JPS62284818A - Driving method for steel pipe pile - Google Patents

Abstract

PURPOSE:To improve the excavating capacity of ground, by retaining a rotary cutter not to be rotated in a steel pipe, to excavate the ground with the rotary cutter, and by settling the steel pipe and an excavator together to hoist the excavator only. CONSTITUTION:The whole excavator 1 is fixed on a steel pipe 5, and the hydraulic motor 9 of the excavator 1 is worked to turn a rotary cutter 2, and the excavation of ground 34 is started. After that, an excavating section 3 is moved down by a specified distance, and the rotary cutter 2 is swung at a specified angle. This working is repeated, and when the excavation is processed by the stroke component of a lifting cylinder 23, then the excavating section 3 is moved upward by the working of the lifting cylinder 23 first, and the fixing of a fixed arm is released to move the steel pipe 5 downward. As a result, the steel pipe is left as it is, as a pile, and the driving of a new steel pipe pile is not needed, and the number of man-hours can be extremely reduced.

Description

[Detailed description of the invention] 3. Detailed description of the invention (Industrial application field) The present invention relates to a construction method for driving steel pipe piles into hard ground.

(Prior Art) In order to drive piles into the ground, a method is generally used in which the piles are directly driven using a pile driver such as a vibro hammer or a diesel hammer. However, if the target is hard ground, it is difficult to drive the pile to a predetermined depth using only these pile drivers, and a special alternative method is required.

Figure 4 shows an example of such a special pile driving method.
This is a construction method in which a plurality of piles are held together, jet water 33 is jetted from the tip of the water supply pipe 32, and the piles are driven into the ground 34 using a pile driver (not shown). However, according to this construction method, the strength of the rock that can be poured is at most 3
00Kgf/C-, and there was a problem that the range for a was narrow. Therefore, when targeting ultra-hard ground where the rock strength exceeds 300 kgf/c-, a so-called pre-poling method is used, in which a vertical hole is excavated using a separate excavator, and then piles are erected and fixed in the vertical hole. We had no choice but to adopt the construction method.

By the way, excavators conventionally used for such pre-poling methods usually have a cutter 35 as shown in FIG.
A hollow shaft 3 is provided with an excavator body 36 at the tip of the vine, and extends from the excavator body 38. In use, the rotary table 38 is supported on a pedestal 39 provided on a support device (not shown), while the entire excavator is mounted on the tip of a hollow shaft 37. It is suspended from a crane (not shown) via a swivel joint 40. Then, the rotation of the rotary table 3B is transmitted to the excavator main body 35 via the shaft 37, and! 811!1
The ground 34 is excavated by the cutter 35 which rotates under the weight of the machine body 38. In addition, during this excavation, the excavated earth and sand are removed from the hollow shaft 37, the joint 40, and the hose 4.
The earth is discharged through 1.

(Problems to be Solved by the Invention) However, in the pre-poling method using the old excavator, there is an extra man-hour of having to drive a pile into the shaft after digging a shaft with the excavator. This poses a problem in that it is costly and time consuming. Furthermore, since the entire excavator including the excavator body 3B must be rotated, a large amount of power is required, and the rotary table 38, which is the drive source, is placed on the ground far from the cutter 35, resulting in a large power loss. Moreover, since the reaction force of excavation is taken from this rotary table 38, there is a problem that the excavation capacity decreases as the excavation progresses.

The present invention has been made in view of the above-mentioned conventional problems.
The purpose of the present invention is to provide a driving method that enables easy driving of steel pipe piles into hard ground by using an excavator that extracts reaction force from steel pipes.

(Means for solving the problem) Therefore, the present invention inserts an excavator with a rotary cutter into a steel pipe, holds the steel pipe non-rotatably, and extracts a reaction force from the inner wall of the 1w4 pipe. The present invention is characterized in that the ground is excavated by a rotary power ivy, the steel pipe and the excavator are both lowered, and then only the excavator is pulled up.

(Function) In the steel pipe pile driving method with the above configuration, the entire excavator is inserted into the steel pipe, and the excavator and the steel pipe are allowed to sink together. If the pipes are raised, the steel pipes will remain as their predecessors, and there will be no need to drive new steel pipe piles, resulting in a significant reduction in man-hours.

In addition, since the ground is excavated using the rotary cutter of the excavator, there is no need to rotate the entire excavator as in the past, which not only reduces the capacity of the drive source, but also allows the drive source to be installed near the excavation point. This makes it possible to reduce power loss. Furthermore, since the reaction force of excavation is taken from the inner wall of the steel pipe, the reaction force point can be set near the excavation point, making it possible to apply a large cutting force to the rotary cutter, which significantly improves the ability to excavate the ground. - Hit.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIGS. 1 and 2 show the structure of an excavator for carrying out the steel pipe pile driving method according to the present invention and its installation mode. In these figures, l is an excavator,
It basically has the same structure as that shown in Japanese Patent No. 12495. This excavator l has a rotary cutter 2
an excavation part 3 having a structure, a support part 4 that supports the excavation part 3 so as to be able to rotate and move up and down, and a steel pipe 5 in which the support part 4 is to be cast.
It generally consists of a fixing part 8 having upper and lower grippers 6, 7 for tensioning and fixing.

The rotary cutter 2 is rotatably driven by a hydraulic motor 9 with a reduction gear, and this hydraulic motor 3 is fixed to a bracket 11 that is pivotably mounted under a hollow first support frame 10. There is. The bracket 11 is also supported by an elevating cylinder 12 which is pivoted to the first support frame 10, and the operation of the cylinder 12 causes the entire excavation part 3 to swing as shown by the chain line. .

At the upper end of the first support frame IO, a first support frame 10 extending upwardly is provided.
The lower end of the support pipe 13 is coupled, and the upper end of the first support pipe 13 is coupled to a second support frame 15 having a gear 14 integral therewith.

In addition, the first support frame 10 and the second support frame 15
are slidably fitted and supported by a third support frame 17 and a fourth support frame 18, which are connected via a second support pipe 18 arranged so as to surround the first support pipe 13, respectively. On the other hand, a motor 14a that rotationally drives the gear 14 is fixed to the fourth support frame 18,
As a result, when the gear 14 rotates, the rotation is transmitted to the first support frame 10 via the second support frame 15 and the first support pipe 13, and the rotary cutter 2
It begins to rotate in unison with 1.

On the other hand, the fixing part 8 is made up of upper and lower fixing frames 19.2° that house the upper and lower grippers 6.7, respectively, and a fixing pipe 21 that connects the upper and lower fixing frames 19.20. The second support pipe 18 is slidably disposed within the fixed pipe 21. The grippers 6.7 are provided at three equally spaced positions in the circumferential direction, and one of the grippers 8a, 7a is supported by a tensioning cylinder 22.22 and can move forward and backward. That is, when the grippers 8a and 7a advance due to the operation of the tensioning cylinder 22, the upper and lower fixing frames 19 and 20 are firmly fixed to the inner wall of the steel pipe 5.

Incidentally, a lifting cylinder 23.23 is bridged between the fourth support frame 18 and the lower fixed frame 20, so that the upper and lower fixed frames 19.2
0 is fixed to the steel pipe 5 and the lifting cylinder 23 is operated, the entire support part 8 can be moved up and down by the stroke of the cylinder. FIG. 1 shows the lifting cylinder 23.
represents the contracted state.

In addition, a swivel joint 2 is installed around the first support frame lO.
4 is attached, and the piping 25 is surrounded by this. Further, a shear discharge hose 26 whose suction port faces around the rotary cutter 2 is inserted into the support portion 8 .

Hereinafter, a method for driving steel pipe piles using the excavator I having the above configuration will be described with reference to FIGS. 3(a) to 3(c).

First, as shown in FIG. 3(a), the steel pipe 5 to be cast is erected on the ground 27, and is supported by a fixed arm 28 provided on the crane vehicle 27.
9 and insert it into the steel pipe 5, and the rotary cutter 2
Activate the tensioning cylinder 22 at the position where it contacts 34, and the excavator! The whole is fixed to a steel pipe 5.

Next, the hydraulic motor 9 of the excavator 1 is activated to rotate the rotary cutter 2, and excavation of the ground 34 is started. Simultaneously with the start of excavation, the lifting cylinder 23 is operated to move the excavation part 3 through the holding part 8.
is lowered by a predetermined distance, and at that position, the elevation cylinder 12 is operated to swing the rotary cutter 2 at a predetermined angle, and then the motor 14a is operated to rotate the rotary cutter 2. By repeating the above operation, when the excavation part 3 has been dug by the stroke of the lifting cylinder 23, the excavation part 3 is once raised by the operation of the lifting cylinder 23, the fixing of the fixed arm 28 is released, and the steel pipe 5 is lowered. Thereafter, by repeating the above operation for a plurality of cycles again, the ground @34 is gradually dug as shown in FIG. 3(b).

During this time, the pickpockets are discharged via the hose 29.

Then, when the specified progress has been made, the excavation Il! All operations of 1 are stopped, as shown in FIG. 3(C).

The excavator 1 is suspended again by the wire 29 and lifted from the steel pipe 5. The remaining steel pipe 5 becomes a steel pipe pile, and the series of driving operations is completed.

In the above embodiment, the stroke of the lifting cylinder 23 is considered as one cycle, and the excavation is progressed by repeating this cycle. However, instead of this, for example, if the fixed arm 28 is provided with a feeding mechanism for the steel pipe 5, it is possible to Excavation can proceed continuously by eliminating the lifting and lowering operation by the cylinder 23.

(Effects of the Invention) As explained above in detail, the steel pipe pile driving method according to the present invention is such that the entire excavator is inserted into the steel pipe, and the excavator and the steel pipe are made to sink together. Therefore, if only the excavator is pulled up, the steel pipe remains as a pile, and there is no need to drive a new steel pipe pile, resulting in a significant reduction in man-hours.

In addition, since the ground is excavated using the rotary cutter of the excavator, not only does a small-capacity drive source suffice, but the power can be used more effectively by installing the drive source near the excavation point. effective. Furthermore, the reaction force of the excavation was measured from the inner wall of the steel pipe near the excavation point.

A large cutting force can be applied to the rotary cart, which has the effect of significantly improving the ability to excavate hard ground.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the structure and usage of an excavator for carrying out the method of driving steel pipe piles according to the present invention, and Fig.
IT-L [Cross-sectional view along the arrow line, Fig. 3(a) to (
c) is a schematic diagram sequentially showing the implementation mode of the steel pipe pile driving method according to the present invention, and FIGS. 4 and 5 are schematic diagrams showing the implementation mode of the conventional pile driving method. ■ ... Excavator 2 ... Rotary cutter 5 ... Steel pipe 6.7 ... Gripper 34 ... Ground patent applicant Toyo Construction Co., Ltd. agent Patent attorney Yumi Kaly Figure 3 (Q) (b ) (() 4th
Draft procedure amendment 1, Indication of the case 1986 Keko = Hour ρλ No. 127750 2, Name of the invention Method for driving steel pipe piles 3, Relationship with the person making the amendment Name of the patent applicant Toyo Construction Co., Ltd. 4, Agent address: 1-6 Shufu no Tomo Building, Kanda Surugadai, Chiyoda-ku, Tokyo Name (8271) Yumi Kaede (and 1 other person) 6, Subject of amendment 7, Contents of amendment (1) Specification, page 6, line 15 Correct "swing" to "elevation". (2) On page 9 of the specification, line 2, “ground fi 27J” is “ground 3”.
Correct to 4. (3) “Hose 29” in the first line of page 10 of the specification is corrected to “Hose 2EIJ”. (4) In the drawings, Figures 3 (a) to (c) and 5 are revised as shown in the attached drawings. 8. Inventory drawings of attached documents (Figures 3 (a) to (C), Figure 5) 1 copy No. 3
Figure (G) (b) (.)51f
fl

Claims (1)

[Claims] (1) Insert an excavator with a rotary cutter into the steel pipe, hold the steel pipe non-rotatably, and excavate the ground with the rotary cutter while taking a reaction force from the inner wall of the steel pipe. A method for driving steel pipe piles, characterized in that the excavator is lowered together with the excavator, and then only the excavator is pulled up.