JP3404566B2 - How to build an underwater tunnel - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for constructing a subsea tunnel.

[0002]

In the submersion method, which is one of the methods for constructing a subsea tunnel, a group of boxes connected and integrated to a predetermined length is manufactured in a dry manufacturing yard and floated. The tunnel is towed to the site, submerged in a trench on the bottom of the water that has been excavated beforehand, and connected sequentially, and then backfilled to complete the tunnel. Therefore, in the case of the conventional burial method, it is necessary to have a vast production board in accordance with the length of a group of boxes towed at one time, which is uneconomical in terms of construction period and construction cost.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method of constructing a subsea tunnel which can shorten the construction period and the construction cost. .

[0004]

As a means for solving the above-mentioned problems, the present invention as claimed in claim 1 is characterized in that a group of boxes integrally connected and integrated is sequentially extruded to the water bottom and then extruded. A method for constructing a subsea tunnel, characterized in that a group of boxes having a predetermined length is separated, floated, towed to a predetermined place, and then sunk.

As a second aspect of the present invention, in the method of constructing a water-bottomed tunnel according to the first aspect, a water stop wall is erected in the water area on the extrusion start side of the box, and the water level is set on the shore side of the water stop wall. An adjustable extrusion yard was provided, and with this extrusion yard,
Provided is a method of constructing a water-bottomed tunnel, characterized in that a group of boxes which are connected and integrated are pierced through the water blocking wall and sequentially pushed out to the water floor.

As a third aspect of the present invention, in the method of constructing a water-bottomed tunnel according to the second aspect, water is injected into the extrusion yard at a water level lower than the water area outside the water blocking wall, and the front surface of the box body is inspected. Provided is a method for constructing a water-bottomed tunnel, which is configured to reduce the force required for pushing out a group of boxes by reducing the water pressure acting on.

Further, as a fourth aspect, in the method of constructing a water-bottomed tunnel according to the third aspect, the water level in the extrusion yard is set so that the box group is not pushed back to the extrusion yard side. And a method for constructing a subsea tunnel.

As a fifth aspect of the present invention, in the method of constructing a water bottom tunnel according to any one of the second to fourth aspects, a reaction force receiving wall or a beam is erected on the push-out side of the water blocking wall. Provided is a method for constructing a water-bottomed tunnel, characterized in that a reaction force is applied to a reaction force receiving wall or a beam to extrude a box group. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The method of constructing a submarine tunnel of the present invention is performed in the following procedure.

<a> Construction of water blocking wall First, a groove for setting a group of boxes is excavated at the bottom of the water area 100. After placing the retaining steel sheet pile along the edge of the excavation planned line of the trench, a double deadline 102 is constructed near the bank side of the revetment 101, as shown in FIG. Then, the inner side of the Doru steel sheet pile is excavated, and as shown in FIG. 6, the groove 103 is excavated from the start side coastal portion to the double deadline 102. The shape of the groove 103 is excavated in an arc shape or a straight shape in accordance with the design shape of the underwater tunnel.

Next, as shown in FIG. 7, a water blocking wall 200 is constructed at a position where water is flooded for a predetermined distance from the start side coastal portion. The construction position of the water blocking wall 200 is preferably constructed at a water depth where the entire box can be submerged. As shown in FIG. 2, for example, the shape of the water blocking wall 200 is a gate shape with an opening for passage of a group of boxes in the excavated groove 103, and the size of the opening is the box cross section. Design slightly larger than the external shape.

A water blocking member, such as a wire brush, that contacts the peripheral surface of the box is provided on the inner surface of the opening. It should be noted that the shape of the water blocking wall 200 may be such that only column members are erected on both sides of the box when the water depth at the construction position is shallower than the water depth in which the entire box is submerged.

<B> Construction of Extruded Yard / Production Yard As shown in FIGS. 2 and 3, an extrusion Yard 300 and a production Yard 310 are provided in order from the water blocking wall 200 to the land portion. , These two halves 300 and 310 are constructed on the extension of the groove 103.

Further, a temporary storage space 320 for materials and the like is provided on the flat surface portion of the manufacturing word 310 on the land side. A friction reducing device 210 such as a water caster is laid on the slopes. In addition, a braking reaction force receiving wall 220 or a beam, such as a gate type, as shown in FIGS.

Conventionally, the extrusion yard 300 and the fabrication yard were used.
Although 310 is provided in the land area along the coast of the water area, as in the present invention, the water level is lowered by installing the water blocking wall 200, and these yams are provided in the water area to extrude the group of boxes. The distance can be shortened.

<C> Installation of sliding bearings As shown in FIGS. 2 and 6, sliding bearings 230 are installed along the bottom surface of the groove 103 at predetermined intervals. Sliding bearing 230 Water barrier 200
The installation distance from is at least as long as the length of the group of boxes towed at one time. As an example of the slide bearing 230, a steel-framed concrete pedestal is supported by a steel pipe pile, and an iron plate or the like is attached to the surface of the pedestal.

<D> Manufacture of Box and Pre-Extrusion Manufacturing A box 310 of a reinforced concrete structure, a steel shell type composite structure and the like is manufactured in a dry state by the manufacturing 310.
The box 400 is made by constructing one block on the production yard 310 in a flow-wise manner for each block part, and successively staking concrete to successively construct a predetermined number of blocks.

For example, 10 blocks are integrally manufactured in units of 100 m, and the units of 10 blocks are connected by a joint structure using a bulkhead or the like. In addition, in the box 400,
Built-in various sinking equipment such as ballast tanks.

As an example of a concrete manufacturing method of the box 400, as shown in FIGS. 2 and 3, for example, assembling and welding the bottom plate steel plate 401, assembling the bottom plate reinforcing bar 402, placing concrete on the bottom plate 403, and side wall reinforcing bar 404. Are assembled, the side wall 405 is concrete-cast, the upper deck rebar 406 is assembled, the upper deck 407 is concrete-cast, the waterproof sheet 408 is attached, and the protective concrete 409 is cast.

The box 400 sequentially manufactured as described above is
Until the original extruder 250 is installed, the temporary extruder is used for extrusion. For example, using a center-hole jack installed at the bottom of the water blocking wall 200, pull the bottom plate 403 with a PC steel wire, and perform pre-extrusion work until the tip of the box 400 penetrates the reaction force receiving wall 220. .

<E> Initial extrusion of the box When the tip of the box 400 passes through the reaction force receiving wall 220, the original extruder 250 is installed. As a specific example, a water blocking wall
A predetermined number of PC steel wires 240 are stretched between 200 and the reaction force receiving wall 220, and an extrusion device 250 is installed on the way.

As a concrete example of the extrusion device 250, as shown in FIG. 4, a pair of center-hole jacks 251 and 252 capable of gripping and releasing the PC steel strand 240 are used. These are moved to the concave part provided on the upper floor slab 407 of the box 400 and the moving platform 253.
Install by fixing.

After the box 400 has penetrated the reaction force receiving wall 220, the initial pushing operation is performed by the pushing device 250 until the tip of the box 400 penetrates the water blocking wall 200. Center
The operation of the hole jacks 251 and 252 is such that while holding and releasing the wedges at both ends of the jack alternately, one of the jacks is extended and at the same time the other is contracted.
Move to push out the box 400. When the pushing device 250 approaches the water blocking wall 200, push the pushing device 25 to the reaction force receiving wall 220 side.
Replace 0 and repeat the above operation.

<F> After the water injection extrusion is repeated and the box 400 penetrates the water blocking wall 200, as shown in FIG. 7, the revetment 101 is removed, the groove 103 is extended, and the slide bearing is supported as necessary. Install 230 in the same manner as above. Next, the double deadline 102 is removed and water is poured. At this time, the extrusion yard 300 and the manufacturing yard
Water does not penetrate into 310 due to the water blocking wall 200.

Next, by injecting water into the extrusion yard 300 at a water level lower than the water area outside the water blocking wall 200, the water pressure acting on the front surface of the box 400 is reduced to extrude the group of boxes 400. The force required for the box is reduced and the group of boxes 400 is set so as not to be pushed back to the push-out yard 300 side. That is, due to the coefficient of friction between the gradient of the manufacturing yard 300 and the sliding bearing 230 that supports the weight of the moving boxes 400, the boxes 400 are stopped even if water pressure from the outer water area acts. State.

<G> Extrusion of Boxes As described above, the production and extrusion of the boxes 400 are repeated to extrude the group of boxes 400 along the groove 103. At this time, ballast water to prevent floating is poured into the box 400. The safety factor for levitation may be about 1.03.
Then, as shown in FIG. 1, a box of a length that can be towed at a time.
400 groups (eg 10 blocks) penetrate the water stop wall 200,
When all the water is submerged, the extruder is stopped once.

<H> Towing and Sinking of Boxes As shown in FIG. 1, water is injected into the joints (between bulkheads) of the 400 boxes to be towed, and the 400 groups tow are separated. The submersible work boat 500 moored on the surface of the water raises the group of boxes 400 while removing the ballast water in the boxes 400 according to the lifting capacity.

Then, after preparing for the sinking such as the freeboard adjustment of the box 400 and the installation of the measuring system at the sinking site,
A group of 400 boxes will be towed and settled to the place of the settling. The group of submerged boxes 400 will be connected to the existing one. The above separation, levitating, towing, sinking and connecting work are repeated.

After the last group of boxes 400 is sunk, the tail end of this group of last boxes 400 and the tip of the extruded box 400 are connected and backfilled to complete the tunnel. When the tail end of the last group of boxes 400 and the tip of the extruded box 400 are connected, the extruded box 400 can be further extruded and connected.

With respect to the equipment for pushing out the box 400, the pushing device 250 and the reaction force receiving wall 220 are removed. Next, the seawall
After 104 was restored and backfilling 105 was performed to drain the soil, the water blocking wall 200, friction reducing device 210, and sliding bearing 230
Remove equipment such as. This completes the extrusion construction of the subsea tunnel.

In the above description, the case of constructing a concave arcuate tunnel having a height difference between the both ends and the center of the tunnel has been described, but the case of constructing the tunnel on the same horizontal plane is also conceivable. In these cases, when it is necessary to construct the bottoms of the box-making and extruding yard on a horizontal plane, water-extruding walls are provided at both front and rear ends of the extruding yard. As an example, it may be possible to adjust the water level in the inside.

[0032]

As described above, the present invention constructs a push-out wall by providing a water blocking wall in the water area on the starting side, constructs a group of boxes, and pushes out while connecting them. It eliminates the need for a vast production yard that matches the entire length of the towed group of boxes. Therefore, it is possible to reduce the construction period and the construction cost.

[Brief description of drawings]

1 is an explanatory view of the entire construction of the present invention

[Fig. 2] An explanatory view of an extrusion yard and a production yard.

[Fig. 3] Explanatory diagram of extrusion yard and production yard

FIG. 4 is an explanatory view of an extruder.

FIG. 5 is an explanatory diagram of an extrusion process

FIG. 6 is an explanatory diagram of an extrusion process

FIG. 7 is an explanatory diagram of an extrusion process

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Takaku 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Within Taisei Corporation (56) Reference JP-A-57-66297 (JP, A) JP 55-105095 (JP, A) JP-A-9-144038 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) E02D 29/063-29/077

Claims (5)

(57) [Claims] 1. A method comprising the steps of successively pushing the connected and integrated box groups to the bottom of the water, separating and pushing up the pushed box groups of a predetermined length, and towing them to a predetermined location and then laying them down. , How to construct an underwater tunnel. 2. The method for constructing a water-bottomed tunnel according to claim 1, wherein a water stop wall is erected in the water area on the extrusion start side of the box, and the water level is adjustable on the shore side of the water stop wall. A method for constructing a water-bottomed tunnel, characterized in that a box group is provided, and the group of connected and integrated boxes is pierced through the water-blocking wall to be pushed out to the water bottom one after another by means of this extrusion yard. 3. The method of constructing a water-bottomed tunnel according to claim 2, wherein water is injected into the extrusion yard at a water level lower than that of the water area outside the water blocking wall to reduce the water pressure acting on the front of the box. A method for constructing a water-bottomed tunnel, characterized in that the force required for pushing out a group of boxes is reduced by doing so. 4. The water bottom tunnel construction method according to claim 3, wherein the water level in the extrusion yard is set so that the box group is not pushed back to the extrusion yard side. How to build a tunnel. 5. The method for constructing a water-bottomed tunnel according to claim 2, wherein a reaction force receiving wall or a beam is erected on a side of the water blocking wall on which the water is extruded, and the reaction force receiving wall or A method for constructing an underwater tunnel, characterized in that it is constructed so as to extrude a group of boxes by applying a reaction force to the beam.