JPH0369709A - Method of constructing shore protection structure - Google Patents

Abstract

PURPOSE:To enable simple execution of a work at a low cost by a method wherein a structure is sunk in water in a manner that a pile head protruded from a sea bottom is inserted in the joining hole of a concrerte structure, and underwater concrete is placed in the joining hole and a gap between piles to secure a caisson. CONSTITUTION:After a pile 1 is driven in a seat bottom, the pile is cut at a given height so that a pile head part 1a is protruded from the sea bottom. After a caisson, being a concrete structure, having a floating chamber 4 and a joining hole 5 formed in a bottom plate 6 is manufactured, the caission is floated in water and tagged to a place, where the pile 1 is driven, by means of a boat 3. Through regulation of injection of water in the floating chamber 4, the caission is sunk, and the pile head part 1a is inserted in the joining hole 5. Further, underwater concrete 9 is placed in a gap between the pile 1 and the joining hole 5 to secure the caisson.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method of constructing a seawall structure such as an artificial island as a hydraulic structure.

[Conventional technology]

For artificial islands, the reclaimed area is surrounded by a sea wall and the inside is filled with earth and sand to preserve the land.

Methods for constructing such seawalls are conventionally divided into methods that use concrete blocks or caissons, and methods that create cofferdams using steel sheet piles, steel plate cells, etc.

In particular, when the submarine ground is a soft soil layer, the method using concrete blocks or caissons does not require one or more methods such as deep mixing, sand replacement, sand piles, and rubble mounds to form the installation foundation. method to improve soft ground.

[Problem to be solved by the invention]

Among the conventional bank protection construction methods described above, those that involve improving soft ground during foundation formation often require this to be performed as separate construction work, which requires a large amount of construction time and cost.

In addition, in cofferdam construction methods that use metal members such as steel sheet piles,
In areas with harsh corrosive environments, such as splash zones, steel materials are severely corroded, and even with anti-corrosion measures such as concrete coatings, it is not sufficient in the long term.

The present invention solves the disadvantages of the conventional example, and provides a method for constructing a seawall structure that can be constructed easily and inexpensively, and the completed seawall structure has high durability against corrosion by seawater. It is in.

[Means to solve the problem]

In order to achieve the above object, the present invention drives a pile so that the pile head protrudes into the seabed, and tows a concrete structure having a floating chamber and a joint hole in the bottom plate to the piling site,
The pile is sunk so that the head of the pile is inserted into the joint hole, and underwater concrete is placed in the gap between the joint hole and the pile to fix it, or the pile has a floating chamber and the joint hole is formed in the bottom plate. The gist of this method is to tow a concrete structure, sink it into a designated location, then drive piles into joint holes, and finally place underwater concrete in the gap between the joint hole and the piles to secure the structure.

[Effect]

Construction of reinforced concrete structures supported by piles is common on land, but due to the difficulty of underwater construction and the resulting lack of reliability, it has not been carried out in trenches except for exceptionally small-scale construction. Not yet.

According to the present invention, parts of the concrete structure can be fabricated in advance on the ground, and all that is required is to tow it, sink it, and join it to the piles. Therefore, underwater work is also simple and minimal.

In addition, the resulting seawall structure in the Supranosh zone is a concrete structure, which is sufficiently resistant to corrosion by seawater.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIGS. 1 to 4 are longitudinal sectional side views of each step showing a first embodiment of the construction method for a seawall structure of the present invention.

First, as shown in Fig. 1, a trench 1 is placed on the seabed at the seawall construction site using a work boat 2 or the like. At the time of driving, the upper end of the pile l protrudes above the water surface, but it is then cut at a predetermined height such that the pile head 1a protrudes above the seabed, as shown in FIG.

On the other hand, on the ground, a caisson as a concrete structure having a floating chamber 4 and a joint hole 5 formed in the bottom plate 6 as shown in FIGS. It is floated in water and towed by a boat 3 to the location where the drag l is installed.

In this case, the buoyancy chamber 4 has a volume necessary for levitation, and in order to balance the levitation posture, it must have multiple chambers.

The joining hole 5 is larger than the diameter of the resistor 1 and is formed outside the floating chamber 4, with reinforcing bars 7 arranged around it as shown in FIGS. 8 and 9, and as described later, When joining with the bottom plate 6, it is desirable that the bottom plate be shaped so that the resistor 1 can be easily inserted and can withstand the punching shear that occurs between the resistor 1 and the bottom plate 6.

As shown in FIG. 10, the pile head 1a of the pile 1 is dug down to the required depth, and the metal fitting 8 is inserted into the bottom support as shown in FIG.

The caisson that has come above this pile 1 is submerged by adjusting water injection into the floating chamber 4, and the pile head 1 is placed so that the bottom support rests on the metal fitting 8.
a into the joining hole 5. In addition, the amount of water injected into the floating chamber 4 should be adjusted so that excessive overcurrent does not act on the bottom receiver and the metal fitting 8, and the caisson does not move due to subsequent changes in the tide level or the influence of concrete placed underwater, which will be described later. Necessary to maintain a good balance.

Then, as shown in Figure 12, a water-inseparable admixture (or separation reducing agent) is mixed into the gap between the resistor 1 and the joint hole 5 to give consistency to the concrete and prevent material separation in water. Underwater pouring concrete 9, which is underwater inseparable concrete, is placed and fixed.

After doing this, as shown in Fig. 4, the inside area surrounded by the caissons is reclaimed to create a reclaimed land 1o.

FIG. 17 shows a second embodiment of the present invention, in which an L-shaped block is used instead of a caisson as the concrete structure.

Details of the curved block are shown in FIGS. 13 to 16.
It is the same as the caisson described above in that it has a floating chamber 4 and a joint hole 5 is formed in the bottom plate 6, and the steps are also the same.

Furthermore, as another example, although not shown, the first
In the example, the bank protection structure shown in FIG. 3 was first deposited, and then the piles l were driven into the joint holes 5 and the pile heads were cut.
Finally, it is also possible to use a method of pouring and fixing concrete 9 that does not separate underwater into the gap between the pile 1 and the joint hole 5.

This method has the advantage that it is relatively easy to align the placement position of the resistor l compared to the first embodiment.

〔Effect of the invention〕

As described above, the construction method of the seawall structure of the present invention eliminates the need for ground improvement work to support concrete structures such as caissons using conventional construction methods even if the seabed ground is soft, and furthermore, it minimizes the need for underwater construction. This can be expected to significantly shorten the construction period and reduce construction costs.

In addition, the splash zone of the completed seawall structure is made of concrete, and is sufficiently resistant to corrosion by seawater.

[Brief explanation of drawings]

Figures 1 to 4 are longitudinal sectional side views of each process showing the first embodiment of the construction method for a seawall structure of the present invention, Figure 5 is a plan view of the caisson used, and Figure 6 is the same as that of Figure 5. A-A line sectional view, 7th
The figure is a sectional view taken along B-B'm of the same as above, Figure 8 is a vertical cross-sectional side view of the joining hole portion, Figure 9 is a cross-sectional plan view of the same as above, and Figures 10 to 1.
Figure 2 is a vertical side view showing the process of joining piles and concrete structures, Figure 13 is a plan view of the L-shaped block used, Figure 14 is a sectional view taken along the line A-A in Figure 13, and Figure 15 is a cross-sectional view of the L-shaped block used. Same as above B
-B sectional view, Fig. 16 is the same C-C sectional view, Fig. 17
The figure is a longitudinal sectional side view showing a second embodiment of the present invention. 1... Resistance 1a... Pile head 2...
・Work boat 3...Ship 4...Floating room
5...Joining hole 6...Bottom plate
7...Reinforcing steel bars 8...Bottom supports are metal fittings 9...Concrete placed in water 10...Landfill site Figure 1

Claims (2)

[Claims] (1) Piles are driven so that the pile heads protrude into the seabed, and a concrete structure with a floating chamber and a joint hole formed in the bottom plate is towed to the pile driving site, and the pile head is inside the joint hole. A method of constructing a seawall structure, which is characterized by inserting the structure into the pile, and fixing it by pouring underwater concrete into the gap between the joint hole and the pile. (2) A concrete structure with a floating chamber and a joint hole formed in the bottom plate is towed and sunk in a designated location, then piles are driven into the joint hole, and finally concrete is placed underwater in the gap between the joint hole and the pile. A construction method for a seawall structure characterized by pouring and fixing.