JPH073055B2 - Underwater pile driving hammer and underwater pile driving method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pile driving hammer used when driving a pile such as a steel pipe on a water bottom, and an underwater pile driving method using the pile driving hammer.

(Prior Art) Generally, in order to drive ready-made piles such as RC piles and steel pipe piles into the bottom of the water,
The above-mentioned ready-made pile was driven in with a pile driving hammer of a pile driving ship. This will be described with reference to FIGS. 4 to 6. The ready-made piles 23 are installed on the pile-driving leader 22 of the pile-driving ship 21, and the pile-driving hammer 24
Is installed on the ready-made pile 23.

Then, the ready-made pile 23 is erected on the water bottom 25, and the pile driving hammer 24 is operated to perform the pile driving work.

FIG. 4B shows a state in which the pile driving work has been completed. From this state, as shown in FIGS. 4C and 4D, the ready-made pile 23 is cut at a predetermined water depth position D.

Here, the cut pile 23a is not wasted,
As shown in FIG. 4 (e), similar piles 23a are collected, arranged in series so as to have a required dimension length, and welded and joined.
The recycled pile 26 thus produced is used again as the ready-made pile 23.

Next, the pile driving hammer for pile driving will be described. Examples of this type of pile driving hammer include a diesel pile hammer and a hydraulic pile hammer. Of these, the former diesel pile hammer is composed of a striking ram, an anvil, a cylinder, a fuel pump, and the like, and drives the pile by moving the ram up and down on the same principle as a two-cycle diesel engine. The diesel pile hammer is widely used because of its strong driving force and good construction efficiency, but recently, its use is often restricted due to noise countermeasures.

On the other hand, the latter hydraulic pile hammer is composed of a hydraulic pile hammer body, a hydraulic unit, an operation control panel and the like. Explaining these, as shown in FIG. 5, the hydraulic pile hammer main body 27 is divided into a ram drive device 28 and a striking force transmission device 29. This ram drive 28 is a hydraulic control
It consists of 30 and hydraulic cylinder 31. And the hydraulic control unit
30 is equipped with a hydraulic unit 32 via a hydraulic pipe,
Further, an operation control panel 33 is provided. Reference numeral 34 indicates a casing, and 35 indicates a ram.

In order to operate the hydraulic pile hammer main body 27, as shown in the explanatory view of FIG. 6, there is a method of raising the ram 35 and then free fall, or a method of accelerating the ram 35. To explain this, in the free fall method, pressure oil is supplied from the hydraulic unit 32 into the rod chamber of the hydraulic cylinder 31 to raise the ram 35 to a predetermined height, and then the valve is switched to move the pressure oil in the rod chamber to the head side. It is a method of returning the ram 35 to the back and dropping it. On the other hand, in the accelerated fall method, when the ram 35 drops, the upper and lower chambers of the hydraulic cylinder 31 are switched to communicate with each other, so that the downward acceleration is obtained by multiplying the hydraulic pressure by the difference in the cross-sectional area of the upper and lower chambers of the hydraulic cylinder 31. Force F
It is a method of dropping the ram by adding.

In this way, the striking force of the ram 35 is the striking force transmitting device.
29 ram cushions 36, anvil 37 and pile cushions
It is transmitted to the pile 39 through 36a and the cap 38. As a result, the pile 39 is driven into the water bottom 25.

Since the water bottom 25 into which the pile 39 is driven often has different hardness, it is necessary to change the impact force of the ram 35 according to the softness of the water bottom 25. Therefore, the fall height of the ram 35
The operation control panel 33 using a timer, a photoelectric switch, a proximity switch, or the like (not shown) is used to adjust steplessly or stepwise.

In addition, the ram cushion 36 and the pile cushion 36a
Is made of cushioning material such as wood or rubber,
The striking force of the ram 35, which is its role, is equalized and the amount of noise generated is reduced.

(Problems to be Solved by the Invention) The conventional pile driving method described above has the following drawbacks. That is, since piles such as sheet piles and steel pipes are erected on the bottom of the water and the pile head protruding above the water surface is hit with a hammer, if the water depth becomes deep and the pile becomes long, the length of the pile driving leader will also be limited. Because there is
It becomes difficult to drive the pile.

Also, for the same reason, piles are often unavoidably long, which is uneconomical.After the completion of the pile driving work, the piles are cut at a predetermined water depth position and the cut piles are regenerated. Since the strength of the welded part of the recycled pile is inferior, it is expensive to produce and transport the recycled pile, and it is economically wasteful. Moreover, the pile is cut when the water depth is deep. It is difficult to work because it is often difficult to work, and when the water depth is deep, it is sufficient to hit the pile head underwater to prevent the pile length from increasing, but the construction accuracy is poor. At the same time, there were drawbacks such as difficult construction management.

The object of the present invention was made in view of the above-mentioned drawbacks,
An object of the present invention is to provide an underwater pile driving hammer capable of accurately driving a pile in water, and further to provide an underwater pile driving method in which construction management using the underwater pile driving hammer is easy.

(Means for Solving the Problems) The gist of the underwater pile driving hammer according to the present invention for solving the above problems and achieving the object is to provide a ram drive device for ascending and dropping a ram for hitting, and a hitting of the ram. In a pile driving hammer having a substantially cylindrical shape having a striking force transmission device for transmitting a force to a driving pile through a ram cushion and an anvil, the driving pile is arranged along an axis of the hammer. There is a through hole in which the guide pipe erected on the pile head is inserted.

The gist of the underwater pile driving method of the present invention is that a small-diameter guide pipe is erected at the center of the pile head of the driving pile along the axis of the driving pile, and the guide pipe is of the center hole type. After mounting the underwater pile driving hammer, after driving the driving pile to the bottom of the water with the underwater driving hammer, remove the underwater driving hammer, the guide pipe the pile head of the driving pile Is to disconnect from.

(Operation) As described above, according to the underwater pile driving hammer of the present invention,
Since a through hole was provided along the axis of the pile, it was possible to equip the guide pipe erected on the pile head of the pile so that it could move up and down, and the pile could be driven accurately in water.

According to the underwater pile driving method according to the present invention, after the pile is erected on the bottom of the water, the underwater pile driving hammer is inserted into the guide pipe erected on the pile head of the pile, and the pile pipe is mounted on the pile head. Since the pile is hit with the underwater pile driving hammer, the impact force on the pile can be accurately applied.

Then, after the pile driving work, the guide pipe is cut,
Since the pile driving work is completed, it is not necessary to monitor the driving situation by the diver for the pile driving work, and the construction management becomes easy.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is an explanatory view showing a construction procedure of the underwater pile driving method of the present invention. FIG. 2 is a sectional view showing the structure of an underwater pile driving hammer. FIG. 3 is a front view of a guide pipe erected on a pile head of a ready-made pile such as an RC pile or a steel pipe pile.

In the figure, reference numeral 1 is a pile driving work ship, 2 is a pile driving work ship 1.
Pile driving leader, 3a and 3b are suspension wires, 4 is a center hole type underwater pile driving hammer, 4a is a hydraulic pump connected to the underwater pile driving hammer 4, 5 is a pile such as a steel pipe, 5a Indicates a steel guide tube.

Explaining the underwater pile driving method according to the present invention, as shown in FIG. 1 (a), the pile driving work vessel 1 is towed by a towing ship (not shown) to a planned water area for pile driving work.

A pile 5 and an underwater pile driving hammer 4 are installed on a pile driving leader 2 of the pile driving work ship 1. At this time, the underwater pile driving hammer 4 is inserted into the guide pipe 5a which is erected on the pile head 5b of the pile 5, and the pile head hammer 4 is inserted into the pile head 5b.
Equipped on 5b.

Next, the wires 5a and 3b for suspending the pile 5 and the underwater pile driving hammer 4 are unwound, the pile 5 is erected on the water bottom 7, and the underwater pile driving hammer 4 is also immersed in the water 8. To do.

At this time, if the tip 5c of the guide tube 5a is projected above the water surface, the tip 5c can be measured by a surveying instrument to know the position of the pile 5. And underwater pile driving hammer 4
Hit the pile 5 with. The operation method of the underwater pile driving hammer 4 is that a hydraulic control unit, a hydraulic unit, and an operation control panel (not shown) provided on the rear end side of the hydraulic pipe 4a are connected via a hydraulic pipe 4a connected thereto. ) Is performed in the same manner as the hydraulic pile hammer described in the above-mentioned conventional example. Further, the ram hitting method includes a free fall method and an accelerated fall method as in the conventional example.

Since the underwater pile driving hammer 4 moves up and down along the guide pipe 5a, the impact force thereof correctly acts on the pile 5 in the vertical direction. Since the guide pipe 5a is erected at the center of the pile head 5b of the pile 5 along the axis of the pile 5, the impact due to the impact on the pile 5 causes the center hole type underwater pile. There is no danger that the hammer 4 will fall off the pile head 5b. Therefore, since it is not an unstable structure in which the outer periphery of the pile head 5b of the pile 5 is simply fitted and guided by a tubular object, the underwater pile driving method of the present invention is reliable in terms of the reliability of the pile driving work. Has become high.

Next, as shown in FIG. 1 (b), after driving the pile 5 to a predetermined depth L, the wires 3a and 3b are wound up by a winch and the underwater pile driving hammer 4 is piled up. To house. Then, as shown in FIG. 1C, the rear end portion 5 of the guide tube 5a is
The guide tube 5a is cut at a '. As a result, unlike the conventional case, generation of the pile for regeneration is eliminated, and since the guide pipe 5a having a small diameter may be cut, the cutting work becomes easy even in the deep sea.

As a result, the pile driving work of the piles 5 by the pile driving work ship 1 is completed.

Next, the structure of the underwater pile driving hammer 4 used in the above-mentioned underwater pile driving method will be described.

The underwater pile driving hammer 4 according to the present invention is shown in FIG.
As shown in (b), it comprises a cylindrical casing 10, a hydraulic cylinder portion 11, closing lids 11a and 11b, a head portion 12, a rod portion 13, a ram 14, a ram cushion 15 and an anvil 16. In this way, the underwater pile driving hammer 4 is composed of the ram driving section and the striking force transmitting section for transmitting the striking force of the ram 14. Further, through holes 17a, 17b, 17c through which the guide pipe 5a penetrates are provided so as to project along the axis of the underwater pile driving hammer 4.
Actuating the underwater pile driving hammer 4 which is an assembly of these components to generate a striking force is basically the same as the conventional method. High pressure oil and low pressure are supplied from the hydraulic unit via the hydraulic pipe 4a. Oil is supplied to the lower chamber 18 and the upper chamber 19 of the hydraulic cylinder 11, the head 12 is raised to raise the ram 14 to a required height, and then the valve of the hydraulic unit is switched to allow the ram 14 to fall freely. This is done by colliding with the anvil 16 through the ram cushion 15. In this case, ram
Although 14 was freely dropped, it goes without saying that the accelerated fall method may be used as described in the conventional example. Incidentally, Fig. 2 (b)
Reference numeral 20 indicates a pile cushion, and 6 indicates a cap. The ram cushion 15 and pile cushion 20
Serves to equalize the impact force of the ram 14 and protect the pile head 5b. These cushions are made of materials such as wood and rubber. The cap 6 positions the underwater pile driving hammer 4 and the pile head 5b.

In addition, the gas in the vacant chamber 21 of the casing 10 rises in the ram.
Since it is compressed by 14, the hydraulic pressure that tries to raise the ram 14 is hindered. Therefore, a vacant chamber 21a (ram 1
It is a space formed between the lower end surface of 4 and the ram cushion 15. It is preferable to provide one or more communication holes (not shown) for connecting to (1). With this communication hole,
The gas in 21 becomes movable to the vacant chamber 21a, and the ram 1
It will not hinder the rise and fall of 4.

In this way, the hydraulic underwater pile driving hammer 4 was formed. However, considering that the pile driving is performed underwater, the diesel hammer has a structure that is too complicated, and the hydraulic type is the most preferable because it has a simple structure. However, it goes without saying that the structure, the material, etc. can be appropriately changed without changing the gist of the present invention.

As a result, it is possible to provide a medium-duty pile driving hammer with high pile driving accuracy and easy construction management.

(Effect of the invention) As described in detail above, according to the underwater pile driving hammer according to the present invention, the pile driving hammer including the ram driving device and the hammering force transmission device in the casing can be used as a driving pile. Since the through hole into which the guide tube is fitted is provided so as to project, the following effects can be obtained.

Since the guide pipe is fitted in the pile driving hammer, the pile driving hammer moves up and down along the guide pipe, the impact force is correctly transmitted to the pile head, and the pile driving in water can be performed accurately. In addition, construction management becomes easy.

It is not necessary to lengthen the pile driving leader of the pile driving work vessel according to the water depth of the pile driving place, the pile driving work vessel can be downsized, it is economical, it is easy to move, and the work efficiency is improved.

Since the underwater pile driving hammer according to the present invention is used in water, there is no need to worry about noise measures as in the conventional case.

Further, according to the underwater pile driving method according to the present invention, a guide pipe is erected on the pile head of the pile to be placed, and the guide pipe is vertically movable so that the underwater pile driving hammer is mounted and the pile is driven. Since it is installed, it has the following effects.

Unlike the conventional method, the piles cut after the completion of the casting are not reused and used, so that the problem of the proof stress of the recycled piles is eliminated.

Eliminating inefficient work such as welding and transportation for recycled piles.

The guide pipe is cut after the driving pile has been hit, but since the guide pipe has a small diameter, the cutting work can be easily performed and the work efficiency is improved.

Since the guide pipe is erected on the pile head, it is only necessary to change the length of the guide pipe according to the water depth, it is not necessary to change the length of the pile itself and it is economical, and before starting the pile driving work, Since the tip of the guide tube is projected above the water surface, the position of the pile can be measured. By the guide pipe erected in the center of the pile head along the axis of the pile, the impact action of the underwater pile driving hammer can be surely constructed, and the impact from the underwater pile driving hammer causes the impact from the pile head. It has an excellent effect that the reliability of the underwater pile driving work is improved without the risk of the underwater pile driving hammer being detached.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a construction sequence of the underwater pile driving method of the present invention, FIG. 2 (a) is an exploded perspective view showing components of the underwater pile driving hammer of the present invention, and FIG. 2 (b). Is a sectional view of the underwater pile driving hammer of the present invention, FIG. 3 is a partially enlarged front view of the pile,
FIG. 4 is an explanatory view showing a construction order of the conventional pile driving method,
FIG. 5 is an explanatory view showing a conventional pile driving hammer and its driving device, and FIG. 6 is an explanatory view of a driving method of a ram for striking. 1 ... Pile driving work boat, 2 ... Pile driving leader, 3a, 3b ... Suspension wire, 4 ... Underwater pile driving hammer, 4a ... Hydraulic pipe, 5 ... Pile, 5a ... Guide pipe, 5b ... Pile head, 7 ... water bottom, 10 ... casing, 11 ... hydraulic cylinder part, 12 ... head part, 13 ... rod part, 14 ... ram, 15 ... ram cushion, 16 ... anvil , 17a, 17b, 17c …… through hole, 18 …… lower chamber, 19 …… upper chamber, 20 …… pile cushion.

Claims (2)

[Claims] 1. A generally cylindrical body provided with a ram drive device for ascending and descending a ram for striking and a striking force transmitting device for transmitting the striking force of the ram to a driving pile through a ram cushion and an anvil in a casing. -Shaped pile driving hammer, wherein a through hole into which a guide pipe erected on the pile head of the driving pile is inserted is provided along the axis of the pile driving hammer. Hit hammer. 2. A small-diameter guide pipe is erected at the center of the pile head of the driving pile along the axis of the driving pile, and a center hole type underwater pile driving hammer is installed in the guide pipe. It is fitted, after the driving pile is driven to the bottom of the water with the underwater pile driving hammer, the underwater pile driving hammer is removed, and the guide pipe is cut from the pile head of the driving pile. Underwater pile driving method.