JPH02153115A - Floating method and device for submerging caisson - Google Patents

Abstract

PURPOSE:To execute work economically by setting an upper end above the surface of water via a water-tight packing on an upper surface after sand packed in a caisson is removed, and by covering the lower section with a cover provided with a rise section, to drain water with a pump in water and to permit the caisson to float on. CONSTITUTION:The upper section work 3 and cover concrete 4 or the like of a submerging caisson 2 are removed, and sand 5 packed in the caisson is removed by a sand pump or the like, and the floating device of the steel cover 6 or the like of a steel plate 6A and a plurality of H shape steels 6B is suspended in water with a crane or the like to cover the upper section of the caisson 2. Besides, between the upper surfaces of the outer peripheries of the cover 6 and the caisson 2, a water-tight packing 7 is set, and the upper end of the cover 6 is positioned above a water level W, L, and the respective members of the caisson 2 at the lower section are partitioned off by the partition walls 8 and rise sections 9. Then, through the respective chambers, the same water levels are respectively monitored by a pump in water and a drain quantity is regulated, and the caisson is permitted to float horizontally. As a result, a crane vessel is not needed, and work can be executed with safety.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for floating a submerged caisson, such as a submerged breakwater, by sliding on a rubble surface due to an external force such as waves larger than a design value. and devices.

[Conventional technology]

Caissons such as breakwaters are installed on the rubble mound 1 on the seabed as shown in Figure 4, but sometimes they slide off the rubble mound 1 due to external forces such as waves shown by arrow W that are larger than the design value. The caisson 2 may fall and become submerged in water, and in this case, the commonly used method for recovery in this case has been to hoist the submerged caisson 2 using a crane ship, etc.
This requires a crane ship or the like with a very large capacity, which increases the work cost, is uneconomical, and has the problem that the work is dangerous.

[Problem to be solved by the invention]

The present invention has been made to solve the above-mentioned conventional problems, and provides a method for floating a submerged caisson that can economically and safely float a caisson that has slipped from a predetermined installation location and is submerged in water. The object of the present invention is to provide a flotation device for use in this purpose.

[Means to solve the problem]

As a means for solving the above-mentioned problems, the method of floating a submerged caisson of the present invention involves removing the superstructure and cover concrete of a submerged caisson, removing the filling sand using a sand pump, etc., and then resurfacing the caisson. A steel lid is placed on the outer surface of the caisson through a gasket such as a bubble sponge to maintain the water quality, and the inside of the caisson is passed through a submersible pump.
This method is characterized by levitating the caisson by adjusting the amount of water discharged so that the water level in each chamber of the caisson is at the same level. and a steel lid to be placed over the top of the submerged caisson from which the filling sand has been removed, is provided with a rising part whose upper end is located above the water surface and whose lower part is at the intersection of the bulkheads that partition each chamber of the caisson; It is constructed by installing a water seal such as a bubble sponge between the steel lid and the upper surface of the outer periphery of the caisson, and the steel lid is placed over the submerged caisson through the water seal to drain water. , which creates buoyancy on the caisson and causes it to float.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of a procedure for levitating a submerged caisson by applying the method of the present invention and a levitation device used for the operation will be described below.

First, as shown in Fig. 4, the superstructure 3 of the caisson 2, which has fallen off the rubble mound 1 and submerged in water due to abnormal external forces, etc.
The cover concrete 4 and the like are removed by means such as a concrete breaker, and the filling sand 5 in the caisson 2 is removed by a sand pump or the like.

Next, as shown in Fig. 1, a steel plate 6A and a number of H-shaped steels 6B
The flotation device for the submerged caisson of the present invention, such as the steel lid 6, is suspended in the water by a crane or the like, and is placed over the top of the caisson 2. In between, for example, a gasket 7 for water nectar, such as a bubble sponge, is installed.

Further, as shown in FIGS. 2 and 3, this steel lid 6 has an upper end located above the water surface W, L, and a lower end that corresponds to each chamber of the caisson 2, for example, as in this embodiment. A rising portion 9 is provided at a position where partition walls 8, which are indicated by diagonal lines in FIG. 1 and partitioned into 12 chambers, intersect for convenience.

That is, in this embodiment, there are 4 rooms for 12 rooms in caisson 2.
rising portions 9 are provided, and these rising portions 9
By using multiple submersible pumps to drain water from all rooms in caisson 2, the water level in each room is monitored and the amount of water drained is adjusted individually so that the water level in each room is approximately at the same level. , levitate caisson 2 horizontally.

In addition, in order to be able to easily install the steel lid 6 even if the submerged caisson 2 is tilted, and to prevent the steel lid 6 from slipping off even after installation, a seal is placed at the end of the steel lid 6. is provided with a slip stop lO as shown in FIGS. 1 and 3.

On the other hand, the caisson 2 floated as described above is lowered and installed at a predetermined position on the upper part after the leveling work for repairing the rubble mound l shown in Fig. 4, and after filling the inside with filling sand 5, The upper lid structure will be rebuilt and the restoration work for the caisson will be completed.

[Effects of the Invention] As explained above, according to the method for floating a submerged caisson of the present invention, buoyancy is used to float the caisson, so there is no need for a large lane ship as in the conventional method. Since all that is required is a lane capable of suspending a flotation device made of a steel lid, the flotation work can be carried out very economically, and moreover, the work can be carried out safely.

In addition, since the rising parts of the steel lid are placed at the intersections of the partition walls that partition each chamber of the caisson, the number of rising parts is reduced to 4 when the number of rooms in the caisson is 12, for example. It is economical because drainage work can be done with only a few rising parts.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a steel lid constituting a flotation device for a submerged caisson according to the present invention, Fig. 2 is a side sectional view taken along the line AA in Fig. 1, and Fig. 3 is a sectional view taken along B-B in Fig. 1. 4 is a schematic side sectional view of a submerged caisson. 2...Caisson, 3...Superstructure, 4...Lid concrete, 5...Filling sand, 6...Steel lid, 7...Putskin for water honey, 8...Partition wall , 9... Rising part, W
, L...water surface.

Claims (1)

[Claims] 1. After removing the superstructure of the submerged caisson and removing the filling sand inside the caisson, a packing for water is placed on the upper surface of the caisson so that the upper end is positioned above the water surface. A method for floating a submerged caisson in which the caisson is raised to the surface while the water inside the caisson is drained via a submersible pump by covering the caisson with a lid that has a rising part at the intersection of the partition walls that partition each chamber of the caisson. 2. A steel lid that is placed over the top of the submerged caisson from which the superstructure and filler sand have been removed is fitted with a raised part whose upper end is located above the water surface and whose lower part is located at the intersection of the bulkheads that partition each chamber of the caisson. A flotation device for a submerged caisson, further comprising a packing for water honey between the steel lid and the upper surface of the caisson.