JPH0745772B2 - Form support for arch concrete construction - Google Patents

Description

Description: [Industrial field of application] The present invention relates to the support of a formwork applied to the construction of arch concrete in an arch bridge or the like.

[Prior Art] In bridge structures such as roads and railways, deterioration and damage of slab concrete erected on the bridge piers have recently become a major problem. Deterioration and damage of slab concrete is caused by the material properties of concrete that is strong in compression and weak in tension.It is cracked due to repeated drying shrinkage and moving concentrated load, and the water that infiltrates from it accelerates the rust expansion of the rebar. It seems that the concrete will come off and the reinforced concrete will deteriorate.

Then, in order to deal with such deterioration of concrete, a bridge type suitable for the characteristics of concrete was examined, and a concrete arch bridge, which has been forgotten today, has been attracting attention. Since this arch bridge becomes a full-section compression member when dead load is applied, it has an excellent structural type as a concrete structure. With this type of bridge, deterioration of concrete is prevented and durability is greatly improved. Things are certain.

However, when constructing a concrete structure such as an arch bridge, the construction aspect, especially the facility of the formwork required for the construction of arched concrete between the bridge piers, becomes a big problem. As a general example of this construction, first construct each pier up to the required height, then erect an arched formwork between the piers and place concrete, but in this case, many formworks are used. If it can be supported by vertical stanchions, it will be easy and economical to construct, but in the actual construction, it will be between the arch form and the outer form set opposite to this. Since the concrete to be placed will be piled up sequentially from the bottom of both forms, at the initial stage of placing concrete, the load exerted on the form of concrete will be applied to the form surface. It works at right angles. On the other hand, the pillars that support the formwork part can be supported in the vertical direction but almost in the horizontal direction because the angle of intersection of the formwork with the arch support butter is largely deviated from the right angle direction. . Therefore, the arch support butter is required to have a structure in which a horizontal member is provided to withstand a horizontal load. This inevitably results in a truss structure.

Therefore, in actual practice of arch concrete construction, the arch support is supported as a truss structure by a large number of upright columns, and the formwork is attached to the support. However, in this way, the support work by the truss assembly becomes a heavy structure and the construction becomes large-scale. Moreover, the formwork and its supporting work not only have to be assembled and disassembled for each unit of construction, and the construction work must be repeated.In addition, if the arch shape of arch concrete changes, the supporting work will be adjusted to the arch shape each time. The new shape and structure will be used for assembly. Therefore, the work of assembling and dismantling for each construction section between each pier is extremely complicated,
Not only does it take a lot of time and days, but the amount of waste of materials also becomes large, and enormous cost is required.

The present inventor, in view of such an actual situation, has a Japanese Patent Application No. 60-139297.
With the invention of No. etc., we have developed economical and easy-to-construct support for arch concrete formwork. According to the supporting work of this invention, a triangular unit supporting element is formed by the main rod and the pair of side rods, and a large number of them are pin-coupled to each other at the end of the main rod, and at the connecting portions of the both side rods are sub-subtracted from each other. With a structure that is connected by a rod, the support of the truss structure that supports the form is strong and easy to assemble and disassemble, and the arch shape can be changed simply by changing the length of the auxiliary rod. Therefore, it is possible to apply it again to the construction of arch concrete with various sizes and arch shapes, and it is possible to make a great improvement over the whole construction such as material saving and simplification of construction. is what happened.

[Problems to be solved by the invention]

By the way, in a temporary structure such as a supporting structure, it is economically important to use a standardized member having a diversion property as a member constituting the temporary structure.

The supporting work according to the present invention is also designed so that it can be widely applied to arch concretes of different spans by combining unit supporting elements of the same structure which are unitized. However, if a supporting work with a span considerably longer than the design standard is to be constructed, the unit supporting elements up to that point will have insufficient strength. Therefore, also in the support work of the above invention, there is a natural limit to the width of adaptation to the size of the span length.

The present invention has been made for the purpose of broadly expanding the range of application in the supporting work of the method of combining the above-mentioned unit supporting elements, and the above-mentioned unit supporting element has most of the stress ( It is a type for arch concrete construction with a large adaptability that uses unit support elements by focusing on the fact that compressive stress) acts and making it a structure that can double and increase the strength of the main rod. It is intended to provide frame support work.

[Means for solving problems]

The structure of the present invention will be described with reference to FIGS. 1 and 2 corresponding to the embodiment. According to the present invention, a large number of supporting elements 15 formed by connecting a main rod 11 and a pair of side rods 12 and 12 into a triangular shape, The main rods 11 are connected to each other by pin couplings 17 at the end portions thereof, and the connecting portions of the two side rods 12 and 12 of each supporting element 15 are connected to each other by a sub rod.
18 are connected to each other to form an arch-shaped bridge groove,
A reinforcing main rod 22 is arranged outside the main rod 11 of each supporting element 15,
The reinforcing main rods 22 are connected to each other 23 at the other end of the connecting rod 21 whose one ends are pivotally attached to the connecting pins 17 of the main rods 11.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 1 and 1 are leg structures constructed at a predetermined interval before placing arch concrete 8, 2 is an arch form frame that is laid between the leg structures, and 10 is the arch It is an arch-shaped supporting work for supporting the form, and the arch-shaped form 2 is a flap material 3 formed in an arch shape.
Are arranged in parallel and are appropriately connected by a lateral flap material (not shown), and a weir plate 4 is attached to the outside of the flap material 3.

The arch-shaped supporting work 10 is such that the one ends of the side rods 12 and 12 are bound to the both ends of the main rod 11, 13 and the other ends thereof are bound to each other via a joining plate 14, 16. 16 to form the supporting element 15 formed in a triangular groove, and using this as a unit member, a large number of them are connected to each other by the pins 17 at the ends of the main rods 11 and 11, and the connecting plate 14 of each supporting element 15, 14 are connected to each other by a sub-bar 18 shorter than the main bar 11 to form an overall arch-shaped truss structure. The sub rod 18 may be attached to the connecting plate 14 by pin connection, but as shown in FIG. 2, the auxiliary plate 20 is pin connected to the connecting plate 14.
Alternatively, the auxiliary rods 18 may be fixed to the plate 20 by welding. The size of the curve formed by the arch support structure 10 is determined by the length of the auxiliary rod 18. Therefore, the arch support structure 10 can be freely changed in its degree of curvature by changing only the length of the auxiliary rod 18, and the degree of curvature can be freely increased or decreased for each support element 15 units. It will also be possible to accommodate the construction of arch-shaped frames that bend in a complicated manner.

In addition, at the connecting points of the main rods 11 and 11 of each supporting element 15,
One end of the connecting rod 21, 21 having a required length is pivotally attached via 17.
Outside the main rods 11, 11, reinforcing main rods 22, 22 formed in the same manner as the main rods 11 are arranged at intervals with the main rods 11, and both ends thereof are the main rods 11, 11 respectively. Are connected to the other ends of the connecting rods 21, 21 pivotally attached to the connecting pins 17, 17 by pins 23, 23. As a result, the three adjacent reinforcing main rods 22, 22 and the continuous rod 21 are connected to each other by the pin 23.

In the illustrated example, since the reinforcing main rod 22 has the same length as the main rod 11, a slight deviation may occur in the length direction between the main rod 11 and the reinforcing main rod 22. However, as shown in the figure, the deviation is such that the inclination of the connecting rods 21, 21 does not actually cause any trouble. It should be noted that part or all of the reinforcing main rod 22 can be made slightly longer than the main rod 11.

In FIG. 1, the uppermost two reinforcing main rods are made longer than the others. Since using standardized parts as much as possible will increase the economic efficiency, use the same reinforcement rod as the main rod and reduce the number of non-standard lengths used as much as possible. It is desirable to do.

Then, screw rods 27 and 27 are attached to the reinforcing main rod 22 of each supporting element 15 so as to pass through the reinforcing main rod 22, and a pair of nuts 28 screwed to the screw rod 27 with the reinforcing main rod 22 sandwiched therebetween. , 28 are fixed by tightening, and the projecting length from the reinforcing main rod 22 can be adjusted by adjusting the screwing relation position with the nut 28. The outer end portion of the screw rod 27 can be connected to the flap member 3 of the mold 2 and the pin 7 so as to be freely attached.

As shown in FIG. 1, the arch supporting structure 10 having the above-described structure includes the main rods 11 and 11 of the supporting elements 15 and 15 at both ends and the reinforcing main rod 22,
The end portions of 22 are fixed to the brackets 24 and 24 fixed to the piers 1 and 1 by the pins 25 and 25 to be constructed. And, this arch support 10 is provided in a plurality of rows at a required interval in the depth direction of the arch concrete to be constructed, and each of these supports is a part of the connecting plate 14, the side rod 12 or the main rod 11, and the reinforcement. Main rod 22
Are connected to each other by a connecting rod 26 (see FIG. 2). It should be noted that the connection of the side rods 12, the main rods 11, and the reinforcing main rods 22 is omitted in the drawing.

The formwork 2 is erected on the frame arch support. That is, the flap material 3 is arranged outside the reinforcing main rods 22, 22 of the arch support, and the pin 7 is inserted into the pin hole of the flap material 3 and the pin hole at the end of the screw rod 27 which are provided in advance. It is fixed to the reinforcing main rod 22 via the screw rod 27, and the weir plate 4 is attached to the outer surface of the flap material 3. At that time, the position and the arc of the mold can be appropriately adjusted by adjusting the protruding length of the screw rod with respect to the main rod 22.

After erection of the formwork 2, the auxiliary formwork 6 is installed between the end of the formwork 2 and the pier 1, the outer formwork 5 is erected, and the concrete 8 is placed between both formwork 2 and 5. To do. Concrete 8
After curing, the outer frame 5 and the auxiliary frame 6 are removed, then one of the nuts 28 is loosened and the other is tightened to shorten the protruding length of the screw rod 27, and the mold is inserted through the flap material 3. The frame 2 will be pulled toward the reinforcing main rod 22, and as a result, the form 2 will be separated from the concrete 8 as shown in FIG.

After the construction of the arch concrete 8 is completed, it is usual to dismantle and remove the formwork 2 and the supporting works 10, but in this case,
Attach the bracket 24 with the main rod 11 and the reinforcing main rod 22 to the pier 1
It is not fixed to the pier 1, and a long rail is laid on the pier 1 in the depth direction, and a moving wheel is attached to the end of the main rod 11 so that the arch support 10 can be moved along the rail. For example, as shown in FIG. 3, the mold 2 can be moved to the next construction site without being disassembled in a state of being separated from the concrete 8.

FIG. 4 shows another example in which the shape of the connecting rod 21 connecting the main rod 11 and the reinforcing main rod 22 is changed. The reinforcement main rod 22 is
Usually, it is preferable to apply the same one as the main rod 11,
In such a case, when the arch-shaped curvature is large or the arch span is large and the number of supporting elements 15 coupled is large, the displacement between the main rod 11 and the reinforcing main rod 22 becomes large, and the connecting rods become large. It may be impossible to deal with the inclination of 21 alone. In such a case, as shown in FIG. 4, the connecting rod 21 'connected at the top is formed in a substantially triangular shape, and the ends of the reinforcing main rods 22, 22 connected at the top are spaced from each other. By connecting the connecting rod 21 'with the pins 23', 23 ', the large misalignment between the main rod 11 and the reinforcing main rod 22 can be eliminated. The triangular connecting rod 21 'can also be applied to the other connecting rods 21.

〔The invention's effect〕

As described above, according to the present invention, the unit supporting element is formed by the main rod and the pair of side rods, and a large number of them are pin-coupled to each other at the end of the main rod, and at the connecting portion of the two-sided rods. An arch support is formed by connecting them to each other with sub-rods, and reinforcing main rods are arranged in parallel to the main rods outside the main rods of each supporting element in the arch support work. Since the rods are connected to each other in the form of a link with a connecting rod,
The support of the truss structure that supports the formwork can be made firm and easy to assemble and dismantle, and the arch shape can be changed by changing only the length of the sub-rod, so that it can be used in various sizes. It is possible to apply it again to the construction of different arch concrete, and it is possible to achieve the material saving and labor saving. In addition, since the reinforcing main rod is connected to the main rod that receives most of the stress through the connecting rod, the main rod and the reinforcing main rod oppose each other evenly, and the strength is doubled. It will be. Therefore, it becomes possible to use the supporting elements applied to the construction of a small arch span for the construction of a large arch span, and the range of application of the arch support work is greatly expanded. Since arch support can be configured by diverting and combining almost the same members for various types of large and small, the economical efficiency of arch support can be significantly increased and the construction cost can be greatly reduced. It has many excellent effects.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a construction mode using a supporting work according to an embodiment of the present invention, FIG. 2 is an enlarged side view showing a part of the supporting work, and FIG. 3 is a formwork in FIG. FIG. 4 is a side sectional view showing a state in which the is peeled off, and FIG. 4 is a side view of a main part showing another embodiment. 1 ... Bridge pier, 2 ... Arched formwork 5 ... Outer formwork, 8 ... Concrete 10 ... Arch support, 11 ... Main rod 12 ... Side rod, 15 ... Unit support element 17 ... Pin, 18 ... Sub-rod 21 ... Link Rods, 22 ... Reinforcing main rods 23 ... Pins, 24 ... Brackets 25 ... Pins, 27 ... Screw rods 28 ... Nuts

Claims (1)

[Claims] 1. A large number of supporting elements formed into a triangle by connecting a main rod and a pair of side rods to each other are connected to each other at the end portions of each main rod by pin connection, and at the same time, on both side rods of each supporting element. The connecting parts are connected to each other by the sub-rods to form arch-shaped bridge grooves, and the reinforcing main rods are arranged outside the main rods of each supporting element, and one end is connected to the connecting rods of the main rods. A form support for arch concrete construction, characterized in that the reinforcing main rods are connected to each other at the other end of the pivotally connected connecting rod.