JP3988652B2 - Tunnel branch and junction structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a branching / merging portion structure of a tunnel, and more particularly to a branching / merging portion structure of a plurality of shield tunnels.
[0002]
[Prior art]
A subway or road tunnel is provided with a branching / merging portion as required. When a tunnel is constructed by the shield method, a plurality of tunnels are connected in the lateral direction when constructing such a branch / merging portion.
[0003]
Although the disclosure of patents or non-patent documents has not been confirmed, conventionally, when constructing a branching / merging portion in a shield tunnel, a structure as shown in FIGS. 4 to 5 has been used. The shield tunnel shown in the figure has first and second shield tunnels 1 and 2 having a circular cross section and the same diameter.
[0004]
The shield tunnels 1 and 2 are formed by excavating the shield machine 3 disposed on the tip side to form the excavation surface having the cross-sectional shape shown in FIG. 5, and are segmented along the excavation surface on the rear side of the shield machine 3. 4 is assembled.
[0005]
As shown in FIG. 5, the first and second shield tunnels 1 and 2 are formed by directly connecting the ends of the circular cross-sections in the lateral direction so as to overlap each other. The upper and lower connecting segment pieces 6 and 7 are arranged at the joint 5 between the segments 4 of the adjacent shield tunnels 1 and 2 by cutting.
[0006]
These connecting segment pieces 6 and 7 are joined to the segment 4 at both end faces, and are opposed to each other with a predetermined interval in the vertical direction. ing.
[0007]
In the tunnel having such a shape, in order to structurally stabilize the tunnel, the middle pillar 8 is arranged for each ring of the segment 4 as shown in FIG.
[0008]
In addition to the configuration in which the shield tunnels 1 and 2 are directly connected as described above, the structure for connecting a plurality of shield tunnels in the horizontal direction is, for example, as shown in FIG. There is also a structure in which the tunnels 1a and 2a are arranged adjacently in parallel so as to be adjacent to each other, and a coupling portion 5a is formed between the two to indirectly connect the shield tunnels 1a and 2a.
[0009]
Even in such a tunnel, the middle pillar 8a is provided between the upper and lower coupling portions 5a in order to ensure the stability of the shape.
[0010]
However, all the tunnels having the above-described structures have technical problems described below.
[0011]
[Problems to be solved by the invention]
That is, the former tunnel that directly connects the shield tunnels 1 and 2 shown in FIG. 5 and the latter tunnel that indirectly connects the shield tunnels 1a and 2a shown in FIG. It is often used, and it is also considered to be used for a crossover line of a subway or a branch / branch junction of a road tunnel.
[0012]
However, because these shield tunnels are provided with the middle pillars 8 and 8a so as to partition the inside of the tunnel, it is difficult to secure a wide space. When employed in the crossover section, there is a problem that the lanes of the vehicle and the subway cannot be changed between the shield tunnels by the middle pillars 8 and 8a.
[0013]
The present invention has been made in view of such conventional problems. The object of the present invention is to reduce the number of central pillars as much as possible, thereby ensuring a wide space and lanes. It is to provide a tunnel that can be changed and its construction method.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a tunnel branch / merging portion structure in which a plurality of shield tunnels are connected laterally in the ground, and a horizontal surface that surrounds the outer periphery of the branch / merging portion on substantially the same plane. Consists of a beam part, a pair of arch parts that are supported at both ends by the horizontal beam part, and curved at the upper side along the longitudinal direction of the branch / merge part, and the branch / merge part And a plurality of suspension members installed between the upper part of the shield tunnel and the arch part.
[0015]
According to the structure of the branching / merging part of the tunnel configured as described above, the branching / merging part is configured by including an arch part supported at both ends by a horizontal beam part that surrounds the outer periphery of the branching / merging part on substantially the same plane. Since there are multiple suspension members installed between the upper part of the shield tunnel and the arch part, the branching / merging part is suspended and supported by the arch part via the suspension member. By supporting the load of the part, the structure is stabilized, and the middle pillars need only be installed on both ends of the branching / merging part. In some cases, the middle column is not provided at the branching / merging portion.
[0016]
The shield tunnel that constitutes the branching / merging portion can be provided with a plurality of ground anchors that are driven into the ground from below.
[0017]
According to this configuration, the shield tunnel constituting the branching / merging portion is supported from the lower side by the ground anchor and can be balanced in the vertical direction, so that the structure is further stabilized.
[0018]
The horizontal beam portion and the arch portion can be constructed by a shield machine or a propulsion device that starts from a start shaft constructed from the shield tunnel.
[0019]
The arch portion can be filled with concrete in a shield tunnel constructed by the shield machine.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of a tunnel branching / merging portion structure according to the present invention.
[0021]
In the branching / merging portion structure shown in the figure, the small-diameter shield tunnel 10 and the large-diameter shield tunnel 12 having a circular cross-section with different diameters are adjacently constructed so as to be substantially parallel to each other, and the joint portion 14 straddling the both is formed. Thus, the shield tunnels 10 and 12 are indirectly connected to form a branching / merging portion 16.
[0022]
The shield tunnels 10 and 12 are arranged adjacent to each other so that the tunnel axes are parallel to each other at the branching / merging portion, and the shield tunnels 10 and 12 are connected to each other through a coupling portion 14. It is in the 2 state which mutually communicates.
[0023]
The shape of each shield tunnel 10, 12 is maintained by assembling a plurality of segments 10a, 12a obtained by dividing a cylindrical body in the circumferential and axial directions along a surface excavated by a shield machine. The coupling portion 14 includes an upper coupling segment 14a and a lower coupling segment 14b that are arranged in parallel in the vertical direction.
[0024]
The upper and lower coupling segments 14a and 14b of the coupling portion 14 are integrally fixed to portions where the segments 10a and 12a of the shield tunnels 10 and 12 are removed at both ends in the lateral direction. In addition, these joint segments 14a and 14b can be replaced with cast-in-place concrete.
[0025]
In addition, a horizontal beam portion 18 is provided on the outer periphery of the branching / merging portion 16 so as to surround it on a substantially same plane. The horizontal beam portion 18 of the present embodiment includes a pair of horizontal beam portions 18 a and 18 b extending in the transverse direction of the shield tunnels 10 and 12 and a pair of vertical beam portions extending in the longitudinal axis direction of the shield tunnels 10 and 12. It is composed of beam portions 18c and 18d and has a substantially rectangular shape.
[0026]
The horizontal and vertical beam portions 18a to 18d have a hollow cylindrical shape inside, and cube-shaped first to fourth shafts 18e to 18h are arranged at intersections thereof. In addition, in FIG. 1, the 4th shaft 18h is hidden behind, and is not shown on drawing. A pair of arch portions 20 are provided between the vertical shafts 18e and 18g and between the vertical shafts 18f and 18h provided at both ends of the vertical beams 18c and 18b.
[0027]
The arch portion 20 is hollow or solid inside, and both ends thereof are supported by shafts 18e to 18h, respectively, and extend in the longitudinal axis direction of the small-diameter and large-diameter shield tunnels 10 and 12. Each arch portion 20 is curved to the upper side so that the central portion thereof is close to the longitudinal axis of the small-diameter and large-diameter shield tunnels 10 and 12, and has a predetermined angle toward the shield tunnels 10 and 12 side. It is inclined at.
[0028]
A plurality of suspension members 22 are installed between the upper portions of the shield tunnels 10 and 12 constituting the branching / merging portion 16 and the arch portion 20. The suspension member 22 is made of, for example, a steel rod, and is disposed so as to be parallel to each other at a central portion excluding both end sides of the arch portion 20.
[0029]
As shown in detail in FIG. 2 and FIG. 3, each suspension member 22 penetrates the segments 10 a, 12 a of the shield tunnels 10, 12 and attaches a stopper 26 with a reinforcing member 24 interposed therebetween. Thus, the lower end side is fixed to the shield tunnels 10 and 12. In addition, the upper end side of each suspension member 22 is fixed to the inner surface of the arch portion 20 in the same state as the structure shown in FIGS.
[0030]
Furthermore, in the case of the present embodiment, the small-diameter and large-diameter shield tunnels 10 and 12 constituting the branching / merging portion 16 are provided with a plurality of ground anchors 28 placed in the ground from the lower part thereof. .
[0031]
In the case of the present embodiment, the ground anchor 28 is made of, for example, a steel rod having a predetermined length, and extends from the lower part of the small-diameter and large-diameter shield tunnels 10 and 12 so that a pair expands in a C shape on both sides. The plurality of ground anchors 28 are arranged in parallel along the longitudinal axis direction of the tunnel 12 at a predetermined interval, and one end of each ground anchor 28 is fixed in the ground.
[0032]
1 is a central pillar provided in the coupling portion 14 of the small-diameter and large-diameter shield tunnels 10 and 12, and in the case of this embodiment, the central pillar 30 It is arranged only on the end side of the merging portion 16 and is not provided in the central portion.
[0033]
This is because the suspension member 22 is arranged only at the central part of the arch part 20 and not at the end part side of the arch part 20, and is provided for reinforcement of this part, but the center of the branching / merging part 16 Since there is no middle pillar 30, lane changes such as vehicles and subways are possible.
[0034]
Next, the construction method of the branching / merging portion 16 having the above configuration will be described. When the branch / merging portion 16 having the structure shown in FIG. 1 is constructed, when the small-diameter and large-diameter shield tunnels 10 and 12 reach positions near the planned construction location of the junction, first, the shield tunnels 10 and 12 are formed. From the inside, a ground improvement area is formed in a portion sandwiched between both tunnels 10 and 12 by a freezing method or the like.
[0035]
This ground improvement area corresponds to the portion directly above and below the connecting portion 14 of the shield tunnels 10 and 12, and when the ground improvement area is formed, the segments 10a and 12a are removed and the shield tunnels 10 and 12 are removed. Are coupled to each other in the lateral direction. In addition, when forming such a ground improvement area, the reinforcement work for a deformation | transformation prevention is performed inside the small diameter and large diameter shield tunnels 10 and 12 in advance.
[0036]
Next, from the inside of the large-diameter shield tunnel 12, the lower part of the segment 12a is broken, and a start shaft 32 of the shield machine is formed below the segment 12a. In addition, the formation position of the start shaft 32 is not restricted to the place shown in the figure, and can be provided in arbitrary places. Next, a shield machine is started in the left-right direction from the inside of the start shaft 32 to form a horizontal beam portion 18 a of the horizontal beam portion 18.
[0037]
When the horizontal beam portion 18a is formed, the first and second shafts 18e and 18f are respectively constructed at the front end sides thereof, and shield shield machines are started from the constructed shafts 18a and 18b, respectively, and the vertical beam portion 18c. , 18d are constructed in a direction perpendicular to the transverse beam portion 18a. The horizontal beam portion 18 and the arch portion 20 can be formed not only by a shield machine but also by a propulsion method using a propulsion device.
[0038]
When the vertical beam portions 18c and 18d are constructed to a predetermined length, the third and fourth shafts 18g and 18h are constructed at the tips thereof. And if the horizontal beam part 18b is constructed | assembled by the shield machine between the shafts 18g and 18h, the horizontal beam part 18 will be completed.
[0039]
Next, the arch part 20 is constructed by the shield machine between the vertical shafts 18e and 18g and between the vertical shafts 18d and 18h. The material 22 is installed. When the installation of the suspension member 22 is finished, concrete may be placed in the arch portion 20 to make the hollow portion solid.
[0040]
When a plurality of grant anchors 28 are driven from the lower part of the small-diameter and large-diameter shield tunnels 10 and 12 into the ground, the branching / merging part 16 shown in FIG. 1 is constructed. In addition, what is necessary is just to construct | assemble the middle pillar 30 in the suitable time after forming the connection part 14. FIG.
[0041]
Now, according to the branching / merging part structure configured as described above, the arch part 20 is supported at both ends by the horizontal beam part 18 surrounding the outer periphery of the branching / merging part 16 on substantially the same plane. Since a plurality of suspension members 22 are installed between the upper portions of the shield tunnels 10 and 12 constituting the junction 16 and the arch portion 20, the branch / merging portion 16 is connected to the arch portion 20 via the suspension member 22. Since it is supported by suspension, the structure is stabilized by supporting the load of the branching / merging part 16 by the arch part 20, and the middle column 30 may be installed only at both ends of the branching / merging part. Depending on the case, the middle pillar 30 may not be provided at all.
[0042]
With such a structure, since it is not necessary to provide the middle pillar 30 in the central portion of the branching / merging portion 16, it is possible to reduce the number of middle pillars 30 as much as possible. A wide space is secured in the central portion, and as a result, lanes can be changed for branching or merging of vehicles and subways in the central portion.
[0043]
In the case of the present embodiment, the shield tunnel 12 constituting the branching / merging portion 16 is provided with a plurality of ground anchors 28 placed in the ground from the lower part thereof.
[0044]
For this reason, the shield tunnel 12 constituting the branching / merging portion 16 is supported by the ground anchor 28 from the lower side and can be balanced in the vertical direction in cooperation with the suspension member 22, thereby further stabilizing the structure. .
[0045]
In the above embodiment, the case where the present invention is applied to a double shield tunnel having a circular cross section is illustrated. However, the implementation of the present invention is not limited to this structure, and the double cross section having the same diameter is used. It can also be applied to tunnels with other cross-sectional shapes such as a structure, a triple structure with a circular cross-section, and a square shape.
[0046]
【The invention's effect】
As described above in detail, according to the tunnel branching / merging portion structure according to the present invention, it is possible to secure a wide space by changing the number of middle pillars as much as possible and to change lanes. Become.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing one embodiment of a tunnel branching / merging portion structure according to the present invention.
FIG. 2 is a cross-sectional explanatory view of a main part of FIG.
FIG. 3 is an explanatory side view of FIG. 2;
FIG. 4 is a cross-sectional view showing an example of a conventional tunnel.
FIG. 5 is an enlarged view taken along line AA in FIG.
FIG. 6 is a cross-sectional view showing another example of a conventional tunnel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Small diameter 1 shield tunnel 12 Large diameter shield tunnel 14 Joint part 14a Upper joint segment 14b Lower joint segment 16 Branching / merging part 18 Horizontal beam part 20 Arch part 22 Lifting material 24 Reinforcement material 28 Ground anchor

Claims (4)

In the tunnel junction / junction structure that connects multiple shield tunnels laterally in the ground,
A horizontal beam portion that surrounds the outer periphery of the branching / merging portion on substantially the same plane;
A pair of arch portions that are supported at both ends by the horizontal beam portion and are curved along the longitudinal direction of the branching / merging portion on the upper side thereof;
A tunnel branching / merging part structure comprising a plurality of suspension members installed between the upper part of the shield tunnel constituting the branching / merging part and the arch part. 2. The tunnel branching / merging part structure according to claim 1, wherein the shield tunnel constituting the branching / merging part is provided with a plurality of ground anchors placed in the ground from below. 2. The tunnel branch according to claim 1, wherein the horizontal beam portion and the arch portion are constructed by constructing a start shaft from the shield tunnel, and by a shield machine or a propulsion device started from the start shaft.・ Confluence structure. 3. The tunnel branching / merging portion structure according to claim 2, wherein the arch portion is filled with concrete in a shield tunnel constructed by the shield machine.

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