JPH10183998A - Form timbering for building arched concrete body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use unit form timbering for building an arched concrete body. SOLUTION: A form timbering unit is composed of a segment structure 3a in which support poles 4, 4 are connected to opposite ends of a truss 3a, and end structures 3b in which support pole 4 is secured to one end of the truss 3b which are coupled to and planted to leg structures B, B, respectively, and a plurality of the segment structures 3a are arranged being spaced from one another, and the structures 3a, 3b are coupled together through the intermediary of coupling members 5 so as to form an overall form timbering A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a form support for connecting arched structures such as trusses and columns to construct arch concrete in an arch bridge or the like.

[0002]

2. Description of the Related Art In the construction of arch concrete in an arch bridge or the like, a form support (see, for example, Japanese Patent Publication No. 3-64001) for erection of an arched truss between an abutment and a pier is used. The economy has been significantly improved.

[0003] However, even if the above-mentioned form support is directly applied to a long span, it becomes a large-scale structure and its advantages are lost. Therefore, for the construction of arch concrete having a long span, for example, a form supporting method using a combination of a divided truss and a column as described in Japanese Patent Application Laid-Open No. H2-240311 has been developed and is often used. It has become.

[0004]

The construction of arch concrete is carried out by casting concrete on a formwork set on a formwork support, and this concrete is simultaneously cast over the entire span. Since it is not physically possible to do so, a section is set within a range where concrete can be cast at once, and split casting is performed. In general, this split driving is performed sequentially upward from both lower ends of the form in consideration of workability.

[0005] In such a case, in the above-mentioned conventional form supporting method using a combination of a divided truss and a column, it forms a continuous beam over the entire span.
In the early stage of concrete placement, the lower end of the form support is deformed downward by the casting load, and the middle part tends to be deformed upward accordingly. And, when the concrete was driven into the middle part, the middle part of the form support tried to be deformed downward by the load, and the hardened concrete at the both ends that had been cast earlier came to be pushed up, Excessive stress will be applied to the concrete.

In addition, since the ground on which the pillars are erected is originally uncertain, the pillars may sink more than expected due to a large load such as cast concrete. In such a case, excessive stress is generated in the form support. Further, if the deformation of the form support becomes large, there is a problem that the arch concrete itself cannot obtain the form and strength as designed.

Further, in the case of a temporary structure such as a formwork support, it is possible to reduce the cost by forming the structure using inexpensive general members as much as possible, so that the structure can be used repeatedly. There is a problem that it is important in construction economy.

Accordingly, the present invention takes advantage of the formwork support by the combination of the split truss and the strut, and solves the above-mentioned problems in the conventional formwork support by dividing and forming a fixed-size truss. As a unit, the divided structure of the form support consisting of the support structure and the pillars can be formed as a unit by mainly connecting them to each other. An object of the present invention is to provide a formwork support that can cope with settlement and is particularly suitable for construction of arch concrete with a long span.

[0009]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. A divided structure a formed by joining the upper ends of
The end structure b formed by connecting the upper end of the support 4 to one end of the truss 3b is used as a unit, and the above-mentioned structures b, b are respectively attached to the leg structures B, B constructed opposite to each other. Is connected to the other end of the truss 3b, and a plurality of the divided structures a are arranged at intervals between the two end structures b. a, each truss 3 of divided structure a adjacent to each other and end structure b
The end portions of a and 3b are connected by a connecting member 5 except for some portions.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view showing one embodiment of the present invention, FIGS. 2 to 4 are enlarged views of each part, and FIG. 5 is a further enlarged view of the support column.

As shown in FIG. 1, a form supporter (hereinafter referred to as a supporter A) of the present invention includes an abutment, a pier, and the like constructed at predetermined intervals before the arch concrete C is cast. It is installed between the leg structures B, B, and an arch-shaped formwork 1 is installed on the upper surface thereof. The shoring A is composed of a plurality of divided structures a including a truss 3a having a required length and a pair of columns 4 and 4, and an end structure including a truss 3b having a required length and a single column 4. b.

As shown in FIG. 5, the divided structure a comprises a truss 3a and columns 4,4. The truss 3a is formed to have a length suitable for transportation and lifting. A plurality of side rods 8, 8 are provided at intervals on an upper chord formed by connecting a plurality of main rods 7, 7 with pins or the like. Are connected to each other, and the other ends of the side rods 8, 8 are connected to the lower chord material 9. The structure of the truss 3a is not limited to the above-mentioned structure, and a conventionally known general truss can be used.

As shown in FIG. 7, the column 4 has brackets 11a, 11b at the upper and lower ends of a column 10 made of a cylinder, a prism, or the like.
The bracket 11a at the lower end is provided with a seat 12 having a receiving plate 13 at the lower end so as to be tiltable by a pin 14. A pair of the columns 4 is a bracket at the upper end thereof.
11b, 11b are attached to both ends of the truss 3a, and pins 15
To form a divided structure a.

The end structure b is composed of a truss 3b and a single support 4 as shown in FIG. The truss 3b has the same structure using the same members as the truss 3a described above, but the length thereof is appropriately increased or decreased according to the construction mode such as the span length of the form support A. In addition, this support 4
It is formed in the same structure as the support 4 described above.
The support column 4 is rotatably connected by a pin 15 with the upper end bracket 11b attached to one end of the truss 3b.

As shown in FIG. 4, the supporter A embeds or anchors a pair of end structures b with the other end of the truss 3b to which the column 4 is not connected, respectively, in the leg structure B. It is bound by a pin or the like to a bracket 16 firmly installed with bolts or the like, and the support column 4 is erected on the ground D, and an appropriate number of divided structures a is provided between the both end structures b. Are arranged at a required interval from the end structures b and b, and the columns 4 and 4 are arranged upright on the ground D. Then, the end structures b, b, the divided structures a, a, and the divided structures a, a
The members a and 3b are connected to each other by connecting members 5 and 5 formed of rods or the like, and are framed. In addition, at the time of erection of the shoring A, each of the columns 4 is, as shown in FIG.
It is preferable to support the ground D via a load release seat 17 which can be cut in the lateral direction.

Further, in the above-mentioned support A, when placing the arch concrete C, it is necessary to provide a place where the divided structures a and the end structures b are not connected to each other.
For example, as shown in FIGS. 1 and 2, a discontinuous portion d of the structural body is formed in the support A by excluding the connection by the connecting member 5 between the divided structural bodies a, a at the center. The discontinuous portion d may be formed at the time of erection of the shoring A, or may be connected with the connecting member 5 (indicated by a chain line in FIG. 2) at the time of erection, and prior to the installation of the arch concrete C. Connecting member 5
May be removed and formed. Further, even when the discontinuous portion is connected by the connecting member 5 or the like, the connected portion can be a connection that can be separated from each other in the span direction of the support A via the connecting member 5 or the like. The discontinuous portion d is not limited to the central portion as shown in the figure, but can be appropriately set at a connection point between the other divided structures a and the end structures b.

The support A is formed and erected such that the upper surface thereof has an arch shape as a whole. Therefore, each support 4
Will be used at a height from the ground D necessary to form the arch shape. In general, in the case of a long span, since the arch shape becomes flat, the required height difference between the ends of the shoring A and the pillars 4 and 4 at the center is not so large. Although several types of columns having different heights are prepared and used, the columns may be provided with a telescopic adjustment device, and may be used at a height required for the adjustment.
In addition, it is also possible to install a pedestal (not shown) of necessary height such as concrete, which can be easily removed later, at the standing position of the pillar D on the ground D, so that the length of each pillar can be equalized. It is.

In practice, the support structure having the above-described structure is arranged in a plurality of rows at predetermined intervals in the depth direction of the arch concrete C to be constructed, and is connected to each other using a connecting member or the like. The formwork 1 is mounted on the upper surface of the erection work A via support members 6 and 6, such as a required height of a butter material and a receiving stand. Then, the arch concrete C is cast on the formwork 1.

The arch concrete C is cast by setting a section that can be cast at one time in the span direction.
In general, first, concrete in the lowermost (both ends) section of the arch concrete C is connected to the leg structure B and cast, and thereafter, the concrete is sequentially joined upward. At this time, the truss 3b and the struts 4 of the end structure b receive the concrete placing load, and the truss 3b is bent. b is connected only to the other divided structure a via the connecting member 5 and is not integrated by rigid connection, so that each behaves independently, and the other divided and end structure due to the bending thereof. The influence of stress generation on a and b is extremely small.

In this case, even in the case where the column is slightly settled, since the support A has the discontinuous portion d, the structures a and b follow the settlement. ,
Movement in the vertical direction or in the span direction of the support A is allowed, so that the load on the column 4 of each structure a can be shared without trouble, and the excessive load on the trusses 3a and 3b (especially It is possible to prevent a compression load on the rod 7 from being applied. Therefore, the shoring A needs to have a strength almost as designed, and the economics of the shoring A can be improved.

[0021]

As described above, according to the present invention,
A form supporting structure for constructing arch concrete is divided into a plurality of unitized structures: a split structure with struts connected to both ends of the truss, and an end structure with struts connected to one end of the truss. Because it is formed side by side and connected by a connecting member in series, when constructing arch concrete of various spans, changing the number of divided structures used or adjusting the length of the end structure, In addition, it is possible to cope with it only by changing the length of each pillar as needed, and particularly, it is easy and economical to construct various arch concretes having a long span. In addition, the unitization of the structure enhances the repetitive utilization, reduces the consumption of materials, and significantly reduces costs.

Each of the unitized structures is erected independently by connecting with each other by a connecting member.
One of them forms a discontinuous part as a structure, so even if each structure is deformed or the support is slightly settled in the process of piling concrete, each structure is independent. It behaves and moves in the vertical direction following the settlement, and the respective structures are allowed to move in the span direction as a whole, so that excessive stress can be prevented from being generated in the support work. Therefore, the economic efficiency of the shoring can be maintained. In addition, arch concrete with less residual stress can be prevented when applying concrete, preventing abnormal stress from being applied to the hardened concrete and causing the concrete to be separated. Can be constructed.

[Brief description of the drawings]

FIG. 1 is a schematic overall view showing one embodiment of the present invention.

FIG. 2 is an enlarged front view showing the central portion.

FIG. 3 is an enlarged front view showing a part following the central part.

FIG. 4 is an enlarged front view showing the same end.

FIG. 5 is a front view of a divided structure.

FIG. 6 is a front view of the end structure.

FIG. 7 is a front view of a column.

[Explanation of symbols]

 A Form support B Leg structure C Arch concrete D Ground a Divided structure b End structure d Discontinuous part 1 Formwork 3a, 3b Truss 4 Support 5 Connecting member 6 Support 7 Main rod 8 Side rod 9 Lower chord 10 Pillar 12 Seat 16 Bracket

Claims (1)

[Claims] A split structure formed by joining the upper ends of the struts to both ends of the truss, and an end structure formed by joining the upper ends of the struts to one end of the truss as units. On the leg structures, the end structures are respectively erected by connecting the other ends of the trusses, and a plurality of the divided structures are spaced apart from each other between the both end structures. Arranged and connected to each other of the divided structures and the end structure and the end of each truss of the adjacent divided structure by connecting members except for some parts, for arch concrete construction Formwork support.