JPH0469252B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a construction method for an underwater structure.

[Conventional technology]

Generally, when constructing structures such as bridge piers in the sea or in rivers using reinforced concrete, most of the construction is done on or below Tsukishima. For this reason, it was necessary to construct a large-scale rocky island before starting the main construction work.

[Problem that the invention seeks to solve]

For this reason, it took a considerable amount of time and construction cost to construct the Tsukishima and remove the part of the Tsukishima after constructing the underwater structure, which had the drawback of unavoidably prolonging the construction period and increasing the construction cost.

This invention was proposed in order to solve the above-mentioned conventional problems, and aims to provide a construction method for underwater structures that can significantly shorten the construction period and significantly reduce construction costs. .

[Means for solving problems]

The method for constructing an underwater structure of the present invention is to form a double wall with an outer wall and an inner wall, and to have a vertically continuous slit on the periphery of the box, and a partition wall to reinforce the outer wall and the inner wall at a predetermined position. The provided box is installed and fixed on the seabed, and then a hole of a predetermined depth is formed in the seabed ground directly below the slit of the box using an excavator using the slit as a guide. The idea is to construct an underwater structure of a predetermined size by placing reinforcing bars in the slit and then pouring concrete to create a continuous wall in the slit and the ground below it.

〔Example〕

Hereinafter, the construction method of the present invention will be explained step by step.

In a dog or the like, a box 1 of a predetermined size is formed of steel or reinforced concrete.

The box 1 is formed into a cylindrical shape with a rectangular cross section having a predetermined diameter depending on the scale of the underwater structure to be constructed, and is also formed into a double wall with an outer wall 2 and an inner wall 3.
A slit 4 of a predetermined width is formed continuously between the outer wall 2 and the inner wall 3 in the vertical direction at the peripheral edge of the box 1, and a bottom 5 is formed at the lower end of the slit 4. Note that the bottom 5 may not be formed in some cases.

In addition, by forming partition walls 6 continuously in the vertical direction in the slit 4, the outer wall 2 and the inner wall 3
Reinforce. The partition wall 6 is attached to the outer wall 2 and the inner wall 3 integrally or detachably. To removably attach the partition wall 6, for example, a lip groove is provided inside the outer wall 2 and the inner wall 3, which are continuous in the vertical direction, and the partition wall 6 having an H-shaped cross section is slidably attached to this lip groove.

On the other hand, at a construction site for an underwater structure, the underwater ground A is excavated to a predetermined depth using conventional construction methods, and the bottom surface of the excavation is made as horizontal as possible.

Next, the completed box 1 is sailed to the construction site. In this case, buoyancy can be imparted to the box 1 by sealing the slit 4 and the central portion of the box 1.

Further, the bottomless box 1 is transported on a barge and is sunk by a crane ship.

Subsequently, the box 1 is sunk and installed on the seabed ground A, and the peripheral portion of the box 1 is buried back to fix the box 1 to the seabed.

Subsequently, an excavator (not shown) that guides the slit 4 forms a hole 7 of a predetermined depth in the lower seabed ground A directly below the slit 4. In the structure with the bottom 5, when drilling the hole 7, the slit 4
The bottom 5 is pierced by an excavator and the bulkhead 6
The seabed ground immediately below will also be excavated.
Finally, the hole 7 is drilled in a continuous groove shape, such as a rectangular shape, corresponding to the shape of the slit 4. In addition, a stabilizing liquid (muddy water) shall be used so as not to damage the side surface of the drilled hole 7 as much as possible.

Next, a required amount of reinforcing steel cages (not shown) are arranged in the slit 4 and the drilled hole 7, and then concrete 8 is poured to create an underground continuous wall in the slit and the ground below it.

Also, depending on the purpose of the structure, the hollow part 9 of the box 1 may be
Completely fill with crushed stone, earth, or concrete.

By the above construction order, an underwater structure of a predetermined scale can be constructed.

Note that the box 1 is not limited to a rectangular cross section, but may have a circular or polygonal cross section. Furthermore, the construction site is not limited to the ocean, but can also be a lake or river. During construction, partition walls 6 were removed one by one.
It is also possible to connect adjacent slits 4 in cross section.

〔Effect of the invention〕

Since the present invention has the above configuration, it has the following effects.

Since there is no work to construct the temporary structure of the Tsukishima and to remove the Tsukishima after construction of the underwater structure, the construction period can be significantly shortened and the construction cost can be significantly reduced. Moreover, since the work on the water can be completed in a short period of time, there is less exposure to storms and work safety can be ensured.

Even if a safety liquid is used to excavate underwater ground, since the excavation is carried out within a double-walled slit consisting of an outer wall and an inner wall, there is no fear that the stabilizing liquid and excavated soil will flow out to the outside, and environmental pollution countermeasures can be improved.

A continuous wall of reinforced concrete is integrally constructed in the slit and the lower ground, making it an underwater structure, so an underwater structure of a predetermined scale can be reliably constructed, and the area occupied during construction is small, making it easy to work.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a vertical sectional view showing the installation state of the box, and FIGS. 2 and 3 are - in FIG. 1.
It is a line, - line sectional view. 1...Box, 2...Outer wall, 3...Inner wall, 4...
Slit, 5...Bottom, 6...Partition wall, 7...Drilling,
8...Concrete, 9...Hollow part.

Claims (1)

[Claims] 1 A double wall is formed by an outer wall and an inner wall, a vertically continuous slit is provided at the periphery of the box, and partition walls are provided at required positions to reinforce the outer wall and inner wall, and the box is installed on the bottom of the water. , and then using an excavator using the slit as a guide to form a hole to a predetermined depth in the underwater ground directly below the slit of the box,
A construction method for an underwater structure characterized by placing reinforcing bars in the drilled holes and slits, and then pouring concrete to create a continuous wall in the slits and the ground below them.