and (b) of the face plate d, and the mortar produced when the surface molds A _{1 to} A ₄ are removed. The separation gap C between the class C and the face plate d does not occur.

FIG. 5 shows another example of the basic embodiment of the present invention. In this example, each surface formwork
A plurality of engaging holes 3 and 3 are provided on each end side of the horizontal flap material 1 of A _{1 to} A _4.
Are provided at intervals. Therefore, the connecting rod 4
The length of the lateral flap material 1, that is, the lateral width of the surface molds A _{1 to} A ₄ can be adjusted by selecting one of the engaging holes 3 and 3 at the coupling position with and the size of the reinforcing frame D is different. It can also be applied to things.

6 and 7 show an example of another embodiment of the present invention. In this embodiment, a mountain-shaped bracket 6 having bolt insertion holes (not shown) at both ends of each horizontal flap material 1, 1 is provided on the outer surface of the horizontal flap material 1 (not shown). It is provided on the side opposite to the mounting side of the vertical flap material 2. Then, the adjacent lateral flap members 1, 1 are joined to each other by inserting the tightening bolt 7 into the brackets 6, 6 and screwing and tightening the nuts 8, 8. In this case, the support point 3 of the lateral flap material 1 is the intersection of the axis O of the lateral flap material 1 and the tightening bolt 7. Then, the intersection point 3 is set so as to be located at a position inside by a considerable distance L from the end of the face plate d as described above.

FIG. 8 shows another example of another embodiment of the present invention. A plurality of chevron-shaped brackets 6 are connected to one end of each lateral flap material 1, 1. . Also in this case, similarly to the embodiment of FIG. 5, by selecting one of the brackets 6 and 6 in which the tightening bolt 7 is continuously provided and connecting the brackets 6 and 6, the length of the lateral flap material 1, 1; Form A ₁ ~
The width of A ₄ can be adjusted appropriately.

It should be noted that the present invention is not limited to the reinforcement work of the existing column structure having a quadrangular cross section as in each of the above-described embodiments, but is widely applicable to those having various polygonal flat cross sections. Can be applied.

[0030]

As described above, according to the present invention,
When joining the surface formwork to be joined and arranged on the outer surface of the reinforcing frame to each other at the end of the horizontal flap material, the connecting point of each horizontal flap material is located inward from both ends of the face plate of the reinforcing frame. Since the connecting point becomes the fulcrum of the lateral flap material against the lateral pressure, the bending shape of the lateral flap material due to the lateral pressure becomes a unique bending curve of the face plate that swells and deforms under the lateral pressure. It can be almost similar.

As a result, the bending of the face plate due to the placement of the mortar can be suppressed without causing a special bulging stress on the face plate, and therefore, the reinforcement frame and the mortar that have been placed due to the removal of the formwork device. There is almost no peeling from other materials, a highly integrated bond can be made, and the strength of the reinforcement work can be guaranteed.

Further, since the formwork device allows the surface formwork to flex and suppresses the flexure of the face plate of the reinforcing frame,
Like a conventional formwork, it can be constructed using inexpensive temporary members, so that the formwork cost is low and the construction is simple and efficient.

[Brief description of drawings]

FIG. 1 is a plan view showing a basic embodiment of the present invention.

FIG. 2 is a side view showing the main part.

FIG. 3 is an explanatory diagram showing bending of a face plate and a lateral flap material.

FIG. 4 is an explanatory view showing a bending shape of a face plate and a lateral flap material when a mortar is placed.

FIG. 5 is a plan view showing another embodiment of the present invention.

FIG. 6 is a plan view showing another embodiment of the present invention.

FIG. 7 is a side view showing the main part.

FIG. 8 is a plan view showing another embodiment of the present invention.

FIG. 9 is a plan view showing an example of a conventional mold apparatus.

FIG. 10 is a comparison diagram of a bent state of a lateral flap member and a face plate of a conventional mold device.

FIG. 11 is an explanatory view showing a state in which the flexure is suppressed when the same mortar is placed.

FIG. 12 is an explanatory view showing a state of the face plate and the placed mortars after removing the conventional form device.

[Explanation of symbols]

A ₁ , A ₂ , A ₃ , A ₄ surface form B B Existing column structure C Mortar D Reinforcement frame d ₁ , d ₂ , d ₃ , d ₄ Face plate 1 Horizontal flap 2 Vertical flap 3 Engagement hole ( (Connecting point, support point) 4 Connection rod 5 Hole 6 Bracket 7 Tightening bolt 8 Nut

Claims (3)

[Claims] 1. A formwork device arranged along the outer surface of each face plate of a reinforcing frame to be coated around an existing pillar structure, wherein each face formwork joined to the outer surface of each face plate is , A formwork for an existing pillar structure reinforcing work, characterized in that they are joined to each other at the ends of the transverse flaps, and the connecting points are set at positions closer to the inside than the vicinity of both ends of the face plate. apparatus. 2. A formwork apparatus for reinforcing an existing column structure according to claim 1, characterized in that the ends of the transverse flaps are joined together by a connecting rod. 3. Brackets are provided at both ends of the horizontal flap material,
The formwork apparatus for an existing pillar structure reinforcing work according to claim 1, wherein the horizontal flap members of each surface formwork are connected to each other by tightening bolts which are inserted through the brackets.