JPS5942160B2 - Tunnel primary winding method using bend panels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides for the primary winding of an excavated tunnel by temporarily fixing pend panels to the shoring built in the tunnel and using this as a formwork. Concrete is filled between the sheet pile and this bent panel (tunnel using a bent panel - this relates to the FIJ construction method).

The conventional tunnel-subtraction construction method includes the following construction methods.

(1) Construction method using loose center and center form (2) Construction method using buried formwork (1) Method uses a center with metal foam applied to the outside of the steel frame and uses this as the formwork. This is similar to the formwork used in this volume.

Then, the primary winding is constructed by moving the center one after another over the entire tunnel cross section, but this method produces a smooth and beautiful finish, but is very expensive if the length of the tunnel construction is short.

Contrary to method (1), method (2) has been widely used because it can be easily used when the construction length is short.

A keystone plate or expanded metal is usually used as the filling formwork.

In the case of fc using this keystone plate, the state of concrete filling is difficult to check from the outside because the concrete surface is not exposed, which poses a quality control problem.

Extended metal is used as a double layer with a wire mesh, but the mortar in the concrete tends to leak, which is not desirable in terms of quality control and is also not desirable in terms of the working environment.

Furthermore, during construction, keystone metal or expanded metal has to be placed in concrete while contacting the shoring, which is time consuming and has poor workability.

The method of the present invention takes advantage of the advantages of both.

This will be explained based on what is shown in the drawings.

1 is the ground for the excavated tunnel, 3 is the H-shaped shoring built on its inner surface, and 2 is the sheet pile inserted between the shoring 3 and the ground 1. .

Reference numeral 4 denotes a nut which is fitted onto the shoring 3, and a form tie 5 is screwed into this nut 4, so that the form tie 5 is erected on the three sides of the shoring.

Since a large tension of about 3 tons is applied to the form tie 5, a long nut 4 with a height of 20 m is used to prevent distortion of the connecting part and to ensure a sufficient thread length.

6 is a square pipe, and two of them are installed around the form tie 5.

This square pipe is bent using a bender so that it has the same curvature as the shoring 3.

The length of one square vibro is 2080 m, and it can be used by adding more to make the construction easier.

For this purpose, a socket-shaped tube 7 with a slightly smaller diameter is inserted into the end of the tube, and the next square vibro is inserted into this socket-shaped tube 7 to add on.

The cross-sectional size of the square vibro is 60 x 60 x 2.3 m-m.
If the position is appropriate, the socket-shaped tube T is 50 x 50 x 2.
．． 3m-m.

Reference numeral 8 denotes a pend panel, which is held between the three supporting surfaces and the square vibro surface.

The pend panel 8 uses a plywood veneer formwork material that has been used as a formwork material for conventional round piers and manholes.

The pendo panel 8 has a thickness of 28 m, a width of 700 m, and a length of 1 m.
At 050m, the curvature is bent in advance so that it comes into close contact with the three sides of the shoring.

The thickness of 28mm is the maximum lateral pressure of 4 when concrete is placed.
, 8 t ,/m2.

Reference numeral 9 is a washer with bent ears 9' and 9'w on both sides, and when the washer 9 holds the double-sided vibro and 6, the ears S/ and S/ prevent both pipes from coming off. I'll hold onto this.

Numeral 10 is a nut that tightens the washer 9 against both pipes.

12 is the iron plate of the remains used when constructing the apson part of the crown;
Reference numeral 3 denotes an insertion hole for a fastener (not shown) for fastening the pend panels 8 on both sides of the top plate between the ends thereof.

To explain the construction order, after the shoring 3 is erected on the ground 1 excavated in the shape of a tunnel, nuts 4 are placed on the shoring 3 at a predetermined pitch, that is, 1
Directly every 050 m-m.

Next, the form tie 5 is screwed onto this and set upright, and the washer 9 and tightening nut 10 are fitted.

Construction begins from the bottom, and two square vibrators, 6
0 pairs are installed in parallel.

Then, the two pend panels 8, 8 are sequentially inserted from above between the adjacent square vibrators 6, and the square washers 9 are tightened with the nuts 10 to bring the pend panels 8, 8 into close contact with the support 3.

Since the length of the square vibro is 2080 m, and the length of the pendo panel 8 is 1050 m, m, one square vibro supports the two pendo panels 8, 8 as described above.

In fact, when two pendo panels 8 are dropped into the square vibro, in order to make it easier to install the next pendo panel 8, the pendo panel 8 is placed about 10 cm from the square vibro.
It is arranged appropriately so that it appears at the top.

Also for this reason, the bottom and top pend panels 8
The length of the square vibro is appropriately shorter than the standard length.

When the installation of the pendo panel 8 is completed, concrete 11 is poured from the upper opening to the vicinity of the upper end of the pendo panel 8.

Next, in the same manner, the next two pend panels 8 are attached and filled with Conc')-NHc-.

This operation is carried out symmetrically on both sides of the tunnel, maintaining the same height.

Then, do this sequentially until you reach the top.

For tightening at the top, the remains iron plate 12 is hung in the gap between the ends of the left and right pend panels 8°, and a fastener (not shown) is inserted into the insertion hole 13 to tighten it.

Then, a hole large enough for the pouring hose to be inserted is excavated above the top end of the shoring 3, and concrete is poured through the hole to complete concrete pouring.

It is dismantled after a suitable curing time, but the order of dismantling is as follows:
This and all (do in reverse order).

Disassembled pendo panel 8 angle vibro square washer 9 Sako cat iron plate 1
Formwork materials such as No. 2 are placed on a movable scaffold (not shown) and moved to the location where the arrows will be placed, and this concrete placement for each section is repeated again.

Note that the cross-sectional shape of the square vibro in the construction method of the present invention is not limited to this, as long as it can achieve the same purpose.

In some cases, a rectangular pipe with a horizontally long cross section is used, and a through hole is drilled along its center line into which the form tie 5 can be inserted. It is also possible to install the form tie 5 by inserting the form tie 5 therein.

As you can see from the above explanation, this construction method is based on the
Like the conventional fill-in formwork method, the formwork is fixed directly to the shoring, and like the center method, the formwork can be repurposed and used repeatedly.

Therefore, similar to the Center method, the concrete surface is exposed after construction, making it possible to check the filling status of the poured concrete.

In addition, since the surface of the formwork is smooth compared to the buried formwork method, the poured concrete flows very well, and unlike expanded metal, there is no mortar leakage, making it very easy to control quality. It's advantageous.

From the bottom to the top, pend panels can be assembled one after another and concrete can be poured one after the other, so it is possible to construct a wide internal cross-section, similar to the fill-in formwork method, which is different from the center construction method. Unlike the fill-in formwork method, the formwork can be easily assembled by simply contacting the Naratra 6 with the shoring in advance, so the workability is very good.

Moreover, since it can be reused many times, it can be constructed at a lower cost than the fill-in formwork method, and of course, it is also cheaper than the center method.

[Brief explanation of drawings]

Fig. 1 is a side view showing the left half of the tunnel constructed by the construction method of the present invention, Fig. 2 is an enlarged side view showing the installation state of the formwork material in the lower left part of the tunnel, and Fig. 3 is an enlarged side view of the top of the tunnel. , FIG. 4 is an enlarged cross-sectional view of a part of FIG. 1, and FIG.
The figure is a perspective view of the square pipe, and Figure 6 is a perspective view of the remains of the steel plate. 2... Sheet pile, 3... Shoring, 5...
...Form tie, 6...Square pipe, 9...
...Washer.

Claims (1)

[Claims] 1. Plant the form ties at appropriate intervals on the shoring constructed in the excavated tunnel ground, and from the bottom of the tunnel, install two square pipes along the shoring, centering on the form ties, and then install them next to each other. Insert pend panel 2 between each shoring and each square pipe between the supports, tighten it with washers attached to form ties, and pour concrete between the sheet pile and bend panel through the upper opening of the pend panel. Tunnel-sequential construction method using pendo panels that are carried out sequentially to the top.