JPH0534477B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a segment used in a shield construction method.

<Prior Art> Generally, when constructing a tunnel using the shield construction method, it is necessary to fill the excess excavation space or void created between the segment and the circumferential surface of the ground with a backfilling material such as mortar.

Recently, methods of filling voids with the amount of backfilling material suppressed as much as possible have been studied.

In this filling method, a flexible bag is attached to the outer periphery of the segment facing the ground, and this bag is filled with backfilling material. This is a method of backfilling while preventing penetration.

In such cases, the segments used must be protected by hard materials such as thin steel plates, plywood plates, and FRP plates (fiber-reinforced plastic plates) to prevent the bags from being damaged during transport, assembly, and detachment from the tail of the shielding machine. Protected by a board.

<Problems to be Solved by the Present Invention> The conventional segments described above have the following problems.

(b) The lid, which serves as a protective plate attached to the segment, is made of a hard plate that does not easily bend, so when it is removed by the expansion pressure of the bag, it will not be destroyed and will be pressed against the ground. .

As a result, gaps are generated between the unevenness of the excavated ground and the protection plate, causing ground subsidence.

(b) Since the outer periphery of the segment is not sealed,
Groundwater flows into the Sheetold mine.

(c) A fixing means is required to prevent the protective plate from easily coming off while handling the segments.

As means for fixing the protective plate, methods such as bonding the protective plate with adhesive or providing fixing arms have been adopted, but these operations are time-consuming.

<Object of the present invention> The present invention was made to solve the above-mentioned problems, and it is possible to easily attach a protective lid to protect the bag body, and to securely close the gap between the segment and the ground. The purpose is to provide a segment in the shield method that can be solved.

Another object of the present invention is to prevent the occurrence of unfilled spaces with the lining material inside the bag, and to inject the lining material even into the inside of the bag.

<Structure of the present invention> An embodiment of the present invention will be described below with reference to the drawings.

<A> Segment structure A segment 1 according to the invention is shown in FIG.

The segment main body 11 is an arc-shaped curved plate, and a connecting hole 12 is provided protruding from the peripheral edge of the flange.

Then, the opening of a rubber bag 2 for filling with a backing material is fixedly attached to the outer curved surface side of the segment 1.

Furthermore, a filling hole 13 is formed in the segment body 11 located within the opening of the bag body 2.

<B> Bag protection means: Around the entire outer curved surface of the segment body 11,
Ribs 3 are integrally attached to surround the bag body 2.

The rib 3 is made of a rigid band-shaped plate such as a steel plate, and is provided to protrude from the segment body 11 at a certain height, and when the bag body 2 is housed therein, the bag body 2 is closed with a protective lid 5, which will be described later. It is a structure that protects the

<C> Protective lid The protective lid 5 can cover and hold down the bag body 2 without being easily destroyed during the handling operation of the segment 1, and is not fragile due to the expansion pressure of the bag body 2 during backfilling. Constructed of materials that can be broken into small pieces.

As such a material, a material having brittle properties such as foamed rigid urethane or foamed phenol is used.

<d> Method of manufacturing the protective lid The protective lid 5 is manufactured in the following manner. (FIG. 5) First, the bag 2 is placed in a folded state in a space surrounded by the ribs 3.

Next, place the formwork 6 on the upper edge of the rib, and
The surrounding area is blocked from above.

Next, a stock solution of foamed rigid urethane is injected into the space surrounded by the formwork 6 and the ribs 3.

Then, the space between the bag body 2 and the formwork 6 is filled with foamed hard urethane.

As a result, the foamed rigid urethane hardens between the mold 6 and the bag body 2, and the protective lid 5 is formed.

Since the bag body 2 is pressed against the outer surface of the segment body 11 due to the foam molding of the protective lid 5, the space closed by the protective lid 5 is closed without leaving any extra voids.

Therefore, the air inside the bag body 2 is discharged to the outside, and when filling the bag body 2 with the backing material 4, the generation of voids can be prevented and the entire area of the bag body 2 can be filled with the backing material 4.

Furthermore, the protective lid 5 is firmly adhered to the circumferential surface of the rib 3 due to the self-adhesive properties of urethane foam.

Further, since the bags 2 inside the ribs 3 are unevenly overlapped, the thickness of the protective lid 5 is uneven.

Of course, it is also possible to process urethane foam into a lid shape in advance and fix it using an adhesive.

<E> Bag body The bag body 2 is a bag for controlling unnecessary outflow of the backing material 4, and is made of a rubber bag having flexibility and elasticity, or a nylon bag having breathability in addition to the above properties. Can be used with cloth bags such as

It is also possible to make the protective lid 5 easier to destroy by providing unevenness in advance on the circumferential surface of the bag body 2 due to the difference in wall thickness, and applying concentrated pressure to some places on the protective lid 5 when the bag body 2 is inflated. It is.

<F> Method of filling the backing material (1) Assembling the segments (Fig. 2) As described above, the segment 1 closed with the protective lid 5 of the bag body 2 is transported to just below the erecta device.

The outer curved surface of segment 1 is rib 3 and protective lid 5
Since segment 1 is covered by
Even if the bag body 2 is pulled out, the bag body 2 will not protrude and be damaged.

The segments 1 in which the bag body 2 is protected and housed are sequentially assembled and lined onto the ground 7 immediately after excavation using an erector device.

(2) Backfilling work Next, from the inside of segment 1, fill hole 13
One end of a grout hose 8 is connected to the groove, and a backfilling material 4 such as mortar is filled.

Since air inside the bag body 2 is removed during foam molding of the protective lid 5, when filling the backing material 4, air does not accumulate inside the bag body 2, and the entire space can be filled.

(3) Destruction and removal of the protective lid The bag body 2 gradually expands due to the filling pressure of the backing material 4.

Since the protective lid 5 that presses down the bag body 2 is made of a brittle material, if the expansion pressure of the bag body 2 is transmitted to a part of the protective lid 5, the protective lid 5 will be broken into small pieces. . (Fig. 3) When the protective lid 5 is crushed and pressed against the earth by the bag body 2, it is plastically deformed according to the unevenness of the earth 7, which causes a gap to be formed between it and the earth 7. Never.

Further, since the flexible bag body 2 expands and deforms following the unevenness of the earth 7 and the crushed protective lid 5, no gap is generated between the segment 1 and the earth 7. (Fig. 4) <Effects of the present invention> Since the present invention is as explained above, the following effects can be obtained.

<A> Since the protective lid is made of a material with a certain degree of strength and brittleness, the protective lid can be easily crushed by the expansion pressure of the bag when filling with the backing material.

Therefore, the voids generated between the segments and the ground can be reliably eliminated.

<B> The protective lid can be fixed to the segment using hard urethane foam with excellent self-adhesive properties.

Therefore, in this case, there is no need for conventional fixing means such as adhesive bonding, and the protective lid can be easily attached.

<C> Groundwater does not flow into the segment pit from the outer peripheral surface of the segment.

<D> The bag body is not simply held down by a single flat plate, but is closed by a protective lid formed by foaming without any gaps.

Therefore, the free movement of the bag body can be restricted, and the protective lid can be prevented from being accidentally damaged.

<E> Since the protective lid has a certain level of strength, it can reliably prevent breakage during transportation and assembly of the segments.

<F> During foam molding of the protective lid, almost all of the air inside the bag is released by the foaming pressure, so this prevents the creation of unfilled spaces inside the bag when filling with backing material. The backing material can be spread to every corner of the bag body.

Therefore, it is possible to prevent ground subsidence due to the generation of voids and stabilize the ground.

[Brief explanation of the drawing]

Figure 1: Perspective view of the segment according to the present invention, Figure 2; Explanatory diagram when assembling the segment, Figure 3.
Figure: An explanatory diagram when filling the backing material, Figure 4: An explanatory diagram when the bag is inflated, and Figure 5: An explanatory diagram when the protective lid is foam-molded.

Claims (1)

[Claims] 1. A rib attached around the outer surface of the segment, a bag housed in a space surrounded by the rib, and a material that is easily plastically deformed, such as foamed rigid urethane, placed over the bag. A segment used in the shield construction method, which consists of a lid that is filled with an undiluted material, foamed and hardened, and placed between the outer surface of the segment and the bag in a compressed state.