JPH0251002B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to shoring.

Shoring supports structures such as bridge girders during construction work, and is composed of steel materials, pipes, etc. Construction of bridge girders using such supports has conventionally been carried out as follows.

That is, the bridge girder is lifted up by a crane and placed on a support installed near the bridge pier, and after the bridge girder is positioned using the support, it is lowered and placed and fixed on the bridge pier. The work of hoisting a bridge girder using the above-mentioned crane, that is, the lifting work, is more difficult as the bridge girder is larger and the height of the support is higher, and it is accompanied by great danger. Also,
The lowering work of the bridge girder is carried out in the following manner by stacking a large number of steel members on the shoring, installing a number of hydraulic jacks on top of the steel members, and supporting the bridge girder with the hydraulic jacks.

First, a new hydraulic jack was installed in the lower part where the steel material was removed from the location where the hydraulic jack was installed, and the jack supported the bridge girder, and the hydraulic jack that had previously supported the bridge girder was replaced. The bridge girder is gradually lowered by repeating a series of steps: removing the steel material, removing the steel material at that location, and then reinstalling the hydraulic jack at the location where the steel material was removed.

However, in such a process, it takes time and effort to attach and detach the hydraulic jack and remove the steel material, resulting in extremely poor workability and safety issues.

On the other hand, the shoring must be removed after the bridge girder is erected, but since there is only a small gap between the shoring and the erected bridge girder, it is necessary to remove the shoring mechanically using a crane or the like. Unable to remove
The shoring was manually disassembled and removed, making it extremely difficult to work.

The present invention was made with the aim of solving the above-mentioned technical problems, and provides a shoring system that enables quick and safe work of launching and lowering structures such as bridge girders and removing the shoring work itself. It is something.

Embodiments of the present invention will be described below with reference to the drawings.

The shoring A of this embodiment has an underframe a having four hollow supports 1 as shown in FIGS. 1 to 3, and is slidably fitted into each of the supports 1 of this underframe a. , and four screw rods 2 protruding from the pillar 1.
It has a structure that is expandable and retractable.

The underframe a has a planar rectangular frame by connecting each support with side frames 6a and 6b. The support column 1 is made of a pipe material having a circular cross section as shown in FIGS. 4 and 5, and its upper end is closed to prevent rainwater from entering the inside. A pair of hydraulic jacks 3 are attached along the axis to the outer periphery of the end of the support 1 from which the screw rod 2 projects, that is, the lower end.

The hydraulic jack 3 is fixed with the ram 3a facing downward between two upper and lower flanges 7 and 8 welded to the column 1, and the ram 3a slidably passes through the lower flange 8 and extends below the lower end of the column 1. protrudes to. The hydraulic jacks 3 of each of these columns 1 are each connected to one hydraulic pump (not shown), and are expanded and contracted in synchronization with each other.

The screw rod 2 fitted into the support column 1 is a relatively thick pipe material with threads cut across the entire length of the outer periphery, and has a flange portion 2a at the upper end and a lower end that is grounded via a pedestal 9. There is. The flange portion 2a is for preventing the screw rod 2 from coming off from the column 1, and is designed so that when the screw rod 2 protrudes the most from the column 1, it comes into contact with a guide 1a at the lower end inside the column 1. A first stopper 4 and a second stopper 5, which support the pillar 1 and the screw rod 2, are screwed into the protrusion of the screw rod 2 from the pillar 1. The first stopper 4 comes into contact with the lower end of the support column 1, and has a handle 4a on its outer periphery for rotational operation. 2nd stopper 5
is in contact with the ram 3a of the hydraulic jack 3,
It is located below the first stopper 4 and has a larger diameter than the first stopper 4, and has a handle 5a on the outer periphery for rotation operation.
is provided. Side frames 10 and 11 are attached to the lower part of the screw rod 2 with the rod 2 largely protruding from the support 1.
At 11, each screw rod 2 is connected. The side frames 10 and 11 are used to ensure the rigidity of the lower part of the shoring A when the screw rod 2 protrudes and the shoring A is extended as described above, and when the shoring A is contracted. It is removable.

The shoring A of the present embodiment as described above supports structures such as the bridge girder B and lifts and lowers them, and can be used in the following three ways.

The first case is when shoring A is used alone; in this case, shoring A directly supports bridge girder B on the upper surface of underframe a.

The second case is when one or more shoring A is stacked together with conventional shoring and connected to each other. In this case, shoring A can be installed at the top, in the middle, or at the bottom. It may also support the bridge girder B directly or indirectly.

The third case is when a plurality of supports A, for example two supports A, are stacked and connected to each other as in this embodiment.
In this case, each shoring A expands and contracts, so that the bridge girder B can be raised and lowered to the greatest extent possible.

It goes without saying that in the above three usage modes, the shoring A can be used upside down.

Therefore, when the bridge girder B is lifted up and lowered, each of the supports A is expanded and contracted at the same time or in a special manner, but since the work is the same, only the expansion and contraction work of one of the supports A will be explained.

The work of expanding and contracting the shoring A is performed from the most contracted state of the shoring A as shown in FIGS. 4, 6, and 7.

When the shoring A is in its most contracted state, the first stopper 4 and the second stopper 5 are vertically adjacent to each other, as shown in FIG. While in contact with the pedestal 9, it is in contact with the ram 3a of the hydraulic jack 3. Then, by extending the hydraulic jack 3 as shown in FIG. 6 from this state, the column 1 slides upward along the screw rod 2 by the amount of the extension stroke, and the underframe a rises and the bridge girder B to lift up. After the extension operation of the hydraulic jack 3 has stopped, the first stopper 4 is rotated and moved upward as shown in FIG. 7, and the lower end of the column 1 is brought into contact with the stopper 4 to prevent the lower frame a from descending. do. After the hydraulic jack 3 is retracted, the second stopper 5 is rotated and moved upward, and the second stopper 5 is brought into contact with the ram 3a of the retracted hydraulic jack 3.

By repeating the above operations, the underframe a is intermittently raised until the flange 2a at the upper end of the screw rod 2 comes into contact with the guide 1a, the support A is extended, and the bridge girder B is raised to a predetermined height. Raise it to position.

On the other hand, the shrinking work of the shoring A is performed as shown in FIGS. 8 to 10 from the most expanded state of the shoring A. When the shoring A is fully extended, the first stopper 4 is in contact with the lower end of the support column 1, and the second stopper 5 is in contact with the ram 3a of the hydraulic jack 3, as shown in FIG. From this state, as shown in FIG. 9, the second stopper 5 is rotated to move downward by the extension stroke of the hydraulic jack 3, and then the hydraulic jack 3 is extended to move the ram 3a to the second stopper. 5 and support the underframe a and the bridge girder B with the hydraulic jacks 3. Then,
After rotating the first stopper 4 and moving it downward by the contraction stroke of the hydraulic jack 3, by contracting the hydraulic jack 3 as shown in FIG. 10, the column 1 slides downward by the contraction stroke. Then, the underframe a is lowered until it is supported by the first stopper 4, and the bridge girder B is lowered.

By repeating the above operations, the underframe a is intermittently lowered, the shoring A is contracted, and the bridge girder B is lowered to the pier C. After the bridge girder B has lowered to the pier C, the shoring A is contracted by removing the lower side frames 10 and 11 until the second stopper 5 comes into contact with the pedestal 9 at the lower end of the screw rod 2, and the shoring A is moved downward from the bridge girder B. They are separated from each other and removed by a crane or the like (not shown) in order from the top.

In addition, when constructing a concrete slab (floor slab) between bridge piers, the shoring A can also be used as a means to support a form for pouring concrete.

In this case, after the concrete slab has hardened, the shoring A is shrunk in the same manner as described above, so that it can be moved far away from the concrete slab and easily removed using a crane or the like.

As explained above, the present invention includes an underframe having a plurality of hollow supports, and a screw rod that is slidably fitted into each support of the underframe and protrudes from the support. A pair of hydraulic jacks are attached to the outer periphery of the end of each column of the frame on the side where the screw rod protrudes, along the axis, and a pair of hydraulic jacks is attached to the protruding portion of the screw rod from the column. Since the first stopper and the second stopper that abuts the ram of the hydraulic jack are sequentially screwed together from the column side, the following effects are achieved.

The shoring itself is moved intermittently by rotating the first stopper and the second stopper and moving them up and down, and by extending and contracting the hydraulic jack while alternately supporting the column and the screw rod with these two stoppers. By expanding and contracting, lifting and lowering of structures can be carried out quickly and safely, and work efficiency can be improved.

After the structure is hoisted up and installed in a predetermined location, the shoring is shrunk and separated from the structure by a large distance downward, allowing the shoring to be quickly removed using a crane or the like.

Since both the first stopper and the second stopper are arranged adjacent to each other, the operator can operate both stoppers without making a large change in posture, resulting in excellent workability.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the shoring of the present invention in use, Fig. 2 is an enlarged front view of the shoring, Fig. 3 is a side view of the same, and Fig. 4 is a partially cutaway front view showing an enlarged view of the main parts. Figure 5 is an enlarged sectional view taken along the - line in Figure 4;
Figures 1 to 10 are explanatory views of the expansion and contraction operations of the shoring. In the diagram, A... Shoring, a... Underframe, 1... Support, 2... Screw rod, 3... Hydraulic jack, 4... First stopper, 5... Second stopper,
3a... Hydraulic jack ram.

Claims (1)

[Claims] 1.Equipped with an underframe having a plurality of hollow supports, and a screw rod that is slidably inserted into each support of the underframe and protrudes from the support, the screw rod is installed in each support of the underframe. A pair of hydraulic jacks are attached to the outer periphery of the end of the protruding side along the respective axis lines, and the protruding part of the screw rod from the column has a first stopper that comes into contact with the end of the column, and a ram of the hydraulic jack. Shoring is made by sequentially screwing together a second stopper that comes into contact with the support from the support side.