JP2977272B2 - Formwork support for arch concrete construction - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a formwork support applied to construction of arch concrete in an arch bridge or the like.

(Conventional technology) When constructing a concrete structure such as an arch bridge, a construction surface thereof, particularly a form supporting facility required for construction of an arch type concrete spanning between piers (including an abutment) becomes a major problem. It is easy if it can be done only by supporting the formwork with a number of vertical pillars like the support of a horizontal slab, but it is not as easy as a horizontal slab because the arch type has a sloped part . In any case, the concrete load applied to the formwork acts in the direction perpendicular to the formwork surface, so the arch concrete on the slope will apply not only the vertical direction but also the horizontal direction load to the support. . Since the shoring columns are usually vertically erected, the arch shoring must add a structure that can withstand the horizontal direction. This inevitably results in a truss structure or the like, and the shoring becomes a heavy structure and the construction is complicated.

In view of such a situation, the present inventor has developed an economical and easy-to-install arch concrete form shoring, for example, as disclosed in JP-A-62-78357 and JP-A-63-22967. In addition, the architectural truss structure was used as the shoring, and both ends were supported on top of the existing pier. As a result, the structure of the shoring work has been simplified, the materials and costs have been reduced, and the construction has been performed efficiently.

In the support of these inventions, a main unit and a pair of side units form a triangular unit support element, many of which are pin-connected to each other at the ends of the main unit, and the sub-units are connected to each other at the connection part of the both-side units. The truss structure supporting the formwork is strong and easy to assemble and disassemble, and the arch shape can be changed only by changing the length of the sub-rod. Therefore, it can be applied repeatedly to the construction of arch concretes of various sizes and arch shapes, and large improvements can be achieved over the entire construction, such as saving materials and simplifying construction. Was. In addition, because of the addition to the main rod, it is possible to apply even to a support with a considerably long span.

However, even with the shoring according to the present invention, it is impossible to increase the number of main rods, so that the applicable span length is naturally limited.

However, the superiority of this invention support in the construction of arch concrete has been recognized, and arch concrete of a long span (for example, 80 m or more) which has not been considered as being inferior to conventional technology and economical. The demand for the realization of has been increasing. On the other hand, there has been a demand for a support for flat large arc arch concrete.

Therefore, the present inventor has found that a form supporting structure applied to the construction of such a long-span arch concrete or a flat arch concrete is connected to a split truss of a length obtained by dividing the arch concrete span into an appropriate number. And a structure in which an arch-shaped truss frame structure is formed and a connecting portion of each divided truss is supported by a column (refer to Japanese Patent Application No. 1-62864 (Japanese Patent Application Laid-Open No. 2-240311)).

(Problems to be Solved by the Invention) In the above-mentioned formwork support, when the supporting column for supporting the joint portion between the divided trusses is erected on the ground which is strong and has no danger of sinking, such as rock, The load sharing between the arch truss structure and the strut will be performed almost as designed.
However, the struts cannot always be erected on solid ground. When the concrete is cast, the struts may sink slightly, depending on the condition of the ground and construction. If so,
An excessive load exceeding the design value will be applied to the arch truss frame structure. In such a case, it is necessary to raise the sunk support to return the load sharing to the support to the design value. For that purpose, you can use a column that can be adjusted in height, but since there are multiple columns,
Height adjustment is very troublesome, and it is difficult to distribute the load to the shoring evenly.

The present invention has been made in order to solve the above-described problems, and in the case where the column slightly sinks, without adjusting the height of the column, adjusting the axial force of the main rod of the arch truss frame,
It is intended to reduce its substantial length so that it can follow the subsidence of the strut so that the load distribution can be corrected and equalized extremely easily.

(Means for Solving the Problems) Regarding the configuration of the present invention for achieving the above object,
To explain with reference to the drawings corresponding to the embodiment, the form support of the present invention has a required number of triangular support elements 10 formed by connecting a main rod 11 and a pair of side rods 12, 12. The main rods to each other
At the ends of 11, 11 are joined 13 to form a divided arch truss 3, and a large number of the divided arch trusses 3 are connected at their ends 4 to form an arch truss frame A, and both ends of the arch truss frame A are connected to an abutment. Alternatively, the pier 1 is connected to the pier 1 with pins 5,5, and the divided arch trusses 3,3 are connected to each other.
4 in a form supporter supported by columns 6 and 6 erected on the ground B, at least one of the main rods 11 is
The divided main rods 11a, 11b are slidably coupled to each other in the longitudinal direction of the main rod 11, and the divided main rods 11a, 11b are connected to each other.
The adjustment main rod 23 is provided with a jack 27 for adjusting the axial force of the main rod 11 between b.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

First, the outline will be described with reference to FIG. 1. Reference numerals 1 and 1 denote abutments on which arch concrete 2 is erected, which may be piers. Numeral 3 is a divided arch truss formed by dividing the span of the arch concrete 2 into a large number and having a short length, and formed in a curved shape along the arc surface of the arch concrete 2. A large number of the divided arch trusses 3, 3 are connected to each other by pins 4 at their ends to form an arch truss frame structure A having a shape along the entire arc surface of the arch concrete 2 as a whole. 1, 1 and 1 are rotatably supported by load receiving pins 5 and 5, and a connecting portion 4 of each of the divided arch trusses 3 and 3 is a support 6 and 6 standing upright on the ground B.
Is combined with the upper end of the frame to form the entire form support. An arched formwork 7 is installed on the upper surface of this formwork support.

The divided arch truss 3 is, as shown in FIG.
And a pair of side rods 12,12, a support element 1 framed in a triangle
0 is a unit, a plurality of which are connected to each other by connecting pins 13, 13 at the ends of the main rods 11, 11, and each support element 10,
The main rod 11 is connected between the connecting points of the side rods 12 and 12 in FIG.
With the pin connection 15,15 by the shorter auxiliary rod 14,14,
The same main rods 11, 11 are further pinned on the main rods 11, 11 at both outer ends.
The connecting rods 13 and 13 are connected to each other, and the extending rods 16 and 16 are provided between the connecting portions of the other ends and the side rods 12 and 12 to form a curved arched truss as a whole. The magnitude of the curvature of the divided arch truss 3 is determined by the length of the auxiliary rod 14. Therefore, the degree of curvature of the divided arch truss 3 can be freely changed by changing only the length of the auxiliary rod 14 and the length of the extension rod 16, and the curvature of the arch can be changed. Since the length of the arch can be freely increased or decreased in units of ten supporting elements, it is possible to freely cope with an arch form having a complicated shape and dimensions using standardized members.

The above-mentioned divided arch truss 3 has a large number (four in the illustrated embodiment) connected to each other at the outer ends of the main rods 11, 11 located at their ends, and forms the arch concrete 2 formwork. 7, a truss frame structure A having an overall arch shape suitable for mounting the truss 7 is formed.

As shown in FIG. 4, the above-mentioned arch truss frame structure A is configured such that the outer ends of the main rods 11, 11 at both ends thereof are fixed to a support base 17 installed on the abutment 1 with anchor bolts 18, 18. It is rotatably connected to the bracket 19 by the load receiving pin 5 and is supported by the abutments 1 and 1.

On the other hand, on the ground B between the abutments 1 and 1 where the arch truss structure A is to be installed, the columns 6 and the heights reaching the joints of the divided arch trusses 3 and 3 are provided at positions corresponding to the connecting portions of the divided arch trusses 3 and 3 respectively.
6 is erected. The strut 6 shares a part of the vertical load applied to the arch truss frame structure A. As shown in FIGS. 2 and 5, the floating connecting body 20 is swung by the pin 21 at the upper end of the strut 6. It is movably mounted, and the tip of the floating connecting body 20 is rotatably connected to the connecting pin 4 to which the divided arch trusses 3, 3 are connected. In addition, a support plate 22 is provided at an intermediate portion of the floating connecting body 20 so that the main rods 11, 1
By supporting each of the connecting ends of (1), the connecting pin 4
It is possible to reduce the load on the connecting portion including the above.

In the support of the present invention, the main rods
One of the jacks 27 adjusts the axial force of the main rod 11.
Is provided as an adjustment main rod 23 with a. This adjustment main rod
As shown in FIG. 3, the main rod 11 is divided into two main rods 11a and 11b, and one of the divided main rods 11a is inserted into the other divided main rod 11b as shown in FIG. The other split main rod 1
1b, a tongue 25 into which the insertion rod 24 is slidably inserted.
The insertion rod 24 and the tough part 25 are engaged with each other, and receiving holes 26 and 26 are provided at appropriate places of the insertion rod 24 and the tough part 25, and a hydraulic jack 27 is interposed therebetween. ing. Therefore, if the jack 27 is expanded and contracted, the two divided main rods 11a and 11b slide with each other as shown by the arrow in FIG.
The length of the adjustment main rod 23 changes, and if the length is increased, the axial force of the adjustment main rod 23 and the other main rods 11 is increased. Will decrease.

In the form support having the above structure, a plurality of rows are provided at predetermined intervals in the depth direction of the arch concrete to be constructed, and are connected to each other using a connecting rod or the like (not shown).

The formwork 7 is provided with the main rods 11, 11 of the above-described formwork support.
It is erected via supporting members 28, 28 such as bolts and butter materials attached to the horn.

Therefore, when the support 6 is erected on the ground B, which is hard and does not sink, like the rock, the form shoring is almost designed to share the load between the arch truss frame A and the supports 6,6. It will be done on the street. However, the strut 6 cannot always be erected on such a firm ground, and when the concrete is poured in due to the condition of the ground or construction,
The support 6 may sink slightly. In that case, an excessive load exceeding the design value is applied to the arch truss frame structure A. This excessive load is mainly due to a large number of connected main rods.
It appears that the axial force increases to 11,11, and the axial force also acts on the jack 27 of the adjusting main rod 23. Therefore, in this case, if the jack 27 is slightly shortened, the length of the adjustment main rod 23 is shortened, whereby the arch truss frame structure A shrinks and the design load follows the sunk support 6. The state is maintained, and the predetermined load sharing between the arch truss frame structure A and the columns 6, 6 can be achieved.

As described above, the jack 27 interposed in the adjustment main rod 23 provided in the connected main rods 11, 11
Because it receives the same load as 1,11,
The axial force to 1,11 can be adjusted arbitrarily. Therefore, if the pressure of the jack 27, for example, the oil pressure is set to a predetermined value, even if there is a fluctuation due to the sinking of the column 6, the jack 27 can be extended and contracted in accordance with the fluctuation, and the main rod can be automatically moved.
It is also possible to always keep the axial force of 11 at a predetermined value.

(Effect of the Invention) The form support for arch concrete construction according to the present invention includes:
With the configuration described above, the following excellent effects can be obtained.

(1) The arch truss frame structure is formed by connecting a plurality of divided arch trusses with a large number of connections, and the connection portion is supported by a column erected on the ground. A part can be shared by the pillars, thereby not only making the support without strengthening the entire arch truss frame structure, but also constructing a long span or flat arch concrete. Can be easily and economically performed.

(2) Since at least one of the plurality of connected main rods is an adjustable main rod whose length can be adjusted by a jack and the axial force of the main rod can be adjusted, when the concrete is cast, the support column sinks. Even if an excessive load is applied to the arch truss structure, the length of the arch truss structure can be substantially reduced slightly by adjusting the pressure by reducing the jacks, so that the arch truss structure can freely follow the sunk support. Thus, the predetermined load sharing between the arch truss frame structure and the column can be performed without any trouble, and the strength of the shoring can be properly maintained.

(3) The adjustment of the load distribution between the arch truss frame and the strut is performed by jacks, so that it can be remotely controlled from the ground and can also be automatically adjusted, making the work safe and extremely simple. become.

[Brief description of the drawings]

1 is a schematic front view showing an embodiment of the present invention, FIG. 2 is an enlarged front view of the same part, FIG. 3 is an enlarged front view showing an adjusting main rod portion, and FIG. 4 is an end of an arch truss frame structure. FIG. 5 is an enlarged front view showing the joint between the divided arch trusses and the support. A: Arch truss frame structure, B: Ground, 1 ... Abutment, 2 ... Arch concrete, 3 ... Split arch truss, 4 ... Connecting pin for split arch truss, 5 ... Load receiving pin, 6 ... Post , 7 ... Form, 10 ... Supporting element, 11 ... Main rod, 11a, 11b ... Split main rod, 12 ... Side rod, 13 ... Pin, 14 ... Sub-rod, 17 ... Support base , 19… bracket, 20… floating connector, 21… pin, 23… adjustment main rod, 27… jack

Claims (1)

(57) [Claims] A required number of triangular support elements formed by connecting a main rod and a pair of side rods are connected to each other at an end of the main rod to form a divided arch truss. Are connected to each other at the ends to form an arch truss structure, and both ends of the arch truss structure are pin-connected to an abutment or a pier, and the connecting portion of the divided arch trusses is supported by a column standing on the ground. In the shoring, at least one of the main rods is divided into main rods so as to be slidable in the length direction of the main rods, and a main rod is interposed between the divided main rods. A formwork support for arch concrete construction, characterized in that it is a main adjustment rod with a jack for adjusting the axial force.