JPS6027333B2 - Method of sinking a box-shaped concrete foundation structure at the bottom of the water - Google Patents

Description

[Detailed Description of the Invention] Conventionally, in order to carry out revetment work on beaches, riverbanks, etc., for example, as shown in Fig. 1, a box-shaped foundation structure b made of concrete is sunk on the water bottom a, and a box is filled inside. Fill with earth and sand c,
Concrete blocks d are stacked on top of this, and the upper surface is finished flat with mortar e to form a quay f, and between this quay and the coast, riverbank, etc. is normal.

An object of the present invention is to provide a method for safely and economically sinking a box-shaped concrete foundation structure as described above to the bottom of water. Conventionally, the method shown in FIGS. 2 and 3, for example, has generally been used to sink box-shaped concrete foundation structures such as those described above to the bottom of water. In other words, the method shown in Fig. 2 is to float a box-shaped concrete substructure i with a cylindrical temporary wall i made of steel plates attached to the water around its upper surface on the water surface at the location where the box-shaped substructure is to be submerged. A water supply pipe k and a drainage pipe are inserted inside, and a water supply pump n installed on a work boat m supplies loaded water p through the suction pipe o and the water supply pipe k into the box-shaped foundation structure j and the temporary wall i. The box-shaped substructure j is then deposited on the water bottom q. However, if the footing position of the box-type foundation structure j deviates from the predetermined position during levering, the load water p is pumped through the drainage pipe and the discharge pipe s by the drainage pump r installed on the work boat m. The submergence is completed by draining the water to the outside, resurfacing the box-shaped substructure i, and correcting its position. In addition, the method shown in Fig. 3 uses a box-shaped concrete foundation structure i whose upper entrance is closed with a temporary cover u made of a steel plate through which a ventilation pipe t, a drainage pipe, and a water supply pipe k are penetrated in an airtight and watertight manner. Similar to the method shown in the figure, this box-shaped substructure j is floated on the water surface at the place where it is sunk, and a work boat m is placed inside it.
This box-shaped foundation structure i is sunk on the water bottom q by injecting loaded water p through a suction pipe o and a water supply pipe k using a water supply pump n installed above (in this case, the box-shaped foundation structure (The air inside the object j is discharged to the outside from the ventilation pipe t.) At this time, if the footing position of the box-type foundation structure j deviates from the predetermined position, the drainage pump r on the work boat m The loaded water p is drained through the drainage pipe 1 and the discharge pipe s, and the box-shaped foundation structure j is resurfaced. ) The installation is completed by correcting the hem position. Among the conventional methods described above, the method shown in Figure 2 requires the installation of a large temporary wall p with a height greater than the water depth at the location where the box-shaped substructure j is sunk, so a large amount of material for this temporary wall is required. The disadvantage is that steel plates are required, which increases the construction cost and is economically disadvantageous.

Furthermore, the method shown in Fig. 3 has the disadvantage that if there is an abnormality in the drainage pump r, water supply pump n, drainage pipe, water supply pipe k, ventilation pipe t, etc., it is extremely difficult to repair or replace it. There is. The purpose of the method of the present invention is to eliminate such disadvantages, and one embodiment of the method of the present invention will be described below with reference to FIGS. 4 and 5. In other words, the method of the present invention shown in this drawing, as shown in FIG. A box-shaped concrete foundation horizontal structure 4, on which a temporary cover 2 made of, for example, a steel plate, is attached with a shaft having a shape and is removably attached with bolts 3, is boiled on the water surface at the place where this structure is to be sunk, as shown in FIG. A water supply pipe 5 and a drainage pipe 6 are inserted into the shaft 1 installed on the temporary cover 2 of the box-shaped foundation structure 4, and then a water injection pump 8 and a drainage pump 9 installed on the work boat 7 are used. The hemming position of this structure is adjusted by adjusting the amount of the load water 12 injected into the box-shaped foundation structure 4 through the water injection pipe 5, suction pipe 10, drainage pipe 6, and discharge pipe 11. It is placed in a predetermined position on the bottom 13 of the water. However, once the lever has been submerged, a diver, for example, enters the water and removes the bolts 3, the temporary cover 2 and the shaft 1, and also removes the water supply pipe 5, drainage pipe 6, etc., and completes the box-shaped concrete foundation structure 4. This completes the installation of the As described above, according to the present invention,
During the work of submerging a box-type concrete foundation structure, the water injection pipe, drainage pipe, etc. inside the shaft may be blocked by foreign objects, for example.
If any other abnormality occurs, a worker will enter the shaft, inspect the water injection pipe, drainage pipe, etc., and repair it.
Since replacement etc. can be carried out extremely easily, there is an advantage that the box-shaped concrete foundation structure can be extremely safely and economically sunk to the bottom of the water.

Furthermore, since the box-type foundation structure is sunk using loaded water and does not require any other special fixing means on the water bottom, it has the advantage that the work can be done quickly and easily.

In addition, only the box-type foundation structure is ultimately submerged in water, and this box-type foundation structure has a relatively simple shape and is easy to configure, so it has the advantage of being very economical. be.

Furthermore, since the temporary cover with the shaft attached to the box-type substructure is designed to be removed eventually, it can be reused for other box-type substructures, which also has the advantage of being economical. be.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an example of conventional bank protection construction, Figures 2 and 3 are explanatory diagrams of two examples of the conventional method of sinking a box-shaped concrete foundation structure on the water bottom, and Figures 4 and 5 are The figure is an explanatory diagram of one embodiment of the method of the present invention. 4...Box-shaped concrete foundation structure, 5...
・Water injection pipe, 6...Drainage pipe, 1...Shaft, 2
...Temporary lid, 8...Water pump, 9...
... Drain pump 〇. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. After floating a box-shaped concrete foundation structure on the water surface at the location where the structure is to be submerged, workers can easily enter and exit the box-type concrete foundation structure and insert and remove water injection pipes, drainage pipes, etc. through the opening on the top of the box-type foundation structure. A temporary cover with a shaft having a cross-section of width and a height greater than the water depth of the submerged location of this box-type foundation structure is removably attached, and then water injection pipes, drainage pipes, etc. are inserted into the shaft. Load water is injected into the box-shaped foundation structure through these pipes using a water injection pump and a drainage pump while controlling the amount of water, and the box-shaped foundation structure is sunk at a predetermined position on the water bottom. A method for sinking a box-shaped concrete foundation structure at the bottom of water, characterized by removing a temporary cover with a shaft.