JP3809631B2 - Submarine tunnel connection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a submarine tunnel connection method constructed on the seabed between land areas across the sea.
[0002]
[Prior art]
Generally, submarine tunnels that connect airports and other man-made islands to the mainland, shield tunnels that are constructed by assembling lining with segments at the rear and sequentially extending the tunnel each time a shield tunneling machine is drilled, docks, etc. Submerged tunnels constructed by submerging and sequentially connecting cylindrical submerged boxes constructed in the production yard are mainly used.
[0003]
[Problems to be solved by the invention]
The above-described shield tunnel is hardly restricted by the situation on the bottom surface of the water, but depends on the soil quality at the excavation position, and requires a large earth covering, that is, a ground thickness from the tunnel lining top surface to the ground surface. This covering usually requires the same thickness as the tunnel diameter, and when using an auxiliary method such as ground improvement, it needs to be 1/2 the tunnel diameter.
[0004]
For this reason, when constructing a submarine tunnel by the shield method, it is necessary to maintain a certain depth below the bottom of the water, so it is necessary to dig under the bottom of the water to reach the land, and the tunnel length to the land becomes longer. .
[0005]
On the other hand, submerged tunnels require marine work such as dredging and subsidence, so there are restrictions due to marine conditions, but they are highly adaptable to soil quality and require less soil covering than shield tunnels. Because it can be installed on the top, it can be installed along the sea floor to reach the land.
[0006]
For this reason, the buried tunnel can be made shorter than the shield tunnel.
[0007]
In general, if the number of lanes is small, shield tunnels often require less construction cost per m than submerged tunnels. However, since the shield tunnel is extended, the overall construction cost does not differ greatly from the submerged tunnel.
[0008]
However, the conventional submarine tunnel has either a shield tunnel or a submerged tunnel over its entire length, and there is a problem that the cost is high in either case.
[0009]
In view of such a conventional problem, the present invention has been made by providing a submarine tunnel connection method that is advantageous in terms of cost compared to the conventional method.
[0010]
[Means for Solving the Problems]
The feature of the present invention for solving the conventional problems as described above and achieving the intended purpose is that a submerged tunnel extends from the land to the appropriate depth of shield tunnel excavation of the bottom of the water, and the seabed side end of the submerged tunnel In the submarine tunnel connection method that connects the part with the shield tunnel constructed at the appropriate depth of excavation below the bottom of the water,
At the planned connection position between the submerged tunnel and the shield tunnel, a connection box consisting of a precast block with the land side as the submerged box connecting part and the offshore side as the shield tunnel connecting part is submerged to a predetermined depth below the bottom of the water surface. After the back side of the shield tunnel connection part of the box is backfilled and the ground stabilization process is performed by freezing or grouting, the shield tunnel is dug from the offshore side through the backfill part toward the shield tunnel connection part. At the same time, a sloping road with a submerged tunnel is constructed on the land side of the submerged tunnel connecting portion, and the submerged tunnel and the shield tunnel are connected via the connection box .
[0011]
The connection box is formed in a box shape with a precast block molded on land, and the end of the submerged tunnel is configured to fit the connection with the submerged box, and the joint surface of the end of the shield tunnel is A rectangular opening larger than the outer shape of the shield excavator is formed, and a temporary lid for maintaining watertightness is provided slightly inside the opening. By connecting the opening on the side of the shield and submerged tunnel and the opening on the side of the shield tunnel, the space inside the connection box 3 is formed in an expanded shape from the side of the submerged tunnel 1 to the side of the shield tunnel to connect different types of tunnels. It is preferable to do .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0013]
FIG. 1 shows an example of a submarine tunnel A, in which 1 is a submerged tunnel, 2 is a shield tunnel, 3 is a connection box, 4 is a revetment, and 5 is a land tunnel.
[0014]
Under the water bottom, the ground below the water bottom is excavated with the shield excavator 6, and the linings 7, 7,. On the other hand, a submerged tunnel 1 is constructed by laying a plurality of submerged boxes 8, 8... The submerged tunnel 1 and the shield tunnel 2 are connected via a connection box 3, and further, the land-side end of the submerged tunnel 1 is connected to a tunnel 5 constructed on land via a vertical hole revetment 4. The land of artificial islands and the like are connected to the submarine tunnel A.
[0015]
As shown in FIGS. 6 to 8, the connection box 3 is formed into a box shape with a precast block formed on land, and the end portion on the side of the sinking tunnel is configured to be connected to the sinking box. An opening 9 is formed so as to communicate with. On the other hand, a rectangular opening 10 larger than the outer shape of the shield excavator 6 is formed at the joint surface on the shield tunnel side end, and a temporary lid 11 (bulk head) for maintaining watertightness is provided slightly inside. It has been.
[0016]
Further, as shown in FIG. 8, the buried tunnel side opening 9 and the shield tunnel side opening 10 are communicated to expand the space 3a inside the connection box 3 from the buried tunnel 1 side toward the shield tunnel 2 side. As shown in FIG. 3, by forming in such a shape, even atypical tunnels can be suitably connected.
[0017]
The temporary lid 11 is removed when the shield excavator 6 reaches the end of the connection box 3 and the connection work with the shield tunnel 2 is completed.
[0018]
In addition, the connection portion between the submerged tunnel 1 and the shield tunnel 2, that is, the backfilled portion 12 at the top of the connection box 3, is frozen or grouted toward the end of the shield tunnel 2 to improve the ground.
[0019]
Next, the submarine tunnel connection method will be described sequentially.
[0020]
First, as shown in FIG. 9, dredging work is performed in accordance with the installation of the sinking boxes 8 and 8 and the connection box 3 to form a water bottom, and the connection box 3 is installed at a predetermined position as shown in FIG. . At this time, an access shaft 13 connected to the inside of the connection box 3 is attached to the upper part of the connection box 3, so that workers can enter and leave and carry in materials from the access shaft 13.
[0021]
Next, as shown in FIG. 11, the sinking box 8 is laid on the land side end face of the connection box 3 and the ends are joined together. Then, as in the conventional method, the sinking boxes 8, 8... Are sequentially set and connected to the land side.
[0022]
On the other hand, as shown in FIG. 12, the offshore side connection portion of the connection box 3 is backfilled with soil, and after the backfill portion 12 is subjected to ground stabilization processing by freezing or grouting, the backfill portion 12 from the offshore side. The shield excavator 6 is dug toward the offshore side connection portion of the connection box 3 and the shield tunnel 2 is constructed by sequentially installing linings 7, 7.
[0023]
Then, as shown in FIG. 13, the shield excavator 6 is advanced to the end of the connection box 3 on the shield tunnel 2 side, the end of the shield tunnel 2 is connected to the connection box 3, and then the temporary lid 11 is removed. In this way, the shield tunnel 2 and the buried tunnel 1 are communicated with each other via the connection box 3. Further, after the connection is completed, the access shaft 13 attached to the upper part of the connection box 3 is also removed.
[0024]
Next, as shown in FIG. 14, the vertical hole revetment 4 is installed, and the earth and sand 14 is refilled in the seabed portion in front of the revetment according to the installation angle of the submerged boxes 8, 8.
[0025]
Then, as shown in FIG. 15, the sinking box 8 is connected to the vertical hole revetment 4, and the sinking boxes 8, 8.. The submerged tunnel 1 is completed by connecting the end submerged box 1a and the end submerged box 1b constructed from the vertical hole revetment side with a key element box 1c.
[0026]
Finally, as shown in FIG. 16, the submerged tunnel 1 is backfilled with soil, a land tunnel portion 5 connected to the submerged tunnel 1 through the vertical hole revetment 4 is constructed, and the road bed 15 is constructed to construct the submarine tunnel. Construct A.
[0027]
In addition, the connection box 3 should just be a shape where the submerged tunnel 1 and the shield tunnel 2 are connected suitably.
[0028]
【The invention's effect】
As described above, the submarine tunnel connection method according to the present invention uses the submerged tunnel between the land and the appropriate depth of the shield tunnel in the bottom of the water, and the seabed side end of the submerged tunnel has an appropriate depth of excavation under the bottom of the water. By connecting with the shield tunnel constructed in the above, the length of the entire tunnel can be shortened compared to the case of construction using only the shield tunnel, and the cost can be reduced. Since the construction cost per m is lower in the shield tunnel, the overall cost can be reduced.
[0029]
In addition, at the planned connection position between the submerged tunnel and the shield tunnel, a connection box with the land side as the submerged box connecting portion and the offshore side as the shield tunnel connecting portion is installed at a predetermined depth below the bottom of the water surface, and the submerged tunnel connecting portion is connected. By constructing a ramp with a submerged tunnel between the part and the land, and connecting the shield tunnel and the submerged tunnel by excavating the shield tunnel from the offshore side toward the shield tunnel connecting part, Two different types of tunnels, the submerged tunnel and the shield tunnel, can be suitably connected.
[0030]
The connection box is composed of a precast block molded on land, and the connection box is sunk to a predetermined depth below the bottom of the water at the position where the connection is planned, and the shield tunnel connection part side of the connection box is backfilled. back after freezing or soil stabilization by grouting handle portion, by which is adapted to boring shield tunnel toward the shield tunnel connecting section through part backfilled from offshore, the connection box making the shield tunnel The safety of the joint is improved.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of an embodiment of a submarine tunnel according to the present invention.
FIG. 2 is a plan view showing a connection portion between a buried tunnel and a shield tunnel in FIG. 1;
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a sectional view taken along the line BB of the above.
FIG. 5 is a sectional view taken along the line CC of the above.
6 is a front view showing the connection box in FIG. 2. FIG.
FIG. 7 is a rear view of the above.
FIG. 8 is a cross-sectional view taken along the line DD in FIG.
FIG. 9 is a state explanatory sectional view showing a state in which dredging work is performed in the submarine tunnel connection method according to the present invention.
FIG. 10 is a state explanatory sectional view showing a state in which the connection box installation work is performed.
FIG. 11 is a state explanatory sectional view showing a state in which the above-mentioned sinking box setting work has been performed.
FIG. 12 is a state explanatory sectional view showing a state in which the connection box backfilling operation is performed.
FIG. 13 is a state explanatory sectional view showing the shield tunnel construction state of the above.
FIG. 14 is a state explanatory sectional view showing a state where the submerged tunnel and the shield tunnel are connected.
FIG. 15 is a state explanatory sectional view showing a state in which the construction of the buried tunnel is performed.
FIG. 16 is a sectional view for explaining the state of the completed submarine tunnel.
[Explanation of symbols]
A Submarine tunnel 1 Submerged tunnel 2 Shield tunnel 3 Connection box 4 Vertical hole revetment 5 Land tunnel 6 Shield excavator 7 Covering 8 Submergence box 9 Opening 10 Opening 11 Temporary cover (bulkhead)
12 Backfill part 13 Access shaft 14 Earth and sand 15 Road bed

Claims (3)

In the submarine tunnel connection method that connects the land from the land to the shield tunnel excavation depth at the bottom of the water with a submerged tunnel, the seabed side end of the submerged tunnel is connected to the shield tunnel constructed at the depth of excavation below the bottom of the water,
At the planned connection position between the submerged tunnel and the shield tunnel, a connection box consisting of a precast block with the land side as the submerged box connecting part and the offshore side as the shield tunnel connecting part is submerged to a predetermined depth below the bottom of the water surface. After the back side of the shield tunnel connection part of the box is backfilled and the ground stabilization process is performed by freezing or grouting, the shield tunnel is dug from the offshore side through the backfill part toward the shield tunnel connection part. In addition, a submarine tunnel connection method is characterized in that an oblique road by a submerged tunnel is constructed on the land side of the submerged tunnel connecting portion, and the submerged tunnel and the shield tunnel are connected via the connection box . The connection box is formed into a box shape with a precast block molded on land, the end of the submerged tunnel is configured to fit the connection with the submerged box, and the shield tunnel excavation is made on the joint surface of the end of the shield tunnel The submarine tunnel connection method according to claim 1, wherein a rectangular opening larger than the outer shape of the machine is formed, and a temporary lid for maintaining watertightness is provided slightly inside the opening . The connection box communicates with the opening on the submerged tunnel side and the opening on the shield tunnel side, and the space inside the connection box 3 is formed in an expanded shape from the submerged tunnel 1 side toward the shield tunnel side. The submarine tunnel connection method according to claim 1 or 2, wherein:

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