JPH0635797B2 - 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 shaft in the ground by the shield construction method, as shown in FIG. 10, 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 this assembled segment tube 10 is formed.
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 and the excavation horizontal shaft is filled with the backfill injection material through, for example, a grout hole 105 provided in advance in the segment.

However, in this method, the manufacturing cost of the segment is high, and the weight of the segment is large, so that it is 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.

Further, as another conventional example in which the above-mentioned drawbacks are improved, as shown in FIG. 11, one in which an annular body 202 is arranged between the rear inner side of the shield outer cylinder 201 of the shield machine 200 and the cylindrical segment 203. is there. The annular body 202 is connected to the adjustment jack 203 fixed to the shield machine 200, and the annular body 2
There is a structure in which a concrete pressure-feeding pipe 206 for placing concrete is arranged between the outer peripheral surface of the tubular segment 203 and the inner peripheral surface of the excavated lateral shaft so as to penetrate through 02.

Then, in this configuration, as the shield machine 200 is dug, the fresh concrete is pumped into the space 205 between the horizontal shaft 204 and the segment 203 formed by the shield machine 200.
The space 205 that has been pumped further is 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.

Therefore, as another method, FIG. 12 (a) to (c)
As shown in Fig. 3, rebar 301 is assembled at the tail part of the shield machine 300, inner frame 302 is assembled inside it, and concrete 3
Place 03 and press shield 30 through shield jack 30
According to 4, there is also a method of pressing concrete 303 and at the same time utilizing the reaction force to dig the shield machine.

However, in this case, since the next set of the reinforcing bar 301 and the formwork 302 cannot be started until the cast concrete 303 exhibits a certain level of strength, the excavation speed is slow and the reinforcing bar 30
There was a problem that assembly of 1 also took time and effort.

(Means for Solving Problems) The present invention is intended to solve these problems, and an object of the present invention is to obtain a tunnel having a desired strength, which enables smooth excavation work. It is to provide an economical shield construction method and a shield machine that can perform.

That is, in order to achieve the above object, the present invention is, in short, a tunnel wall formed by the forward movement of the shield machine and a cylindrical form frame / reaction force receiving outer periphery slightly smaller than the shield cylinder disposed in the shield cylinder. In the space between the side and the side, there is installed a reinforcing member formed by incorporating a plurality of reinforcing members whose expanding portions can expand adjacent to each other in a substantially cylindrical shape, and pumping a filling material such as concrete. It is designed to be filled with.

(Operation) In the present invention, the expansion portion spreads in the filling material placed between the pit wall formed by the advance of the shield machine and the form and reaction force receiver provided in the shield cylinder. The filling material has sufficient strength by being provided with a reinforcing material which is formed in a tubular shape as a whole, for example, a reinforcing bar.

Further, when the reinforcing material is expanded, the expanded portions overlap each other in the circumferential direction and form a substantially annular shape, so that the bending load effectively acting on the tunnel is effectively counteracted.

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. In these drawings, reference numeral 1 is a substantially cylindrical shield cylinder made of a steel plate or the like, and a partition wall 1a is formed in the front part of the shield cylinder 1. .
And, a bearing 2 is provided at a substantially central portion of the partition wall 1a,
A shaft 3 extends through the partition wall 1a via the bearing 2. 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 excavating the excavated earth and sand in the cutting face chamber 5. This is an earth discharging device, which is composed of, for example, an earth discharging pipe connected to a pump, a screw conveyor, etc., the front end is connected to the lower part of the partition wall 1a, and the earth and sand excavated by the cutter 4 is discharged inside the mine by this earth discharging device 6. .

Further, 7 is an appropriate number of shield jacks for advancing the shield machine, and 8 is a frame for the reaction force thereof, which is also used as a mold and is assembled in a tubular shape. Reference numeral 9 designates a filling material such as concrete, for example, in the space between the inner peripheral wall of the side shaft formed forward of the shield machine, that is, the outer wall of the form / cumulative force frame 8. Concrete supply pipe for installation,
Reference numeral 10 denotes an annular lining pressure-bearing portion, which is provided in the rear portion of the shield cylinder 1 and advances as the shield advances. The lining pressure-bearing portion 10 has an expandable reinforcement member 11 described later. A plurality of holes 10a for passing through are formed so as to be separated from each other in the substantially circumferential direction.

The lining support portion 10 is fixed inside the shield rear portion.

12 is a space between the formwork / reaction force receiver 8 and the lining bearing 10 or a hole
This is a tail seal for preventing concrete leakage provided on the outer peripheral portion of 10a, etc., and prevents concrete leakage into the machine. Further, 13 is concrete cast in the space.

Next, the expandable reinforcing member 11 made of, for example, a reinforcing bar used in the present invention will be described. It is desirable that the reinforcing material 11 be present in, for example, a tubular concrete 13 and work integrally with the concrete 13 against an external force such as earth pressure in the ground.

FIG. 2 shows the expandable reinforcement member 11.
Numeral 11 is arranged in the axial direction of the shield cylinder 1 and has a substantially round bar-shaped base 11a which can be successively spliced, and one end of which is connected to the outer periphery of the base 11a and the other end of which can be expanded in a substantially arrow shape. Expanded part 11
It consists of b and. The reinforcing member 11 is preferably configured such that the base portion 11a is a reinforcing bar and the expanding portion 11b is a spring reinforcing bar, but the material is not necessarily limited to iron, and the expanding portion 11b is a spring. Other metal or synthetic resin having such elastic restoring force may be used. In addition, the base 11a is also a reinforcement member 11
A metal or a synthetic resin may be used as long as it has a function of defining the position and the direction. Further, it goes without saying that the reinforcing material 11 may have irregularities on the surface or the tip thereof may be bent in order to increase the adhesive force with the concrete.

Further, the cross-sectional shape of the reinforcing material 11 is, as shown in FIGS. 3 (a) to 3 (c), respectively, both sides are round, or square, plate-shaped, or a shape such that the entire cross section is circular or oval. Good.

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

The ground is excavated by the cutter 4, and the excavated earth and sand is in the face chamber 5.
The excavated earth and sand in the face chamber 5 is discharged to the inside of the mine through the earth unloading device 6 in the excavation process of being taken in and extending the shield jack 7.

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 lining pressure support plate 10 provided in the rear portion of the shield cylinder, for example, a filling material such as ready-mixed concrete is illustrated. It is supplied from the concrete supply pipe 9 by a concrete pump or the like, and fills the space under pressure.

However, in this case, when the excavation and the lining for one cycle are completed, as shown in (a), the shield jack 7 is tightened as shown in (b).

Then, one cycle of the reinforcing material 11 is used for the lining pressure bearing plate 10.
It is joined to the existing reinforcing material 11 (see FIG. 7 (a)) protruding from the hole 10a, and the form and reaction force receiver 8 is newly assembled on the inner peripheral side thereof.

Next, as shown in FIG. 3C, the shield jack 7 is extended to apply a reaction force to the formwork / reaction force receiver 8 to move the shield machine forward, and at the same time, the space behind the concrete supply pipe 9 behind the lining bearing portion. Place concrete 13 on the part. When the shield machine advances, the earth is excavated by the cutter 1 and the earth is discharged by the earth discharging device 6 by a method such as a screw conveyor or fluid transportation.

The reinforcing material 11 that functions to reinforce the concrete 13 in these processes is, as shown in detail in FIG. 5 (a), the lining bearing pressure that advances as the shield machine is propelled or part of the shield machine is advanced. Following the shape of the hole 10a of the part 10, it is initially closed and moves from the inside of the shield to the inside of the lining concrete. At this time, the lining bearing 10
Since the concrete 13 immediately behind is shortly after placing,
Although not yet set, the concrete 13 in the lining part, which is a few cycles behind, has already set since some time has passed since it was placed, so the reinforcement material 11 is fixed to the existing lining part. , Its position does not move.

Next, as shown in (b) and (c), when the entire reinforcing material 11 passes through the hole 10a and enters the concrete 13 which is not yet solidified, the expanding portion of the reinforcing material 11 is generated by its strong elastic force. 11
b returns to its initial form. That is, it expands.

In this way, as shown in FIG. 6, a plurality of reinforcing members 11 are circumferentially arranged inside the lining so that the expanded portions 11b of the adjacent reinforcing members 11 overlap each other in a substantially annular shape inside the lining. By doing so, it is possible to obtain the same effect as arranging the reinforcing bars in a grid shape in the circumferential direction.
No. 13 is strong against bending load due to earth pressure and water pressure.

The reinforcing material 11 may be arranged in the lining in a ring shape at the substantially central portion of the lining as shown in FIG. 7 (a), or as shown in FIG. Than 2
It may be arranged in a double layer, and it is not always necessary to arrange it uniformly over the entire circumference.
The left and right parts may be arranged from the outside, a double or triple arrangement may be partially provided, or the intervals may be changed.

FIG. 8 shows a second embodiment of the present invention. As a reinforcing material using an elastic material used in this embodiment,
(A) As shown in the figure, a single plate of elastic material may be processed. In other words, in this embodiment, the notch 11c is formed in the plate-shaped elastic member 11A, and the pair of elastic arms 11d formed by the notch has a structure that opens to the left and right as shown in FIG. Further, the tip end of the elastic arm 11d made of an elastic material opened to the left and right can be made wider or the hole 11e can be opened to increase the adhesive force with the concrete. At this time, the hole 10a formed in the lining support portion 10 has an elongated, substantially rectangular shape.

In the illustrated embodiment, the shield has a circular cross-sectional shape as shown in FIG. 6, for example. However, not only a circular shape but also an oval shape, a substantially quadrangular shape, an oval shape, a horseshoe shape, and the like are possible. Such a reinforcing member is often required for a non-circular cross section because a bending moment due to soil and water pressure is relatively large in an annular cross section.

That is, it is well known that the bending stress usually generated in the tunnel in the soft ground is as shown in FIG. 9 (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. 9 (b), the reinforcing bars corresponding to this are biased toward the inside of the cross section at the cross section of the tunnel, and to the outside of the cross section at the left and right sides of the tunnel, and It is desirable to provide a stiffener. Therefore, even if the shield has a circular cross section, the holes 10a for installing the reinforcing material in the lining pressure bearing portion 10 may be arranged in an elliptical shape so that the reinforcing material 11 is formed in the same shape. By doing so, it is possible to effectively counter the bending stress generated in the tunnel due to soil and water pressure in the ground.

Further, it goes without saying 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 present invention, a substantially annular lining bearing portion is provided in the rear portion of the shield cylinder, and a formwork and reaction force receiver is incorporated inside the lining bearing portion to protect the shield. Expansion that can be expanded into the space where the filling material such as concrete is pumped between the mine wall formed along with the advancement and the outer peripheral side of the above-mentioned formwork and reaction force receiver that are sequentially installed along with it A plurality of reinforcing members each having a portion are positioned in the space through the holes formed in the lining support portion, and the expanded portion thereof is widened so that adjacent reinforcing members have a substantially tubular reinforcing member. Since the excavation work is performed, (a) Since it is not necessary to assemble the reinforcing bars one by one as in the past, the work time can be shortened accordingly.

(B) The concrete part of the lining that has not solidified yet
Since it is always sealed, it is possible to move to the work of the next cycle even if the concrete of the previous cycle is not solidified, so the lining speed becomes faster.

(C) Since the construction period can be shortened from the above, there is an economical effect.

(D) Further, when the expanded portions are expanded, they overlap each other and form a substantially annular shape, so that sufficient strength can be obtained against bending load due to earth pressure or water pressure.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a shield machine according to a first embodiment of the present invention, and FIG. 2 is a perspective view of an example of a reinforcing bar used in the present invention.
FIGS. 3 (a) to 3 (c) show various modifications of the same reinforcing bar,
Figures (a) to (c) are explanatory views of the process of excavation, and FIG. 5 (a) to
(C) is an explanatory view of the operation of the reinforcing material, FIG. 6 is an explanatory view showing a state in which the reinforcing material is provided in the structure formed by the filling material such as concrete, and FIG. 7 (A) is the lining bearing pressure. Part, formwork and reaction force receiver as viewed from the rear of the shield partition wall toward the inside of the mine, (b) is an explanatory view of the above in which the arrangement of the holes of the lining bearing part is different, and FIG. 8 (a), ( (B) is a second embodiment of the present invention, FIG. 9 (a) is an explanatory view of bending stress generated in the tunnel, (b) is another example of the shape of the reinforcing material, and 10th.
Each of FIGS. 1 to 12 is a conventional example. 1 ... Shield cylinder, 10 ... Lining bearing part, 10a ... Hole, 11 ... Reinforcing material

Claims (2)

[Claims] 1. A pit wall formed by advancing the shield and a mine wall formed by advancing the shield, and the form and the molds sequentially incorporated therein, by installing a form and reaction force receiver inside a lining pressure bearing provided in the rear part of the shield cylinder. At the time of inserting a plurality of reinforcing members having an expanding portion capable of expanding in a substantially circumferential direction into a space between the reaction force receiving member and the outer peripheral side through a proper number of holes formed in the lining supporting portion. Insert the reinforcing material in the shape of a substantially round bar or plate and position it in the space, and the expanding portions expand and overlap each other in the circumferential direction to form a substantially annular shape, such as concrete. A shield construction method characterized by advancing a shield machine by filling a filling material. 2. A filler is filled in a space between the outer periphery of a formwork / reaction force receiver installed inside a lining pressure-supporting portion fixedly provided at the rear portion of the shield cylinder and a pit wall formed by excavation. Means and a means for installing a plurality of reinforcing members having an expanding portion capable of expanding through an appropriate number of holes formed in the lining support portion in the space, wherein the reinforcing member is a hole A shield machine having a substantially round bar shape or a plate shape when inserted, and overlapping each other in a circumferential direction when expanded to form a substantially annular shape.