JP2000017669A - Underwater excavation construction method for constructing open caisson - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underwater excavation construction method for constructing an open caisson, by which the quick execution of works is carried out without deteriorating the excavation capacity of a ground at the time of the building of the open caisson in large depth and which contributes even to the reduction of cost. SOLUTION: Guide rails 12, 12 to be disposed near the lower end section of the open caisson 1 are arranged in a freely vertically movable manner along guides 10, 10 extended to upper and lower sections in the vertical direction of the internal side face of the open caisson 1. A cutter 15 for an underwater excavator 13 with a cutter installed to the guide rails 12, 12 in a freely travelling manner is formed in an extensible and rotatable manner while a ground is excavated up to specified excavation depth while monitoring a TV monitor for a remote control chamber 17, and the open caissons 1 can be penetrated successively into an excavated pit 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater excavation method for constructing an open caisson, and more particularly to an underwater excavation method for constructing an open caisson while excavating a ground to a large depth by remote control. It relates to the excavation method.

[0002]

2. Description of the Related Art One side of a conventional underwater excavation method for constructing an open caisson will be described with reference to FIG. FIG. 2 is a longitudinal sectional view showing a state where the open caisson 1 is sunk. In submerging the open caisson 1, a crawler crane 3 is arranged on a jacket scaffold 2 constructed on the sea, and a ground M is excavated by a grab bucket 4 suspended by the crawler crane 3. Further, the upper end portions of the anchors 5, 5... Which are previously cast around the vicinity of the sinking of the open caisson 1 are extended to a position above the jacket scaffold 2, and each of the anchors 5, 5. Are installed at the upper end of the anchor, and the anchors 5, 5
Are the reaction force receivers, and are laid down to a predetermined depth while penetrating the open caisson 1 into the excavation hole 7 by the pressurizing operation of the pressurizing devices 6, 6,.

In the figure, reference numeral 8 denotes the open caisson 1
Is penetrated to a predetermined depth, the open caisson 1
Underwater concrete cast near the lower end of
Indicates bottom slab concrete cast on the underwater concrete 8.

[0004]

The grab-bucket method for constructing the above-mentioned conventional open caisson has the following problems.

[0005] There is a limit to the speed at which the crawler crane raises and lowers the grab bucket, and when the grab bucket is deepened, the construction capacity is greatly reduced. When excavating the ground by the grab bucket method, the construction capacity is easily influenced greatly by the properties of the soil, and in particular, some auxiliary measures are required for a gravel layer having an N value of 50 or more, which greatly increases the construction cost.

[0006] Because excavation at the cutting edge formed at the lower end of the open caisson cannot be performed uniformly, variation occurs in the settlement accuracy (inclination) of the open caisson. Since the excavation by the grab bucket is discontinuous, the construction work of the open caisson on the ground and the excavation work cannot be performed in parallel, and the construction takes a long time.

[0007] Since the excavation at the cutting edge portion formed at the lower end portion of the open caisson cannot be performed uniformly, the press input of the open caisson becomes large,
The cost of press-in equipment increases.

In view of the above-mentioned deficiencies, the present invention can improve the construction accuracy without lowering the excavating ability of the ground when constructing an open caisson at a large depth, can further shorten the construction period, and can reduce the cost. There are technical issues that need to be solved to enable underwater drilling for the construction of open caisson that can contribute to
An object of the present invention is to solve the problem.

[0009]

SUMMARY OF THE INVENTION The present invention has been proposed in order to achieve the above object, and is an open caisson that is open up and down, and a guide rail to be arranged near the lower end of the open caisson. Is disposed movably up and down along a guide extending vertically above and below the inner surface of the open caisson, and further, a cutter of the underwater excavator with a cutter movably mounted on the guide rail. The present invention provides an underwater excavation method for constructing an open caisson, which is formed so as to be extendable and retractable and swivel, excavates the ground to a predetermined excavation depth by remote control, and allows the open caisson to sequentially penetrate into the excavation hole. Things.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to FIGS. The same components as those in the conventional example shown in FIG. 4 are denoted by the same reference numerals.
On the inner surface of the open caisson 1, guides 10, 10,... Are provided as shown in FIG. Thus, the guide 1
Are formed so that the respective ends of the elevating member 11 connected to the girder are loosely fitted, and the elevating member 11 can be freely moved up and down. Also, among the elevating members 11, the members assembled on the left and right in FIG. 3 are guide rails 12, and an underwater excavator 13 with a cutter is attached to the guide rails 12. Thus, the underwater excavator 13 with cutter is configured to be able to travel freely within the travel range of the guide rails 12, 12 by the slide block 14, and the cutter 15 of the underwater excavator 13 with cutter is an intermediate one. It is formed to be extensible and pivotable via an arm 16 and the like, and is formed so that the ground can be excavated by the cutter 15 while monitoring a television monitor of a remote control room 17 installed on the ground. As a result, the lower end of the open caisson 1 can be uniformly excavated in the vicinity of the blade 1a (the blade opening) and the ground M formed in a sharp shape. Of course, the underwater excavator 13 with the cutter is naturally lowered and fixed near the lower end of the open caisson 1 when excavating the ground.

The earth and sand excavated by the cutter 15 is sucked into a mud discharge pipe 19 by a sand pump 18 together with muddy water. An air lift pipe 20 is connected to the discharge port of the sand pump 18 of the exhaust pipe 19,
Further, the air lift pipe 20 is connected to an air compressor 21 installed on the ground, and the air compressor 21
Compressed air flows through the air lift pipe 20 through the exhaust pipe 1
9, the earth and sand and the muddy water sucked into the exhaust pipe 19 are sent into the cyclone screen 22 on the ground by an air lift through the exhaust pipe 19. In the cyclone screen 22, the mixture of the muddy water and the earth and sand is subjected to solid-liquid separation, and the separated muddy water is separated into a sedimentation tank 23.
The muddy water in the sedimentation tank 23 is supplied to the open caisson 1 by the submersible pump 24 in accordance with the set water level in the open caisson 1. On the other hand, the sediment separated by the cyclone screen 22 is sent into a sediment pit 25, and the sediment in the sediment pit 25 is loaded on a dump truck 27 by a backhoe 26 and transported.

After the open caisson 1 has completed excavation of the cutting edge portion of the open caisson 1 and the ground M by the underwater excavator 13 with a cutter, the open caisson 1 is opened if the weight of the open caisson 1 is insufficient or the sinking weight is insufficient. After a rod is penetrated into the vicinity of the caisson 1 by a pressure device 6, 6,..., Such as a center hole jacker, installed at the upper end of an anchor 5, 5,. The crawler crane 3a waiting on the jacket scaffold 2 performs an extension work for the next one rod, excavates to a predetermined excavation depth, and repeats the penetration of the open caisson 1 while repeatedly performing the open caisson 1. 1 at a large depth.

Further, a remote operation excavation system is provided in the remote operation room 17, and ground excavation operation is performed based on an operation command of the remote operation excavation system, thereby improving construction accuracy and improving construction accuracy. The excavation process can be shortened, construction costs can be reduced, and safe construction is possible.

Further, since the underwater excavator 13 with the cutter is installed on the elevating member 12 incorporated in the well girder, when a trouble occurs in the underwater excavator 13 with the cutter or the like, or when maintenance is performed, Lifting member 1
1 can be lifted and removed, so that repair or maintenance work for such accidents can be performed extremely easily.

Further, when the ground M is excavated by the underwater excavator 13 with the cutter, groundwater flows in naturally in keeping with the excavation and maintains the balance, so that supply of new transparent water is unnecessary. .

In the figure, reference numeral 28 denotes a generator, 29 denotes a pump control panel, and 30 denotes a power line. Further, the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.

[0017]

According to the present invention, as described in detail in the above-mentioned embodiment, an elevating member is vertically movably provided on a guide provided on the inner surface of the open caisson in a vertical direction. Since the underwater excavator with a cutter is mounted on the guide rail of the above, the underwater excavator with the cutter can travel freely within the range of the guide rail, and the cutter can be extended and retracted and swiveled, and the Since the excavation operation is performed based on the operation command of the open caisson remote operation excavation system while monitoring the television monitor in the operation room, excavation of the open caisson cutting edge portion and the ground is performed uniformly. Therefore, the construction accuracy is improved and the excavation process is shortened, the construction cost is greatly reduced, and furthermore, it contributes to safety and is most effective especially for construction of an open caisson at a large depth, and The underwater excavator with a cutter can move up and down along the guide on the inner surface of the open caisson, so that the underwater excavator with a cutter can be lifted during maintenance or when a trouble occurs. This is an invention that has a truly remarkable effect, such as that the repair or maintenance work can be performed extremely easily and contributes to a significant cost reduction as a whole.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an embodiment of the present invention and illustrating a laid state of an open caisson.

FIG. 2 is a partially cutaway longitudinal sectional view showing the vicinity of an underwater excavator with a cutter.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an explanatory vertical sectional view showing a conventional open caisson sunk state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Open caisson 6 Pressurizing device 7 Drilling hole 10 Guide 11 Elevating member 12 Guide rail 13 Underwater excavator with cutter 17 Remote control room

Continued on front page (72) Inventor Shigeru Watanabe 2-10-5 Katamachi, Miyakojima-ku, Osaka-shi, Osaka Inside Kumagaya Gumi Osaka Branch (72) Inventor Hidenobu Yoshida 2- 10-5 Katamachi, Miyakojima-ku, Osaka-shi, Osaka No. Kumagaya Gumi Osaka Branch (72) Inventor Noriyasu Terada 2-10-5 Katamachi, Miyakojima-ku, Osaka City, Osaka Inside Kumagaya Gumi Osaka Branch

Claims (1)

[Claims] 1. An open caisson that is open up and down,
A guide rail to be disposed near the lower end of the open caisson is vertically movably disposed along a guide extending vertically above and below the inner surface of the open caisson. The cutter of the underwater excavator with a cutter movably mounted on the excavator is extensible and swivelable, and excavates the ground to a predetermined excavation depth by remote control, and the open caisson can sequentially penetrate into the excavation hole. Underwater excavation method for building open caisson.