JPH09217575A - Drilling construction method and drilling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling construction method and drilling device whereby drilling can be performed even in the presence of hard rocks or boulder layers. SOLUTION: This drilling method comprises driving a casing 2 in while causing full-round rotation or rotating or oscillating the casing 2 by means of an oscillating drilling machine 1, and removing earth and sand by means of a hammer grab 20 inserted in the casing 2. In this case, a crushing unit 5 having at its lower end a down-the-hole hammer that is driven by highpressure air to provide impacts on arriving at a hard layer 22 is inserted into the casing 2 and driven and rotated by a rotary driving unit 4 secured to the casing 2 to crush the hard layer 22, with the debris 25 removed by the hammer grab 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an all-casing excavation method of full-circle rotation or right-and-left swing type in which a casing having a cutter bit at the lower end is pushed while rotating and excavated (hereinafter referred to as full-circle excavation method). In particular, the present invention relates to an excavation method for easily crushing and removing hard rocks, boulders, and the like in the casing thereof, and an excavating device therefor.

[0002]

2. Description of the Related Art The full-circle rotary excavation method (including the swing all-casing method of the vent method) enables excavation with a much larger diameter than other excavators such as an auger excavator, cobbles, boulders, It is also possible to remove bedrock, concrete, etc., and is often used for construction of cast-in-place piles on hard ground such as consolidated gravel layer, cobblestone layer, boulder layer, bedrock layer.

This all-round excavation method will be described with reference to FIG. 6. As shown in FIGS. 6 (a) and 6 (b), the casing 2 is rotated while the casing 2 is rotated by the all-round rotary excavator 1 installed on the ground surface. The excavation proceeds by pushing it into the casing 21 and removing the earth and sand in the casing 2 above the casing 2 with the hammer grab 20. As shown in FIG. When it reaches the layer 22, it cannot be crushed and removed by the hammer grab 20, so the chisel hammer 30 is inserted into the casing 2 as shown in (c), and the chisel hammer 30 is dropped as shown in (d). Hard rocks and boulders are crushed by the impact, and then the crushed rocks are removed above the casing 2 by a hammer grab 20 as shown in (e) to excavate. Line, and finally the drilling is completed by withdrawing the casing 2 as shown in (f).

[0004]

However, when crushing hard rocks or boulders by the drop impact of the chisel hammer 30, the hard rocks or boulders are particularly hard and are in close contact with the inner circumference of the casing 2. In this case, even if the central portion can be crushed, the portion in the vicinity of the peripheral wall of the casing 2 cannot be easily crushed, and there is a problem that it takes a very long time to completely crush it. Further, when the excavation depth becomes deeper than the groundwater level, when the chisel hammer 30 collides with the water surface, its falling energy is absorbed and buoyancy acts, so that the crushing force sharply decreases and it becomes difficult to crush. There was a problem. The chisel hammer 30 does not always jump straight up after colliding with the hard rock or boulder depending on the shape and properties of the hard rock or boulder.
Has a problem that it collides with the peripheral wall of the casing 2 and is damaged.

In view of the above conventional problems, it is an object of the present invention to propose an excavation method and an excavation device capable of easily excavating hard rocks or boulders.

[0006]

In order to achieve the above-mentioned object, the present invention, if indicated by reference numerals in the drawings, is the excavation method of claim 1, in which the entire circumference is rotated or rocked. In the excavation method in which the casing 2 is pushed in by the excavator 1 while rotating or rocking and the hammer grab 20 inserted into the casing 2 removes the earth and sand, when the hard layer 22 is reached, it is driven by high pressure air to be driven. The crushing unit 5 having down-the-hole hammers 13, 23 at the lower end is inserted into the casing 2, and the down-the-hole hammers 13, 2 are inserted.
While smashing 3, the crushing unit 5 is rotationally driven in a state of receiving a reaction force in the casing 2 to crush the hard layer 22,
The structure in which the crushed material 25 is removed by the hammer glove 20 is adopted.

Further, in the excavator according to the second aspect of the present invention, the full-circle rotary or rocking excavator 1, the rotary drive unit 4 which can be fixed in pressure contact with the inner peripheral wall of the casing 2 and has the rotary drive means 9, and the rotary drive. The crusher 3 is composed of a crushing unit 5 having down-the-hole hammers 14 and 24 driven to rotate by means 9 and driven by high pressure air at the lower end.

Further, according to a third aspect of the present invention, the kelly rod 1 has a different diameter portion that penetrates the rotary drive unit 4 so that the rotary drive unit 4 can move relatively and has a different diameter portion for transmitting the rotational force by the rotary drive means 9.
The crushing unit 5 is connected to the lower end of 0 and the kelly rod 10
A swivel joint 15 for suspension is attached to an upper end portion of the device, and high-pressure air is supplied to the crushing unit 5 via the swivel joint 15 and the Kelly rod 10.
Is adopted.

According to the present invention, the rotary drive unit 4 is provided with a plurality of reaction force plates 6 which are in pressure contact with the inner peripheral wall of the casing 2 and a plurality of hydraulic rams 7 which move the reaction force plates 6 in the radial direction in the circumferential direction. 4. The structure according to claim 3, wherein the rotary cylinder 8 is disposed, the rotary cylinder 8 through which the Kelly rod 10 penetrates is disposed in the center, and a hydraulic motor 9 for rotationally driving the rotary cylinder 8 is provided. .

Further, in a fifth aspect of the present invention, a plurality of down-the-hole hammers 13 are arranged at the lower end of the crushing unit 5, and each down-the-hole hammer 13 is rotatably mounted. The configuration described in 1. is adopted.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An excavation device according to an embodiment of the present invention will be described below with reference to FIGS.

In FIG. 3, reference numeral 1 is a full-circle rotary or rocking excavator, and 2 is a casing for being pushed or excavated into the ground 21 while being rotated or left-right rocked by the full-round rotary excavator 1. The all-round rotary or rocking excavator 1 is well known, and a chuck device is provided in a rotary body having an insertion hole of a casing 2 and a hydraulic motor for rotating or rocking the rotary body and the rotary body in the axial direction. A press-fitting / pulling-out device for moving is provided, and the rotor is rotated or swung by driving a hydraulic motor in a state where the casing 2 is gripped by a chuck device, and is pushed into the ground 21 while rotating or swinging the casing left and right. , Or is configured to be pulled out.

In FIGS. 1 and 2, 2a is a casing 2.
It is a cutter bit attached to the lower end of. Reference numeral 3 denotes a crusher that is inserted when the casing 2 has reached the hard layer of the ground, and includes a rotary drive unit 4 and a crush unit 5. On the outer periphery of the rotary drive unit 4, a plurality of reaction force plates 6 that are in pressure contact with the inner peripheral wall of the casing 2 are arranged at predetermined intervals in the circumferential direction, and a hydraulic ram 7 that moves each reaction force plate 6 in the radial direction. Is provided. In addition, a rotary cylinder 8 is rotatably arranged in the central portion, and a hydraulic motor 9 that rotationally drives the rotary cylinder 8 is provided. As a rotation mechanism of the rotary cylinder 8 by the hydraulic motor 9, a pinion (not shown) fixed to the output shaft of the hydraulic motor 9 is meshed with a gear (not shown) provided on the outer periphery of the rotary cylinder 8. Well-known rotation transmission means is applied. A rectangular tube hole 8a is formed in the shaft core of the rotary cylinder 8 so that the prismatic Kelly rod 10 can move through in the axial direction. The cross-sectional shape of the Kelly rod 10 is not limited to a quadrangle, and may be any cross-sectional shape having a different diameter portion capable of transmitting rotation. For example, a protrusion may be provided on one side or both sides of a cylinder. In addition, the rotary drive unit 4
A hydraulic supply port 11 for supplying a hydraulic pressure to the hydraulic ram 7 and the hydraulic motor 9 is provided at an appropriate position on the upper end of the hydraulic hose 12, and a hydraulic hose 12 connected to the hydraulic supply port 11 is extended to the outside of the casing 2. There is.

The crushing unit 5 is connected to the lower end of the kelly rod 10 and rotates in conjunction with the rotation of the kelly rod 10. The crushing unit 5 includes a down-the-hole hammer 13 (13a to 13a) which is a plurality of air hammers configured to vibrate the hammer bit 14 with high pressure air.
13d), the hammer bit 14 of which projects from the lower end of the crushing unit 5. The positions of the down-the-hole hammers 13 (13a to 13d) are appropriately set so that the hammer bit 14 can crush almost the entire inner cross section of the casing 2 by the rotation of the crushing unit 5. Also, each down the hole hammer 13,
Hammer bits 14 are rotatably mounted around their respective axes, and as the crushing unit 5 rotates, the hammer bits 14 vibrate while performing a rotation operation that combines revolution and rotation to increase the crushing force. Is configured. Needless to say, the hammer bit 14 may be attached to the down the hole hammer 13 so as not to rotate.

The Kelly rod 10 extending upward from the upper end of the crushing unit 5 through the rotary cylinder 8 of the rotary drive unit 4 is provided with an air passage (not shown) for supplying high pressure air to the down the hole hammer 13. A swivel joint 15 that rotatably supports the kelly rod 10 and supplies high-pressure air is arranged at the upper end of the kelly rod 10. A suspension hook 16 is provided on the swivel joint 15 and a lifting metal fitting 17 is connected thereto. . Reference numeral 18 is an air hose connected to the swivel joint 15.

Next, an excavation method using the excavation device having the above-mentioned structure will be described with reference to FIG. As shown in (a) and (b), the casing 2 is pushed into the ground 21 while rotating or swinging the casing 2 by the all-round rotation or swing excavator 1 installed on the ground surface, and the soil in the casing 2 is removed. When excavation proceeds by removing the upper part of the casing 2 with the hammer grab 20, and when reaching the hard layer 22 such as hard rock or boulder as shown in (b), the hammer grab 20 crushes and removes it. Therefore, as shown in (c), the crusher 3 is suspended by a crane and inserted into the casing 2, and as shown in (d), the hydraulic hose 12 is used to fix the rotary drive unit 4 to the hydraulic ram 7. Hydraulic pressure is supplied to the rotary drive hydraulic motor 8 to fix the rotary drive unit 4 in the casing 2, and the rotary drive unit 4 rotates the crushing unit 5 in a state where the casing 2 receives a reaction force. While driving, the lifting of the kelly rod 10 is released so that the crushing unit 5 descends by its own weight, and high pressure air is supplied from the swivel joint 15 to the crushing unit 5 to drive the hammer bit 14 with the down-the-hole hammer 13. To do. As a result, the hammer bit 14 crushes the hard layer 22 by the striking action and performs a moving operation that combines the revolution and the rotation, whereby the hard layer 22 of the entire cross section in the casing 2 is efficiently crushed. When the hard layer 22 is crushed by the crushing unit 5 to a predetermined depth, the kelly rod 10 is pulled up and the rotary drive unit 4 is crushed.
The rotation drive unit 4 and the casing 2 while being supported above.
Of the ground 2 while the casing 2 is rotated or rocked by the excavator 1 in the state where the casing 2 is released.
1 and then again as shown in (e) (d)
Similarly to the above, the hard layer 22 is crushed, and as shown in (f) below, excavation by the casing 2 and crushing by the crusher 3 are repeated up to the required depth, and thereafter, the crushed material 25 as shown in (g).
Is removed above the casing 2 with a hammer grab 20. Needless to say, during the steps (d) to (f), the crushed material may be removed from the casing 2 by the hammer grab 20 as shown in the step (g). Finally, as shown in (f), the casing 2 is removed to complete the excavation.

As described above, according to this embodiment, even if there is a hard layer 22 such as hard rock or boulder, the crusher 3 is inserted into the casing 2, and the crushing unit 5 is rotated while the down-the-hole hammer at the lower end is rotated. By driving 13 to strike, almost the entire cross section in the casing 2 can be easily and efficiently crushed, and even when the ground water level is high and the crushing unit 5 is submerged, the inner peripheral wall of the casing 2 can be further crushed at the time of crushing. There is no fear of being hurt. Also, the crushing unit 5
Since a plurality of hammer bits 14 are rotatably mounted at the lower end of the hammer, a large crushing force is obtained by vibrating the hammer bit 14 while rotating the crushing unit 5 while performing a rotating operation that combines revolution and rotation. be able to. In addition, since the crusher 3 can be used simply by suspending it with a crane, a single crane can be shared by the hammer grab 20 and the crusher 3, and the cost of using heavy machinery can be reduced and the construction site with a small space can be comfortably used. Can be installed.

In the above embodiment, the crushing unit 5 is provided with a plurality of down-the-hole hammers 13. However, as shown in FIGS. 4 and 5, the crushing unit 5 is provided with a single down-the-hole hammer 23. Alternatively, the single hammer bit 24 may be used to crush almost the entire cross section in the casing 2.

[0019]

According to the first aspect of the present invention, when the hard layer is reached, the crushing unit is inserted into the casing, and the crushing unit is rotationally driven under the reaction force of the casing. By oscillating the down-the-hole hammer at its lower end with high-pressure air, the hard layer on almost the entire inner cross section of the casing can be crushed, and then the crushed material is removed with a hammer grab to form a hard rock or boulder layer. However, even if the groundwater level is high and it is submerged, it is possible to excavate easily and efficiently, and there is no risk of damaging the inner peripheral wall of the casing.

According to a second aspect of the present invention, a full rotation or rocking excavator, a rotary drive unit which can be fixed in pressure contact with an inner peripheral wall of the casing and which has a rotary drive means, and is rotationally driven by the rotary drive means. Since it has a crusher consisting of a crushing unit having a down-the-hole hammer driven by high-pressure air at the lower end, when the hard layer is reached, simply inserting the crusher into the casing makes the above construction method efficient. It can be carried out.

According to the third aspect of the invention, the hydraulic ram for fixing the rotary drive unit and the rotary drive for rotary drive can be obtained by simply suspending the swivel joint at the upper end of the kelly rod by the crane and inserting the crusher in the casing. The crusher can be operated as described above by supplying the hydraulic pressure to the hydraulic motor of the and the high pressure air to the crushing unit that is driven to rotate from the swivel joint, thus making a single crane a hammer grab and a crusher. It can be used as a common equipment and can reduce the cost of using heavy equipment and can be installed easily even in a construction site where space is limited.

According to a fourth aspect of the present invention, the rotary drive unit is provided with a plurality of reaction plates that are in pressure contact with the inner peripheral wall of the casing and a plurality of hydraulic rams that move the reaction plates in the radial direction in the circumferential direction. Since the rotary cylinder through which the kelly rod penetrates is arranged and the hydraulic motor that rotationally drives the rotary cylinder is provided, it can be securely fixed to the inner peripheral wall of the casing by the lining method, and the relationship between the rotary cylinder and the kelly rod can be secured. The crushing unit can be reliably rotated through the coupling.

According to the fifth aspect, when a plurality of down-the-hole hammers are rotatably attached to the lower end of the crushing unit, the down-the-hole hammers vibrate while performing a rotating operation that combines revolution and rotation with the rotation of the crushing unit. By doing so, the excavating force can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main configuration of an excavating device according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional front view of the same embodiment.

FIG. 3 is an explanatory diagram of an excavation process according to the same embodiment.

FIG. 4 is a perspective view showing a main configuration of an excavating device according to another embodiment of the present invention.

FIG. 5 is a partial cross-sectional front view of the same embodiment.

FIG. 6 is an explanatory diagram of an excavation process by a conventional excavation device.

[Explanation of symbols]

 1 All-round rotary excavator 2 Casing 3 Crusher 4 Rotary drive unit 5 Crusher unit 6 Reaction plate 7 Hydraulic ram 8 Rotating cylinder 9 Hydraulic motor 10 Kelly rod 13 Down the hole hammer 14 Hammer bit 15 Swivel joint 23 Down the hole hammer 24 Hammer bit

Claims (5)

[Claims] 1. An excavation method in which a casing is rotated or oscillated by an all-around rotating or rocking excavator while the casing is rotating or rocking, and earth and sand are removed by a hammer grab inserted in the casing. Insert a crushing unit with down-the-hole hammer driven by air at the lower end into the casing.While crushing the down-the-hole hammer, the crushing unit rotatably drives the casing while receiving the reaction force to crush the hard layer. The excavation method is characterized by removing crushed materials with a hammer grab. 2. An all-round rotating or rocking excavator, a rotary drive unit which can be fixed in pressure contact with the inner peripheral wall of the casing, and has a rotary drive means, and is rotationally driven by the rotary drive means, and the lower end is hit with high pressure air. And a crusher including a crushing unit having a driven down the hole hammer. 3. A crushing unit is connected to the lower end of a kelly rod having a different diameter portion for penetrating the rotary drive unit in a relatively movable manner and for transmitting rotational force by the rotary drive means,
The excavator according to claim 2, wherein a swivel joint for suspension is attached to an upper end portion of the kelly rod, and high pressure air is supplied to the crushing unit via the swivel joint and the kelly rod. 4. The rotary drive unit is provided with a plurality of reaction plates, which are in pressure contact with the inner peripheral wall of the casing, and a hydraulic ram, which moves the reaction plates in the radial direction, arranged in the circumferential direction. The excavator according to claim 3, wherein a hydraulic motor is provided for arranging the tubular body and rotationally driving the rotary tubular body. 5. The excavating device according to claim 2, 3 or 4, wherein a plurality of down-the-hole hammers are arranged at the lower end of the crushing unit, and the down-the-hole hammers are rotatably mounted.