JPH0310799B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing an immersed tunnel.

Conventionally, in this type of method, a strong structure such as a ventilation tower on both sides of an immersed tunnel route is used as a reference, and the immersed tunnel box is constructed while being joined to the same structure.

The main reason why this method is adopted is that the box joining method uses water pressure by draining the water from the joint of the boxes, so there is no large reaction force when the boxes to be joined are pulled together. This is because it is necessary to have a strong structure that can absorb the horizontal reaction forces caused by currents and waves until it is completed.

With this method, construction of the immersed tunnel could only be done after the construction of the ventilation towers on both sides of the tunnel route had been completed, which led to the drawback that the construction period was long.

The present invention was proposed to eliminate these drawbacks, and it does not require the construction of a ventilation tower on the land side.
A box support is constructed at an arbitrary position on the immersed tunnel line, a box is sunk into the support and fixed at a predetermined position, and the next box is sequentially installed based on the box on the support. The invention relates to a method for constructing an immersed tunnel, characterized in that the ventilation tower and the immersed box, which was sunk before the ventilation tower, are connected by a final joint.

The present invention will be described below with reference to the illustrated embodiments.

Without waiting for the construction of the ventilation tower on the land side, a support body 2 with a groove-shaped cross section supported by piles 1 is constructed at an appropriate position on the immersed tunnel line, and a reference box 3 is placed on the support body 2.
to be deposited. Positioning of the box 3 when it is sunk is performed by vertical jacks 4 and horizontal jacks 5 attached to the bottom plate 3a and side plates 3b of the box 3.

The cylinder 4a of the vertical jack 4 has a rectangular outer shell in order to reduce the surface pressure against the horizontal force, and this rectangular cylinder fits into the square hole 2 of the support 2.
It is designed to fit into a. By expanding and contracting the vertical jacks 4 and horizontal jacks 5, the mounting position of the box 3 relative to the support body 2 is adjusted in the vertical and horizontal directions, thus completing the positioning of the box 3. After that, the gap between the square cylinder of the vertical jack 4 and the square hole 2a of the support 2 is filled with mortar. When injecting mortar, utilizing the fact that the jack 4 is composed of a center hole jack, a grout injection pipe 6 is installed in the center hole of the jack 4, and mortar is injected through the injection pipe 6. It is something to do. In the figure, reference numeral 7 denotes a horizontal resistance thick handle that projects from the bottom of the box 3 and fits into the thick handle on the bottom of the support 2. Further, the uplift of the box 3 is performed using the ballast inside the box 3.

After completing the installation of the standard box 3 as described above, the boxes 3' on both sides are constructed.
Rubber gaskets 9 are provided on the joint end surfaces of the boxes 3' in areas other than the joint with the ventilation tower 8 shown in the figure and the closing part of the central part of the box group. 3, drain the water in the joint space formed between the bulk head of both boxes and the gasket 9, and press the gasket 9 to the joint surface of the box 3 in a watertight manner by water pressure. The conventional construction method will be adopted. At this time, even if the water in the joint space is removed, a slight water pressure corresponding to the water head difference (H ₂ - H ₁ ) between the adjacent boxes 3 and 3' is generated, and the horizontal reaction force of the support 2, that is, the pile 1
has no significant impact. (See FIG. 7) Furthermore, when adjacent boxes are joined, the difference in water head is small, and when a large number of boxes are joined, the horizontal reaction force is distributed to each support.

In addition, when joining the closing part like the part shown in Fig. 5, the case 3' is joined underwater by applying an underwater joint structuring agent 10, etc., as shown in Fig. 6. Construction should be done so that large hydraulic reaction forces do not act on the box or support.

In the present invention, as described above, without constructing a ventilation tower on the land side, a box support is constructed at an arbitrary position on the route of the immersed tunnel, and the box is sunk on the support and placed in a predetermined position. By fixing it, a reference box is constructed that is firmly and accurately installed on the immersed tunnel line, and the next boxes are successively connected using this box as a reference, and finally, the ventilation tower and the above-mentioned ventilation tower are connected. The ventilation tower is connected to the immersed box, which was sunk before the ventilation tower, through a final joint. Therefore, according to the present invention, the immersed tunnel box can be connected from any location with respect to the reference box. As a result, when the box is sunk, it is now possible to construct parts such as the sea route regulation part and the ventilation tower mounting part separately, and it is also possible to construct parts such as the marine passage regulation part and the installation part of the ventilation tower separately. There is no need to start sinking the box, and construction of the ventilation tower and sinking of the box can be carried out at the same time.
This can shorten the overall construction period.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1 is a side view showing the submerged state of a reference box in an embodiment of the method for laying a box for an immersed tunnel according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a positioning portion of the reference box. FIG. 4 is a view taken along the arrow in FIG. 3, FIG.
FIG. 7, which is an enlarged view of the part shown in the figure, is a water pressure balance diagram when the boxes are joined. 1...Pile, 2...Support, 3...Reference box,
3′...Box.

Claims (1)

[Claims] 1. Without waiting for the construction of the ventilation tower on the land side, construct a box support at any position on the immersed tunnel line, sink the box onto the support, fix it in a predetermined position, and place the box on the support. The next box is successively submerged and connected using the box as a reference, and finally the ventilation tower and the submerged box that was sunk before the ventilation tower are connected by a final joint. How to build a tunnel.