JPS6119764B2 - - Google Patents

Description

[Detailed Description of the Invention] Currently, there is a demand for the development of port technology that can be used at deep water locations with poor sea and soil conditions while preserving the marine environment. In particular, in soft ground where sludge and the like have accumulated, environmental problems in removing sludge and economic problems in ground improvement, etc., have become major issues. In fact, when a breakwater structure is constructed using gravity stabilization, a large amount of cost and construction time is required for ground improvement, mound creation, etc.

The present invention has been proposed in order to eliminate these drawbacks, and consists of a spud that is inserted into the four corners of the caisson so that it can be raised and lowered via lifting and lowering gripping devices, and a support pile penetration hole is provided in the bottom plate. The present invention relates to a pile-supported breakwater caisson, characterized in that the spuds are configured to be used as piles after installation.

Since the caisson according to the present invention is constructed as described above, after being towed to a predetermined position, the spud, which is fitted into the caisson so that it can be raised and lowered, is lowered by the lift gripping device and landed on the bottom. At the same time as water is poured into the caisson, the elevating and lowering gripping device is operated to lower the caisson to a predetermined position, thereby ensuring the fixation of the caisson part under construction. A support pile is inserted through the penetration hole to a specified support layer, and the caisson is supported by the support pile.
At this time, the spuds are also used as support piles.

According to the present invention, the caisson that has been towed to a predetermined position is supported on the seabed support layer via the spuds and support piles inserted into the caisson, so there is no need to perform ground improvement. , it is possible to construct a wave-break structure on soft ground, and the support pile is built inside the caisson using the support pile penetration hole of the caisson bottom slab and then towed to the specified position.
Support piles can be driven immediately, so
This can shorten the construction period.

In addition, since the rotation of the support pile is restrained near the submerged caisson bottom plate, its free protrusion length can be shortened, and not only straight piles but also oblique piles can be constructed, and deformation when external forces are applied can be reduced. In combination with the use of spuds to double as piles, it is possible to construct foundation piles economically.

Further, according to the present invention, since the caissons manufactured on land serve as the outer shell of the structure, large structures can be rapidly constructed, and the on-site construction period can be shortened.

By making the caisson of the present invention a transparent type, it is possible to dissipate waves without preventing the flow of seawater, which is advantageous for environmental conservation.Also, by providing fenders on the front or rear wall, it is possible to dissipate waves without preventing the flow of seawater. Furthermore, by providing slit holes in the front wall and a retarding section inside the caisson, wave reflectivity can be significantly reduced, making it difficult for nearby ship navigation and fishing operations. Do not cause any problems.

The present invention is also characterized in that in the caisson, the support pile penetration hole provided in the bottom slab is closed with a temporary cover that withstands only water pressure and is punched out when the column falls, and the penetration hole is buoyancy is imparted to the caisson by making it withstand water pressure when the caisson is towed, so that the caisson can be towed smoothly to a predetermined position, and the work of penetrating the support pile through the penetration hole can be carried out without any hindrance. The purpose is to ensure that

The present invention will be described below with reference to the illustrated embodiments.

A is a concrete caisson which itself constitutes the frame of the completed structure, with spuds 1 disposed at its four corners and supported so as to be able to rise and fall via a known elevating and lowering gripping mechanism B.

A support pile penetration hole 3 is bored in the bottom slab 2 of the caisson A, and when towing with the support pile installed, a casing pipe 4 is drilled on the extension of the penetration hole 3.
This temporarily supports the support pile 5 made of, for example, a steel pipe pile. In addition, the penetration hole 3
In the case of floating towing, the bottom plate 2 is sealed by a temporary cover 6 temporarily supported by bolts on the lower surface of the bottom plate 2 so as to withstand water pressure during towing.

In the case of a wave-dissipating type caisson, a vertical slit hole 7 having an aperture ratio according to necessary conditions is provided in the front wall of the caisson A, and a drop iron plate 8 is fitted therein. In the case of a transparent wave absorber, vertical slits will be provided in both the front and rear walls, and the interior will be filled with chestnut stone, crushed stone, etc. as necessary after construction is completed on site.

(See Figures 1 and 2) Only the section of the caisson A where the spud 1 is installed is left open on both the top and bottom to allow the spud 1 to move up and down freely, and has a slit section on the front or back wall. In such a case, a drop iron plate 8 or a rubber plate is fitted as described above to prevent water from entering.

In the case of floating towing, a temporary cover 6 is provided over the support pile penetration hole 3 of the bottom slab 2, and the caisson A is towed to a predetermined position with the spud 1 and support pile 5 erected. In the case of pneumatic towing, support pile penetration holes are provided in both the bottom slab and the top slab, and the top slab is temporarily covered for towing, or the penetration holes are provided only in the bottom slab and a pneumatic cap is provided to secure the caisson in place. Towed to location. Note that C in the figure is a tugboat. (See Figure 3) After caisson A was towed to a predetermined position, caisson A was positioned using the towboat and anchor wire. Next, the spud 1 is lowered by the elevating and lowering gripping mechanism B, and is brought to the bottom. After the spud 1 reaches the bottom, water is poured into the caisson A and at the same time the elevating and lowering gripping device B is operated to lower the caisson A to a predetermined position. If there is a possibility that the ground will be scoured, construction will be carried out to prevent scouring using asphalt mats, etc. (See Figure 4) Next, by removing the fulcrum between the casing pipe 4 of the temporarily supported support pile 5 and the support pile 5, the support pile 5 will fall and cover the temporary cover 6 of the penetration hole 2. After removing the support pile 5 and allowing the support pile 5 to sink freely, use an offset hammer or a vibrohammer to drive the support pile 5 to a predetermined support layer. D in the figure is a pile driving ship.

After driving the support piles 5, the casing pipe 4 and the support piles 5 are temporarily assembled using a shear connector and a liner plate, and top concrete is placed in the row of piles to provide an upper strut. When the pile head is installed underwater, the support pile 5 is driven down to the required position in the water by hammer driving. (See Figure 5) When the driving of the support pile 5 is completed and the top concrete strut of the pile row reaches the required strength, the gap between the bottom slab 2 and the support pile 5 is tightened to the support pile 5 by a diver. The concrete is sealed with a waterproof band 9 (see FIGS. 7 and 8), and underwater concrete 10 is placed.
The inside of caisson A should be kept in a water-retentive state or filled with chestnut stone, etc., as necessary.

In the case of a wave-dissipating caisson or a wave-dissipating transmission caisson, the steel plate or rubber plate fitted into the slot in the front or rear wall is pulled up, and concrete is poured for the top slab E, parapet, etc. to complete the structure. . (See Fig. 6) Figs. 9 to 12 show various structures using the caisson of the present invention, Fig. 9 shows an upright wave-dissipating and transmitting dam, Fig. 10 shows a wave-dissipating dam, and Fig. 11 shows a large-scale structure. wave-dissipating dyke,
FIG. 12 shows a low wave force trapezoidal transmission type wave breakwater, and in the figure, parts equivalent to those of the above embodiment are given the same reference numerals.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Fig. 1 is a plan view showing an embodiment of a caisson according to the present invention, Fig. 2 is a longitudinal sectional view thereof, and Figs. 3 to 6 are longitudinal sectional views showing construction steps of a structure using the caisson. 7 is a vertical cross-sectional view of the water stop portion of the support pile, FIG. 8 is a plan view thereof, and FIGS. 9 to 12 are slope views showing each example of a structure using the caisson of the present invention. It is. A...Caisson, B...Spud lifting/lowering gripping device, 1...Spud, 2...Bottom plate, 3...Support penetration hole, 5...Support pile, 6...Temporary cover.

Claims (1)

[Claims] 1 Spuds are inserted into the four corners so that they can be raised and lowered via lift gripping devices, and support pile penetration holes are provided in the bottom slab, and the penetration holes can only withstand water pressure and cannot be driven by falling piles. A pile-supported caisson for a breakwater, characterized in that the spud is closed with a temporary cover that can be removed, and the spuds are used as piles after the caisson is installed.