JP3787807B2 - Tunnel construction method using shield excavator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tunnel construction method using a shield excavator capable of excavating both a standard mine and a widening mine.
[0002]
[Prior art]
The shield method is considered to be a typical method for tunnel excavation, especially road and rail tunnel excavation in urban areas, and more and more long-distance excavation and deepening are required.
In the case of a railway tunnel, that is, a subway, a station portion must generally be provided every 500 to 1000 m, and in the case of a road tunnel, an emergency parking zone must be provided approximately every 500 m. That is, it is necessary to widen the tunnel at regular intervals. Further, in the case of the shield method, it is necessary to sequentially discharge the earth and sand from the excavation to the outside of the mine and to carry a segment for sequentially covering the excavated mine into the mine. For this reason, when constructing a small-diameter tunnel, it may interfere with the exchange of transportation means that frequently reciprocates inside and outside of the mine, or the installation of relay equipment for mine ventilation. In some cases, it was preferable to provide a widened portion inside.
Conventionally, after constructing a shield tunnel with a predetermined cross section, the widened part is built in the tunnel by removing the segment partially and excavating and lining the widening pit, or using a shield excavator dedicated to the widening pit. It was.
[0003]
[Problems to be solved by the invention]
As described above, in the method of excavating and lining a widening pit by removing a segment after building a shield tunnel, the ground conditions that can be constructed are limited. In other words, since a hollow is temporarily generated, the ground cannot be self-supported if it is a soft ground, and it is very difficult to perform soil retaining or water stopping. In addition, when using a shield excavator dedicated to a widening pit, it involves work such as disassembling, transporting, and assembling the shield excavator, which requires a great deal of labor and cost, and causes an increase in the construction period.
[0004]
This invention is made | formed in view of the said situation, and it aims at providing the tunnel construction method which can respond to various ground conditions and can perform tunnel construction more economically and in a short period of time.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is a shield excavator, wherein a cutter for advancing a standard pit and a widening pit having a predetermined cross-sectional area is provided in front of the shield main body, and the widening pit is provided in the shield main body. A widening member is provided to project at least a part of the skin plate toward the widening pit when digging, and the widening member is substantially flush with the skin plate when digging only the standard pit. And forming at least a part of the skin plate and projecting outward of the skin plate when the widening pit is dug, and a first widening plate that can be disposed substantially parallel to the skin plate, When digging the widening pit, the first widening plate is provided so as to be connected to both edges of the skin plate in the circumferential direction, and the both edges of the first widening plate and the slide are provided. A tunnel construction method for constructing a standard tunnel and a widening tunnel by using a shield excavator provided with a second and a third widening plate for connecting the first and second widening plates. In addition, the second and third widening plates are removed from the first widening plate, and a standard tunnel is constructed by sequentially lining a standard well segment inside the skin plate, When starting the process, a widening pit that is gradually widened in a wedge shape by the cutter is dug, and a divided segment having a gap in the portion where the second and third widening plates are located is placed inside the skin plate. after lining, it constitutes the widening member is attached to the second and third widening plates in the first widening plate through the gap portion, wherein the the enlarged width member By sequentially projecting in accordance with the shape of the wide pit and lining the widening pit of the wedge in divided segments corresponding to the shape of the widening pit of the wedge, when widening pit is widened to a maximum width, the skin plate and the wider A widening tunnel is constructed by lining the widening pit segment inside the member.
[0008]
As described above, in the shield excavator used in the present invention, both the standard pit and the widening pit can be excavated by one shield excavator, and the widening member is configured by three widening plates. Therefore, the widening member can be made a strong structure. Further, since the widening member has a simple configuration, it can be easily projected toward the widening pit in a short time, and therefore the earth retaining or water stoppage of the widening pit can be sufficiently performed. Moreover, in such a tunnel construction method using a shield excavator, since the widening pit is dug using the divided segments and gradually widening in a wedge shape, the soil and sand are sequentially taken into the shield excavator from the widening pit. While doing so, it is possible to build widening tunnels from standard tunnels with few cavities.
[0009]
The invention according to claim 2 is the tunnel construction method according to claim 1 , wherein at the time of lining the widening pit segment or the divided segment, a part of the widening pit segment or the divided segment is formed. In addition to projecting inward to a position pressed by the pressing jack in the shield body, a spacer that is removed from the widening pit segment or the divided segment after the pressing jack is separated to a predetermined position is used. .
[0010]
Thus, since the spacer is used for the widening pit segment or the segment, the widening pit can be dug while the position of the pressing jack in the shield excavator is fixed at one place.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a tunnel construction method according to the present invention will be described with reference to FIGS.
First, the shield excavator used for the tunnel construction method will be described.
As shown in FIG. 1, the shield excavator 1 includes a cutter 2 for excavating a standard mine, a copy cutter 2a as an overcutter that can be projected and retracted from the cutter 2 and excavates a widening pit, and a substantially cylindrical shape. A shield body 3 having a skin plate 4, a pressing jack 5 provided inside the skin plate 4, and a widening member 6 provided on the shield body 3 are provided.
[0012]
The cutter 2 has a substantially disk shape, and is rotatably supported by a cutter support portion 3 a of the shield body 3 as shown in FIG. 5 and provided at the front end of the shield body 3. The cutter 2 is configured so that earth and sand can be taken into the shield excavator 1 while excavating the standard mine by a cutter bit and a hole (not shown) provided at the tip. In the following, the “standard mine” refers to a mine that is dug only by the cutter 2 and has a cross-sectional area substantially the same as the outer diameter of the cutter 2.
The cutter 2 incorporates a copy cutter 2a that can be projected and retracted in a direction in which the standard mine is widened from the outer side, that is, in a direction substantially orthogonal to the excavation direction. The copy cutter 2a has a rod shape and is immersed in the cutter 2 when excavating the standard mine. When the copy cutter 2a protrudes from the cutter 2, it rotates around the axis in the protruding direction and is provided on the outer peripheral surface thereof. The widening pit can be advanced by a number of cutter bits (not shown). Further, in order to take in the earth and sand that has been dug by the copy cutter 2 a into the shield excavator 1, a take-in hole 2 b is provided in the vicinity of the copy cutter 2 a in the outer peripheral portion of the cutter 2.
In the following description, the “widening pit” refers to a pit that cannot be excavated by the cutter 2, that is, a portion of the pit that has been excavated using the copy cutter 2a.
[0013]
The shield body 3 includes a cutter support portion 3a that supports the cutter 2, and a cylindrical skin plate 4 that is connected to the rear of the cutter support portion 3a in a substantially cylindrical shape.
The skin plate 4 is connected in a substantially cylindrical shape behind the cutter support portion 3a, and the cutter 2 and the skin plate 4 have substantially the same outer shape and cross-sectional area. Inside the skin plate 4, segments are lined sequentially. The segment refers to a widening shaft segment integrated with a standard well segment, a segment segment, and a spacer, which will be described later.
A pressure jack 5 is provided inside the skin plate 4 in the shield body 3. The pressing jack 5 presses the segments that are sequentially lined on the inner side of the skin plate 4 and advances the shield excavator 1 by the reaction force.
[0014]
The widening member 6 includes a side plate (first widening plate) 6a, and an upper plate (second widening plate) 6b provided to be connected to the upper edge and the lower edge of the side plate 6a. It is comprised from the lower plate (3rd widening plate) 6c.
The side plate 6a is substantially flush with the skin plate 4 to form a part of the skin plate 4 when excavating only the standard pit, and the side plate 6a is external to the skin plate 4 when excavating the widening pit. It protrudes in the direction and is arranged substantially parallel to the skin plate 4.
The upper plate 6b and the lower plate 6c are provided so as to be connected to the upper and lower edges of the side plate 6a protruding from the skin plate 4 when the widening pit is dug, respectively. The edge and lower edge and the skin plate 4 are connected.
The upper plate 6b and the lower plate 6c are removed from the side plate 6a when the shield excavator 1 excavates only the standard mine. That is, the widening member 6 is assembled only when the widening pit is dug.
[0015]
Next, a tunnel construction method using this shield excavator 1 will be described.
When the standard mine is advanced, the upper plate 6b and the lower plate 6c are removed from the side plate 6a, and the skin plate 4 and the side plate 6a integrally formed with the skin plate 4 are omitted in cross section. Keep it cylindrical. Thus, as the standard mine is dug, the short cylindrical standard mine segment 10 can be sequentially covered so as to cover the entire inner surface of the skin plate 4. The pressing jack 5 sequentially presses the standard mine segment 10 covered in the foremost part in the excavation direction, and the shield excavator 1 is excavated by pressing the shield excavator 1 in the excavation direction by the reaction force. . That is, as the shield excavator 1 advances, the standard mine behind it is sequentially covered with the standard mine segment 10, and a standard tunnel is built.
[0016]
When starting excavation of the widening pit, the copy cutter 2a is gradually protruded from the cutter 2, and the widening pit is also excavated while excavating the standard pit. That is, as shown in FIG. 5 and FIG. 8, the widening pit is dug so as to be gradually widened in a wedge shape. At the same time, preparation for assembling the widening member 6 is performed. That is, the divided segment 11 is lined in place of the standard mine segment 10 so that the widening member 6 can be assembled and widened.
As shown in FIG. 10, the divided segment 11 is divided at a portion where the upper plate 6 b and the lower plate 6 c are located when the widening member 6 is assembled. That is, by forming the gap S thicker than the thickness of the upper plate 6b and the lower plate 6c at these division positions, the division segment 11 does not hinder the assembly and widening operation of the widening member 6. At the time of covering the divided segment 11, the gap spacer 11a is inserted into the gap S, and the entire inner surface of the skin plate 4 is covered with the divided segment 11 and the gap spacer 11a.
In this state, the standard mine and the widening pit are continued for a while.
[0017]
When the widening pit is dug about several meters, the widening member 6 is assembled and the widening pit is retained. At this time, as shown in FIG. 11, the segment segment 11 is reinforced from the inside with a segment reinforcing material 11 b, and the gap spacer 11 a is removed. Then, as shown in FIG. 12, the widening member 6 is assembled by attaching the upper plate 6b to the upper edge of the side plate and the lower plate 6c to the lower edge of the side plate 6a through these gaps S. When the assembly is completed, as shown in FIG. 2, the widening member 6 is first protruded forward in the digging direction, and the widening pit is retained. With the widening of the widening pit, as shown in FIG. 3, the rear side of the widening member 6 is also projected, and the earth retaining of the wedge-shaped widening pit is sequentially performed.
In addition, the segment 11 which covers a wedge-shaped widening pit also uses the thing of the shape corresponding to this shape one by one. In the example of FIG. 8, the divided segments 11 are indicated by reference numerals 11 </ b> A to 11 </ b> D due to the difference in shape, but are gradually widened from 11 </ b> A to 11 </ b> D. These divided segments 11 </ b> A to 11 </ b> D are reinforced from the inside with a segment reinforcing material 11 b when the widening member 6 passes, and gap portions S are formed after passing through the widening member 6. -Fix and make it possible for the divided segments 11A to 11D to be self-supporting even if the segment reinforcement member 11b is removed.
[0018]
When the widening pit is widened to the maximum width, as shown in FIG. 4, the upper plate 6b and the lower plate 6c are connected and fixed to the skin plate 4 with the front side and the rear side of the widening member 6 protruding as much as possible. To do. From here to until the widening pit is reduced, the widening pit is dug in this state. That is, since the widening member 6 does not operate during this period, the widening pit segment 12 shown in FIG. 13 is used in place of the divided segment 11, and the widening pit is covered as shown in FIG. I will go.
A spacer 13 is fixed inside the widening pit segment 12 or the divided segment 11 by a fixing means such as a bolt so as to form a part of the widening pit segment 12 at the time of lining. The spacer 13 is used to dig up the shield excavator 1 with the reaction force when pressed by the pressing jack 5, and protrudes inward to a position pressed by the pressing jack 5. This spacer 13 will be removed later.
In addition, the spacer 13 fixed to the division | segmentation segment 11 (11A-11D) becomes a shape corresponding to each division | segmentation segment 11A-11D, The code | symbol is shown in FIG. 8 as 13A-13D.
[0019]
When returning to the standard digging after the completion of the widening pit excavation, the copy cutter 2a is gradually immersed in the cutter 2, and the widening pit is excavated so as to be sequentially reduced to a wedge shape. Since the widening member 6 performs the earth retaining of the widening pit while performing the reduction operation from here, the fixing of the upper plate 6b and the lower plate 6c and the skin plate 4 is released, and the widening pit segment 12 as shown in FIG. Instead, the divided segments 11D to 11A are sequentially lined. That is, the procedure is the reverse of the above-described start of the widening pit, and the widening member 6 is gradually embedded into the skin plate 4 from the front side as shown in FIG.
[0020]
When the excavation of the widening pit is completed, as shown in FIG. 1, the widening member 6 is accommodated in the skin plate 4, and the side plate 6 a is substantially flush with the skin plate 4. From here, the upper plate 6b and the lower plate 6c are removed from the side plate 6a in order to return to the standard mine. Then, the standard mine is lined again using the standard mine segment 10 to construct a standard tunnel.
[0021]
When the excavation progresses so far, the shield excavator 1 does not need to take a reaction force by the spacer 13, so the spacer 13 is removed from the widening pit segment 12. That is, after the pressing jack 6 is separated from the spacer 13 to a predetermined position, the spacer 13 can be removed.
After the spacer 13 is removed, as shown in FIG. 9, the widening tunnel covered with the widening pit segment 12 is constructed.
[0022]
In the shield excavator 1 according to the present embodiment, the widening member 6 is configured by three plates, that is, the side plate 6a, the upper plate 6b, and the lower plate 6c. And can be easily projected toward the widening pit in a short time. Therefore, the earth retaining or water stoppage of the widening pit can be sufficiently performed, and the reliability and durability of the shield excavator 1 can be increased.
[0023]
Moreover, in the tunnel construction method according to the present embodiment, by using the divided segment 11, the widening pit is advanced while being gradually widened in a wedge shape from the standard pit, and the standard is being sequentially reduced from the widening pit to a wedge shape. It can be returned to the mine. Therefore, it is possible to build the widening tunnel from the standard tunnel while sequentially taking in the earth and sand from the widening pit into the shield excavator 1 and generating almost no cavity. As a result, it is possible to cope with various ground conditions, to ensure the reliability after tunnel construction, and to eliminate the need for special equipment and materials for excavation of widening pits, economically and in a short period of time. Can be built.
[0024]
Furthermore, since the spacer 13 fixed inside the widening pit segment 12 or the divided segment 11 is used to be pressed by the pressing jack 5, the position of the pressing jack 5 in the shield excavator 1 is one place. It is possible to dig up both the standard mine and the widening mine while being fixed in place. For this reason, it is not necessary to move the pressing jack 5 when the widening pit is excavated, the structure of the shield excavator 1 can be simplified, its reliability and durability can be improved, and tunnel construction is more economical. Can be done.
[0025]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a tunnel construction method that can cope with various ground conditions and can perform tunnel construction more economically and in a short period of time.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an embodiment of a shield excavator used in a tunnel construction method according to the present invention.
2 is a schematic perspective view showing a state in which a widening member protrudes in the shield excavator of FIG. 1. FIG.
3 is a schematic perspective view showing a state in which the widening member further protrudes in the shield excavator shown in FIG. 2; FIG.
4 is a schematic perspective view showing a state in which the widening member further protrudes in the shield excavator of FIG. 3; FIG.
FIG. 5 is a diagram showing an embodiment of a tunnel construction method according to the present invention, and is a side sectional view when a shield excavator starts excavation of a widening pit.
FIG. 6 is a sectional side view when the shield excavator is excavating a widening pit.
FIG. 7 is a side cross-sectional view when the shield excavator finishes the widening pit.
FIG. 8 is a cross-sectional view showing the entire widening tunnel.
FIG. 9 is a cross-sectional view showing a state where a spacer is removed from the widening tunnel.
FIG. 10 is a sectional view showing an example of divided segments used in the tunnel construction method according to the present invention.
FIG. 11 is a cross-sectional view showing the same segment.
FIG. 12 is a cross-sectional view showing the positional relationship between the divided segments and the upper and lower plates.
FIG. 13 is a cross-sectional view showing a widening pit segment and a spacer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shield excavator 2 Cutter 2a Copy cutter 3 Shield main body 3a Cutter support part 4 Skin plate 5 Pressing jack 6 Widening member 6a Side plate (1st widening plate)
6b Upper plate (second widening plate)
6c Lower plate (third widening plate)
10 Standard well segment (segment)
11 Divided segments (segments)
12 Segment for widening pit (segment)
13 Spacer S Gap

Claims (2)

In front of the shield body, a cutter for digging a standard pit and a widening pit with a predetermined cross-sectional area is provided,
The shield body includes a widening member that projects at least a part of the skin plate toward the widening pit when the widening pit is dug.
In the widening member,
When digging only the standard pit, it is substantially flush with the skin plate to form at least a part of the skin plate, and when digging the widening pit, it projects outwardly from the skin plate. A first widening plate that can be arranged substantially parallel to the skin plate;
When digging the widening pit, the first widening plate is provided so as to continue to both edges of the skin plate in the circumferential direction, and the both edges of the first widening plate and the skin plate The second and third widening plates connecting the two;
A tunnel construction method for constructing a standard tunnel and a widening tunnel using a shield excavator provided with
When excavating only the standard mine, the second and third widening plates are removed from the first widening plate, and the standard tunnel is covered by sequentially lining the standard mine segment inside the skin plate. Built,
When starting the excavation of the wider pit, while boring the widening pit to be widened gradually wedge with the cutter, the divided segments with a gap at a portion where the second and third widening plates are located After lining the inside of the skin plate, the second and third widening plates are attached to the first widening plate through the gap to form the widening member, and the widening member is matched to the shape of the widening pit. The wedge-shaped widening pit is covered with divided segments corresponding to the shape of the wedge-shaped widening pit, and when the widening pit is widened to the maximum width, the widening pit is placed inside the skin plate and the widening member. A tunnel construction method characterized in that a widening tunnel is constructed by lining a segment for use.    At the time of lining the widening pit segment or the divided segment, a part of the widening pit segment or the divided segment is formed to extend inward to a position pressed by the pressing jack in the shield body, and the pressing jack is predetermined. The method for constructing a tunnel according to claim 1, wherein a spacer removed from the widening pit segment or the divided segment after being separated to a position is used.

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