JPS6220352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arm-type underwater excavator used for constructing foundations for bridge piers and the like built on the ocean.

Conventionally, one method of constructing a pier foundation on the ocean is to float and tow a reinforced concrete barge, which has a plurality of pits and whose upper part is closed with a lid, to a predetermined location and install it on the underwater ground; After arranging a large number of earth retaining piles along the outer periphery of the earth retaining pile and driving them into the underwater ground, each earth retaining pile and barge are connected by appropriate means to prevent water leakage between the earth retaining piles and to reduce the lateral pressure applied to the earth retaining piles. In order to reduce this, compressed air is sent to the underside of the barge to form a pressurized air work chamber, and workers enter the pressurized air work chamber to excavate the underwater ground using a shovel type excavator. A known method is to construct a pier foundation by pouring additional concrete into the excavated cavity at the bottom.

However, in the case of the conventional pier foundation construction method, workers have to work in a pressurized work room at the bottom of the barge, which creates a poor and dangerous working environment, and has the problem of low excavation efficiency. .

It is also known to open the upper part of the shaft, excavate the underwater ground below the shaft with a clamshell that moves up and down inside the shaft, and excavate the underwater ground below the wall of the barge using jet water. There is.

However, in the case of this excavation method, excavation efficiency is low, and when the underwater ground is hard, excavation is difficult or impossible.

An object of the present invention is to provide an arm-type underwater excavator that can advantageously solve the above-mentioned problems.

Next, the present invention will be explained in detail using illustrated examples.

First, as shown in FIGS. 1 and 2, a barge 1 made of reinforced concrete having a large number of vertically penetrating vertical holes 2 is manufactured, for example, in a dock at a shipyard. A lid (not shown) is attached to the top of the barge 2, and after being floated and towed to a destination on the ocean, the lid is removed and the barge 1 is lowered to the underwater ground 3.

Next, a large number of earth retaining piles 12 are arranged closely or close to each other along the outer periphery of the barge 1 and are driven into the water bottom ground 3, and even if the water bottom ground 3 below the barge 1 is excavated, the barge 1 In order to prevent the barge 1 from descending, the barge 1 and each retaining pile 12 are coupled. As this coupling means, for example, each earth retaining pile 12
Concrete 13 may be placed between the head of the barge 1 and the upper part of the outer circumference of the barge 1, or other suitable connection means may be employed.

Next, as shown in FIGS. 3 and 4, a vertical column 4 made of a steel pipe pile with a circular cross section is inserted into the approximate center of the vertical hole 2 in the barge 1 and driven into the underwater ground 3. The interior is filled with reinforcing concrete 14 as required.

5 to 7 show an arm-type underwater excavator according to an embodiment of the present invention, in which an annular excavator holding member 6 fitted into the vertical column 4 so as to be able to rise and fall freely; A fixing fluid pressure cylinder 5 facing the outer surface of the vertical column 4 is fixed, and an annular rotating frame 8 is rotatably attached to the lower part of the holding member 6, and an annular driven gear 1 is attached to the rotating frame 8.
5 is fixed to the holding member 6, and a swing drive device 7 consisting of an underwater motor and a speed reducer is fixed to the holding member 6, and a pinion 16 fixed to the output shaft of the swing drive device 7 is connected to the annular driven gear 15. are interlocked with.

The upper end of the excavating arm 10 is attached to the lower part of the revolving frame 8 via a horizontal shaft 17 so as to be able to move up and down, and the lower end of the excavating arm 10 has a cutter drive device 18 consisting of a submersible electric motor and a speed reducer.
is fixed, and a drum-shaped rotary cutter 9 with a large number of picks attached to the front and circumferential surfaces is fixed to the output shaft of the cutter drive device 18, and furthermore, the middle part of the arm 10 and the rotating frame 8 are connected to the arm elevation. The excavating arm 10 is connected to the vertical column 4 by the hydraulic cylinder 19.
is tilted up and down in a vertical plane that includes the center line of the

A steel support frame 20 disposed above the shaft 2 is placed on the top surface of the barge 1 and is detachably fixed to the top of the shaft 4 with bolts or the like. The upper end of the lifting fluid pressure cylinder 21 is connected to the upper end of the suspension support/muddy water transport pipe body 23 which is constructed by connecting a large number of steel pipe units 22. The lower end of the tubular body 23 is connected to the holding member 6 .

The lower end opening of the metal slurry suction pipe 11, which has a suction function using an air lift pump or suction pump (not shown), is arranged close to the upper part of the rotary cutter 9, and is made of a rubber flexible hose. The lower end of the flexible mud water transport pipe 24 is connected to the upper end of the mud water suction pipe 11, and the upper end of the mud water transport pipe 24 is connected to the pipe body 23.
is connected to the bottom of the. Further, one end of the muddy water discharge pipe 25 is connected to the upper end of the pipe body 23, and the other end of the muddy water discharge pipe 25 is connected to a sedimentation tank 2 installed on the top surface of the barge 1.
A control box 27 is installed on the upper surface of the barge 1, and the control box 27, each of the hydraulic cylinders, each submersible electric motor, an elevation angle detector attached to the holding member 6, and a turning angle detector are installed on the upper surface of the barge 1. Detectors such as angle detectors, rotation position detectors, rotation speed detectors, ammeters, etc.
The arm-type underwater excavator is connected by a hose, cable, etc., and is operated while watching a display meter based on data from the detector in the control box.

When excavating using the arm-type underwater excavator of the above embodiment, first the rotary cutter 9 is placed near the vertical column 4, and the fixing fluid pressure cylinder 5 is relaxed or placed in a low pressure support state. , so that the underwater excavator can descend along the vertical column 4 by its own weight.

Next, while rotating the rotary cutter 9, the lifting fluid pressure cylinder 21 is extended to cut the rotary cutter 9 into the underwater ground 3, and then the fixing fluid pressure cylinder 5 is tensed and held in a strong pressure support state. The member 6 is firmly fixed to the vertical column 4.

Next, the rotating frame 8 and the part supported by it are rotated, and the rotary cutter 9 excavates, and the rotary cutter 9 moves around the vertical column 4 360 degrees.
After turning, the arm 10 is swung in a direction in which its lower end part moves away from the vertical column 4, and the rotating cutter 9 is moved by a distance approximately equal to its diameter, and then the rotating frame 8 and the parts supported by it are moved. The rotary cutter 9 is rotated 360 degrees in the opposite direction to perform excavation with the rotary cutter 9, and the same operation is repeated thereafter to perform excavation while enlarging the excavation diameter.

The earth and sand excavated by the rotary cutter 9 and other excavated debris are immediately sucked into the muddy water suction pipe 11 along with the muddy water, and then the flexible muddy water transport pipe 24 , the hanging support and muddy water transport pipe body 23 , and the muddy water discharge pipe 25 are sucked in together with the muddy water. Afterwards, it is discharged into the settling tank 26.

After excavating to a predetermined excavation diameter, the arm 10 is swung until the rotary cutter 9 reaches a position close to the vertical column 4, and then the fixing fluid pressure cylinder 5 is relaxed or placed in a low pressure support state. After that, the lifting hydraulic cylinder 21 is extended and the rotary cutter 9 is cut into the underwater ground 3 again. Next, after the fixing fluid pressure cylinder 5 is tensed to a strong pressure support state, excavation is performed while sequentially increasing the excavation diameter as described above.

After excavation is performed until the extension limit of the lifting hydraulic cylinder 21 is reached, the joint of the upper end pipe unit 22 of the hanging support/muddy water transport pipe 23 is separated, and the lifting hydraulic cylinder 21 is removed. After shortening the length of the pipe body 23 and extending the length of the pipe body 23 by adding a steel pipe unit 22, excavation is carried out again as described above.

After excavating the underwater ground below one shaft 2 and the underwater ground below the circumferential wall of that shaft to the required depth, for example, deep hard rock, the arm-type underwater excavator is moved to the shaft in the other shaft. After excavating the water bottom ground below all the shafts and the water bottom ground below the peripheral wall of all the shafts to the required depth,
As shown in FIG. 9 and FIG. 9, supplementary concrete 28 is placed across the cavity created by the excavation and the lower part of the barge 1, and a top slab concrete 30 having a protrusion 29 is placed at the top of the barge 1. Complete the foundation for the pier. Note that the protrusion 29
Piers will be installed on the bridge.

In the case of Fig. 8, supplementary concrete 28 and top slab concrete 30 are poured while leaving the vertical column 4, but as shown in Fig. 10, after the vertical column is extracted and collected, the supplementary concrete 28 and the top slab concrete 30 are placed. A concrete slab 30 may also be placed.

When carrying out this invention, a hydraulic cylinder, for example, is used as the fluid pressure cylinder.

In the case of the above embodiment, one arm-type excavator is attached to the revolving frame 8, but in order to improve excavation efficiency, two arm-type excavators are attached to both sides of the revolving frame on the diameter line. Good too. Further, the cross-sectional shape of the vertical column 4 may be any shape other than circular.

If a moving device such as a wheel is attached to the lower part of the support frame 20, after the lower part of one pit has been excavated, the support frame can be easily moved to the upper part of another pit.

According to this invention, the vertical pillar 4 is inserted into the substantially central part of the vertical hole 2 of the barge 1 and is driven into the underwater ground 3.
and a fixing fluid pressure cylinder 5 facing the vertical column.
A holding member 6 for an excavator equipped with an excavator is fitted so as to be able to rise and fall freely, and a swing frame 8 that is rotated by a swing drive device 7 is attached to the lower part of the holding member 6, and a rotating cutter 9 is provided at the lower part. The upper part of the excavation arm 10 is attached to the rotating frame 8 so as to be able to move up and down freely. The excavating arm 10 is rotated around the vertical column 4, and the excavating arm 10 is swung to move the rotary cutter 9 toward or away from the vertical column 4, and then the rotating frame 8 and By repeating the operation of rotating the excavation arm 10, the underwater ground below the shaft 2 of the barge 1 can be easily and highly efficiently excavated by mechanical force, and further It is possible to excavate a wide area, and even in hard ground, it can be easily excavated with the rotary cutter 9, and the barge 1
It is safe because there is no need for workers to enter the lower part of the machine to perform the work. In addition, since it is possible to excavate underwater, it is possible to excavate in a state of pressure equilibrium with the water level inside and outside being almost the same, which makes it possible to almost eliminate the collapse of the ground due to external pressure. The excavator holding member 6 is guided and lowered by the driven vertical column 4, and the excavator holding member 6 can be fixed at an arbitrary height of the vertical column 4 by the fixing fluid pressure cylinder 5. , it is possible to excavate to any depth regardless of the height of the barge 1, and since the lower end opening of the mud water suction pipe 11 is located close to the rotary cutter 9, the excavated earth and sand etc. Debris can be immediately and efficiently sucked in and discharged, and as a result, almost no earth, sand or other excavation debris remains in the cavity created by excavation, making it possible to place high-quality supplementary concrete, etc. .

[Brief explanation of the drawing]

Figure 1 is a vertical side view showing the barge installed on the underwater ground and the earth retaining piles driven in. Figure 2 is its plan view, and Figure 3 is a vertical column inserted into the center of the shaft of the barge. FIG. 4 is a longitudinal sectional side view showing the state in which it is driven into the underwater ground, and FIG. 4 is a plan view thereof. 5 to 7 show the state of use of an arm-type underwater excavator according to an embodiment of the present invention, in which FIG. 5 is a vertical side view, and FIG. 6 is a top view of the underwater excavator. FIG. 7 is an enlarged vertical side view of the lower part of the underwater excavator. FIG. 8 is a longitudinal side view showing a completed pier foundation, FIG. 9 is a plan view thereof, and FIG. 10 is a longitudinal side view showing another example of a completed pier foundation. In the figure, 1 is a barge, 2 is a pit, 3 is the underwater ground, 4 is a vertical column, 5 is a fixing fluid pressure cylinder, 6
1 is a holding member, 7 is a swing drive device, 8 is a swing frame, 9 is a rotating cutter, 10 is an excavation arm, 1
1 is a mud water suction pipe, 12 is an earth retaining pile, 15 is an annular driven gear, 16 is a pinion, 18 is a cutter drive device,
19 is a fluid pressure cylinder, 20 is a steel support frame, 21 is a lifting fluid pressure cylinder, 22 is a steel pipe unit, 23 is a pipe body for suspending support and transporting muddy water, 24
25 is a flexible mud water transport pipe, 25 is a mud water discharge pipe, 26 is a sedimentation tank, 27 is a control box, 28 is concrete, and 30 is top slab concrete.

Claims (1)

[Claims] 1. A holding member for an excavator, which is equipped with a vertical column 4 that is inserted into the approximate center of a vertical hole 2 of a barge 1 and driven into the underwater ground 3, and a fixing fluid pressure cylinder 5 that faces the vertical column 4. A rotating frame 8 is attached to the lower part of the holding member 6 and is rotated by a rotating drive device 7. An arm-type underwater excavator, characterized in that it is attached to the revolving frame 8 so as to be able to move up and down freely, and the lower end opening of the muddy water suction pipe 11 is disposed close to the rotary cutter 9.