JPS6135331B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for concrete earth retaining shoring when underground structures such as shafts and shafts are constructed deep underground.

For example, a continuous underground wall, etc., is constructed in advance to construct the main body wall of a shaft or shaft, and while excavating the inside of this structure one after another, multiple stages of RC structures are constructed to serve as earth retention shoring along the inside of the main body wall. In the past, the ground was used as formwork support.

That is, the ground is excavated to the planned lower end line of the RC structure, and after shaping, a formwork is constructed on the ground.

Therefore, at the bottom of each level of excavation, work such as floor excavation, land leveling, leveling concrete (or dumping formwork), etc. is required, and concrete is poured into formwork above the ground to achieve the specified strength. It is not possible to move on to the next excavation process until a curing period has passed, and during this period the work is suspended, resulting in extremely low efficiency. On the other hand, there is a type of reverse-rolling method in which concrete is poured sequentially from above and the formwork is also suspended from above (Japanese Patent Application Laid-Open No. 57-19420
issue). According to this, the lower part of the formwork can be excavated immediately after concrete is poured without passing through the curing period, and the above-mentioned inconvenience can be solved. However, this requires support from above the frame, which is continuous vertically.
Therefore, the hanging members are suspended from above in a series, and as the construction progresses, the length of the hanging members increases.As a result, as the construction progresses, the number of members increases, making handling difficult.

The purpose of the present invention is to eliminate the above-mentioned disadvantages of the conventional example, simplify the work process, eliminate the need for a pause period when moving to the next process, and also move the hanging position of the formwork downward in sequence. By changing the structure, the number of hanging members can be kept to a minimum, and handling is easy and work efficiency can be increased. An object of the present invention is to provide a method and device for constructing concrete earth retaining shoring for underground structures.

According to the present invention, this purpose is to suspend the formwork of the bottom and side wall portions from the upper concrete earth retaining shoring that has already been constructed, and to construct the lower concrete earth retaining shoring using the formwork. This is achieved by sequentially changing the hanging position of the formwork to the lower concrete earth retaining shoring and then constructing the lower concrete earth retaining shoring.

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

FIG. 1 is a partially cutaway plan view showing a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view of the same. First, the apparatus used in the method of the present invention will be explained.

In the figure, reference numeral 1 denotes a hanging steel member made of threaded steel. A nut 2 serving as lifting and hanging means is screwed into the upper end of the hanging steel member, and the lower end is fixed to the lower surface of the hanging support member 3 with a nut 4.

A steel bottom form 7 is placed on the top of the suspension support 3 via a load receiving material 6 made of channel material, fixed by bolting or welding, and furthermore, one side end of this bottom form 7 is placed. The lower end of the side formwork 8 is connected with a pin or the like so that it can rotate to some extent.

The overall planar shape of the hanging supports 3, bottom formwork 7, and side formwork 8 should naturally match the planar shape of the concrete earth retaining structure to be constructed, and in the example of the drawing, the frame wall 13 is octagonal. Since the inner surface of the support was circular, the hanging support 3 and the bottom form 7 were octagonal on the outside and circular on the inside, and the side form 8 was formed in a circle.

Note that all of these are composed of a set of an appropriate number of division bodies.

Further, a center comb shape 9, which is a hoop material, is provided on the inner surface of the upper part of the side formwork 8 to fix the side formwork 8 in a vertically erected state.

On the other hand, a rectangular hanging frame 10 is provided integrally with the hanging support 3, and the hanging holes 10a formed in the hanging frame 10 are inserted into the side formwork 8.
protrudes inward from the

In addition, a sleeve pipe 11 to cover the hanging steel material 1 and washers to be used together with the nuts 2 and 4 as necessary are prepared, and an auxiliary formwork 12 is connected to the outside of the bottom formwork 7.

Next, the method of the present invention performed using the above-mentioned apparatus will be explained.

For example, by a construction method such as a continuous underground wall, the frame wall 13 as an earth retaining wall is constructed in advance, and this frame wall 13
Concrete earth shoring along the inside of 14,1
5 has already been formed, and a shoring 16 is to be formed below the shoring 15.

First, the ground 18 within the frame wall 13 is excavated from directly below the support 15 to directly below the support 16.

The hanging steel 1 is suspended through the through hole formed by the sleeve pipe 11 buried in the shoring 14, 15, and the nut 2 is screwed onto the upper end of the hanging steel 1 protruding from the upper surface of the shoring 14 to hang it. .

At the lower end of the hanging steel material 1, the hanging support material 3, the bottom formwork 7,
The side formwork 8, auxiliary formwork 12, etc. are suspended via nuts 4, reinforcing bars are assembled inside the formwork, and concrete is poured to construct the shoring 16. At this time, a sleeve pipe 11 is set around the hanging steel member 1.

The auxiliary formwork 12 only needs to fill the gap between the frame wall 13 and the bottom formwork 7, and is fixed to the bottom formwork 7 on one side using a simple material such as plywood veneer.

After constructing the shoring 16 in this way, as shown in Fig. 3, the next shoring 1 to be constructed is
Dig the ground 18 to just below point 7. This excavation work can be performed immediately without waiting for the concrete curing period of the shoring 16.

After the curing period has passed, the center comb 9 is loosened to make the side formwork 8 incline a little inward, and the nuts 2 on the shoring 14 are loosened, the hanging steel 1 is lowered and the bottom formwork 7 and the side formwork are loosened. 8 is demolded from the shoring 16.

On the other hand, using a crane or the like, the hanging hole 10a of the hanging frame 10 is
Hold the demolded formwork in the air by suspending it with a wire, remove the nuts 2 from the hanging steel 1, and install the next shoring 1.
Lower the formwork to the construction position in step 7.

In this state, the upper end of the hanging steel member 1 passes through the support 14 and descends to the top surface of the support 15, so this
If the nuts 2 are screwed together and the wire suspension of the hanging frame 10 is released, the bottom form 7 and side form 8 on the hanging support 3 will now be suspended by the support 15. .

Thereafter, lower-level shoring will be constructed in the same manner. Note that the reason why the formwork was not suspended from the support directly above it, but from support at least two levels above, was to prevent the formwork from being held up due to curing after concrete was poured, but this is not necessarily the case. It's not a thing.

FIG. 4 is a longitudinal sectional side view showing a second embodiment of the present invention, and the illustrated example shows the case where the formwork is suspended from the shoring directly above. In this case, the sleeve pipe 11 has at least a larger diameter than the nut 2, and an intermediate fixing nut 2' is screwed into the middle of the hanging steel member 1.
Furthermore, an anchor washer 19 having a notch 19a and which can be set from the side of the hanging steel member 1 as shown in FIG. 5 is used for the nuts 2, 2'.

In this embodiment, after loosening the center comb 9 and the side formwork 8, the intermediate fixing nuts 2', which had been set in advance on the hanging steel 1, are lowered to the top of the shoring 16. Insert the anchor washer 19 between the end and the nut 2'. Shoring 15
When the upper nut 2 is loosened and the anchor washer 19 is removed, the suspension fulcrum of the hanging steel member 1 is shifted from the support 15 to the support 16.

Next, loosen the nuts 2' and gradually lower the suspension supports 3, bottom formwork 7, side formwork 8, etc. Once the entire formwork has been lowered to an appropriate position, temporarily suspend it using the hanging frame 10. Insert the nut 2' into the sleeve tube 11.

At the same time, lower the upper nut 2 to this position and fix it to the top of the shoring 16. Further, the nut 2 is rotated to set the entire formwork to the construction position of the next supporting structure 17. Other methods are shown in Figures 2 and 3 above.
This is the same as the first embodiment shown in the figure.

When this second embodiment is used, compared to the first embodiment, the intermediate hanging period is shortened by using the hanging frame 10, and the work of changing the hanging steel material 1 can be carried out easily.

Furthermore, the entire formwork is large and heavy, and the hanging frame 10
There may be cases where it is not possible to carry out intermediate suspension using .

In this case, a coupler may be provided in the middle of the hanging steel material 1, and the hanging steel material 1 may be temporarily cut at this portion and the intermediate nut 2' of the second embodiment may be inserted therein to reposition it.

As described above, the present invention is an underground structure construction method in which a frame wall is constructed first, and concrete earth retaining shoring is constructed in multiple stages while sequentially excavating the inside of the frame wall. Hang the formwork for the bottom and side walls from the concrete earth retention shoring, use the formwork to construct the lower concrete earth retention shoring, and in this way, sequentially change the hanging position of the formwork to the lower concrete earth retention shoring. Since we decided to relocate the concrete earth retaining shoring and construct the lower level concrete earth retaining shoring, unlike the conventional case where the ground is directly used as formwork shoring, the concrete earth retaining shoring can be installed without waiting for the concrete curing period after construction. Not only can excavation be carried out immediately and work can be carried out efficiently, but only short hanging members are required, and the length will remain long even if the construction position of the earth retaining shoring is moved to a lower level. Since there is no problem, handling is easy and construction efficiency can be increased.

In addition, the work such as floor excavation, site leveling, leveling concrete, or waste form work at the lower end of the excavation of each stage of concrete earth retaining shoring is unnecessary, and construction can be easily performed with a small number of steps.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing an embodiment of the present invention, Fig. 2 is a longitudinal sectional side view of the same, Fig. 3 is a longitudinal sectional side view showing the next step after Fig. 2, and Fig. 4 is a partially cutaway plan view showing an embodiment of the present invention. A vertical side view showing the second embodiment, and FIG. 5 is a plan view of the nut portion. 1... Hanging steel material, 2, 2', 4... Nut, 3...
... Hanging support material, 6 ... Load receiving material, 7 ... Bottom formwork, 8
... Side formwork, 9 ... Center comb shape, 10 ... Hanging frame, 10a ... Hanging hole, 11 ... Sleeve pipe, 12
...Auxiliary formwork, 13...Structure wall, 14, 15, 1
6,17... Concrete earth retaining shoring, 19...
Anchor washer, 19a...notch. 〓〓〓〓

Claims (1)

[Claims] 1. In an underground structure construction method in which a frame wall is constructed first, and multiple stages of concrete earth retaining are constructed while excavating the inside of the frame wall one after another, the upper concrete earth retaining which has already been constructed is The formwork for the bottom and side walls is suspended from the shoring, and the lower concrete earth retaining shoring is constructed using the formwork, and in this way, the hanging position of the formwork is sequentially transferred to the lower concrete earth retaining shoring. A method for constructing concrete earth retaining shoring in an underground structure, characterized by constructing a lower level concrete earth retaining shoring. 2. The method for constructing concrete earth retaining shoring in an underground structure according to claim 1, wherein the earth retaining shoring for suspending the formwork is at least two steps higher than the earth retaining shoring to be constructed.