JP2655322B2 - Construction method of revetment structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a revetment structure such as an artificial island as a hydraulic structure.

[0002]

2. Description of the Related Art Artificial islands and the like are constructed by enclosing a landfill area with a seawall and burying the inside with earth and sand. Conventionally, such revetment construction methods are broadly classified into a method using a concrete block or caisson and a method of creating a deadline such as a steel sheet pile or a steel sheet cell.

[0003] In particular, when the seabed ground is a soft soil layer, in the method using the concrete block or caisson, one or more of deep mixing, sand replacement, sand piles, and rubble mounds are used to form an installation foundation. Has improved soft ground in several ways.

[0004]

Among the above-mentioned conventional revetment construction methods, those in which improvement of soft ground is required for foundation formation,
This often has to be done as a separate construction, which requires a lot of construction time and cost.

[0005] In the shut-off method using a metal member such as a steel sheet pile, the corrosion of the steel material is severe in a severely corrosive environment such as a splash zone. Not enough.

Further, Japanese Patent Application Laid-Open No. 63-40024 discloses a method of constructing an underwater buried structure that does not require ground improvement work. This is done by towing a caisson whose peripheral side wall is formed by a double wall, setting the pile to the supporting ground using the double wall as a guide, and then driving concrete to the double wall to form a pile and caisson. It is a rigid connection between

However, in Japanese Patent Application Laid-Open No. 63-40024, an opening is formed in advance at a position where a caisson pile is driven, and the opening is formed with an iron plate or the like so that seawater does not enter the caisson during towing. Because it is closed with a thin plate and a float is attached to the outer wall of the caisson to increase buoyancy,
The number of members used increased and handling was complicated.
On the other hand, when grounding the caisson on the seabed, this float must be removed to reduce buoyancy, and after grounding, the thin plate must be removed before driving the pile,
The number of processes increased and the construction period was delayed.

The present invention eliminates the disadvantages of the prior art described above, is simple and inexpensive, requires less work and can shorten the construction period, and the completed revetment structure has high durability against corrosion by seawater. An object of the present invention is to provide a method for constructing the obtained revetment structure.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a concrete structure having a large number of floating chambers and a joint hole formed in a bottom plate of a chamber other than the floating chamber located on the side. Seawater into the chamber having the joint hole so as to have the same water volume as the sea surface, and float in water in a state where the floating posture is balanced by storing an appropriate amount of water in the floating chamber, and The concrete structure is submerged in the sea floor by adjusting the water injection into the floating room at this predetermined location, and then piled into the joint hole. The gist of the invention is to cast and fix underwater non-separable concrete mixed with a separable admixture.

According to the present invention, the use of a concrete structure manufactured in advance on the ground makes it possible to simplify the process and shorten the construction period. In addition, when towing a concrete structure, seawater is flooded in the room with the joint hole so that it has the same water volume as the sea surface, and an appropriate amount of water is stored in other floating rooms. It can be done in a good condition. Furthermore, since the pile is driven after the concrete structure is submerged at a predetermined position, it is relatively easy to adjust the driving position of the pile.

[0011] Seawater is flooded in a room having a joint hole for placing a pile, but without removing the seawater in the room, a water-immiscible admixture is filled in a gap between the joint hole and the pile. Since the mixed underwater non-separable concrete is cast, the process can be performed easily and quickly. Further, as the obtained revetment structure, the splash zone is a concrete structure, which can sufficiently withstand corrosion by seawater.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 are longitudinal side views of respective steps showing a first embodiment of a method for constructing a seawall structure of the present invention.

First, a seawall structure having a large number of floating chambers 4 on the ground as shown in FIGS. 4 to 6, and having a joint hole 5 formed in a bottom plate 6 of a chamber other than the floating chamber 4 located on the side. Make caisson as a concrete structure. In addition,
The joining hole 5 is larger than the diameter of the pile 1 described below,
As shown in FIGS. 7 and 8, a reinforcing reinforcing bar 7 is provided around the periphery.

In this caisson, seawater is immersed in the chamber having the joint hole 5 so as to have the same water volume as the sea surface, and an appropriate amount of water is stored in the floating chamber 4 to balance the floating posture. Floats underwater and tow the ship 3 to a predetermined location.

At a predetermined place, the caisson is submerged on the sea floor by adjusting the amount of water injected into the floating chamber 4. It should be noted that the injection of water into the floating chamber 4 is performed in a well-balanced state in which no excessive load acts on the bottom plate 6 and the caisson does not move due to the subsequent change in tide level or the influence of the submerged concrete described below. It is necessary to

Next, the pile 1 is cast into the joint hole 4 using the work boat 2 or the like. At the time of casting, the pile 1 projects above the water surface, but thereafter, the pile head 1a is cut at a predetermined height so as to project to the sea floor.

As shown in FIG. 9, the pile head 1a is dug down to an appropriate depth, a formwork is installed on the bottom plate 6 around the joint hole 5, and the inside of the pile head 1a, the pile 1 The concrete is made viscous in the gap between the and the joining hole 5 and in the formwork,
Underwater cast concrete 9, which is a water-inseparable concrete mixed with a water-inseparable admixture (or a separation-reducing agent) that prevents the separation of materials in water, is cast, and the pile 1 and the joint hole 5 are firmly connected. Fix it. After this, the inside surrounded by the caisson is buried to form the landfill 10.

FIG. 14 shows a second embodiment of the present invention.
This is a case where an L-shaped block is used as a concrete structure instead of a caisson. The details of the L-shaped block are shown in FIG.
13 to FIG. 13, the point that the floating chamber 4 is provided and the joining hole 5 is formed in the bottom plate 6 is the same as that of the caisson, and the process is also the same.

[0019]

As described above, the construction method of the revetment structure of the present invention eliminates the need for ground improvement work for supporting a concrete structure such as a caisson by the conventional method, even if the seabed ground is soft, and Underwater work can be reduced as much as possible to greatly shorten the construction period and reduce construction costs. Further, the towing can be performed in a state where the floating posture of the concrete structure is well balanced. Furthermore, since the pile is driven after the concrete structure is submerged at a predetermined position, it is relatively easy to adjust the driving position of the pile.

Seawater is flooded in a room having a joint hole for placing a pile, but without removing the seawater in the room, a gap between the joint hole and the pile is filled with a water-immiscible admixture. Since the mixed underwater non-separable concrete is cast, the process can be performed easily and quickly. Further, as the obtained revetment structure, the splash zone is a concrete structure, which can sufficiently withstand corrosion by seawater.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a first step showing a first embodiment of a method for constructing a seawall structure of the present invention.

FIG. 2 is a vertical sectional side view of a second step showing the first embodiment of the method for installing a seawall structure of the present invention.

FIG. 3 is a vertical sectional side view of a third step showing the first embodiment of the method for constructing a seawall structure of the present invention.

FIG. 4 is a plan view of a caisson used in the first embodiment of the method of constructing a seawall structure of the present invention.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a sectional view taken along line BB of FIG. 4;

FIG. 7 is a vertical sectional side view of a joint hole of a caisson used in the method of constructing a seawall structure of the present invention.

FIG. 8 is a cross-sectional plan view of a joint hole of a caisson used in the method of constructing a seawall structure of the present invention.

FIG. 9 is a longitudinal sectional side view showing a joint state between a pile and a concrete structure in the method for constructing a seawall structure of the present invention.

FIG. 10 is a plan view of a caisson used in a second embodiment of the method for constructing a seawall structure of the present invention.

FIG. 11 is a sectional view taken along line AA of FIG. 10;

FIG. 12 is a sectional view taken along line BB of FIG. 10;

FIG. 13 is a sectional view taken along line CC of FIG. 10;

FIG. 14 is a vertical sectional side view showing a second embodiment of the method for constructing a seawall structure of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pile 1a ... Pile head 2 ... Work boat 3 ... Ship 4 ... Floating room 5 ... Joint hole 6 ... Bottom plate 7 ... Reinforcing steel 9 ... Underwater concrete 10 ... Landfill

Claims (1)

(57) [Claims] 1. A concrete structure having a large number of floating chambers and having a joint hole formed in a bottom plate of a chamber other than the floating chamber located on the side, and having the same water volume as the sea surface in the chamber having the joint hole. So that the seawater is flooded, and the floating chamber contains an appropriate amount of water, floats in the water in a state where the floating posture is balanced, and is towed to a predetermined installation location, and into the floating chamber at the predetermined location The concrete structure is submerged into the sea floor by adjusting the water injection, and then piled into the joint hole, and finally, the underwater non-separable concrete mixed with the water-immiscible admixture is poured into the gap between the joint hole and the pile. Construction method of revetment structure characterized by installing and fixing.