JP2844024B2 - Fixed caisson blade and water-stop 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 caisson blade fixing and water stopping structure.

[0002]

2. Description of the Related Art When constructing an artificial island on the sea and constructing facilities such as a nuclear power plant or a sewage treatment plant on the artificial island, construction work is avoided due to severe natural conditions (weather, sea conditions) in the sea construction. At the same time, in order to protect the natural environment, it is necessary to reduce construction and systematize construction work at the current location as much as possible. Therefore, a rapid construction method as shown in FIG. 5 has been considered as a construction method under such conditions. In this method, an annular caisson 1 is manufactured using an existing dock or a dry dock, and the caisson 1 is towed to an installation site. This is a method in which concrete 3 is cast and fixed.

[0003]

In the case of the above construction method, the caisson can be applied to any shape such as a circle and a rectangle.
External water pressure acts on the outer periphery of the caisson body due to the dry-up inside the caisson (the right half in FIG. 5), and the body deforms inward. In addition, there is a problem that earth pressure and residual water pressure act on the periphery of the caisson skeleton due to backfilling in the caisson (the left half in FIG. 5), causing outward deformation of the skeleton. Further, at the time of such deformation, the cutting edge 11 and the filled concrete 3
And a gap is generated between them, which causes a problem of a decrease in water stoppage.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to reduce the deformation of a caisson skeleton when an external force acts on the skeleton, and to reduce the cutting edge of the blade. It is an object of the present invention to provide a caisson blade port fixing and water-stopping structure capable of improving water-stopping. That is, the caisson blade portion is slidably installed in a groove excavated at the bottom of the water, and an elastic member in a horizontally compressed state is arranged around the blade portion. And a water stop structure.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. <A> Structure of sliding bearing In order not to generate stress in the frame when the caisson 1 is deformed, the blade port 11 is configured to be slidable in the horizontal direction according to the deformation of the caisson 1. For that purpose, a sliding bearing composed of the low friction body 4 and the low friction elastic body 41 is adopted. First, a low friction member 4 such as a stainless steel plate having a low friction coefficient is attached to the bottom surface of the blade opening 11 of the annular caisson 1 by welding or the like. Further, a low friction elastic body 41 having a low friction coefficient and elasticity is attached to the lower surface of the low friction body 4. For the low friction elastic body 41, a rubber plate or the like coated with Teflon is used. Therefore, the friction coefficient of the contact surface between the low friction body 4 and the low friction elastic body 41 is extremely low, and the blade port 11 can slide when the caisson 1 is displaced. Further, the low friction elastic body 41 also has a purpose of achieving uniform contact with the rock surface. <B> Elastic body A plate-like elastic body 5 for absorbing the horizontal displacement of the caisson 1 and for stopping water is attached to the entire circumference of the inner and outer peripheral surfaces of the blade opening 11. The elastic body 5 is made of a rubber plate or the like, and is made to have a thickness sufficient to absorb the horizontal displacement of the caisson 1. <C> Inflation material injection pipe In the skeleton of the caisson 1, an inflation material injection pipe 6 is installed vertically, and the opening at the lower end of the infusion pipe 6 extends over the entire inner and outer peripheral surfaces of the blade opening 11. Open multiple locations. In addition, the upper end of the injection pipe 6 is connected to a pump for feeding an inflatable material at sea. <D> Cover plate A cover plate 7 projecting in the horizontal direction is joined to the upper portion of the elastic body 5 on the inner and outer peripheral surfaces of the blade opening 11 by welding or the like. The cover plate 7 has a projecting area capable of closing the upper surface of the installation groove 2. In addition, a packing 71 made of rubber or the like is attached along the lower edge of the protruding tip side, and on the upper surface,
A reinforcing plate 72 such as a triangular plate is joined. When the expanding material is filled, the upper surface of the installation groove 2 can be closed by the cover plate 7, so that the expanding material can be prevented from escaping into water and from contaminating seawater. <E> Expanding material The expanding material 8 is filled in the gap between the blade opening 11 and the installation groove 2,
The blade opening 11 is fixed. This expanding material 8 includes
The main component is calcium oxide (CaO), and a lightweight aggregate or a mixture of sand and water for adjusting the expansion pressure is used. That is, the caisson 1 is fixed and water is stopped by using the expansion pressure generated by the reaction of calcium oxide with water. Since the expanding material 8 contains calcium oxide as a main component, the curing speed is higher than that of a general cement-based filler, and the expanding material 8 can be fixed immediately after the caisson 1 is installed. The fixing strength of the caisson 1 to the rock can be easily changed by adjusting the expansion pressure by changing the composition of the mixture of the expanding material 8 or by changing the strength and thickness of the elastic body 5. be able to.

[0006]

[Construction method] The caisson 1 constructed as described above is towed to the site, and the cutting edge 11 is installed in the installation groove 2 which has been excavated in advance to the installation layer such as rock on the water floor. Next, the expansion material 8 is simultaneously filled into the gaps on the inner and outer circumferences between the blade opening 11 and the installation groove 2 via the injection pipe 6. At this time, since the upper surface of the installation groove 2 is closed by the cover plate 7, the expanding material 8 does not deviate into the water. When the expansion material 8 is hardened, the caisson 1 is fixed to the bedrock or the like.

[0007]

The present invention has the following functions. <A> Suppressing Action of Body Deformation The blade port 11 of the caisson 1 is configured to be slidable in the horizontal direction by a sliding bearing composed of the low-friction body 4 and the low-friction elastic body 41. Therefore, when an external force acts on the caisson 1, the caisson 1 slides in the direction in which the external force acts, so that stress generated in the skeleton is reduced, and deformation of the skeleton can be suppressed. <B> Water Stopping Action of Blade Portion As shown in FIG. 2, the elastic body 5 before filling the expanding material 8 is in a state of maintaining the shape at the time of attachment. The width of the elastic body 5 at this time is indicated by L. When the expansion material 8 is filled,
The inflatable material 8 expands, and as shown in FIG. 3, the elastic members 5 on both the inner and outer sides contract equally by l1 due to the inflation pressure. The blade port 11 is fixed with the elastic body 5 contracted in this manner. Therefore, the elastic body 5 is pressed against the inner and outer peripheral surfaces of the blade opening 11 and the water stopping effect can be enhanced. Next, as shown in FIG. 4, when an external force from the inner peripheral surface acts on the caisson 1 and the frame is displaced, the elastic body 5 on the outer peripheral surface is further compressed by l2. On the other hand, the elastic body 5 on the inner peripheral surface side expands while following the blade port 11 because the compressive force is reduced and the restoring force is applied. Therefore, the blade opening 11
Since the elastic body 5 can maintain the state in which the elastic body 5 is pressed against both the inner and outer peripheral surfaces, a high water stopping effect can be maintained even if the caisson 1 is displaced. The same effect can be obtained when an external force acts from the outer peripheral surface side of the caisson 1.

[0008]

Since the present invention has been described above, the following effects can be obtained. <A> The blade portion of the caisson is configured to be slidable in the horizontal direction. Therefore, when an external force acts on the caisson, the caisson slides in the direction in which the external force acts, so that the stress generated in the skeleton is reduced, and deformation of the skeleton can be suppressed. <B> Even when an external force acts on the caisson from the inner and outer peripheral surfaces, and the frame is displaced, the elastic body can be kept pressed against the inner and outer peripheral surfaces of the blade port. Therefore, even if the caisson is displaced, a high water stopping effect can be maintained. <Iii> Since the expanding material contains calcium oxide as a main component, the curing speed is higher than that of a general cement-based filler, and the expanding material can be fixed immediately after the caisson is installed. Therefore, the caisson can be fixed immediately even in offshore construction under adverse conditions, and the safety is high.

[Brief description of the drawings]

FIG. 1 is an explanatory view of the structure of a caisson blade opening of the present invention.

FIG. 2 is an explanatory diagram of an elastic body in a state where no compressive force is applied.

FIG. 3 is an explanatory view of an elastic body in a state where the elastic body is compressed by expansion of an expansion material.

FIG. 4 is an explanatory view of an elastic body that follows the displacement of a caisson.

FIG. 5 is an explanatory diagram of a conventional technique.

Claims (1)

(57) [Claims] 1. A caisson blade in which a caisson blade is slidably installed in a groove excavated in a water bottom, and an elastic member in a horizontally compressed state is arranged around the blade opening. Fixed part and waterproof structure.