JP2014190038A - Widening tunnel construction method and widening shield machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a construction method of an upper part of a widening tunnel between parallel tunnels, in which connection segments are assembled while excavating the widening tunnel by using a widening shield machine having a simple structure and capable of rapidly excavating; and the widening shield machine used for this method.SOLUTION: A construction method of an upper part of a widening tunnel includes steps of: excavating by a widening shield machine installed between upper parts of parallel tunnels, removing upper segments of each of the parallel tunnels below the widening shield machine, and assembling and erecting connection segments between residual segments left after removal; and performing excavation by the widening shield machine while excavating natural ground in a lower part of the excavation. The widening shield machine used for this method includes an excavation part consisting of an upper plate with a front part formed into a substantially arc shape and a lower plate shaped along the upper part of the parallel tunnels, and excavates the upper natural ground of the parallel tunnels by a plurality of jacks in the upper plate.

Description

  The present invention relates to a tunnel widening method for widening a tunnel region by excavating between parallel tunnels, and a widening tunnel shield machine used therefor.

  Many techniques have already been used as a method of widening the main tunnel and the ramp tunnel, or as a method of widening when a plurality of parallel tunnels are branched or assembled at a station building or the like. Japanese Patent No. 4471521 is presented as one of the techniques.

  The applicant of the present application has also filed as Japanese Patent Application No. 2012-225434.

  However, the former invention by the shield construction method has a large number of cutters and cutter bits installed in the widened section between the two guide holes, and a part of the support structure (segment) is attached to both ends of the drilled section. By providing a crushing rotor for cutting, there is a disadvantage that the equipment becomes large and the construction cost increases.

  The latter tunnel widening section construction method relates to a ground excavation method in which the natural ground between tunnels is divided into a preceding section and a subsequent section, and each is excavated alternately.

Japanese Patent No. 4471521 Japanese Patent Application No. 2012-225434

  In the present invention, as a method of widening between parallel tunnels, the crushing rollers on both sides of the shield machine do not use a complicated and expensive structure as in the invention of Patent Document 1, and excavate natural ground at the front part of the shield machine. The construction method of the widening tunnel and the widening shield machine used for the construction of the widening tunnel capable of speedy finishing with a simple structure that winds the connecting segment widening at the rear part.

  Claim 1 of the present invention solves the above-mentioned problem, the gist of which is a method of widening a tunnel region by excavating between parallel tunnels, and a widening shield machine installed between upper portions of the parallel tunnels. A step of digging along the axial direction of the parallel tunnel, a step of removing an upper segment of the parallel tunnel located under the widening shield machine, and a connecting segment between the remaining segments of each parallel tunnel left after the removal The upper part of the widening tunnel is constructed by assembling the widening shield machine and the process of excavating the ground below the shield machine as well as the widening shield machine.

  According to the invention of claim 2, the groundwater from the ground before the widening is obtained by digging the widening shield machine between the parallel tunnels and installing the preceding tunnel below the ground before the ground excavation at the lower part of the excavation. Or excavated soil from excavation can be transported behind the preceding tunnel.

  The invention of claim 3 constructs the widened tunnel by adding a step of widening the lower part of the parallel tunnel before or after the step of constructing the upper part of the widened tunnel.

  According to a fourth aspect of the present invention, the widening shield machine of the invention forms a substantially arcuate or curved cross section with a substantially arcuate upper plate and a lower plate including a shape along the upper part of the parallel tunnel, and the upper plate at the rear thereof. Inside, a plurality of jacks are provided.

  According to a fifth aspect of the present invention, in addition to the fourth aspect, in order to excavate a substantially arc-shaped cross section, the excavation portion is formed by a cutter head at a central portion and a plurality of screw excavators extended partially by polymerization on both sides thereof. We propose a widening shield machine with

  According to the first to third aspects of the present invention, a widening shield machine is installed between the upper parts of the parallel tunnels, and the tunnel is digged in the axial direction. A new connecting segment is assembled between the remaining remaining segments, and a natural ground below the widening shield machine is excavated. As a result, it is possible to excavate the natural ground in a stable state at the front part, and to construct a widened tunnel in the rear part with a new connecting segment safely and accurately.

  According to a fourth aspect of the present invention, in the front part of the widening shield machine, an approximately arcuate upper plate and a lower plate having a shape along the upper portion of the parallel tunnel are formed, and then a dug portion having a substantially arcuate cross section is formed. Widening shield machine equipped with multiple jacks in the upper plate, expanding and contracting the jack to take the reaction force from the existing connection segment, widening tunnel in a short period of time by promoting widening shield and excavating natural ground It is possible to provide a widening shield machine capable of constructing

  According to a fifth aspect of the present invention, the excavation part of the fourth aspect includes a cutter head at a central position provided in the partition wall, and a screw excavation device extended by partially polymerizing on both sides as viewed from above. Since it is a widening shield machine in which a plurality of jacks for excavation are installed at the rear, and the widening shield machine can be constructed even on relatively solid ground, excavation is possible even in ground with groundwater. By excavating the shield face with a machine without using human power, it is possible to excavate safely and to reduce the number of ground improvement sections, so it is economical and shortens the construction period.

FIG. 3 is a schematic perspective view showing a widened state of a tunnel using the widening shield machine of the present invention in the first embodiment. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG. It is a longitudinal cross-sectional view of FIG. It is DD sectional drawing of FIG. 5, It is explanatory drawing which inject | poured the backing material between the upper direction of a connection segment, and the ground behind the upper board vicinity of the side board of a widening shield machine. It is explanatory drawing between the side part outer side and upper board of a connection segment in the cross-section center part vicinity of a widening shield machine. It is sectional drawing which shows construction of the widening segment of this invention, and the lower tunnel fixing | fixed part. FIG. 5 is an explanatory diagram of a connecting segment assembling apparatus, which is a second embodiment different from FIG. 3. FIG. 2 is a third embodiment different from FIG. 2, in which the left half is provided with a cutter head and a screw excavator as viewed from the front, and the right half is viewed from the rear. It is EE sectional drawing which made the right half part of FIG. 9 the same as the left half part. FIG. 6 is a view showing a longitudinal section of Example 3. It is explanatory drawing of the drill bit of the screw drilling apparatus in FIGS. The diameter of one tunnel in the parallel tunnel of FIG. 2 is smaller than that of the other.

As a feature of the present invention, the widening shield machine has a substantially arcuate cross section formed by a substantially arc-shaped upper plate and a lower plate, or a screw drilling device attached to both sides of the cutter head on the substantially arcuate cross section. With a digging section with an arc-shaped cross-section, multiple jacks installed behind it excavate between existing parallel tunnels in the tunnel axial direction with a widening shield machine, and a new along the existing connecting segment at the rear part of the widening shield machine There is a widening tunnel excavator for assembling connecting segments and a tunnel widening method using it.
Hereinafter, shield machines of various embodiments and tunnel widening methods using the same will be described.

[Example 1]
The widening shield machine A that is placed across the upper portions of the existing parallel tunnels 50 and 60 in FIGS. 1 to 6-1 and 6-2 is a so-called open type shield machine. This widening shield machine A is used on the ground where the stability of the face is maintained, such as the ground where the face is highly independent or the ground 34 whose ground is improved, and the face is directly or manually using a small excavator. Drill and propel. The widening shield machine A includes a substantially arc-shaped upper plate 1, a lower plate 2 having both ends aligned with the outer diameter of the upper portion of the existing segments 14 of the tunnels 50 and 60, and, if necessary, side plates 21 on both ends. A partition wall 8 is formed in the front hood 4 of the partition wall 8 formed by the upper plate 1, the lower plate 2, the side plate 21 and the partition frame 3 at the front of the widening shield machine A. Form. Further, a cutting blade 4 ′ can be attached to the tip of the upper plate, the lower plate, or the side plate in the hood 4. The cross section of the shield machine A is substantially arcuate. In this example, the upper plate and the lower plate are separated from the excavation chamber 10 by the partition frame 3 and the partition wall 8 at the rear thereof. However, depending on the structure of the upper plate and the lower plate, the partition frame 3 may be unnecessary. is there. In FIGS. 1 and 2, side plates 21 are provided at both ends of the upper plate 1 and the lower plate 2, but the end of the upper plate may be curved and joined to the lower plate to form an arcuate cross section. good. The face 5 in the ground 34 in front of the excavation chamber 10 is excavated in the excavation chamber 10 using human power or an excavating tool such as a big hammer. A jack 9 is installed in the working chamber 12 between the partition wall 8 at the rear of the excavation chamber 10 and the reinforcing rib 11 at the rear thereof to promote the widening shield.

  As shown in FIG. 4, at the lower part of the excavation chamber 10, a pair of belt conveyors 20 carrying excavated earth and sand from the both ends in the horizontal direction of the cross section to the center, and a belt conveyor 6 in the tunnel axial direction at the front center crossing it. , Transport excavated earth and sand backward. The belt conveyor 6 passes through the opening 7 provided in the lower part of the partition wall 8 and drops excavated earth and sand into the earth and sand hopper 12 ′ provided in the lower part of the work chamber 12. An opening 12-1 is provided in the lower part of the earth and sand hopper 12 ', and a lower excavation part formed by excavating a natural ground 40 below the shield machine by a known excavation means in parallel with the excavation of the widening shield machine A. Drop the excavated soil to 16. For this purpose, it is preferable to provide an opening lid at the bottom of the earth and sand hopper 12 '(not shown). The excavated earth and sand dropped on the lower excavation part 16 is carried out backward (not shown) by the existing earth and sand loading / conveying device.

A large number of shield jacks 9 are installed in the working chamber 12 between the partition wall 8 and the reinforcing rib 11 on the rear side thereof (in FIG. 3 and FIG. 4, 14 are described in two each between one connecting segment 13). The space created by contracting the jack 9 by propelling the widening shield machine A while the jack 9 is extended while the spreader 9-1 of the jack 9 is brought into contact with the connecting segment 13 behind the reinforcing rib 11 A new connecting segment 13 is assembled as a ceiling part of the widening tunnel, and the widening shield machine A is promoted.
Further, as described above, the lower plate 2 of the widening shield machine A has a shape along the outer diameter (outer peripheral surface) of the existing segment 14 in the upper part of the tunnels 50 and 60, and thus straddles the existing segment 14. The widening shield machine A is dug by placing it in contact and digging, or placing the lower plate 2 through a small amount of uncut soil. For this reason, since it is supported by the segment of the said parallel tunnel at least two places, a widening shield can be dug in the correct attitude | position and a connection segment can be assembled correctly and easily. In addition, a track (not shown) may be provided on the segment 14 and the lower plate 2 so that the widening shield machine does not leave the upper segment 14 of the tunnels 50 and 60.
The lower plate 2 does not need to be entirely plate-like in the case where the surrounding ground where excavation is high is independent, has little groundwater, and does not leak, and is a partial plate-like shape having a gap partially like a fence. It may be a thing.

A preceding tunnel 15 having a smaller diameter is installed in advance in the lower ground 40 between the existing tunnels 50 and 60 below the widening shield machine A of the widening tunnel shown in FIGS. The preceding tunnel 15 uses the conduit 17 to discharge the water from the ground 40 shown in FIG. 2 in order to confirm the effect of the ground improvement performed at the beginning or to drain the remaining water remaining as a result of the ground improvement. Guide with. It is also possible to install a carriage 18 that lays rails in the tunnel and discharges excavated soil (FIG. 3).
The preceding tunnel 15 may be constructed by a known shield method or propulsion method. If the ground is highly self-supporting, it is not necessary to provide a preceding tunnel.

  As shown in FIG. 2, the lower plate 2 at the front of the widening shield machine A is installed across the existing parallel tunnels 50 and 60, and on the lower side of the lower lower plate 2 as shown in FIG. The upper segment 14-1 in the segment 14 of the parallel tunnels 50, 60 is removed, the ground 16 is excavated, and then the connecting segment 13 having a larger diameter than the upper segment 14-1 is connected to the segment assembly device 22 by, for example, a well-known bolt, It is built as a tunnel widened between parallel tunnels by nuts and assembled.

In the parallel tunnels 50 and 60, vertical girders 23 are installed in advance on both sides of each tunnel, and horizontal girders 25 and 26 are provided vertically in the tunnel in the horizontal direction. These are reinforcing materials for maintaining the shape of the tunnel with the removal of the segment of the parallel tunnel when constructing the connection tunnel. A work floor slab 24 is attached to the upper part of the upper cross beam 26.
Two rails 28 are laid in the perpendicular direction (that is, in the tunnel axis direction) of the lower lateral girder 25 installed at intervals. A movable carriage 29 is installed on each rail 28. Further, in each parallel tunnel 50, 60, two rails 36 are laid in the tunnel axis direction on the work floor 24 parallel to the cross beam 25 at a distance from the lower cross beam 25. Two moving carriages 35 are placed in the tunnels 50 and 60. On the movable carriage 35, the upper segment 14-1 is removed and the ground 40 between the parallel segments 50 and 60 is excavated, and then the rail girder 27 (girder provided with rails) is formed between the parallel tunnels 50 and 60. To install. The movable carriage 35 is provided with a segment assembling apparatus 22 that can move on the rail beam 27. The existing segment assembling apparatus 22 grips the connecting segment 13 and lifts it to a predetermined assembling position so that the connecting segment 13 can be assembled between parallel tunnels.

  The excavated earth and sand excavated in the ground 40 between the parallel tunnels 50 and 60 is conveyed to the rear of the tunnel by a steel wheel 29 traveling on the rail 28 on the cross beam 25.

In addition, as shown in FIGS. 6A and 6B, the connecting segment 13 and the ground are provided by the backfill injection pipe 30 installed in the tunnel axial direction between the upper plate 1 and the lower plate 2 in the rear portion of the widening shield machine A. Concrete backing material 31 is injected into the gap between 16.
When injecting the backing material, a tail seal (31-1) is provided to prevent leakage between the connecting segment 13 and the inner plate (2-1) of the shield tail portion into the shield machine. Reference numeral 31-2 denotes a tail plate of the tail portion, which is provided when the gap height is large.

  FIG. 7 shows a widening between the tunnels 50 and 60 using the widening shield machine A of the present invention. After applying the ground improvement material 32 to the lower part between the tunnels 50 and 60, the segment 14-2 is removed and the excavation area of the outer peripheral part of the tunnels 50 and 60 is excavated by the existing means. Then, cast-in-place concrete 33 is placed to build a tunnel fixing part.

[Example 2]
FIG. 8 is a cross-sectional view of a widening tunnel A ′ using a rear mechanism (an embodiment different from FIG. 3) of the segment assembly 39 different from the widening shield machine A of the first embodiment.
The rear part of the widening shield machine A ′ according to the present invention is laid with a rail 36 concentrically formed with the upper plate 1 and a rail 37 concentrically formed with a small diameter at regular intervals, and a segment assembling apparatus therebetween. 39, the connecting segment 13 is connected and assembled by the segment assembling device 22 'movable along the rail 36 and the rail 37 in the space 38.

Example 3
9 to 12 show another front mechanism of the widening shield machine B in which a drilling device is added to the front mechanism of the first embodiment. The rotary excavator disposed in the widening shield machine B here excavates a relatively hard ground, or a face of the ground 34 having a lot of groundwater there.

FIG. 9 shows the front surface in the tunnel axial direction to be excavated at the center of the front part of the partition wall 8 between the upper plate 1 and the lower plate 2 of the widening shield machine B to which the later-described front mechanism is added to the widening shield machine A of the first embodiment. A rotating shaft 41 for rotating a cutter head 43 provided with a large number of cutter blades 42 is rotated by a motor 44 as a drive unit. A plurality of screw excavators 46 are arranged on both sides of the cutter head 43. The screw excavator 46 is rotated by a drive motor 45 and excavates the ground with a screw excavation bit 48. Then, the excavation gap is moved to the center of the shield cross section by the rotation of the screw blade 47 of the screw excavator 46. FIG. 10 shows that four adjacent screw drilling devices 46 are overlapped and arranged side by side when viewed from the top (FIG. 10), and when viewed from the front, three screw drilling devices are stacked on each side. (Fig. 9).
Since the screw excavator 46 is partially overlapped and installed, excavation is possible while moving the excavation gap from both ends to the center by the screw device 46.

FIG. 11 is a longitudinal sectional view (corresponding to FIG. 5 of the first embodiment) in a state where the ground 40 is excavated using the widening shield machine B of FIGS. 9 and 10. The screw conveyor 49 is an alternative to the belt conveyor 6 of the above embodiment, and the excavation gap is taken into the work chamber 12 from the screw conveyor 49 attached to the partition wall 8 that partitions the excavation portion and the work chamber. In this example, the excavation gap excavated by the screw excavator 46 and the cutter head 43 is converted into mud with plastic fluidity by the injection and agitation of the additive. The lower excavation part 16 does not enter between the shield lower plate 2 and the shield lower plate 2. In particular, as shown in FIG. 9, the screw excavator 46 having an arc shape on both sides of a normal cutter head 43 is partially pivoted to the support base 48 by overlapping three units from the bottom to the side (four units in FIG. 10). They are installed and excavated.
FIG. 12 is a cross-sectional view of the screw excavator 46, and a number of bits 48 are arranged on the outer edge of the screw excavator 46. In this way, the face can be excavated by the rotation of the screw and the advance of the widening shield machine. And the screw conveyor 49 for earth removal is arrange | positioned in the center lower part of the widening shield machine in parallel with the tunnel axial direction. Due to the rotation of the rotary motor 49-1, the excavated excavation is sent to the rear of the widening shield machine B and falls to the lower excavation part 16 formed below the earth discharge port 49-2 provided in the lower plate 2. (FIG. 11).
The subsequent steps are the same as in the first embodiment.

  In FIG. 13, the larger diameter of the parallel tunnels is the main tunnel 300 in the road tunnel, and the smaller diameter is the ramp tunnel 400, and the widening shield machine B that widens the upper part of each tunnel has its lower plate 200. Are placed along the top of each tunnel. In the widening shield machine B, the six partition frames 301 and the side plates 201 at both ends are arranged between the lower plate 2 and the upper plate 1. Others are the same as the first embodiment.

The tunnel widening method using the widening shield machine of Examples 1 to 3 will be described below.
First, as shown in FIG. 5, by using the conventional technique, the upper part 14-1 of the parallel tunnels 50 and 60 at the end of the widening section is removed and the ground is excavated by hand digging or excavating heavy equipment. Then, the start base 70 is constructed by constructing the start base 70 of the tunnel widening portion, the reaction force wall 71, the peripheral wall 71-1, and the wellhead concrete 72. Next, in the same way as the underground launch of the widening shield method, a launching stand is installed in the launch base 70, and the parts of the widening shields A, A ', B are sequentially transported from the ground into the parallel shield and assembled on the launching stand. To produce a connecting shield (not shown). Assemble one or more connecting segments behind the widening shield machine and assemble a thrust transmission frame behind it and the reaction wall. Next, the concrete at the entrance is sharpened, the ground is exposed, and the widening shield machine is dug.

  The widening shield machine is propelled by extending the shield jack 9 while excavating the natural ground 34. At the same time, the natural ground 40 below the widening shield machine is excavated, the shield excavation earth and sand are discharged to form the lower excavation part 16, and a work space for carrying in and assembling each segment is secured.

  At this time, the front part of the widening shield machine A, A ′, B is in the ground 34 (FIG. 2), but the lower part of the rear part is excavated separately as described above, and the parallel tunnel 50 60, 100, 200, or 300 and 400, the upper segment 14-1 is removed, and the connecting segment 13 is assembled.

After removing the upper segment 14-1, the extended shield jack 9 is contracted, and as shown in FIGS. 3 and 8, one end of the connecting segment 13 for widening the tunnel is removed by removing the segment 14-1. The remaining segment 14 is joined to one end of the remaining segment 14, and the connecting segment 13 is assembled between the parallel tunnels along the upper plate 1. Specifically, the segment assembling apparatus 22 is moved by a moving carriage 35 that travels on the rail 26 in the tunnel axial direction on the work floor 24, with each connecting segment 13 conveyed by the segment carriage on the rail 28 from the rear of each parallel tunnel. , 22 ′, the connecting segment 13 is lifted by the segment assembling devices 22, 22 ′, and the connecting segment 13 is assembled in an arc shape.
In this embodiment, the rotary excavators for excavating the face are both of the conventional earth pressure type by separating the rear part of the shield by the face part and the bulkheads 8, 8 ′ by keeping the rotary motor part sealed. Can be used as a widening shield machine (including mud pressure). According to this, since the stability of the face is improved, the ground improvement section can be further reduced, which can contribute to shortening the construction period and reducing the construction cost.

  Widening shield machine excavation → Lower ground excavation → Parallel tunnel upper segment removal → Link segment assembly → Widening shield excavation and completion of the sequential process in the required connected tunnel section, the upper part of the widening tunnel is completed, but after that both tunnels below 7 and removing the upper segment 14-1 on the opposite side of the parallel tunnels 50 and 60, 100 and 200, or 300 and 400 as shown in FIG. And cast the cast-in-place concrete 33 to build the tunnel lower fixed part.

  The present invention can be applied to widening work such as a railway upper and lower line tunnel in addition to a road main line tunnel and a ramp tunnel.

DESCRIPTION OF SYMBOLS 1 Upper plate of widening shield machine 2 Lower board of widening shield machine 3 Partition frame 8 of widening shield machine Front partition 9, 45 Telescopic jack 11 Rear bulkhead 13 Connection segment 14 Remaining segment 14 'of parallel tunnel Upper segment 34 of parallel tunnel , 40 Ground 21 Side plate 43 of widening shield machine Cutter head 46 Screw excavator 50, 60, 100, 200, 300, 400 ... Parallel tunnel

Claims (5)

In the method of widening the tunnel area by excavating between parallel tunnels,
Digging a widening shield machine installed between the upper parts of the parallel tunnel along the axial direction of the parallel tunnel;
Removing the upper segment of the parallel tunnel located under the widening shield machine;
Assembling connecting segments between the remaining segments of each parallel tunnel left after the removal;
A method for constructing a widening tunnel, comprising the step of excavating a natural ground below the excavation as well as excavating the widening shield machine.   Prior to the excavation of the lower part of the excavation of the widening shield machine between the parallel tunnels, by adding a step of setting a preceding tunnel below the excavation of the underground water and excavation machine from the natural ground before the widening The construction method of the widening tunnel of Claim 1 which conveyed the excavated soil produced behind a parallel tunnel.   A method for constructing a widening tunnel, wherein a step of widening the lower part of the parallel tunnel is added before or after the step of constructing the upper part of the widening tunnel according to claim 1 or 2. A widening shield machine that digs between the upper parts of parallel tunnels,
Formed in the front part of the widening shield machine is a substantially arcuate cross-section including a substantially arc-shaped upper plate and a lower plate having a shape along the upper part of the parallel tunnel, and the rear part is an inner side of the upper plate. A widening shield machine comprising a plurality of jacks and propelling the widening shield machine.   The excavation section includes a cutter head having a rotational axis at a lower center position of a substantially arc-shaped upper plate in a tunnel axial direction, and a plurality of screw excavators extended by being partially overlapped on both sides thereof. 4. The widening shield machine according to 4.

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