JP2554885B2 - Shield method and shield machine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a shield construction method for constructing a horizontal shaft in the ground and a shield machine therefor.

(Prior art and its problems) Conventionally, when constructing a horizontal shaft or a vertical shaft in the ground by the shield method, as shown in FIG. 6, the inside of the shield machine 100 that digs into the ground Then, for example, a segment 102 made of steel or concrete is assembled and formed into a tubular shape, and the assembled segment 10
In FIG. 2, the reaction force of the thrust of the shield jack 103 provided in the shield machine 100 is taken to excavate the front face of the shield machine 100, and the shield machine 100 is advanced while discharging the shear. Then, the gap (tail void) 104 between the segment 102 and the excavation horizontal shaft is filled with the backfill injection material through, for example, a grout hole 105 which is provided in advance in the segment 102.

However, with this method, the production cost of the segment is high, and the weight of the segment is large, so it was dangerous to transport and assemble from the ground into the shield cylinder.

In addition, since the segment is divided into several pieces, there is water leakage from the joint of the segment, which may hinder the intended purpose of the side pit, such as for power communication or subway.

In addition, as another conventional example in which the above-mentioned drawbacks are improved, as shown in FIG. 7, an annular body 202 is arranged between the inner rear portion of the shield outer cylinder 201 of the shield machine 200 and the cylindrical segment 203. is there. And this annular body 202 is connected to the adjustment jack 203 fixed to the shield machine 200, and penetrates this annular body 202, between the outer peripheral surface of the tubular segment 203 and the inner peripheral surface of the excavated lateral shaft. There is a structure in which a concrete pressure-feeding pipe 206 for placing concrete is arranged in the.

Then, in this configuration, as the shield machine 200 is dug, fresh concrete is pressure-fed from the concrete pressure-feeding pipe 206 into the space 205 between the horizontal shaft 204 and the tubular segment 203 which the shield machine 200 excavates, and this space 205 Are completely filled, thus forming a cylindrical concrete structure 207 and constructing a side shaft.

However, in this method, since reinforcing material such as reinforcing bars is not arranged in the concrete pumped into the space 205, when underground force acts on this tubular concrete structure, it cannot respond to this and the concrete structure The body may be destroyed. To counter this, special steel fibers may be mixed into the same concrete for pressure feeding, but this steel fiber is expensive, economically problematic, and its strength is small and weak. It is disadvantageous in strength on the ground.

For this reason, as another method, a reinforcing bar is assembled at the tail part of the shield machine, an inner diameter frame is assembled on the inside, concrete is placed therein, and concrete is pressed by a shield jack through a press ring, at the same time. There is also a method of using reaction force to advance the shield.

However, in this case, it is said that the digging speed is slow because it is not possible to start the next reinforcing bar and formwork until the concrete that has been cast reaches a certain level of reinforcement, and it takes time and time to assemble the reinforcing bar in the mine. There was a problem.

(Means for Solving Problems) The present invention is to solve these problems, and an object of the present invention is to smoothly perform excavation work and to improve the strength of a concrete structure. It is to provide the shield construction method and the shield machine.

That is, the present invention, in order to achieve the above object, in short, the shaft wall formed by the shield machine, and a cylindrical form frame and reaction force receiving outer peripheral side slightly smaller than the shield cylinder disposed in the shield cylinder. In the space where the filling is charged,
Along with the excavation of the shield machine, a cylindrical reinforcing body made of a reinforcing bar, an iron wire, an iron plate, or the like is continuously installed, and concrete or the like is pumped and filled.

(Operation) In the present invention, a concrete structure is placed between a pit wall formed by the progress of a shield machine and a form and reaction force receiver provided in the shield cylinder, The concrete structure is given sufficient strength by continuously providing reinforcements made of rebars, iron wires, or iron plates having the same shape.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view of a shield machine of the present invention, and FIG. 2 is a sectional view taken along the line AA in FIG. 1, in which 1 is a substantially cylindrical shield tube made of a steel plate or the like. A partition wall 1a is formed in the front part of the shield cylinder 1. And this partition 1a
A bearing 2 is provided at a substantially central portion of the above, and a shaft 3 is provided through the bearing 2 with respect to the partition wall 1a. A rotatable cutter 4 having a well-known structure for excavating the natural ground is provided at the tip of the shaft 3. Further, 5 is a cutting face chamber defined by the cutting face formed by cutting with the cutter 4, the inner peripheral surface of the hood 1b in front of the shield cylinder and the partition wall 1a, and 6 is for discharging excavated earth and sand from the cutting face chamber 5. It is an earth-moving device, which is composed of, for example, an earth-moving pipe connected to a pump, a screw conveyor, etc., and the front end is connected to the lower part of the partition wall 1a. It

Reference numeral 7 is a suitable number of shield jacks for advancing the shield machine, and reference numeral 8 is a reaction force receiving frame that also serves as a form and is also a form and reaction force receiver. 1c is shield cylinder 1
At the rear part of the annular shield cylinder provided at the rear end part, an appropriate number of concrete supply parts of the concrete supply pipe 9 are penetrated through the shield cylinder rear part 1c, and the inner peripheral wall of the side shaft formed by the progress of the shield machine. That is, a filler such as concrete is placed in the space between the pit wall and the outer peripheral side of the form / cumulative force receiver 8. 10 is the tubular concrete structure. Inside the shield tube rear portion 1c, there is provided a tubular portion 11 which has a smaller diameter than the shield tubular rear portion 1c and also has an annular shape. The tubular portion 11 and the outer shield tubular rear portion 1c are substantially concentric with each other. A gap or a groove gap g is formed, and such a groove gap g serves as a reinforcement installation portion, and the cylindrical reinforcement 12 is installed in the space through this portion. The reinforcing body 12 will be described later with reference to FIG.

In addition, 13 is a detachable jack rod that supports the concrete pressure acting on the tubular portion 11, 14 is a jack that supports the concrete pressure, and 15 is between the form and reaction force receiver 8 and the tubular portion 11. And the tubular part 11 and the rear part of the outer shield tube
It is a tail seal for preventing concrete leaks provided between 1c and concrete and prevents concrete leaks into the machine.

Next, the reinforcing body 12 used in the present invention will be described.
The reinforcing body 12 is, for example, present in the tubular concrete structure 10 and desirably works integrally with the coil joint structure 10 against an external force such as earth pressure in the ground, for example, from a reinforcing bar, an iron wire or an iron plate. It consists of

In the case of an iron plate, as shown in FIG. 3, one piece consists of small segment-shaped segment portions 12a, and a suitable number of holes 1 are formed in the plate-shaped segment portion 12a to achieve integration with concrete.
Those provided with 2b are preferred. The number, shape, etc. of the holes 12b are appropriately determined. In addition, it is desirable that the segment portion 12a has a curved plate shape so as to have a desired tubular shape when assembled, but it is not always necessary to preliminarily shape it into a curved plate when the plate thickness is small. Not. Further, the segment portion 12a is connected to other segment portions (not shown) by side portions 12c, 12d, 12e, 12f, respectively, by welding, screwing or the like, and is formed into a tubular reinforcing body 12 as a whole. In addition, it is also effective to provide striped unevenness on the iron plate of the segment 12a or to provide a small piece of spring steel or other iron piece on the surface of the iron plate in order to strengthen adhesion to concrete.

It is also possible to construct a reinforcing body for one segment with reinforcing bars and join them to obtain a cylindrical reinforcing body as a whole. It is desirable to form a net shape and attach a curved surface that roughly matches the shape of the shield cross section to it.
It is better to construct the vertical and horizontal reinforcing bars in the same plane.
It is preferable to prevent leakage of concrete when passing through the tail seal 15, but it is not limited to this, and it goes without saying that a desired reinforcing bar may be assembled and formed in a net shape at the central portion of the shield outer cylinder. .

 Next, the operation of the present invention will be described with reference to FIG.

The ground is excavated by the cutter 4, the excavated soil is taken into the face chamber 5, and the excavated soil in the face chamber 5 is discharged to the inner side of the mine through the earth discharging device 6 in the process of extending the shield jack 7. It will be soiled.

Then, the tunnel wall G formed by the excavation of the shield machine
In the space surrounded by the outer peripheral surface side of the formwork / reaction force receiver 8 and the rear surface of the shield cylinder rear portion 1c and the cylindrical portion 11, for example, a filling material such as ready-mixed concrete is not shown. Concrete supply pipe 9 by pump etc.
It is supplied from, and fills and pressurizes the space.

However, in this case, prior to the concrete pumping,
When the predetermined excavation is completed, as shown in FIG. 4 (a),
The rod 7a of the shield jack 7 is contracted. Also, the tubular part
The rod 13 is contracted by an appropriate number of jacks 14 provided between 11 and the partition wall 1a. At this time, in order to prevent the cast concrete that has not set yet leaking into the shield machine, for example, the tubular portion 11 is fixed by a fixing method (for example, a pin or a key, etc.) not shown in the formwork / reaction force receiver 8. It is preferable to temporarily restrain the forward and backward movements by ().

Then, when the concrete reinforcing body 12 is, for example, a segment-shaped reinforcing body made of a steel plate having a large number of holes, the cylindrical reinforcing body 12 is formed inside the shield tube rear portion 1c of the shield tube, and this reinforcement is performed. One end of the body 12 is connected, for example, by welding or bolting, to a reinforcing body 12 'which is already formed in a tubular shape and which is installed in the space at one end side and is still exposed at the other end side. Then, as shown in FIG. 4 (b), the rod 13 of the jack 14 is extended and the rod 13 is inserted into the cylindrical portion.
Connect to 11.

After that, a new formwork and reaction force receiver 8'is assembled in front of the formwork and reaction force receiver 8 and the rod 7a of the shield jack 7 is assembled to this.
Abut.

The cutter 4 is rotated and the shield jack 7 is extended to start excavation, and, for example, fresh concrete is pumped from the pump through the concrete supply pipe 9, and the well wall G and the form and reaction force receiving 8, 8 ' The space in between fills with pressure. In this way, the above steps may be sequentially repeated.

During the excavation, the tubular portion 11 advances toward the front of the ground together with the shield tubular rear portion 1c, and a newly formed tubular reinforcing member 12 is formed.
Is placed in that position, and as a result, is placed in the tubular concrete structure 10.

At this time, since the annular tail seals 15 are arranged between the reinforcing body 12 and the shield tube rear part 1c and the annular tube-shaped part 11 in the shield tube rear part 1c, respectively, concrete will not leak into the shield. Absent. In this case, a hole for inserting a concrete supply pipe may be provided at an appropriate position of the formwork / reaction force receiver 8 as a means for pumping fresh concrete, and concrete may be poured into the space from this portion.

Thus, in parallel with the excavation or advance of the shield machine or the rear portion of the shield cylinder, the space formed between the mine wall G and the formwork / reaction force receiving member has a sufficient strength after being solidified, such as fresh concrete. Since the fluid that can be filled is continuously pumped and filled, this space is always filled and the well wall G
Since it is pressurized and solidified, there is no collapse of the pit wall G.

In this case, when the concrete is pressure-fed, the cylindrical portion 11 can be appropriately expanded and contracted by the jack 14 to adjust the pressure applied to the poured concrete 10. When the connecting jack 14 is not used, the tubular portion 11 may be connected to the shield 1 by a detachable rod (not shown), for example.

Further, the wall body made of concrete or the like has a reinforcing member 12 made of a reinforcing bar or an iron plate having a desired tensile strength.
Since the concrete is solidified, it is possible to sufficiently withstand a large tensile force of the tunnel structure generated by the unbalanced pressure such as earth pressure in the ground after the concrete is solidified.

Although the shield has a circular cross-sectional shape as shown in FIG. 2 in the illustrated embodiment, not only a circular shape but also an oval shape, a substantially quadrangular shape, an oval shape, a horseshoe shape and the like are conceivable. Since a bending moment due to soil and water pressure is relatively large in the annular cross section, such a reinforcing body is often required.

That is, it is well known that the bending stress that normally occurs in a tunnel in the soft ground is as shown in FIG. 5 (a). That is, the tension acts inside the tunnel at the upper and lower portions of the tunnel, and the tension acts outside the tunnel at the left and right side portions. Therefore, as shown in Fig. 5 (b), the reinforcing bar or plate corresponding to this is upward in the cross section of the tunnel,
It is desirable to dispose a reinforcing member such as a reinforcing bar or an iron plate in the tunnel cross-section direction in the lower part inside the cross-section and on the left and right side parts of the tunnel toward the outer part of the cross-section. Therefore, even if the shield has a circular cross section, by forming the cross section of the shield cylinder rear part 1c of the shield cylinder 1 and the outer peripheral cross section of the cylindrical part 11 contained therein into a so-called elliptical shape, the shield cylinder rear extension The gap or groove for passing the reinforcing body formed by the outer line of the cylindrical portion 11 is formed in the same elliptical shape. Therefore, the elliptical tubular reinforcing body is installed in the concrete through the gaps or the grooves, so that it is possible to effectively counter the bending stress generated in the tunnel due to soil and water pressure in the ground.

It is needless to say that the present construction method and the present apparatus are used not only when constructing a horizontal tunnel but also when constructing a vertical shaft.

(Effects of the Invention) As described above, according to the construction method and the apparatus thereof of the present invention, between the pit wall formed by the shield machine and the outer peripheral side of the form frame and reaction force receiver arranged in the shield cylinder. As the shield machine advances, cylindrical reinforcements such as steel bars and steel plates are continuously arranged in the space, and concrete is pumped in to fill the space. With the reinforcing body, it is possible to realize a concrete structure that has sufficient strength, is easy to build, and can sufficiently resist the bending stress generated in the tunnel in terms of strength.

[Brief description of drawings]

1 is a schematic side sectional view of a shield machine of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, FIG. 3 is an example of a cylindrical reinforcing body used in the present invention, and FIG. FIGS. 5A to 5C are explanatory diagrams of the process of excavation, FIG. 5A is an explanatory diagram of bending stress generated in the tunnel, and FIG. 5B is another example of the shape of the reinforcing body, FIGS. 6 and 7. Are conventional examples. 1c …… rear part of shield cylinder, 8 …… formwork and reaction force receiver, 11 …… cylinder part, 12 …… reinforcement, g …… gap or groove, G …… tunnel wall

Claims (2)

(57) [Claims] 1. A substantially annular tubular portion (11) is provided inside the shield tube rear portion (1c) to form a substantially concentric gap or groove (g) with the shield tube rear portion (1c). , A formwork and reaction force receiver (8) is installed inside the tubular part (11), and the well wall (G) and the formwork and reaction force reception (8) formed as the shield cylinder (1) advances. A space such as the concrete is filled and pressurized in the space between the outer peripheral side and the outer peripheral side, and at the same time, a substantially cylindrical reinforcing body (12) made of a reinforcing bar, an iron wire or an iron plate is passed through the gap or the groove (g) and the pit wall (G). )
A shield construction method characterized by being continuously installed in the space between the outer periphery of the frame and reaction force receiver (8). 2. A space between a shaft wall (G) formed by the forward movement of the shield cylinder (1) and a form and reaction force receiver (8) installed inside the shield cylinder rear part (1c). In the shield construction method of pressurizing to construct a tubular tunnel structure, a substantially annular tubular part (11) is provided inside the shield tube rear part (1c) of the shield tube (1), and the shield tube rear part (1c) Between the tubular part (11) and the space between the pit wall (G) and the outer periphery of the form and reaction force receiver (8), a reinforcing body (12) made of rebar, iron wire or iron plate is continuous. A shield machine having substantially concentric gaps or grooves (g) formed therein.