JP3974251B2 - Tunnel construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tunnel construction method in which the cross section of a large section tunnel obtained by a so-called MMST method is narrowed down.
[0002]
[Prior art]
The tunnel method called MMST (Multi Micro Shield Tunnel) method is to form a plurality of small cross-section tunnels with a rectangular cross section at a predetermined interval, and then connect these small cross-section tunnels to obtain a large cross-section tunnel. Tunnel construction method. In this method, each small section tunnel is constructed with a shield tunneling machine with a small section, so the amount of soil generated by excavation can be greatly reduced, and the scale of temporary equipment and shafts can be reduced, especially in urban areas and urban areas. It is optimal as a tunnel construction method when constructing a tunnel.
[0003]
In the MMST method, first, a shaft is constructed at a predetermined interval, and then, as shown in FIG. A plurality of rings are constructed at predetermined intervals. As shown in FIG. 6, the small-section tunnel 1 includes an outer shell 3 formed in a rectangular shape by combining a plurality of steel plates 2, and a plurality of middle girders 4 arranged at predetermined intervals inside the outer shell 3. It is designed to maintain a hollow inside.
[0004]
Next, as shown in FIGS. 5 (b) and 5 (c), adjacent small-section tunnels 1, 1 are connected by removing some steel plates 2, and concrete is cast into these tunnels 1. A rectangular concrete outer shell housing 5 that constitutes the outer shell of the large-section tunnel 13 is constructed. After that, as shown in FIGS. 5 (d) and 5 (e), the earth and sand in the outer shell 5 is excavated and discharged using a normal excavating machine, and an inner wall 7, an inner floor 8 and a partition wall 9 are contained therein. An internal structure such as the above is constructed, and the large-section tunnel 13 is completed.
[0005]
[Problems to be solved by the invention]
By the way, in order to connect between the adjacent small-section tunnels 1 and 1 as described above, for example, as shown in FIG. It is necessary to slide the sheet piles 11 and 11 from one of the tunnels 1 using a press-fitting machine 10 and to hang them between the shoulders of the tunnels 1 and 1 to perform earth retaining of the isolation portion R. Then, as shown in FIG. 7 (b), the adjacent vertical steel plates 2a and 2a of the tunnels 1 and 1 are removed to remove the earth and sand from the isolation portion R, and the reinforcing bars 12 are arranged there as shown in FIG. 7 (c). The concrete is then cast to form the outer shell 5 of the large section tunnel 13.
[0006]
However, in such a construction method, each of the small-section tunnels 1 and 1 is connected to each other by improvement of a natural ground by injection of a chemical and a soil retaining by passing a sheet pile 11, so that a large-section tunnel 13 is constructed as shown in FIG. In order to narrow down the cross section of the finally obtained large cross section tunnel 13, the small cross section tunnel 1 a is skewed, and the oblique tunnel 1 a and two adjacent tunnels 1 b are connected (the tunnel 19 in FIG. 1 is The following problems occur.
[0007]
That is, since the interval between the tunnels 1a and 1b to be connected widens, it is necessary to increase the construction scale of the ground improvement range by chemical injection or the like in order to prevent the ground from collapsing when the isolation portion R shown in FIG. 7 is excavated. As a result, the construction period will be prolonged and construction costs will rise. Moreover, the ground improvement work to be constructed from the tunnels 1a and 1b in which the work space is constrained is poor in work efficiency and requires high construction costs and a long construction period.
[0008]
The purpose of the present invention, which was created in consideration of the above circumstances, is to construct a construction period, cost and safety for retaining soil when connecting adjacent tunnels when constructing a large section tunnel with a narrowed section using the MMST method. It is to provide a tunnel construction method that can improve the performance.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a tunnel construction method according to the present invention includes a plurality of small cross-sectional tunnels arranged in a circular ground at predetermined intervals between the side portions of each small cross-sectional tunnel, and each of these small cross-section tunnels. Connect the sides of the cross-section tunnel to each other and cast concrete inside each small-section tunnel to form an annular outer shell housing, and remove the inner sand from the outer shell housing to remove the large-section tunnel. in tunnel construction method to obtain, any small section tunnel of a plurality of small cross-section tunnels, after a short predetermined distance than the other small section tunnel by the set machine bundling a plurality of tunneling machines, By starting a part of the excavator from the collective machine, a sub-tunnel having a smaller cross section than the small cross section tunnel is formed by connecting to the small cross section tunnel having the predetermined distance, and the small distance having the predetermined distance is formed. Cross-section ton Le and adjacent to the said sub-tunnel to form an oblique been skewed tunnel along their as one of the plurality of small cross-section tunnels, sides and the sub-sub-section tunnels the predetermined distance form By connecting the side of the tunnel and the side of the oblique tunnel, the cross section of the large-section tunnel is narrowed down.
[0010]
According to the present invention, the oblique tunnel is formed adjacent to the small-section tunnel and the sub- tunnel formed continuously therewith, so that the distance between the tunnels is narrowed and they are connected. The construction period, cost and safety of the earth retaining are improved. In addition, the small cross-section tunnel is formed by a collecting machine in which a plurality of excavators are bundled, and the sub- tunnel is formed by a part of the excavating machines started from the collecting machine. As a result, the economy is improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0012]
As shown in FIG. 1, first, the shafts 14a and 14b are formed at a predetermined interval. And the aggregation machine 15 as shown to Fig.3 (a) is started from one shaft 14a. The collective machine 15 is formed by bundling three independent shield machines 16, 17, and 18 in parallel, and constructs a small cross-sectional tunnel 1 having a rectangular cross section as shown in FIG. 5 (a). Then, when such an aggregator 15 arrives at the other shaft 14b, it is reversed and started toward the other shaft 14a, and a similar small cross section is provided at a predetermined interval along the already constructed small cross section tunnel 1. A tunnel 1b is constructed.
[0013]
And if it arrives at one shaft 14a, it will be reversed and started again toward the other shaft 14b, and the small cross-section tunnel 1c is similarly constructed for a predetermined distance. Thereafter, as shown in FIGS. 3B and 3C, only the central shield machine 17 is separated from the collecting machine 15 to start. Behind the shield machine 17, a tunnel 19 (subtunnel) having a substantially square cross section and a smaller cross section is constructed continuously from the small cross section tunnel 1c. On the other hand, the remaining right and left shield machines 16, 18 are buried as they are. In addition, although the shield digging machine 17 complete | finishes digging in the middle in FIG. 1, you may dig up to the vertical shaft 14b. However, in this case, it is necessary to widen the distance between the tunnels 1a and 1b in the shaft 14b as compared with the illustrated example.
[0014]
Thereafter, another collecting machine 15 shown in FIG. 3 (a) is started from the shaft 14a toward the shaft 14b. This collective machine 15 is bent along the small cross-section tunnel 1c and the small cross-section tunnel 19 from the middle and bent, and another small cross-section tunnel 1a (oblique tunnel) is placed behind the tunnel 1c. , 19 adjacent to each other. Then, the adjacent tunnels 1a, 1c, 19, 1b, and 1 shown in FIG. 1 are connected to FIGS. 5 (a), (b), (c), (d), (e) , FIG. 7 (a), ( As shown in b) and (c) , a large-section tunnel 13 is constructed in which the earth is retained and communicated by using the medicinal injection and the sheet pile 11 and the section is narrowed in the middle.
[0015]
In this way, the tunnels 1c and 19 are interposed between the tunnels 1a and 1b. These tunnels 1a, 1c and 19 serve as earth retaining auxiliary walls when connecting the tunnels 1a and 1b. Since the interval between 1b and 1 is narrowed, the construction period, cost and safety of the earth retaining when connecting them are improved in order to finally obtain a large section tunnel 13 whose section is narrowed in the middle. In other words, if there is no tunnel 19, the distance between the tunnels 1 a and 1 b is widened, so that it is impossible to deal with medicinal injection or earth retaining using the sheet pile 11.
[0016]
The small-section tunnels 1, 1a, 1b, and 1c are formed by a collecting machine 15 in which a plurality of excavators 16, 17, and 18 are bundled as shown in FIG. Since the (sub-tunnel) is formed by the central excavator 17 started from the collective machine 15, the excavator 17 is reused to improve the economy. Further, in the present embodiment, the collective machine 15 is reciprocally used between the shafts 14a and 14b to reduce the cost. However, if priority is given to shortening the construction period, the tunnels 1, 1a, 1b, and 1c are separately assembled. Drilling may be formed almost simultaneously with a machine.
[0017]
1 may be viewed as a plan view, but may be viewed as a side view. That is, in the former case, a large-section tunnel 13 with a narrowed cross section is obtained, and in the latter case, a large-section tunnel 13 with a narrowed side section is obtained. Further, the excavator arriving in the vertical shaft 14b from the bent tunnel 1a (oblique tunnel) in FIG. 1 is then used as an excavator for constructing any of the small-section tunnels 1 in FIG. 5 (a).
[0018]
FIG. 2 is a diagram showing another embodiment. In this embodiment, as shown in FIG. 4 (a), the central and right shield machines 16 and 17 are started integrally from the collecting machine 15 that excavates and forms the tunnel 1c, and approximately 2/3 in the rear thereof. A tunnel 20 (subtunnel) having a cross-sectional area of is connected to the tunnel 1c. Then, as shown in FIGS. 4B and 4C, only the right shield machine 16 is started from there, and a substantially square tunnel 21 (sub-tunnel) is connected to the tunnel 20 behind it. To do.
[0019]
After that, as shown in FIG. 2, another set 15 is started from the shaft 14a toward the shaft 14b. The collecting machine 15 is formed adjacent to each of the tunnels 1c, 20, and 21 by skewing another small section tunnel 1a (slant tunnel) along the tunnels. Then, adjacent tunnels 1a, 1c, 20, 21, 1b, and 1 shown in FIG. 2 are connected to FIGS. 5 (a), (b), (c), (d), (e) , and FIG. 7 (a). , (b), (c) As shown in Fig. 5, a large-section tunnel 13 having a cross-section squeezed on the way is constructed by retaining and communicating with a chemical injection and a sheet pile 11.
[0020]
By doing so, the tunnels 20 and 21 serving as earth retaining auxiliary walls are interposed between the tunnels 1a and 1b, and the distance between them becomes even smaller than that of FIG. That is, since the distance between the tunnels 1a, 1c, 20, 21, 1b is even smaller than that of FIG. 1, the earth retaining work when connecting them in order to construct a large-section tunnel with a narrowed section, Construction can be performed more easily, at a lower cost and more safely.
[0021]
【The invention's effect】
As described above, according to the tunnel construction method according to the present invention, when constructing a large-section tunnel with a narrowed section using the MMST construction method, the construction period and cost for retaining soil when connecting adjacent tunnels, Safety can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a tunnel construction method showing an embodiment of the present invention.
FIG. 2 is a schematic diagram of a tunnel construction method showing another embodiment.
FIG. 3 is a perspective view of a collective machine used in the tunnel construction method of FIG. 1;
4 is a perspective view of an aggregator used in the tunnel construction method of FIG. 2. FIG.
FIG. 5 is a process diagram of an MMST method.
FIG. 6 is an enlarged view of a small section tunnel.
FIG. 7 is an explanatory diagram showing a process of connecting small-section tunnels.
[Explanation of symbols]
1 Small section tunnel 1a Another small section tunnel (skew tunnel)
1b Small section tunnel 1c Small section tunnel
5 Outer shell 13 Large-section tunnel 15 Collecting machine 16 Digging machine 17 Digging machine 18 Digging machine 19 Smaller section tunnel (sub-tunnel)

Claims (1)

A plurality of small cross section tunnels are annularly arranged on the ground with a predetermined interval between the side portions of each small cross section tunnel, and the side portions of each small cross section tunnel are connected to each other and In a tunnel construction method in which concrete is cast inside to form an annular outer shell body, and the inner sand of the outer shell body is removed to obtain a large-section tunnel.
After forming an arbitrary small cross-section tunnel among a plurality of small cross- section tunnels at a predetermined distance shorter than other small cross-section tunnels by a collecting machine that bundles a plurality of excavators .
By starting a part of the excavator from the collective machine, a sub-tunnel having a smaller cross section than the small cross-section tunnel connected to the small cross-section tunnel formed at the predetermined distance is formed .
Forming a small-section tunnel formed at a predetermined distance and a slant tunnel adjacent to the sub-tunnel along the sub-tunnel as one of the plurality of small-section tunnels ;
By connecting the side of the small cross-section tunnel and the side of the sub-tunnel formed at the predetermined distance and the side of the oblique tunnel, the cross-section of the large-section tunnel is narrowed down. Tunnel construction method.

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