JPS6198864A - Mold frame apparatus for arch concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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.

"Prior Art" Recently, in bridge structures such as roads and railways, deterioration and tβ damage of concrete slabs constructed on bridge piers have become 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 kind of concrete deterioration, bridge types that match the characteristics of concrete have been studied, and attention has been focused on the infill concrete arch bridge, which has become forgotten today. 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. It's true.

However, when constructing a concrete structure such as an arch bridge, a major problem arises in terms of the lathe surface, especially the formwork facilities required to construct the arch-shaped concrete between the piers. Referring to the explanatory diagram in Figure 5, as a general example of construction, first, each pier! , ``l'' to the required height, and the arched formwork 2 is supported between the existing piers 100 by a number of vertical supports 3, 3... In this way, easy and economical construction can be carried out. However, in actual construction, the outer formwork 4, which is set opposite to the arched form e+2, and the Since the concrete 5 poured during this period will be piled up sequentially from the bottom of both formworks 2゜4, at the initial stage of pouring the concrete 5, the arrows in Fig. 5 As shown in , the load on the formwork of the concrete 5 acts perpendicularly to the surface of the weir plate (2a).On the other hand, the pillars 3 supporting the formwork part Since the intersecting angle with the butterfly 2b deviates greatly from the perpendicular direction, it is possible to support it in the vertical direction, but it is almost impossible to support it in the horizontal direction.
The arch support putter 2b needs a structure that can withstand horizontal loads by providing horizontal members. This necessarily results in a truss structure.

Figure 6 shows an example in which the arch support pattern 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 supports sleds. Strong shoring is required to support the construction, 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 construction consisting of sheathing boards and buffing materials, without making the formwork a heavy structure. Arch concrete that allows the arch-shaped formwork to be supported almost only by supports, making the formwork simpler and lighter, making the work easier and more efficient, and significantly reducing costs. I am trying to provide formwork.

"Means for Solving the Problems" The present invention provides an arch-shaped formwork to be constructed between existing leg structures, with the upper ends of the supports being spaced apart from each other at a required distance between both ends of the formwork. Tie the bottom ends of each of those pillars together,
It is characterized in that it is supported near the center of the base between both leg structures.

"Embodiments" Examples of the present invention will be described below with reference to FIGS. 1 to 4.

In Fig. 1, 1.1 is the leg structure constructed at a predetermined interval before placing the arch concrete 5, and F is the arch-shaped structure constructed between the leg structures 1.1. The formed formwork body 7 consists of a large number of arch-shaped butterfly materials 7b arranged in parallel, connected to each other by horizontal butterfly materials (not shown), and a weir plate on the outside of the arch-shaped butterfly materials 7b, 7b. 7a is attached.

On the base 6 in the center between both leg structures 1.1, the lower ends of a plurality of columns 8a*8b supporting the form body 7 are placed.
The struts 8a are grounded adjacent to each other and at their outer ends in struts '8a, 8b.

The tips of the pillars 8b are connected to both ends of the form body 7 by pins 9, and the pillars 8b and 8b extend radially upward between the pillars 3B and Ja at the outer ends. Their upper ends are each connected to the form body 7 by pins 9 at required intervals. That is, as shown in the figure, each of the pillars 8 a r 8 b is configured to support the form body 7 in a radial manner with the support point near the center portion on the base 6 . In addition, each of the above-mentioned pillars 8a
, sb are provided with a telescopic mechanism lO at the lower end thereof, and by operating this, the length of each can be freely adjusted.

Furthermore, the required parts of the form body 7 are attached to the existing leg structure 1.1.
Alternatively, it is directly or indirectly fixed to the base 6. That is, in the example shown in FIG. 1, one end of the form body 7 is attached with one end of the tensile member 11 having a telescoping mechanism I2 such as a turnbuckle to the arch-shaped butter material 7b, and the other end is attached to the leg structure l. The other end of the form body 7 is secured to the tip of the outer end support 3a and the base 6 by a tensile material 11. . Note that the middle stage of restraint using the tensile material 11 can have the same configuration at both ends of the formwork body 7, and one end of the tensile material 11 can be placed at another appropriate location on the arched butter material 7b. may be attached to the tip of another appropriate support 8b. Further, as shown in FIG. 2, both ends of the arched butterfly material 7b of the form body 7 may be secured to anchors 13 embedded in the leg structure-1, and furthermore, as shown in FIG. As shown in FIG. 2, one end of the frame body 7 may be secured to the leg structure 1, and the other end may be secured by the tension member 11 as in the other examples.

FIG. 4 shows another example of the arrangement of columns supporting the formwork, in which both 1PIj section structure 1. In addition to the outer end columns 8a, 8a1 and the central column 8b, which are disposed at the center between I, each column 81 is placed at a suitable place on the formwork body 7, for example, each column 81! L + 8b * 8a A means for supporting the middle part of the upper end cover portion 9.9 by support columns 8c, 8c suspended above the base plate 6 is added. In this case, some of the intermediate struts 8b in the example of FIGS. 1 to 3 can be excluded.

The above-described structure of the present invention is applied by making a required number of recesses in the longitudinal direction of the form body 7.

"Function" The present invention is constructed as described above, and the formwork body 7 can be assembled externally or brought in depending on the scale of the arch concrete 5 to be constructed, or assembled at the site. The mold body 7 is supported by supports 8 a + 8 b . 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 15 (see FIG. 5) formed at the top of the outer form 4.

Therefore, the direction of the load of the poured concrete 5 acts perpendicularly to the shedding plate surface, so the horizontal load becomes larger as it goes to both ends of the formwork 7, but the formwork body 7 The radial pillars 8a and 8b form a triangular support structure with good stability,
The radial arrangement of the columns 8a and 8b makes the angle at which they intersect with the formwork 7 at a right angle or close to a right angle compared to only upright columns, so that the force against the horizontal load increases each time. 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; For the load condition of
The formwork 7 is opposed to the leg structure 1 or the base 6 by the restraining force of the tension member II, etc., in cooperation with the respective supports 8 and 10.

The weight of the formwork body 7 and the g of the reinforcing bars placed on the formwork body 7
Since the amount is considerable, it is also related to the inclination angle of the strut, but there are many cases where restraint by the tensile material II as shown in the figure is not necessary. However, even in such cases, it is desirable to provide restraining means for safety.

"Effects of the Invention" As explained above, the formwork apparatus of the present invention has an arch-shaped formwork constructed between existing r-section structures.
The upper ends of each of the pillars are tied together with a required distance of 1) i between the two ends thereof, and the lower end of each of the pillars is supported near the center of the base between the two leg groove structures. Therefore, the arch-shaped formwork is usually of a simple structure consisting of a combination of buffing material and a shedding plate, and it can be used with only supports or with supports as necessary. The formwork for arch concrete construction can be formed into a strong form only by means of restraining the formwork body, and the formwork is lightweight, easy, and has high production efficiency, resulting in a significant reduction in costs. Many excellent effects can be obtained.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the device of the present invention, Figs. 2 to 4 are front views showing other embodiments of the device of the present invention, and Fig. 5 is an explanation of formwork construction for arch concrete. figure,
FIG. 6 is a front view showing a conventional formwork device.

Claims (1)

[Claims] The upper ends of the pillars are tied to the arch-shaped formwork constructed between the existing leg structures, with a required distance between both ends, and the lower ends of each of the pillars are connected to the arch-shaped formwork constructed between the existing leg structures. A formwork device for arch concrete, characterized in that it is supported near the center of a foundation between structures.