JPH0536595B2 - - Google Patents

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 of excavating a pit that cuts into the supporting ground, a cylindrical casing is rotated or reciprocated to be built into the ground, and the earth and sand inside the casing is discharged using a club bucket or the like. Then, 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 bucket, and the hammer's rotational impact and the casing's rotation (or reciprocating rotation) are performed. ) A method is known in which a pit surrounded by a casing is continuously formed in the supporting ground by press-fitting.

(Problem to be solved by the invention) However, in this conventional method, the casing and hammer are rotated separately and independently when excavating the supporting ground, so complicated adjustment and maintenance management work is required for each rotation. Moreover, it has the disadvantage that the equipment used is large and expensive.

The object of the first invention of the present application is to provide a vertical hole excavation method that can eliminate the drawbacks of the conventional method, and the second invention of the present application is to provide a vertical hole excavation method that can be effectively used in the shaft excavation method of the first invention. Our objective is to provide a hole drilling machine.

(Means for Solving the Problems) In order to solve the above problems, the pit excavation method of the first invention of the present application includes rotating a cylindrical casing to build it underground, and discharging the earth and sand inside the casing. When a pit surrounded by Excavating the hard ground by striking the hammer while being rotated by the casing, and rotating and erecting the casing to form a pit continuous with the pit and surrounded by the casing in the hard ground. Further, the vertical hole excavator of the second invention of the present application includes: a cylindrical casing; a casing rotary erecting device that performs erecting underground while rotating the casing; a hammer drilling rod having a striking hammer at its lower end that is driven vertically; a rotation transmitting member is fixedly or removably provided on the inner circumferential surface of the casing; In this case, a rotation driven member is provided which is to be engaged with the rotation transmission member to transmit rotation.

Note that "rotating the casing" in the first and second inventions of the present application includes rotating the casing in one direction and reciprocating at a constant angle. In addition, the "hammer excavation rod" in the second invention of the present application includes a downhole hammer or the like in which the hammer is continuously driven up and down by compressed air;
Those based on hydraulic pressure, engine, etc. may also be used selectively 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, casing 1
is made of a cylindrical steel pipe, and a short auxiliary rotation transmission casing 2 made of a cylindrical steel pipe of the same diameter is attached coaxially to the upper end of the casing, either fixedly by welding or removably by bolts, bolts, etc. On the inner peripheral surface of the auxiliary casing 2, as shown in the second figure, four rotation transmitting teeth 3 extending in the generatrix direction are protruded 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 has a hammer drive mechanism using compressed air built into the lower end of a long cylindrical rod 6 that can be freely inserted into and removed from the casing 1. The hammer 7, which is continuously driven up and down, is connected to the rod 6.
Four rotary driven teeth 8 protrude from the lower end and extend over the entire length in the generatrix direction on the outer peripheral surface of this rod 6.
... are protruded from each other at equal intervals, and the hammer drilling rod 5 is inserted into the casing 1.
When rotated, the rotation transmission tooth 3 of the casing...
are engaged with the rotating driven teeth 8 to transmit the rotation of the casing 1 to the hammer drilling rod 5. 9 is a compressed air guide tube whose one end protrudes from the upper end of the rod 6 and the other end communicates with the hammer drive mechanism; 10 is a flexible air supply tube connected to the protrusion of the guide tube 9 via a swivel joint 11; A tube connects the other end to the air compressor.

The casing rotation construction device 33 is as follows. A substantially rectangular flat box-shaped gearbox 12 is horizontally supported by lifting support legs 14 attached to its four corners via arms 13, and circular casing insertion holes 1 are formed in both the upper and lower plates of the gearbox 12.
5 is opened, and an annular support frame 16 is inserted into the upper plate hole edge of the insertion hole 15 as shown in FIG.
The support frame 1 is rotatably suspended via a ball bearing 17 so as to protrude downward through the support frame 1.
A large annular gear 18 is fixed to the outside of the gear box 12 of No. 6, and a geared motor 1 for rotating the casing is installed on the top surface of the gear box 12.
Small gears 21 and 21 fixed to respective output shafts 20 and 20 of 9 and 19 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 a circular casing insertion hole 22 formed in both the upper and lower plates is connected, and shafts 24, 24 are supported at opposite positions in the diametrical direction within the case 23. ′,
A pair of chuck plates 25, 25 and 25', 2 each having a quarter-arc fastening surface as shown in FIG.
5' is supported swingably, and opposing chuck plates 25, 25' and 2
A chuck hydraulic cylinder 26, 26 and its ram 27, 27 are connected between the other ends of the cylinders 5, 25'.

The lifting support legs 14 are comprised of three stages of single cylinders 28, 29, 30 that are successively joined together as shown in the first figure.
A hydraulic cylinder 31 is attached to one end of the cylinder, and
A ram 32 is connected to the other end of the cylinder, and the cylinder 31
When the hydraulic pressure is released, the entire support leg 14 is contracted.

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.
The casing 1 without the auxiliary casing 2 attached thereto is inserted into the chuck plate 2, and then the chuck hydraulic cylinders 26, 26 are driven backward to remove each chuck plate 2.
The casing 1 is sandwiched between 5, 25, 25', and 25'. Next, by starting the casing rotation motors 19, 19, the rotation is controlled by the small gears 2, 21 and the large gear 18.
and the support frame 16 to the chuck case 23 to rotate the casing 1, and each support leg 1
When the hydraulic pressure of the hydraulic cylinder 31 of 4 is released,
The rotating casing 1 excavates the ground with the excavation blade 4 at the lower end and gradually enters the ground under the weight of the casing, and at the same time, the club basket 34 is used to scrape off the earth and sand inside the casing 1 and remove it from the casing. Discharge. The operation of the casing rotation installation device 33 is carried out after the casing 1 is installed to the minimum shortened position of the support legs 14, and then the chuck plates 25, 2
5' is once released, each support leg 14 is extended to its maximum length, and at that position, the casing is again tightened with the chuck plate to resume rotational erection, and this process is repeated thereafter. By continuing the rotation of the casing 1 and the discharge of earth and sand, a pit surrounded by the casing 1 is formed in the ordinary ground A.

When the casing 1 reaches the supporting ground B as shown in the seventh figure, the casing rotation and earth and sand discharge are stopped, and then the rotation transmission auxiliary casing 2 of the above example is welded or Add coaxially using bolts, bolts, etc.

Next, as shown in FIG. 9, the hammer drilling rod 5 of the above example is inserted into the auxiliary casing 2 and the casing 1 from above. In this state, when the casing rotation and erection device 33 is driven to start rotating and advancing the casing 1 as shown in FIGS. As a result, the hammer 7 rotates and starts making continuous strikes, forming a pit surrounded by the casing 1 in the supporting ground B that is continuous with the existing pit in the normal ground A. The compressed air used by the hammer drive mechanism of the hammer drilling rod 5 is blown 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 into the gap between the hammer drilling rod 5 and the casing 1. It is discharged to the outside from the upper end of the casing.

After entering the supporting ground B to the required depth as shown in Figure 12, move the hammer drilling rod 5 to the casing 1.
When pulled out from the ground, normal ground A is shown in Figure 13.
Casing 1 that continuously bites into supporting ground B from
A pit H surrounded by is formed. The casing 1 can be used as a pile as it is, or it can be pulled out after pouring concrete for pile construction.

As another embodiment, the auxiliary casing 2 for rotation transmission is fixed in advance by welding or the like to the upper end of the casing 1, or is removably attached with bolts, bolts, etc., and the casing 1 with the auxiliary casing 2 is
There is also an example in which a pit excavation is started in the normal ground shown in Figure 6 using the method, and substantially the same steps as in the above example are carried out.

(Effects of the Invention) According to the pit excavation method of the first invention of the present application, 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 second invention of the present application, 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 when used in carrying out the first invention. , use the casing with the rotation transmission member or the casing without the rotation transmission member to excavate a pit in normal ground, and when reaching hard ground, insert the hammer drilling rod into the casing with the rotation transmission member, or use the rotation transmission member. By attaching and inserting a rotation transmitting member into the blank casing, it is possible to continuously perform vertical hole excavation in hard ground, and the entire first invention can be carried out effectively. .

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway front view of a pit excavator, and FIG.
3 is a partially cutaway plan view of the casing rotary building device; FIG. 4 is a sectional view of the casing rotary building device taken along the line of FIG. 1; FIG.
The figure is an enlarged cross-sectional view of Figure 3 with some lines omitted; the following shows the shaft excavation method; Figure 6 is a schematic cross-sectional diagram of the shaft excavation process on normal ground; and Figure 7 is a cross-sectional view of the casing up to the supporting ground. Figure 8 is a cross-sectional view of the same as the above with the auxiliary casing added, Figure 9 is a cross-sectional view of the same with the hammer drilling rod inserted, Figures 10 and 11 are the same as the above with the support ground. FIG. 12 is a cross-sectional view of the same as above showing the process of excavating a pit, FIG. 12 is a cross-sectional view of the same as the above with the excavation completed in the supporting ground, and FIG. 13 is a cross-sectional view of the same with the hammer drilling rod pulled out. DESCRIPTION OF SYMBOLS 1... Casing, 2... Rotation transmission auxiliary casing, 3... Rotation transmission tooth, 5... Hammer drilling rod, 7... Impact hammer, 8... Rotation driven tooth,
33...Casing rotary erection device, A...Ordinary ground, B...Supporting ground.

Claims (1)

[Scope of Claims] 1. While rotating a 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 reaching hard ground, the lower end inserting a hammer excavating body having a striking hammer that is driven vertically into the casing, and excavating the hard ground by striking the hammer while rotating the hammer excavating body as a result of rotation transmission from the casing; A pit excavation method in which a pit surrounded by a casing is formed in hard ground by rotating the casing and is continuous with the pit mentioned above. 2. A hammer excavation rod having a cylindrical casing, a casing rotary erecting device that performs erecting underground while rotating the casing, and a hammer excavating 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 transmitting member is fixedly or removably provided on the inner circumferential surface of the casing, and the rotation is transmitted to the outer circumferential surface of the hammer drilling rod by being engaged with the rotation transmitting member at least when the casing is rotated. A vertical hole excavator equipped with a rotating driven member that rotates.