JPH0345177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a formwork apparatus applied to the construction of arch concrete in arch bridges and the like.

"Conventional technology" Recently, in bridge structures such as roads and railways, deterioration of concrete slabs constructed on piers,
Damage is becoming a major problem. Deterioration and damage to concrete slabs result from the material properties of concrete that are strong in compression but weak in tension.Dry shrinkage and repeated moving concentrated loads cause cracks, and water that enters through these cracks promotes rusting and expansion of reinforcing bars. It is expected that the concrete will flake off and the reinforced concrete will deteriorate further.

Therefore, in order to deal with this type of deterioration of concrete, bridge types that match the characteristics of concrete have been studied, and infill concrete arch bridges, which have been forgotten today, have been attracting attention.
This arch bridge is an excellent structural type for a concrete structure because it becomes a compressed member throughout its cross section when a dead load is applied.This type of bridge prevents deterioration of the concrete and greatly improves durability. That is true.

However, when constructing a concrete structure such as an arch bridge, a major problem arises in terms of construction, especially the formwork facilities required to construct the arch-shaped concrete between the bridge piers. Referring to the explanatory diagram in Fig. 5, in a general construction example, each pier 1, 1 is first constructed to the required height, and many arch-shaped formworks 2 are installed between the existing pier 1, 1. It is conceivable to support it by vertical supports 3, 3, . . . . This allows easy and economical construction. However, in actual construction, the concrete 5 poured between the arched formwork 2 and the outer formwork 4 set opposite thereto is piled up sequentially from the bottom of both formworks 2 and 4. Therefore, at the initial stage of pouring the concrete 5, the load on the formwork of the concrete 5 acts perpendicularly to the surface of the weir plate 2a, as shown by the arrow in Figure 5. . On the other hand, the pillars 3 that support the formwork part can support the formwork in the vertical direction but have little support in the horizontal direction because the angle of intersection with the arch support butterfly 2b of the formwork deviates greatly from the right angle direction. It's almost impossible. Therefore, the arch supporting butterfly 2b needs to have a structure that can withstand horizontal loads by providing horizontal members.
This necessarily results in a truss structure.

Fig. 6 shows an example in which the arch support butter 2b of the formwork is made into a truss structure.As can be seen from this figure, the arch-shaped formwork 2 not only becomes a heavy structure, but also has a structure that supports it. Strong shoring is also required, making the work difficult and requiring a huge amount of expense.

``Problems to be Solved by the Invention'' The present invention solves the problem of constructing arch concrete formwork as described above by using a common structure of shedding boards and batten materials, without making the formwork a heavy structure. An object of the present invention is to provide an arch concrete formwork that can support the arch-shaped formwork almost only by supports, simplify the formwork, reduce its weight, make work easier and more efficient, and significantly reduce costs. That is.

"Means for Solving the Problems" The present invention supports the central part of an arch-shaped formwork body by a central pillar that stands approximately upright at a required distance from the central part of the base, and The parts leading to the ends of the formwork body are supported by inclined supports arranged radially inclined from near the support base of the central support, and the necessary parts of the formwork body are supported by
It is characterized by being secured to the base or existing leg structure.

``Example'' Below, examples of the present invention will be described in Figures 1 to 4.
This will be explained with reference to the figures.

In Fig. 1, reference numerals 1 and 1 refer to leg structures constructed at a predetermined interval before placing the arch concrete 5, and 7 refers to an arch constructed between the leg structures 1 and 1. This formwork body 7 is formed by arranging a large number of arch-shaped butter materials 7b in parallel, which are connected to each other by horizontal butter materials (not shown), and on the outside of the arch-shaped butter materials 7b, 7b. It is formed by attaching a weir plate 7a.

On the base 6 between the two leg structures 1, 1, central supports 8, 8 are provided upright at the center thereof with a required interval, for example, a distance l necessary for work or equipment transportation, etc. The upper end portion thereof is coupled 9 to the arch-shaped butter material 7b of the form body 7 with a pin to support the form body 7. Further, between the joining points 9, 9 of the arch-shaped butter material 7 and the end thereof, the respective upper ends of a plurality of inclined supports 10, 10 are joined by pins 9, 9 at a required interval. The lower ends of each of the inclined columns 10, 10 are grounded on a base 6 close to the lower end of the central column 8, and are erected in a radially inclined manner, each supporting a form body 7. A telescopic mechanism 11 is provided at the lower end of each of the pillars 8, 8, 10, 10, . . . , and by operating this, the length of each can be freely adjusted.

Furthermore, the arch-shaped butterfly material 7 is secured to the existing leg structures 1, 1 or to the base 6 at required locations. That is, one end of a tension member 12 having an expansion/contraction mechanism 13 such as a turnbuckle is attached to both ends of the arch-shaped butter material 7b, and the other end is connected to an anchor 14 embedded in the leg structure 1 via a bracket 15. It is tied together.

2 to 4 show other embodiments of the means for restraining the form body 7 via the arch-shaped butter material 7b. In FIG. 2, one end of the tensile material 12 is This shows an example in which it is attached to the tip of an inclined support 10 connected to the end of the butterfly material 7b, and the other end is tied to an anchor 14 buried in the base 6 near the base of the leg structure 1. FIG. 3 shows an example in which the end of the arch-shaped butterfly member 7 is directly restrained via an embedded anchor 14 in the upper part of the leg structure 1, instead of being restrained by the tension member 12 described above. be. Furthermore, even when restraining is performed using the tension member 12, as shown in FIG.
One end of the tensile material 12 is attached to the tip of a suitable material 1, and the other end is attached to the base or leg structure 1 as shown in the figure.
It can also be tied to the anchor 14 of. The above-described configuration of the present invention is applied at a required number of intervals in the longitudinal direction of the form body 7.

"Function" The present invention is constructed as described above, and the formwork body 7 may be assembled externally and brought in, or assembled on site depending on the scale of the arch concrete 5 to be constructed. The mold body 7 is supported by the pillars 8 and 10, and required portions of the form body 7 are restrained to the leg structure 1 or the base 6. After the form body 7 is erected, the outer form 4 is erected as shown in FIG. 5, and concrete 5 is poured through the gap 16 (see FIG. 5) formed at the top of the outer form 4.

Therefore, the direction of the load of the poured concrete 5 is perpendicular to the shedding plate surface, so the horizontal load becomes larger as it goes to both ends of the formwork 7. 7 is the central column 8
A triangular support structure with good stability is formed by the slanted support 10 and the slanted support 10, and due to its inclination, the angle of intersection with the formwork body 7 of the slanted support is at or near a right angle compared to an upright support. Therefore, the force against the horizontal load is increased. In particular, at the beginning of pouring the concrete 5, an abnormal situation occurs in which a large horizontal load is applied only to the ends of the form body 7, and the form body 7 tends to bend strongly upward; The formwork body 7 is resisted by the restraining force of the leg structure 1 or the base 6 by the tensile material 12, etc., in cooperation with the support columns 8 and 10.

"Effects of the Invention" As explained above, the formwork device of the present invention supports the central part of the arch-shaped formwork body by means of central pillars that stand approximately upright at a required distance from the center of the base. The portions extending from the ends of the formwork body to the ends of the formwork body are supported by inclined supports arranged radially inclined from near the support base of the central support, and the required portions of the formwork body are supported by the base plate. Alternatively, since it was configured to be restrained by the existing leg structure, the arch-shaped form body had a simple structure of a combination of butter and sheathing boards, which is commonly used. By applying this method, the formwork for arch concrete construction can be formed into a strong form using only the restraining means of the supports and the formwork body, and the formwork is lightweight, easy to use, has good work efficiency, and reduces costs. In addition, many excellent effects can be obtained, such as creating passages and open spaces necessary for work and transporting equipment between the central pillars.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of the device of the present invention;
Figures 2 to 4 are front views showing other embodiments of the apparatus of the present invention, Figure 5 is an explanatory diagram of arch concrete formwork construction, and Figure 6 is a front view showing a conventional formwork apparatus. It is. 1... Leg structure, 4... Outer formwork, 5... Concrete, 6... Foundation, 7... Arch-shaped formwork body,
8... Central support, 10... Inclined support, 12...
Moving materials, 14...Anchor.

Claims (1)

[Claims] 1. The central part of the arch-shaped formwork, which is constructed by attaching a weir plate to arch-shaped batten materials, is constructed between the existing arch-shaped leg structures, and the required spacing is placed between the central part of the base. It is supported by a central pillar having an almost upright telescopic mechanism, and the part extending from the center pillar to the end of the form body has a telescopic mechanism arranged at a radial inclination from the vicinity of the support base of the central pillar. A formwork device for concrete arches, characterized in that the formwork body is supported by inclined supports, and required portions of the formwork body are restrained by a base or an existing leg structure.