JP2758716B2 - Shield machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a shield machine and an improvement in a casting method using a cast-in-place type.

[Prior Art] In shield construction, the segment cost accounts for a large proportion of the construction cost. Therefore, there is a construction method of directly laying concrete without using a segment to construct a lining, and this construction method is called a cast-in-place lining construction method.

As one of the cast-in-place lining methods, there is a method in which a cylindrical tail plate of a shield machine is used as an outer frame, and an inner mold is assembled inside the cylindrical tail plate. In this method, concrete is poured into a ring-shaped space formed between the tail plate and the inner formwork, and then the tunnel is constructed by filling the tail void with concrete while performing shield excavation. To go.

However, in this conventional method, concrete that has hardened to a certain strength fills the cylindrical tail plate of the shield machine, so the shield machine can go straight, but it cannot curve, There was a problem that curve construction like the segment shield method cannot be performed.

In addition, the conventional method cannot provide a sufficient water stopping mechanism in a narrow space between the tail plate and the inner frame. For this reason, when performing construction under high water pressure, the shield excavator cannot be advanced unless the cast concrete is sufficiently self-supporting and solidified to a strength that can withstand high water pressure. There was a problem that it could not be shortened.

In addition, as a shield machine having the above-described curve construction countermeasures, for example, a proposal relating to a method disclosed in Japanese Patent Laid-Open No. 1-256700 is also known, and this prior art is compared with the inside of a cylindrical tail plate of a shield machine. A cylindrical inner plate formed of a substantially thin steel plate is provided, and by controlling the direction of the inner plate, the shield excavator can bend.

However, this prior art solves one of the problems described above and enables curve construction. However, no measures against high water pressure are taken, and two problems of curve construction and measures for high water pressure are solved. It cannot be solved at the same time.

The present invention has been made in view of such a conventional problem, and an object thereof is to provide a cast-in-place lining type shield excavator capable of performing curve construction and capable of sufficiently coping with high water pressure, and an object thereof. There is a case to provide a cast-in-place lining type shield construction method using a steel.

[Means for Solving the Problems] In order to achieve the above object, the invention according to claim 1 is characterized in that a space between a cylindrical tail plate and an inner frame assembled inside the cylindrical tail plate is provided. A cast-in-place lining type shield excavator in which lining concrete is poured into the inside to form a lining, while using hardened concrete as the lining concrete, and moving in the excavation direction inside the cylindrical tail plate. Provide a possible cylindrical moving plate, when the poured hard concrete for lining obtained a predetermined strength, move the cylindrical moving plate in the tunnel excavation direction, lining and a cylindrical tail plate The cylindrical tail plate forms a movable clearance capable of bending.

The invention according to claim 2 is characterized in that there is provided secondary casting means for casting concrete for filling into a tail void generated in the clearance portion for movement after the movement of the cylindrical tail plate. [Operation] Next, the operation of the present invention will be described.

In the present invention, a cylindrical moving plate movable in the excavation direction is provided inside the cylindrical tail plate of the shield machine, and when the poured concrete has obtained a predetermined strength, this cylindrical moving plate is provided. In the tunnel excavation direction. Thereby, a clearance for movement in which the tubular tail plate can bend can be formed between the lining formed by the concrete and the tubular tail plate.

Therefore, according to the present invention, the traveling direction of the shield excavator of the cast-in-place lining type can be changed without damaging the lining due to the interference between the tail plate and the lining.

Further, according to the present invention, by using the rapidly hardening concrete as the lining concrete, the time from casting the concrete until it becomes self-supporting so as to have sufficient strength to withstand high water pressure. Is extremely short. Therefore, the shield machine can be moved forward in a relatively short time after the concrete has been poured.
Therefore, even when performing tunnel construction under high water pressure, the lining can be formed in the excavated tunnel inner wall surface in a relatively short time, and the construction period can be shortened.

Embodiment Next, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a preferred embodiment of the cast-in-place lining type shield machine according to the present invention. In the excavator 10 of the embodiment, a cutter 14 is provided on the front surface of a cylindrical shield skin plate 12, and the cutter 14 is rotated to excavate the face 100.

At the rear end side of the cylindrical skin plate 12, a middle bent portion
A cylindrical shield tail plate 20 is provided via 18.

FIG. 3 is a partially enlarged view of the shield tail plate 20 of the shield machine 10.

On the inner peripheral surface of the rear end side of the cylindrical shield tail plate 20, a water-stopping member is provided which abuts against the outer peripheral surface of the lining 200 which is already self-supporting and prevents water from entering the inside of the shield from surrounding ground 110. ing.

As the water-stopping member, various members can be used as necessary. In the present embodiment, the water-stopping brush 22 formed to cover the inner peripheral surface of the shield tail plate 20 in a ring shape is provided in three stages. Provided. The grease 23 is filled between the water stop brushes 22 to reliably prevent water from entering. The replenishment of the grease 23 is performed through a grease supply port (not shown) provided in the water stop brush 22.

Also, this shield machine 10 has a cylindrical tail plate
Assemble the rebar 30 inside the inside 20, and further inside the inside form 24
Are detachably assembled. Then, fresh concrete is poured into a space formed between the shield tail plate 20 and the inner formwork 24.

Further, the shield machine 10 according to the embodiment includes a shield jack 28 and a press jack 34. The shield jack 28 is in contact with the end of the inner formwork 24 via the spreader 26, and propels the shield machine 10 with its reaction force. Further, the press jack 34 presses fresh concrete poured into the shield tail plate 20 and the inner formwork 24 by using a press ring 32 to remove excess water and promote hardening of the concrete. is there.

The above-described casting of fresh concrete is performed through a concrete inlet 36 provided in the press ring 32. In the figure, reference numeral 33 denotes a wife frame.

One of the features of the present invention resides in the use of hardened concrete as the fresh concrete, whereby it is possible to shorten the time required for the poured concrete to stand as a lining to withstand high water pressure. It becomes possible.

As such rapid-hardening concrete, various kinds of concrete can be used as needed, as long as it is a concrete that has been treated to accelerate the development of the initial strength. In this embodiment, a material using a rapidly hardened material for accelerating the development of the initial strength is used.

In the examples, the following table is used as a concrete example of this type of rapid hardening concrete, and FIG. 4 shows the initial strength characteristics.

A second feature of the present invention resides in that a cylindrical moving plate 40 movable in the excavation direction is provided inside the shield tail plate 20, and the tail plate has a cylindrical double structure.

In the embodiment, the moving plate 40 is formed to be slightly longer than the length of the inner mold 24, and the moving jack 42
Is formed so as to be movable in the excavation direction by a distance corresponding to one inner mold.

Thereby, at the stage where the rapidly hardened concrete poured between the tail plate 20 and the inner formwork 24 is self-supporting as a lining having a predetermined water pressure resistance, by moving the moving plate 40 in the excavation direction, the shielding A clearance that allows the shield machine 10 to turn can be formed between the tail plate 20 and the lining. This allows
Even if the shield machine 10 turns, the tail plate
20 does not interfere with concrete poured (lining) and destroy concrete.

In the shield excavator of the embodiment, a secondary casting pipe 44 is provided on the outer peripheral surface of the shield tail plate 20. When the shield excavator 10 advances, the tail void generated behind the tail plate 20 is filled with fresh concrete. Is arranged.

This embodiment has the above configuration, and its operation will be described below.

In the lining type shield construction method of the embodiment, using the above-described shield excavator 10, the direct contact with the concrete 200 (lining) and the water stop brush 22 prevents the groundwater pressure, and the inner formwork 24 is used as a reaction force. While excavating using the shield jack 28, the excavation of the face 100 is performed.

1 (A) to 1 (F) show a series of steps of this in-situ lining type shield construction method.

FIG. 7A shows that after the directly struck concrete 200 becomes independent so as to have a predetermined waterproof pressure, the shield jack 28 and the press jack 34 are pulled back to secure a space for assembling the rebar and the inner formwork. It represents the state that has been done.

In this state, the moving plate 40 is controlled to extend to the rear end side of the shield machine 10.

Next, as shown in FIG.
30, the main bar 30a is a lap joint, the distribution bar 30b is a clip joint 31
Assemble using

Next, as shown in FIG.
Is transported using, for example, a trolley or the like, and is assembled inside the rebar 30 using an erector or the like so as to face the moving plate 40.

And the spreader 26 of the shield jack 28
The press jack 34 is set so as to be in contact with the distal end of the press plate 24 and the press ring 32 is opposed to the ring-shaped space surrounded by the movable plate 40 and the inner mold frame 24.

Next, as shown in FIG. 2D, while the hard concrete is poured as fresh concrete from the concrete inlet 36 provided in the pre-ring 32, the hard concrete poured using the press ring 32 is removed. Apply primary pressure. As a result, the poured hard concrete 21
Excess moisture is removed from 0, and the hardening of the concrete is promoted.

In the present invention, by using hardened concrete as fresh concrete in this way, it is possible to significantly reduce the time required for the poured concrete 210 to stand as a lining having a predetermined waterproof pressure, thereby shortening the construction period. Can be.

Then, when the poured hard concrete 210 is self-supported so as to have a predetermined waterproof pressure, the cylindrical moving plate 40 is moved in the excavation direction as shown in FIG.

As a result, a bendable clearance 300 is substantially uniformly formed between the freestanding and rapidly hardening concrete 210, that is, the lining, and the shield tail plate 20.

The size of the clearance 300 can be arbitrarily set by changing the thickness of the moving plate 40.

Next, as shown in FIG. 2F, the shield excavator 10 is excavated by using the shield jack 28 in accordance with water pressure, curve construction, and the like. At this time, the shield tail plate 20 also moves forward at the same time, but because the clearance 300 described above exists between the tail plate 20 and the concrete 210, even when the shield machine 10 turns,
Curving can be performed without hindrance without interference between the tail plate 20 and the concrete 210.

Furthermore, when such a shield machine 10 moves forward, even if high water pressure is applied from the surrounding ground 110, the inside of the shield is sealed by the abutment between the sufficiently independent concrete 210, 200 and the water stop brush 22. Therefore, intrusion of water can be prevented.

Further, when the shield machine 10 is advanced using the shield jack 28, a tail void is generated behind the tail plate 20.

The apparatus according to the embodiment casts hard concrete as fresh concrete into the tail void from the secondary casting pipe 44 and further uses the press ring 34 for concrete.
The secondary pressurization of 210 promotes the dehydration of concrete 210 and freshly cast concrete to promote concrete strength.

In the cast-in-place lining type shield method of this embodiment,
By repeating such a series of steps, the lining can be formed on the inner wall of the tunnel even under a construction environment of high water pressure while sufficiently responding to a demand for curve construction.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, in the series of steps shown in FIG. 1, the description has been given taking the example of the rebar pre-assembly type. Not even.

[Effects of the Invention] As described above, according to the present invention, when performing in-situ lining type shield excavation, it is possible to simultaneously solve two problems of curve construction and high water pressure countermeasures that could not be solved conventionally. effective.

In particular, according to the present invention, since hard concrete is used as the concrete used for cast-in-place, it is possible to shorten the time required for the cast concrete to become self-supporting as a lining. Can be shortened.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a series of steps of a cast-in-place lining type shield method based on the present invention. FIG. 2 is a schematic sectional view showing a preferred example of a shield machine used in this embodiment. FIG. 3 is an explanatory view of a main part of the shield machine shown in FIG. 2, and FIG. 4 is an initial strength characteristic diagram of the hard concrete used in the present embodiment. 10 ... Shield excavator, 12 ... Skin plate, 20 ...
Shield tail plate, 22… Water stop brush, 24 …… Inner formwork, 26 …… Spreader, 28 …… Shield jack, 32
… Press ring, 34… press jack, 40… moving plate, 42… moving jack, 200, 210… concrete, 300… clearance.

Continuation of front page (72) Inventor Tsukasa Hashimoto 1-7-1 Kyobashi, Chuo-ku, Tokyo Toda Construction Co., Ltd. (72) Inventor Kiyoshi Kurabayashi 1-7-1 Kyobashi 1-chome, Chuo-ku, Tokyo Toda Construction Co., Ltd. (56) References JP-A-60-144498 (JP, A) Practical application Microfilm (JP) photographing the contents of the specification and drawings attached to the application form of Japanese Patent Application No. 63-114029 (Japanese Utility Model Application No. 2-37998). , U)

Claims (2)

(57) [Claims] An in-situ lining type shield for casting lining concrete in a space between a cylindrical tail plate and an inner mold assembled inside the cylindrical tail plate to form a lining. In the excavator, while using hardened concrete as the lining concrete, a tubular moving plate movable in the excavation direction is provided inside the tubular tail plate, and the poured hardening concrete is placed. At the time when the predetermined strength is obtained, moving the cylindrical moving plate in the tunnel excavation direction to form a movable clearance in which the cylindrical tail plate can bend between the lining and the cylindrical tail plate. Features a shield machine. 2. The shield machine according to claim 1, further comprising a secondary casting device for casting concrete for filling into a tail void formed in the moving clearance portion after the cylindrical tail plate is moved.