JPH0416585B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> This invention provides a method for constructing a concrete structure in a vertical direction from bottom to top by using a formwork device disposed inside the structure during construction progress. It also relates to a method of sequentially moving upwards.

<<Prior Art>> Relatively tall cylindrical hollow concrete structures, such as silos, chimneys, or bridge piers, are generally constructed sequentially from the bottom to the top by a sliding form construction method.

In this construction method, the formwork equipment for concrete pouring is sequentially moved upward as construction progresses.
That is, the formwork device is located at the top of the existing part of the structure, and the formwork is placed in order to continue pouring concrete on top of the existing part. After pouring concrete and hardening it, the formwork is removed and the whole structure is raised together with the formwork equipment, and then concrete is poured on top of it.

In order to raise the formwork device along the existing part of the cylindrical concrete structure in this way, conventionally,
Rods serving as support rails for the formwork apparatus are vertically disposed inside the structure. The formwork device is raised using a jack using this rod as a fulcrum.
Rods will be added sequentially as construction progresses,
The formwork device, which has been moved to a certain point, is fixed to this rod. Then, pull up the fulcrum side of the jack along the rod to prepare for the next rise of the formwork device.

<Problems to be Solved by the Invention> As described above, in the method of fixing a rod on the inner surface of a cylindrical concrete structure and moving the formwork device with a jack using this rod as a fulcrum, the formwork device As the scale of the machine increases, the number of rods and jacks must be considerably increased. If a large number of rods are installed, the work requires a lot of manpower and time, increasing the construction period and cost.

In addition, if the number of jacks used becomes too large, it becomes very troublesome to manage them, and it becomes troublesome to control so that all the jacks are extended by the same amount. This causes problems such as the inability to raise the entire formwork device smoothly.

This invention was made in view of the above-mentioned conventional problems, and allows even large-scale formwork equipment to be raised smoothly with simple work without complicating the configuration of the necessary equipment. An object of the present invention is to provide a method for moving a formwork device.

<<Means for Solving the Problems>> Accordingly, in the present invention, a lower beam and an upper beam are connected by a plurality of elevators, and the formwork device is provided on the upper beam. Then, with the end of the lower beam first fixed to the existing part of the cylindrical concrete structure, the elevator is extended to raise the upper beam and the formwork device, and then the end of the upper beam is fixed to the fixed to the existing part of the structure, then with the lower beam unfixed, the elevator is scaled down to raise the lower beam, and then the end of the lower beam is fixed to the existing part of the structure. I fixed it.

<<Operation>> When raising the upper beam and the formwork device, the lower beam whose end is fixed to the existing portion serves as a fulcrum. When raising this lower beam,
The upper beam, whose end is fixed to the existing part, will serve as a fulcrum.

<<Example>> FIG. 1 and FIG. 2 show one embodiment of the present invention.

The embodiment shown in the same figure is applied to the construction of an underground foundation with a flat cross section as shown in FIG. 1, especially when constructing a lattice wall A. After forming and excavating the inside thereof, the lattice wall A is constructed from the bottom to the top.

In constructing the lattice-like wall A, formwork devices 10 described below are installed inside the lattice-like wall A, and FIG. 2 shows one of the formwork devices 10.

In the formwork apparatus 10 shown in FIG.
1. Reinforced scaffolding 14 is locally provided on the three-tiered structure of the middle working floor 12 and the upper working floor 13. 3
A staircase 15 is provided between the working floors 11, 12, and 13 of the steps.

A formwork 16 is erected on the side of the formwork device 10. The formwork 16 is movably attached via turnbuckles 17, 18, so that the formwork 16 can be removed from the fixed concrete surface.
Note that the members 17 and 18 may be not only turnbuckles but also hydraulic jacks.

20 is an upper beam on which the formwork device 10 is mounted, and 30 is a lower beam arranged below it. Upper beam 20
The lower beam 30 has a truss structure.

The upper beam 20 and the lower beam 30 are connected in parallel by a plurality of pantograph elevators 40.
The pantograph elevator 40 includes a screw shaft 42 that is vertically supported by a multi-stage pantograph 41, and a rotating device 43 that rotates a screw nut that is engaged with the screw shaft 42 provided on the lower beam 30 side. It is equipped with The driving source of the rotating device 43 is, for example, an electric motor, and when this is rotated, the screw shaft 42 moves vertically while maintaining a vertical posture. The amount of movement can be accurately controlled by the amount of rotation of the rotating device 43. Therefore, it is not difficult at all to control the plurality of elevators 40 to raise and lower at the same speed by a certain amount at the same time. This can be easily done using normal motor control technology.

By simultaneously expanding or contracting the plurality of elevators 40, the distance between the upper beam 20 and the lower beam 30 can be changed.

In the illustrated state, both the upper beam 20 and the lower beam 30 are fixed to the existing portion of the cylindrical concrete structure 50. That is, the brackets 21 provided at both ends of the upper beam 20 are fixed to the concrete structure 50 with bolts 22, and the brackets 31 at both ends of the lower beam 30 are fixed to the concrete structure 50 with bolts 32.

The operation of raising the formwork device 10 from the above state will be explained.

First, the fixation of the lower beam 30 to the concrete structure 50 is released. Next, each elevator 40 is simultaneously scaled down. At this time, since the upper beam 20 is fixed to the concrete structure 50, the upper beam 20 side serves as a fulcrum, and the lower beam 30 is lifted upward by the elevator 40. Once the lower beam 30 is pulled up to a predetermined position, the lower beam 30 is fixed to the concrete structure 50 at that position.

Next, the fixation of the upper beam 20 to the concrete structure 50 is released. In this state, each elevator 40 is extended simultaneously. At this time, the lower beam 30 fixed to the concrete structure 50 serves as a fulcrum, and the upper beam 20 and formwork device 10 are pushed upward by the elevator 40. Once raised to a predetermined position, the upper beam 20 is fixed to the concrete structure 50 at that position.

In this way, the formwork device 10 is sequentially moved upward as the casting of the cylindrical concrete structure progresses. Incidentally, when lowering it, it can be carried out in the same manner by reversing the above procedure. In addition, demolding of the formwork 16 and
Fixing is performed by operating turnbuckles 17 and 18 interposed between the formwork 16 and the work floor 11, and when removing the formwork, after pouring and curing concrete, the formwork 16 is removed from the concrete surface by 5. After retracting the device approximately 10 cm inward, raise the device, and when fixing it, push it outward in the opposite direction to fix it.

Although the formwork 16 can be easily attached and detached in this manner, the means for moving the formwork 16 is not limited to this, and for example, a hydraulic jack may be used.

Furthermore, in constructing the structure 50, the formwork 1
Concrete is poured with another formwork suspended outside the formwork 16 using a crane or the like and connected to the formwork 16 with tie rods, etc. In this case,
In the sliding construction method, a pair of formwork devices are attached to both ends of a gate-shaped yoke, and the yoke is installed at intervals of several meters in the circumferential direction so that it straddles the wall on which it is being constructed. In particular, the reinforcing bars buried in the wall cannot be made into a large panel that is larger than the span of the yoke, but according to the method of the present invention, there is nothing to restrict the installation of reinforcing bars in the upper part of the wall. It becomes possible to make reinforcing bars into large panels in advance, improving construction efficiency.

<<Effects of the Invention>> As explained in detail above, according to the method for moving a formwork device according to the present invention, it is not necessary to arrange rods that serve as support rails for the formwork device on the cylindrical concrete structure side. This simplifies the work by eliminating the additional work of laying rods. Furthermore, in the past, managing and controlling a large number of jacks was complicated, but with the method of the present invention, this is not necessary, and the formwork apparatus can be moved smoothly by simple control of, for example, a pantograph elevator.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a structure to which the method of the present invention is applied, and FIG. 2 is a sectional view showing an example of a state in which a formwork device is moved and fixed by the method of the present invention. 10... Formwork device, 16... Formwork, 17, 18
... Turnbuckle, 20 ... Upper beam, 21 ...
Bracket, 22...Bolt, 30...Lower beam,
31...bracket, 32...bolt, 40...
Pantograph type elevator, 50... Existing part of cylindrical concrete structure.

Claims (1)

[Claims] 1. A method for constructing a concrete structure vertically from bottom to top, in which a formwork device placed inside the structure is sequentially moved upward as construction progresses. ; The lower beam and the upper beam are connected by a plurality of elevators, and the formwork device is provided on the upper beam; The end of the lower beam is fixed to the existing part of the cylindrical concrete structure; The elevator is extended to raise the upper beam and the formwork device, then the end of the upper beam is fixed to the existing part of the structure, and then the lower beam is unfixed and the formwork device is raised. A method for moving a formwork device, comprising: reducing an elevator to raise the lower beam; and then fixing an end of the lower beam to an existing part of the structure.