JPH04176993A - Natural ground timbering device for tunnel excavation - Google Patents

Abstract

PURPOSE:To accelerate the construction work by liftably installing timbering frames closely stuck to the excavation face and having a cross section shape above an excavator main body, and pressing the excavation face of the natural ground with the timbering frames. CONSTITUTION:Multiple timbering frames 1A, 1B, 1C closely stuck to the excavation face of the natural ground and having a cross section shape are movably connected by connecting jacks 5 above a tunnel excavator 7, and they are liftably installed by jacks 6A-6C. The timbering frames 1A-1C are pressed by the jacks 6A-6C to the natural ground excavated by the tunnel excavator 7. The time required for the shuttering work is reduced, and the construction work can be accelerated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a support device for supporting the ground in the upper part of an excavator in tunnel construction by mechanical excavation.

[Conventional technology]

Conventionally, TBM (Tunnel Boring Ma
Chine) In the case of tunnel construction using an excavator, methods for supporting the ground after excavation include sheet piles,
A method using steel shoring such as H steel and steel pipes, a method of directly covering the excavated surface with concrete by spraying, a method of NATM method using concrete for rock bolts and spraying, and a method of supporting by assembling segments, which has been frequently used in recent years. There are methods.

These supports are normally installed immediately after excavation in order to prevent the ground from loosening, collapsing, and water seepage.Then, this may be used as the main lining, or it may be used as the next lining. A main lining may be constructed on the inside.

[Problem to be solved by the invention]

Any of the above-mentioned rock support methods can be used on the excavated surface of parts other than the excavator body without any problems, but in the rear part of the excavator body, the ground support method can be used without any problem. Due to the narrow space, it was not possible to secure enough work space for the work of installing the shoring, which caused problems such as collisions with the shoring materials and damage to machinery. In addition, even if concrete spraying is supported using the construction method, there are problems such as a worsening of the working environment due to dust and rebound. In addition, the segment material itself is expensive, making it uneconomical.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the main object of the present invention is to provide a method for supporting the excavated surface of the rear part of the main body of a tunnel excavating machine easily and economically, without causing any hindrance to others. The goal is to provide equipment.

[Means to solve the problem]

The above-mentioned problem is a rock support device that is installed in the excavator main body and arranged in the space between the excavator main body and the upper surface of the excavation surface, which covers at least the upper part of the excavation surface and substantially covers the excavation surface. This problem can be solved by comprising a support frame with a cross-sectional shape that can be closely attached, and an elevating support means that supports the support frame so that it can move up and down.

[Function] In the present invention, since the rock support device itself is installed in the excavator main body, it is possible to support the rock at a predetermined location as excavation progresses, and also to improve the distance between the excavator main body and the upper surface of the excavation surface. This basically eliminates the need to work in confined spaces. The earth supporting device includes a supporting frame having a cross-sectional shape that covers at least the upper part of the excavated surface and can substantially come into close contact with the excavated surface, and an elevating support means that supports this supporting frame so that it can be raised and lowered. When the support frame is raised and lowered until it comes into contact with the earth by lifting and lowering the support means, the support frame comes into close contact with the earth excavation surface and supports it.

[Specific configuration of the invention]

Hereinafter, the present invention will be explained in detail based on specific examples shown in the drawings.

FIG. 1 shows a longitudinal cross-sectional view of the earth support device according to the present invention,
FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1, FIG. 3 is an explanatory diagram of the elevation state of the earth supporting device, and FIG. 4 is a partial plan view of the earth supporting device.

As shown in FIGS. 1 and 2, a rail mount 3 is attached to the upper part of the main body of the tunnel excavator 7 along the tunnel direction, and two rails 3a, 3a are attached to the rail mount 3. is permanently installed. And this rail 3
The earth supporting device 1 is placed on the a and 3a.

The rock support device 1 is divided into three parts in the tunnel direction.
It has a continuous structure, and is arranged in the order of IA to IC from the face side, so as to substantially support the ground up to the rear end of the excavator 7. Each of the mountain supporting devices IA to IC is connected in the tunnel direction by a connecting jack 5.5, so that the mutual distance can be freely adjusted.

Each of the mountain support devices IA to IC is composed of a support frame 2 that directly supports the earth, and three lifting jacks 6A to 6C that support the support frame 2 so as to be able to move up and down. The lifting jacks 68 to 6C are mounted on the slide truck 4, which has one end mounted on the supporting frame 2 and the other end mounted horizontally on the rails 3a, 3a.
The two lifting jacks 6B and 6C of the three lifting jacks are arranged parallel to each other. Therefore, as shown in FIG. 3, once the elevating jacks 6B and 6C have been extended by a predetermined amount, they can be fixed and moved up and down along a rotational trajectory by extending and contracting the remaining elevating jacks 6A. can. As mentioned above, by making the rock support device 1 have a split structure and configuring the support frame 2 to be able to move up and down, it becomes possible to use other tunnel excavators with different overall lengths and tunnel cross-sectional diameters, for example. .

As shown in FIG. 2, the supporting frame 2 is configured as a roof-like frame material whose cross-sectional shape forms an arc having the same curvature as the curvature of the excavation cross section, and covers at least the upper part of the excavation surface. be done. The supporting frame 2 includes rigid members 2b, 2b, etc., such as H-steel, arranged in the tunnel transverse direction, and sheet pile members 2a, 2a,..., arranged in a lattice pattern orthogonally to the rigid members 2b, 2b, etc.
As shown in FIG. 4, the sheet pile members 2a, 2a, . . . The separation distance between the ICs is adjusted by the connection jack 5.5.

Since the rock support device 1 according to the present invention temporarily supports the rock at a portion corresponding to the excavation body, it is necessary to perform tunnel lining behind it.

The continuous concrete lining casting equipment for this purpose will be described in detail below.

As shown in FIG. 5, the continuous lining concrete pouring device includes a lining concrete pouring and pressurizing device 10 (hereinafter simply referred to as pouring device), a front slide formwork 20, and a rear slide formwork 30. The reaction force receiver consists of a gripping device 40. The pouring device 10 is separated from other devices, the front slide formwork 20 and the rear slide formwork 30 are connected by a first slide jack group 50, 50..., and the rear slide formwork 3
0 and the reaction force receiver are connected to the grip device 40 by a second slide jack group 60, 60, .

As shown in the cross-sectional view of FIG.
On the other hand, a circular face frame 11b is provided around the outer periphery.

A grip support pedestal 16 fixed to the circular ring lla is provided inside the ring lla, and this grip support pedestal 1
A gripping device 13, which serves as a fixed support means for the pouring device 1, is fixedly mounted on 6.16. The grip device 13 has cylinder shafts 1.3a, 13a that extend and contract in both directions, and is equipped with a gripper 14.14 at the tip thereof for pressing the excavation surface.

Further, the circular ring lla is provided with press jacks 12, 12, etc., which advance and retreat toward the rear side of the tunnel at appropriate intervals in the circumferential direction, and at the tips of the jacks, during concrete pouring. A press ring 17 is provided to constitute the side plate of the formwork and to pressurize the poured concrete in the direction of the tunnel.

The top of the pouring device 10 has a pouring port 18 for pouring concrete, through which concrete is fed by a concrete pump (not shown) with appropriate pressure through a concrete distributor such as a rotary valve. , concrete can be poured. Note that the jack 15.1 provided around the grip device 13
5... is connected to a tunnel excavator, and this pouring device 1
It is for towing 0.

In the front slide formwork 20, as shown in detail in the cross-sectional view of FIG. have. The circular rings 21a, 21a.
... are connected with pins at appropriate positions in the circumferential direction, and the upper part is separated, one lower end of the rectangular frame 22 is fixed to the circular ring 21a, and the side thereof is connected via turnbuckles 24 and 24. connected to the circular ring 21a;
- Can be expanded and contracted in the circumferential direction within a certain range. The upper part of the circular ring 21a has a journal jack 23.
．． 23, so that the height can be adjusted and the structure can be folded. In addition,
As shown by the chain line in FIG. 5, the front slide formwork 20 is fitted into the press ring 17 in an internal state and serves as an inner formwork during concrete pouring, so that the front slide formwork 20 is inserted into the press ring 17 of the pouring device 10. Once the outer diameter has been adjusted to a shape that allows it to be inserted, it is basically fixed during construction.

In addition, the front slide formwork 20 is divided into a front part and a rear part, and the two parts are connected, for example, with connection adjustment bolts,
When constructing a curved section, it is easy to adjust the distance using the connection adjustment bolts mentioned above to create a curvature, and to seal the gap with a packing material to prevent concrete from leaking and to provide a water stop function. It can be adapted to curved construction.

The front slide formwork 20 and the first slide jack group 50
．． As shown in the cross-sectional view of FIG. 8, the rear slide formwork 30 connected with the circular ring 31a
, 31a... are provided with a circular face frame 31b around the outer periphery, and are connected with pins at appropriate positions in the circumferential direction.
By connecting the ends of the circular ring 21a via a grip jack 32, it can be expanded and contracted in the circumferential direction by expanding and contracting the grip jack 32, and the rear slide formwork 30 is fixed to the tunnel excavation surface. This is made so that it becomes a reaction force point when the front slide formwork 20 is pushed forward and when the reaction force receiving grip device 40 is pulled forward.

In this specific example, the front slide formwork 20 and the rear slide formwork 30 are connected to the first slide jack 50.5.
Although they are connected by 0..., it is also possible to omit this and configure them as one piece. In this case, when the integrated sliding formwork moves forward, it moves forward by the second slide jacks 60, 60, with the reaction force receiving grip device 40 as a reaction force point, and when the reaction force receiving grip device 40 moves forward, it moves forward by the second slide jacks 60, 60, etc. , this − body type sliding formwork may be used as a reaction force point.

As shown in FIG. 9, the reaction force receiving grip device 40 in the last row has almost the same structure as the rear slide formwork 30, and has a circular surface frame 41 on the outer periphery of the circular rings 41a, 41a... ．． b is provided around the circumference, and at a suitable position in the circumferential direction,
By making a bottle connection and connecting the ends of the circular ring 41a via the grip jack 42,
By expanding and contracting the grip jack 32, the reaction force receiving grip device 40 can be fixed to the tunnel excavation surface by expanding and contracting in the circumferential direction, so that the reaction force receiving grip device 40 can be fixed to the tunnel excavation surface. I try to make it a point of emphasis.

When pouring tunnel lining concrete under such a continuous pouring device, as shown in FIG. 10, the gripper 73 of the tunnel excavator 7 is fixed to the ground at the tunnel face position, and the cutter head 71 is With rotation,
The ground is excavated by extrusion of the thrust jack 72.

The rear upper part of the main body of the excavator 7 is equipped with a rock support device 1 according to the present invention, which supports the rock after excavation.

When one stroke of excavation (approximately 1.5 m) by the thrust jack 72 is completed, first, the gripper 14 is extended by the grip device 13 of the driving device 10 and the driving device 1
0 itself to the excavation surface.

Then, from the state shown in FIG. 10, the press ring 17 is separated by about 30 cm from the pouring seam of the poured concrete using the press jack 2 of the pouring device 10, and the front slide formwork 20 is
Concrete is poured into the space formed by the circular frame 21b and the press ring 17 through the pouring hole 18. When the space is filled with concrete and the supply pressure of the concrete pump reaches a certain value or more, the supply of concrete is stopped.

Note that the poured concrete is always kept under pressure by the press ring 17.

Next, the grip jacks 32 of the rear slide formwork 30 are extended to fix the rear slide formwork 30 to the excavation surface, and the front slide formwork 2 is fixed to the excavation surface using the first slide jack 50.
Move it forward by an amount. After that, the grip jack 42 of the reaction force receiving grip 40 is extended and fixed to the excavation surface,
The fixation of the rear slide formwork 30 is released, and the rear slide formwork 30 is also moved forward by about 30 degrees.

The process up to this point is regarded as one cycle of pouring, and the press ring 17 is again separated from the pouring joint of the poured concrete by about 30 cm, and the process of pouring concrete is repeated.
1, which corresponds to one stroke of excavation by tunnel excavator 7;
Complete concrete pouring for 5m section.

Next, the grip device 13 of the pouring device 10 is loosened, and the press jacks 12, 12... are extended to push the concrete pouring joint end face with the press ring I7, and the pouring device 1 is moved forward by about 1.5 m as a reaction. Then, fix the pouring device IO to the excavation surface again by extending the grip device 13, pressurize the poured concrete at a predetermined pressure via the press ring 17 by operating the press jacks 12, 12, and so on. Hold for about 30 minutes. The pressurization value is appropriately determined from the viewpoint of ensuring sufficient water-stopping properties against water pressure and minimizing ground subsidence within a range that does not destroy the ground.

Meanwhile, the rear slide formwork 30 is fixed to the excavation surface, and the reaction force receiving grip 40 is moved forward by 1.5 m and held fixed by the second slide jacks 60, 60, and the tunnel excavator 7 excavation will start again.

By the above method, lining concrete is continuously poured.
The concrete is poured under continuous pressure, and is kept under pressure until it hardens, so it adheres to the ground, making it stable without loosening, causing almost no ground subsidence, and improving the surrounding structure. It has no effect on things. In addition, lining concrete can be placed simultaneously with excavation, speeding up construction and significantly reducing the time and effort required for formwork work.

Note that as the concrete to be placed, fly ash and special concrete made by blending this with admixtures such as steel fibers, fluidizing agents, and retarding agents can be used.

〔Effect of the invention〕

As described in detail above, according to the present invention, the ground support of the excavation surface in the rear part of the main body of a tunnel excavator can be performed simply and economically, without causing any other obstacles.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of the earth supporting device according to the present invention, Fig. 2 is a horizontal cross-sectional view taken along the line Fig. 4 is a partial plan view of the earth supporting device, Fig. 5 is a diagram showing a continuous lining concrete casting device according to the present invention, Fig. 6 is a cross-sectional view taken along the line VI-VI in Fig. 1, and Fig. 7 The figure is a horizontal cross-sectional view taken along the line ■-■ in figure 1.
Figure 9 is a cross-sectional view taken along the line ■-■ in the figure, and Figure 10 is a cross-sectional view taken along the line ■-■ in Figure 1 for explaining the procedure for placing lining concrete. DESCRIPTION OF SYMBOLS 1... Earth support device, 2... Shoring frame, 4... Moving trolley, 5... Connecting jack, 6A to 6C... Lifting jack, 7... Tunnel excavator, 10...・Lining concrete placement/pressure equipment, 20... front slide formwork,
30... Rear slide formwork, 40... Reaction force receiving grip device, 50... First slide jack, 60... Second slide jack Fig. 6 Fig. 7 Fig. 8 Fig. 9

Claims (1)

[Claims] (1) A rock support device that is installed on the tunnel excavation machine main body side and arranged in the space between the tunnel excavation machine main body and the upper surface of the excavation surface, which covers at least the upper part of the excavation surface;
1. A rock supporting device for tunnel excavation, comprising a supporting frame having a cross-sectional shape that can substantially come into close contact with an excavated surface, and an elevating support means for supporting the supporting frame in a vertically movable manner.