JP2553349B2 - Form support for arch concrete construction - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of use) The present invention relates to a support for a formwork applied to the construction of arch concrete in an arch bridge or the like.

(Prior Art) When constructing a concrete structure such as an arch bridge, the construction work, especially the formwork support facility required for the construction of arched concrete between bridge piers (including abutments) becomes a major problem. It is easy if it can be done only by supporting the formwork with a large number of vertical columns like the support work of a horizontal slab, but it is not as easy as a horizontal slab because it has a sloped part in the case of an arch. . Since the concrete load applied to the formwork acts in the direction perpendicular to the formwork surface in any case, the arch concrete on the slope part applies not only the vertical load but also the horizontal load to the support work. . Since the support pillars are usually erected vertically, the arch support must have a structure that can withstand the horizontal direction. This inevitably results in a truss structure or something similar, and the supporting work becomes a heavy structure and the construction is complicated. If the arch shape of the arch concrete changes, the supporting work must be manufactured and assembled according to the shape each time, which requires a lot of time and a lot of materials and enormous cost.

The present inventor, in view of such an actual situation, has found that Japanese Patent Application No. 60-1392
With the invention of No. 97 etc., we have been developing 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 support work,
It is economically important to use a standardized material that can be used as a member that constitutes it.

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 structure with an arch span much longer than the design standard range is to be constructed, the unit supporting elements up to that point will lack strength and rigidity. 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 broadening the range of application in the supporting work of the system in which the unit supporting elements are combined.

Two problems arise when trying to apply this type of support to long spans. One is the lack of strength of the main rod, and the other is the lack of rigidity as an arch truss.
Insufficient strength of the main rod means that the strength of the main rod that receives the maximum stress under the condition of full load (concrete load) is insufficient. This is a lack of overall rigidity when the wavy deformation of the arch-type support work that receives partial load exceeds the allowable value.

The deformation of the arch support under full load is not a problem, but the problem under partial load is a characteristic of the arch support.
For example, when concrete loads are applied only to both lower parts of the supporting work, the lower part is displaced inward and the upper part of the arch is lifted up. When a load is applied only to the upper part, the upper part sinks and the lower part bulges outward. Therefore, if the method with the best workability, that is, sequentially piling up from below, is adopted for the placement of arch concrete, the support work will show a wavy deformation during the concrete placement process, which will result in various changes to the concrete. Unfavorable effects of.
If the span length of the arch exceeds a certain limit, this wavy deformation exceeds the allowable range and a problem arises in that the standardized unit combination has insufficient rigidity.

The present invention responds to the lack of strength of the main rod under the load of all concrete by using a standardized main rod with two upper and lower combined rods. By utilizing the effect of additionally arranging a new tension material (reinforcement tension material) and increasing the height of the truss of the arch support work, the strength and rigidity are increased and the standardized unit application range is increased. The aim is to expand to long span arches, resulting in more economically affordable form support for arch concrete construction that is easy to handle.

(Means for Solving Problems) The structure of the present invention will be described with reference to the drawings corresponding to the embodiments. According to the present invention, the main rod 11 and a pair of side rods 12 and 12 are combined to form a triangle. A large number of the supporting elements 15 formed are connected to each other by pin couplings 17 at the ends of the respective main rods 11, and the connecting portions of both side bars 12, 12 of each supporting element 15 are formed shorter than the main rod 11. The auxiliary main rods 16 and 16 are connected to each other to form an arched frame, and the reinforcing main rod 2 is provided outside the main rod 11 of each supporting element 15.
The reinforcing main rods 22, 22 are arranged at the other ends of the connecting rods 21, 21 in which the end portions are pivotally attached to the connecting pins 17 for connecting the main rods 11, 11 to each other.
And the auxiliary rods 20, 20 projecting toward the center direction of the arch at the middle portions of both halves of the arch by the connected secondary rods 16, 16, respectively. Rod 16,
The terminal connecting portions 19 and 16 of 16 and the arch center portion by the auxiliary rods 16 and 16 are connected to each other to provide the reinforcing tension members 30 and 30, and the outer ends of the main rod 11 and the reinforcing main rod 22 at both ends are connected. Each is supported by an existing structure such as the pier 1.

(Example) Hereinafter, an example of the present invention will be described 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 laid between the leg structures; 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 support structure 10 has side rods 12, 12 on both ends of the main rod 11.
A support element in which one end of each of these is connected 13 and the other ends thereof are connected to each other via a connecting plate 14 to form a triangular structure.
15 is formed, and this is used as a unit constituent member,
The ends of the main rods 11 and 11 are connected to each other by pins 17, and the connecting plates 14 and 14 of the supporting elements 15 are connected 19 to each other by the sub-rods 16 shorter than the main rods 11 to form a generally arch-shaped truss. Form into a structure. The sub-rod 16 may be attached to the joint plate 14 by a pin joint 19, but an auxiliary plate (not shown) may be pin-joined to the joint plate 14 so that the sub-rods 16 are fixed to the plate by welding. You may

The size of the curve formed by the arch support structure 10 is determined by the length of the auxiliary rod 16. Therefore, the arch support structure 10 can freely change the degree of curvature by changing only the length of the sub-rod 16, and each support element 15 units even when the arc length of the arch is changed. Since it can be freely increased or decreased, standardized members can be freely used for arch form frames having complicated shapes and dimensions.

At the connecting point of the main rods 11, 11 of each supporting element 15, the pin 1
One end of the short connecting rod 21, 21 is pivotally attached via 7. Outside the main rods 11 and 11, reinforcing main rods 22 and 22 formed in the same manner as the main rods 11 are arranged at intervals with the main rod 11, and both ends thereof are respectively arranged. Connecting rods 21,2 pivotally attached to the connecting pins 17,17 of
It is connected to the other end of 1 by pins 23, 23. As a result, the three adjacent reinforcing main rods 22, 22 and the connecting rod 21 are connected to each other by the pin 23. In this case, since the reinforcing main rod 22 and the main rod 11 have substantially the same length, there will be some deviation in the length direction between the main rod 11 and the reinforcing main rod 22, but the deviation will occur. As shown in the figure, it can be adapted by inserting the reinforcing main rod 22 having a deformed length into the connecting rods 21 and 21 in an appropriate position as needed.

The secondary rod 16 is also reinforced to increase the strength and rigidity of the truss as a whole. Since a tensile stress mainly acts on the sub-rod 16, its reinforcement may be of a structure generally strong against tension. That is, to the connecting plates 14 and 14 in the middle of both halves of the arch by the plurality of connected sub-rods 16 and 16,
The base rods of the auxiliary rods 20 and 20 are connected to each other so as to project toward the center of the arch, and the projecting end portion and the connecting plate 14 of the end portion which is the end connecting portion of the auxiliary rod 16, Since the reinforcing tension members 30 and 30 having the length adjusting devices 29 and 29 such as a turnbuckle are stretched between 14 and between the coupling plates 14 and 14 at the center of the arch, respectively. is there. As a result, the tensile stress acting on the auxiliary rods 16 and 16 is also shared by the reinforcing tension members 30 and 30.

It is desirable that the tension of the reinforcing tension material 30 be adjusted by operating the turnbuckle 29 so that the stress distribution between the auxiliary rod 16 and the reinforcing tension material 30 exactly matches the design value.

The arch support structure 10 having the above-described configuration is a support element at both ends.
Attach the terminal parts of 15, 15 main rods 11, 11 and reinforcing main rods 22, 22 to the pier.
At the required intervals on the brackets 24, 24 fixed to 1, 1,
They are fixed by pins 25 and 25, respectively. Also,
This arch support 10 is the arch concrete 8 to be constructed.
A plurality of rows are provided at a required interval in the depth direction and are connected to each other by appropriate means.

The formwork 2 is erected on the arch support structure 10 which is constructed. That is, the flap material 3 is arranged outside the reinforcing main rods 22, 22 of the arch support structure 10, 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 bridge 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 thereby the form 2 will be separated from the concrete 8.

After the construction of the arch concrete 8 is completed, it is usual to dismantle and remove the formwork 2 and the support structure 10. In this case, the bracket 24 with the main rod 11 and the reinforcing main rod 22 is fixed to the pier 1. If you do not do this, lay a long rail in the depth direction on the pier 1, attach moving wheels to the end of the main rod 11, and move the arch support along that rail. The frame 2 separated from the concrete 8 can be moved to the next construction site without disassembling.

In the above embodiment, a linear material is used as the reinforcing tension material 30, but the reinforcing structure of the reinforcing tension material 30 and the auxiliary rod 20 uses, for example, a rod material for the reinforcing tension material 30 and compresses. A truss structure can also be formed by combining with an auxiliary rod 20 that can withstand stress.

(Effects of the Invention) 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 both sides are connected. At the connecting part of the rod, it is connected to each other by a sub-rod to form an arch support.
Reinforcing main rods are arranged in parallel with the main rods outside the main rods of the supporting elements in the arch support work, and the reinforcing main rods and the main rods are connected to each other in a link shape by a link to compress the compression member. The tension of the auxiliary rod is doubled and the tension side is reinforced by arranging a reinforcing tension member inside the arch connecting the secondary rods to enhance the overall strength and rigidity. Since it can be freely applied to various types of arch support with a long span only by changing the dimensions of the, the applicable range of the standardized support unit can be expanded to that with a long span. The economical efficiency of the support work is significantly increased, the construction cost can be greatly reduced, and the construction period can be shortened.

[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, and FIG. 2 is an enlarged side view showing a main part of the supporting work. 1 ... Bridge pier, 2 ... Arch form 5 ... Outer form, 6 ... Auxiliary form 8 ... Concrete, 10 ... Arch support 11 ... Main rod, 12 ... Side rod 15 ... Unit support element, 16 …… Sub-rod 17, …… Pin, 20 …… Auxiliary rod, 21 …… Reinforcing rod 22 …… Reinforcing main rod, 23 …… Pin 24 …… Bracket, 25 …… Pin 27 …… Screw rod , 28 …… Nut 30… Reinforcement tension material

Claims (1)

(57) [Claims] 1. A large number of supporting elements formed by connecting a main rod and a pair of side rods to form a triangle, are connected to each other by pin connection at the ends of each main rod, and the supporting rods on both sides of each supporting element are connected to each other. The connecting rods are connected to each other by the auxiliary rods formed shorter than the main rods to form an arch-shaped frame, and the auxiliary main rods are arranged outside the main rods of each supporting element. At the other end of the connecting rod, one end of which is pivotally attached to the mutual connecting pin, the reinforcing main rods are connected to each other, and the center direction of the arch is formed in the middle part of both halves of the arch by the connecting sub rods. An auxiliary rod projecting toward the front end of the auxiliary rod, and the projecting end portion of the auxiliary rod is joined to the end connecting portion of the auxiliary rod and the central portion of the arch formed by the auxiliary rod to provide an auxiliary tension member. The arch concrete is characterized in that the outer ends of each are supported by existing structures such as bridge piers. Formwork shoring for the construction.