JPH02136489A - Construction of pit excavation and pit excavator used in the method of construction - Google Patents

Abstract

PURPOSE:To simplify execution by a method wherein a casing is turned by a casing rotating drilling device, and drilled into the ground, soil and sand are discharged, a hammer excavating rod is inserted When the casing reaches the hard ground, and the rod is struck while being followed to the casing and being rotated. CONSTITUTION:A casing rotating drilling device 33 is used, and a casing 1 is inserted, introduced and turned under the state in which a support 14 is extended. The normal ground is excavated by an excavating blade 4 at the lower end of the casing 1, and soil and sand are discharged by a crab basket, thus forming 9 pit. When the casing 1 reaches the support ground, an auxiliary casing 2 for transmitting revolution is extended in a coaxial manner through Welding, etc., and a hammer excavating rod 5 is inserted from an upper section. A striking hammer 7 is struck continuously by compressed air While the rod 5 is followed and revolved by the transmission of rotation from the casing 1, thus excavating the pit. Accordingly, the device is miniaturized, and cost thereof can be reduced.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for excavating a pit for foundation pile construction, etc. in the ground including hard ground such as supporting ground, and a pit excavator used therein. .

(Prior art) Conventionally, as a method for excavating a pit that cuts into the supporting ground, a cylindrical casing is rotated or reciprocated to be built into the ground, and earth and sand inside the casing is discharged using a club packet or the like. A pit surrounded by the casing is formed, and when it reaches the supporting ground, a downhole hammer is inserted into the casing instead of the club packet, and the hammer is rotated and the casing is rotated (or reciprocated) and press-fitted. A construction method is known in which a pit surrounded by a casing is continuously formed in the supporting ground.

(Problem to be solved by the invention) However, in the conventional construction method, the casing and hammer are rotated separately and independently when excavating the supporting ground, which requires complicated adjustment and maintenance management work for each rotation. Moreover, there was a drawback that the equipment used was large and expensive.

The object of the first invention of the present application is to provide a pit excavation method that can eliminate the drawbacks of the conventional method.

It is an object of the second invention of the present application to provide a pit excavator that can be effectively used in the pit excavation method of the first invention.

(Means for Solving the Problems) In order to solve the above problems, a vertical hole excavation method according to the first invention of the present application is provided.

The cylindrical casing is rotated and built into the ground, and the earth and sand inside the casing is discharged to form a pit surrounded by the casing.

When the hard ground is reached, a hammer excavator having a striking hammer that is driven up and down at the lower end is inserted into the casing,
By excavating the hard ground by striking the hammer while rotating the hammer excavating body in a driven manner by rotation transmission from the casing, and by rotating and erecting the casing, the shaft is continuously surrounded by the casing in the hard ground. The shaft excavator of the second invention of the present application has a configuration that forms a shaft in which the shaft is drilled, and a shaft excavator according to the second invention of the present application includes: a cylindrical casing; and a casing rotary erecting device that performs erecting underground while rotating the casing. a hammer drilling rod that can be inserted into and removed from the casing and has a striking hammer at its lower end that is driven up and down; a rotation transmission member is fixedly or detachably provided on the inner peripheral surface of the casing; A rotation driven member is provided on the outer peripheral surface of the rod to be engaged with the rotation transmission member and to transmit rotation at least when the casing is rotated.

The composition is as follows.

Note that "rotating the r casing" in the first and second inventions of the present application includes rotating the casing in one direction and rotating the casing reciprocally at a certain angle, and "the hammer drilling rod" in the second invention of the present application includes In addition to those in which the rehammer is continuously driven up and down by compressed air, such as a down-hole hammer, those driven by hydraulic pressure, an engine, etc. are also selectively used as appropriate.

Embodiments of the present invention will be described below with reference to the drawings.

(Example) First, an example of the pit excavator of the second invention will be described. In Figures 1 to 5, the casing (1) is made of a cylindrical steel pipe, and a short rotation transmission auxiliary casing (2) also made of a cylindrical steel pipe of the same diameter is attached to the upper end of the casing (1) in a fixed state by welding or the like. This auxiliary casing (
2), as shown in the second figure, four rotation transmission teeth (3) extending in the generatrix direction are provided protrudingly spaced from each other at equal intervals. (4)... is a digging blade formed at the lower end of the casing (1).

The hammer drilling rod (5) is equipped with a downhole hammer in this example, and a hammer drive mechanism using compressed air is installed in the lower end of a long cylindrical rod (6) that can be inserted into and removed from the casing (1). A hammer (7), which is continuously driven up and down by the drive mechanism, protrudes from the lower end of the rod (6), and four rotationally driven teeth (8) extending over the entire length in the generatrix direction are provided on the outer peripheral surface of the rod (6). )... are protruded from each other at equal intervals.

When the hammer drilling rod (5) is inserted into the casing (1) and the casing (1) is rotated, the rotation transmission teeth (3) of the casing engage with the rotation driven teeth (8). Stop the rotation of the casing (1) with the hammer drilling rod (5).
). (9) is a compressed air guide tube with one end protruding from the upper end of the rod (6) and the other end communicating with the hammer drive mechanism; (10) is the guide tube (9);
An air supply flexible pipe is connected to the protruding part of the air supply via a swivel joint (11), and the other end is connected to the near compressor.

The casing rotation construction device (33) is as follows.

A rectangular flat box-shaped gearbox (12) is supported horizontally by lifting support legs (14) attached to its four corners via arms (13). ) have circular casing insertion holes (15
) at the upper plate hole edge of the insertion hole (15), especially the fifth hole.
As shown in the figure, insert the annular support frame (16) into the insertion hole (15).
A ball bearing (1
7), and a ring-shaped large gear (18) is attached to the outside of the gear box (12) of this support frame (16).
), and the geared motor (19) and (1) for rotating the casing installed on the top surface of the gear box (12).
The small gears (21), (21) fixed to the output shafts (20), (20) of 9) are meshed with the large gear (18). On the other hand, at the lower end of the support frame (16), a flat chuck case (23) with circular casing insertion holes (22) formed in both the upper and lower plates is installed, and Shafts (24), (24') supported in position
To.

A pair of chuck plates (25), (25) and (25') each having a quarter-arc fastening surface as shown in the fourth figure;
(25') are swingably supported, and a chuck hydraulic cylinder is installed between the opposing chuck plates (25), (25') and the other ends of (25), (25'). (26), (26), the ram (27), (2
7) is connected.

The lifting support legs (14) are composed of three simple bodies (28), (29), which are sequentially joined together as shown in the first figure.
(30), a hydraulic cylinder (31) is attached to one end of the cylinder,
A ram (32) is connected to the other end of the cylinder, and the cylinder (31
) so that when the hydraulic pressure is released, the entire support leg (14) is retracted.

Next, an embodiment of the pit excavation method of the present invention using the above-mentioned excavator will be described together with the function of the excavator.

First, as shown in FIG. 6, using the casing rotation erection device (33) of the above example, with its supporting legs (14)... extended, the casing insertion holes (15), (22) are opened.
Insert the casing (1) without the auxiliary casing (2) into the chuck hydraulic cylinder (
Each chuck plate (25) is moved backward by the backward drive of (26) and (26).
), (25), (25'), (25') sandwich the casing (1) with the zero-order casing rotation motor (19).
), (19) causes its rotation to be caused by the small gear (21),
(21), the large gear (18) and the support frame (16) to transmit the information to the chuck case (23) to rotate the casing (1), and the hydraulic cylinders (31) of each support leg (14)... When the hydraulic pressure is released, the rotating casing (1) excavates the ground with the digging blade (4) at the lower end, and gradually enters the ground under the weight of the casing, and the club basket is removed along with it. (34) using casing (
1) Scrape out the dirt inside and discharge it to the outside of the casing. The casing rotation erecting device (33) is operated once the casing (1) is erected to the minimum shortened position of the support legs (14).

Once the chuck plates (25) and (25') are unfastened, each support leg (14)... is extended to its maximum length, and at that position, the casing is again tightened with the chuck plate to perform rotational erection. The process is restarted and repeated thereafter. By continuing the rotational entry of the casing (1) and the discharge of earth and sand, the normal ground (A
) is formed with a pit surrounded by a casing (1).

When the casing (1) reaches the supporting ground (B) as shown in the 7th figure, stop the casing rotation and earth and sand discharge, and then attach the upper end of the casing (1) to the upper end of the casing (1) for transmitting the rotation as shown in the 8th figure. Add the auxiliary casing (2) coaxially by welding, bolts, bolts, etc.

Next, as shown in Figure 9, the hammer drilling rod (5) of the above example is
are inserted into the auxiliary casing (2) and casing (1) from above. In this state, as shown in Figure 10.11, the casing (1) starts to rotate and move in by driving the casing rotating and building device (33).

The rotation is caused by the rotation transmission tooth (3)... and the rotation driven tooth (8).
)... is transmitted to the hammer drilling rod (5),
As a result, the hammer (7) starts to continuously strike while rotating, forming a pit surrounded by the casing (1) that is continuous with the existing pit in the ordinary ground (A) on the supporting ground CB). The compressed air used in the hammer fighting mechanism of the hammer 11 cutting rond (5) is ejected into the hole from the lower end of the hammer (7), and this blows the fine stones, etc. excavated and crushed by the hammer (7) to the hammer drilling rod. (5) and the casing (1) and is discharged to the outside from the upper end of the casing.

When the hammer drilling rod (5) is pulled out of the casing (1) after entering the supporting ground (CB) to the required depth as shown in Fig. 12, it changes from the normal ground (A) to the supporting ground (B) as shown in Fig. 13. A pit (H) is formed surrounded by a continuously biting casing (1). The casing (1) can be used as it is as a pile, or it can be pulled out after pouring concrete for pile construction.

As another embodiment, the auxiliary casing (2) for transmitting one rotation is fixedly attached to the upper end of the casing (1) by welding or the like, or detachably attached using bolts, bolts, etc., and the casing (1) with the auxiliary casing (2) ) is used to start pit excavation in the normal ground shown in Figure 6, and the following steps are substantially the same as in the above example.

(Effects of the invention) According to the vertical hole excavation method of the first invention, the adjustment of the rotation of the casing and hammer excavation body and the maintenance management work are easier than in the conventional method, and the equipment used is more compact and inexpensive. It is possible to achieve this.

According to the pit excavator of the water pan second invention, it is possible to obtain a pit excavator for hard ground that is easy to adjust rotation and maintain and manage, is small in size, and is inexpensive, and can be used for carrying out the first invention. If so, use the casing with a rotation transmission member or the casing without a rotation transmission member to excavate a pit in normal ground.

When reaching hard ground, insert the hammer drilling rod into a casing with a rotation transmission member, or attach a rotation transmission member to a casing without a rotation transmission member and insert it, allowing continuous hole drilling in hard ground. can be performed continuously, and the entire first invention can be effectively implemented.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a partially cutaway front view of a pit excavator, Fig. 2 is an end view taken along the line nn of Fig. 1, and Fig. 3 is a casing rotary construction device. Fig. 4 is a cross-sectional view of the casing rotary erection device taken along line IV-IV in Fig. 1, and Fig. 5 is an enlarged cross-sectional view of Fig. 3, partially omitted from line ■-V. The excavation method is shown. Figure 6 is a cross-sectional view of the tunnel excavation process on normal ground, Figure 7 is a cross-sectional view of the same as above with the casing built up to the supporting ground, and Figure 8 is the state with the auxiliary casing added. FIG. 9 is a cross-sectional view of the same as above with the hammer drilling rod inserted, and FIG. 10 is a cross-sectional view of same as above.
Figure 11 is a cross-sectional view of the same as above for the shaft excavation process in the supporting ground.
Figure 2 is a cross-sectional view of the same as above with completed excavation in the supporting ground, No. 13
The figure is a sectional view of the same as above with the hammer drilling rod pulled out. DESCRIPTION OF SYMBOLS 1... Casing, 2... Auxiliary casing for rotation transmission, 3... Rotation transmission tooth, 5... Hammer drilling rod,
7... Impact hammer, 8... Rotation driven tooth, 33...
Casing rotation construction equipment, A... Ordinary ground, B...
・Supporting ground. Patent applicant: Yokoyama Foundation Construction Co., Ltd.

Claims (2)

[Claims] (1) While rotating the cylindrical casing and building it underground, the earth and sand inside the casing is discharged to form a pit surrounded by the casing, and when it reaches hard ground, it is driven up and down by the lower end. A hammer excavating body having a striking hammer is inserted into the casing, and the hammer excavating body is rotated as a result of rotation transmission from the casing while striking the hard ground to excavate the hard ground. A pit excavation method in which a pit surrounded by a casing is formed in hard ground by drilling and contiguous with the above pit. (2) A cylindrical casing, a casing rotating erecting device that performs erecting underground while rotating the casing, and a hammer that can be inserted into and removed from the casing and has a striking hammer at its lower end that is driven up and down. a drilling rod, and a rotation transmission member is fixedly or removably provided on the inner peripheral surface of the casing, and at least on the outer peripheral surface of the hammer drilling rod, the rotation transmission member is engaged with the rotation transmission member when the casing is rotated. A vertical hole excavator equipped with a rotary driven member to be transmitted.