JPH10140967A - Excavating method of vertical hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lessen works in a vertical hole as much as possible and increase the working efficiency. SOLUTION: In this excavation method of a vertical hole, a plurality of casings 24 are vertically arranged one after another in an excavated vertical hole while excavating the ground by an excavating machine 20 provided with a cylindrical body 26, an excavating head 30 arranged at the lower end of the body 26, and a transfer mechanism 34 vertically shifting the body 26. The lowering process of the arranged casings 24 while adjusting the dropping speed of the self weight by a shifting structure thereof or the like and the jointing process of the next casing 24 on the uppermost casing 24 already arranged are repeatedly executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for drilling a vertically extending hole.

[0002]

2. Description of the Related Art As one method of excavating a deep vertical hole used for a foundation for a concrete structure, a foundation for a steel tower, a foundation for a bridge pier, etc., excavation in which a drilling head is rotated around an axis of a cylindrical main body. There is a method of excavating using a machine. In this excavation method, the excavator is lowered while rotating the excavation head, and a plurality of segments are temporarily arranged at the excavation site. The segments are assembled sequentially from the bottom of the excavated vertical hole.

However, in the conventional excavation method, since the assembling operation of the segments must be performed at the bottom of the hole where the worker is exposed to the danger of the falling object, the excavator is provided with equipment for protecting the worker from the falling object. Drilling must be interrupted during the assembly of the segment.

[0004] As another method of excavating a vertical hole, there is a method of pushing a long cylindrical casing into an excavation trace from above while rotating forward and backward around its axis. However, in this method, since the casing is pushed down by applying a pressing force to the upper end of the casing on the ground side, the apparatus becomes large-sized, and is not suitable for excavating a deep vertical hole.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to increase the working efficiency by minimizing the work at the hole bottom.

[0006]

A method for excavating a vertical hole according to the present invention comprises the steps of:
While digging the ground with a cylindrical body, an excavator including a digging head arranged at the lower end of the main body and a moving mechanism for moving the main body in the vertical direction, a plurality of casings are vertically inserted into the excavated vertical hole. A method for excavating a vertical hole to be sequentially arranged, wherein a step of lowering an arranged casing and a step of assembling a next casing on the arranged uppermost casing are performed a plurality of times.

[0007] The step of lowering the disposed casing is performed every time the ground is excavated to a predetermined depth by an excavator.
Therefore, by performing the step of lowering the casing and the step of assembling the next casing a plurality of times, a vertical hole is gradually formed, and the casing is gradually lowered in the vertical hole. When a vertical hole having a predetermined depth is formed, the wall surface of the vertical hole is covered with the casing except for the bottom.

According to the present invention, since the disposed casing is lowered at the hole bottom side, there is no possibility of damaging the casing as compared with the case where the casing is pressed down on the ground side. In addition, since the next casing is assembled on the uppermost casing that has already been arranged, it is not necessary to assemble the next casing with the casing that has already been arranged at the bottom of the hole, and work at the bottom of the hole is significantly reduced.

Preferably, the step of lowering the disposed casing is performed by obtaining a reaction force on the wall surface of the vertical hole while adjusting the falling speed of the casing by its own weight by the moving mechanism.
This ensures that the casing is lowered. In addition, each casing preferably has a connecting portion that connects to the casing arranged on the upper side or the lower side. Thereby, all the casings that have been arranged can be reliably lowered by the excavator.

[0010] Each of the casings is formed in a tubular shape in advance, a casing in which a plurality of arc-shaped members are assembled in a casing in which the plurality of members are arranged, and a casing in which a plurality of liner plates are assembled in a casing with a tubular shape. Can be selected from the group. Further, each time the step of lowering the arranged casing is executed one or more times, the step of assembling the next casing can be executed once. Further, each casing can be made using a material selected from the group of metal, concrete and industrial waste treatment materials.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 and 2, an excavator 20 for a vertical hole has an axis 22 extending in a vertical direction and receives a casing 24 disposed at an upper portion. As the casing 24, a short cylindrical casing is used. The casing 24 will be described later in detail with reference to FIG.

The excavator 20 comprises a short cylindrical body 26 coaxial with the axis 22, and an annular first excavating head 28 rotatably disposed about the axis 22 at the lower end of the main body.
A bucket-shaped second drilling head 30 coaxially disposed in the center of the first drilling head 28 and rotated about the axis 22 with the first drilling head 28; , A moving mechanism 34 for moving the main body 26 in the vertical direction, and a receiving means 36 for receiving the casing 24 disposed above the moving mechanism 34.

An annular bottom plate 38 is coaxially connected to the lower end of the main body 26 in an inward flange shape by a plurality of screw members such as bolts and nuts (not shown). Bottom plate 38
On top of this, an annular bed 40 is detachably mounted. The operator can use the ladder to move from the ground to the floor 40 and vice versa. Therefore, the worker checks the floor 40 with the state of the hole bottom,
It can be used as a work floor for performing work or the like for inspecting.

Although not shown, the main body 26, the bottom plate 38
And the floor 40 can each be divided into a plurality of preferably three or more members around the axis 22 of the main body 26, and circumferentially adjacent members can be separated by a plurality of screw members such as bolts and nuts. Are linked. This allows
The body 26, bottom plate 38 and floor 40 can be easily transported and disassembled and removed.

Although not shown, the divided portions of the main body 26 are separably connected to the divided portions of the bottom plate 38 and the floor 40 by a plurality of screw members such as bolts and nuts. Similarly, each of the divided portions of the bottom plate 38 and the floor 40 is separably connected to the two divided portions of the main body 26 by a plurality of screw members such as bolts and nuts. Thereby, the joining strength of the members adjacent in the circumferential direction is increased.

The first excavating head 28 is rotatably supported around the axis 22 at the lower end of the main body 26, and the second excavating head 30 is detachably and coaxially arranged from above. It has a space in the center.

As shown in FIGS. 1 to 5, the first excavating head 28 includes an annular upper plate or upper plate 42, an annular lower plate or bottom plate 44, and a short cylindrical plate. An outer plate portion or outer plate portion 46; a short cylindrical inner plate portion or inner plate portion 48; and a plurality of cutters mounted below the bottom plate portion 44 for excavating earth and sand below the bottom plate portion 44. It has an assembly 50 and a plurality of cutters 52 attached to the outside of the outer plate portion 46 to excavate earth and sand around the outer plate portion 46.

The upper plate portion 42, the bottom plate portion 44, the outer plate portion 46, and the inner plate portion 48 are fixed to each other by welding or the like so as to jointly form an annular internal space extending around the axis 22. . However, the upper plate portion 42, the bottom plate portion 44, the outer plate portion 46, and the inner plate portion 48 may be separably connected by a plurality of screw members such as bolts and nuts.

Although not shown, the first drilling head 2
8 can be divided into a plurality of members around the axis 22 of the main body 26, and members adjacent in the circumferential direction are separably connected by a plurality of screw members such as bolts and nuts. Therefore, each of the upper plate portion 42, the bottom plate portion 44, the outer plate portion 46, and the inner plate portion 48 is also formed of a plurality of members corresponding to the divided members of the first excavation head 28. This allows
The first drilling head 28 can be easily transported, and the first drilling head 28 can be disassembled and removed.

The internal space of the first excavation head 28 is divided into a plurality of chambers by a plurality of partition plates 54. The bottom plate portion 44 forms a frusto-conical lower surface inclined such that the center portion is lower than the peripheral portion, and a plurality of portions (in the illustrated example, facing each other) spaced around the axis 22. 2
) Have openings 56.

As shown in FIGS. 4 and 5, the first excavating head 28 is rotatably mounted on the lower end of the main body 26 by a support shaft 60 and a bracket (not shown) around an axis parallel to the axis 22. A plurality of rollers 62, a receiving ring 64 attached to the upper plate portion 42 so as to extend around the axis 22, and an assembling member attached to the ring 64 by a plurality of screw members such as bolts. Is rotatably attached to the lower end of the main body 26 by the ring 66.

The rollers 62 are arranged at equally spaced positions on a virtual circle around the axis 22, and are assembled to the bottom plate 38 and the floor 40. Each roller 62
Has a circumferentially continuous V-shaped groove 62a on the outer peripheral surface. In the illustrated example, six rollers 62 are provided. Rings 64 and 66 extend about body 22 about axis 22.
It extends coaxially with 6. The ring 66 is provided with the groove 6 of the roller 62.
It has an annular engaging portion 66a slidably fitted to 2a, and an outward gear portion, that is, an external gear portion 66b provided above the engaging portion 66a. However, instead of the external gear portion, an inward gear portion, that is, an internal gear portion may be used.

The roller 62 and the rings 64 and 66 are protected by a cover 68. The cover 68 covers the floor 40
And is removably attached to the inner edge of the floor 40 by a plurality of screw members such as bolts. The rings 64 and 66 and the cover 68 are each divided into a plurality of members around the axis 22, and members that are adjacent in the circumferential direction are separably connected by a plurality of screw members such as bolts and nuts.

Each of the cutter assemblies 50 includes a long base portion detachably attached to the lower side of the bottom plate portion 44 with a plurality of screw members such as bolts, and one edge portion in the width direction of the base member. And a plurality of cutters attached at intervals. Each of the cutter assemblies 50 corresponds to the opening 56 of the bottom plate portion 44, and of the edges forming the corresponding opening 56, the rotation direction of the first excavating head 28 (indicated by arrows in FIGS. 2 and 3). At the edge that is rearward (shown), the cutting edge of the cutter is arranged forward in the rotation direction of the first excavating head 28 and a part of the cutter assembly 50 is overlapped with a part of the opening 56.

The excavated material from each cutter assembly 50 passes through a corresponding opening 56 in the bottom plate portion 44 through the first excavating head 28.
Accepted in the interior space. For this reason, the part which communicates with the lower part of the bottom plate part 44 via the opening 56 in the internal space is the chamber 70 which receives excavated material. Each chamber 70 has an opening 7 formed by lacking a part of the inner plate portion 48.
2 (see FIG. 4), it is communicated with a space for receiving the second excavation head 30.

The outer plate 46 has a plurality of openings 74 (see FIG. 4). Each of the cutters 52 has an opening 7 in such a state that the cutting edge thereof is located forward of the first excavating head 28 in the rotation direction and the cutting edge of the cutter 52 partially overlaps the opening 74.
4 are arranged on the edge. The excavated material from the cutter 52 is moved from the opening 74 formed in the outer plate portion 46 to the chamber 70.
Accepted to.

The first excavating head 28 is a guide 76 for forcibly moving the excavated matter received in the chamber 70 from the opening 72 to the space with the rotation of the first excavating head 28.
Is provided in each chamber 70. However, such an action may be performed by another member such as the base member of the cutter assembly 50, or the cutter assembly 50 may be formed as a plow-shaped cutter so that the cutter assembly 50 performs the operation. You may let it.

As shown in FIGS. 1 to 9, the second excavating head 30 includes a cylindrical tubular portion 80 removably received in the space of the first excavating head 28, It has a bottom 82 closing the lower end, a cutter assembly 84 disposed below the bottom 82, and a plurality of cutters 86 disposed on the outer periphery of the lower end of the tubular portion 80.

The outer peripheral surface of the upper end of the cylindrical portion 80 is reinforced by a belt-like member 88 fixed to the outer peripheral surface of the upper end by a plurality of screw members. The belt member 88 includes a plurality of stoppers 90.
Has been fixed. The cylindrical portion 80 is provided with the first drilling head 2.
8 has an outer diameter slightly smaller than the diameter of the space portion, and a vertical length larger than the first excavation head 28.

The diameter of the rotation locus of the stopper 90 is smaller than the inner diameter of the upper plate 42 of the first excavation head 28 but larger than the inner diameter of the bottom plate 44. Therefore, the second
When the excavating head 30 is inserted into the space of the first excavating head 28 from above, the second excavating head 30 is brought into contact with the bottom plate 44 by the stopper 90 so that the cylindrical portion 80
Is maintained in a state of protruding downward from the bottom plate portion 44, and the first
Is vertically positioned with respect to the excavation head 28.

The cylindrical portion 80 has a plurality of cutouts 92 formed at equal angular intervals around the axis 22 at the upper end so as to receive the excavated matter in the chamber 70 of the first drilling head 28. Have. In the illustrated example, the cutout portions 92 are formed at two opposing locations, similarly to the openings 56 and 72 of the first excavation head 28.

A long member 94 is connected to the upper end of the cylindrical portion 80. The long member 94 extends in the diameter direction of the tubular portion 80. A long suspending member 96 is connected to a longitudinal central portion of the long member 94 at one end thereof so as to be pivotable about an axis extending in the horizontal direction.
The suspension member 96 has a suspension ring 98 at the other end for hooking a lifting machine such as a crane.

The bottom 82 has a plurality of openings 100 for receiving excavates from the cutter assembly 84 into the tubular portion 80. The opening 100 corresponds to the cutter assembly 84, and is formed at two opposing positions in the illustrated example, and has a rectangular shape extending in the diameter direction of the second excavation head 30.

Each of the cutter assemblies 84 includes a plurality of long base members detachably attached to the lower side of the bottom portion 82 by a plurality of screw members such as bolts, and a plurality of cutter members attached to each base member. And The base member of each cutter assembly 84 has an edge that forms a corresponding opening 100 and that is located behind the second drilling head 30 in the rotational direction (the direction indicated by the arrows in FIGS. 2, 3, and 6). In the portion, the cutting edge of the cutter is located forward of the second excavating head 30 in the rotation direction, and a part of the cutter is arranged so as to overlap a part of the opening 100.

The cylindrical portion 80 also has a plurality of openings 102 for receiving the excavated material from the cutter 86 into the cylindrical portion 80.
At the lower end. The openings 102 correspond to the cutters 86, and are formed at two opposing locations in the illustrated example. The opening 102 extends in the circumferential direction of the tubular portion 80.

Each cutter 86 is detachably attached to the lower end of the cylindrical portion 80 by a plurality of screw members such as bolts. Each cutter 86 has a corresponding aperture 102
Of the edges that form the edge, the cutting edge is disposed on the edge that is rearward in the rotation direction of the second excavation head 30 so that the cutting edge is forward in the rotation direction of the second excavation head 30 and overlaps a part of the opening 102. ing.

The cylindrical portion 80 also has a step portion 104 protruding inward at each of two opposing lower end portions.
A part of each opening 102 extends to the step 104, and each cutter 86 is arranged on the step 104. A pin 106 is attached to each step 104 by welding or the like. Both pins 106 protrude outside the cylindrical portion 80 from opposing portions.

The second drilling head 30 also includes a bottom 82
A lid 108 for opening and closing each opening 100 is provided above the bottom 82. Each lid 108 is attached to the upper surface of the bottom portion 82 so as to be pivotable about an axis extending horizontally and substantially parallel to the diameter direction of the cylindrical portion 80. For this reason, each lid 10
8 normally closes the opening 100 by its own weight. However, when the second drilling head 30 is rotated, each lid 10
8 is pushed up by the excavated material by the cutter assembly 84, thereby opening the opening 100.

A cutter 110 is attached to the bottom 82 (see FIGS. 1, 7 and 8). Cutter 11
Numeral 0 is disposed downward at the center of the lower surface of the bottom 82 so as to excavate earth and sand corresponding to the center of the vertical hole to be constructed. The inner diameter of the floor 40, the rings 64, 66 and the cover 68 is larger than the maximum outer diameter of the second excavation head 30.

The drive mechanism 32 includes a plurality of rotation sources 114 having a speed reducer, and gears 116 (see FIG. 5) attached to the output shaft of each rotation source 114. Rotation source 114
Are mounted on body 26 such that gears 116 are equiangularly spaced about axis 22. Each gear 116
Meshes with the gear 66b of the ring 66. For this reason,
As the rotation source 114 is rotated, the ring 66 is rotated about the axis 22 so that the first drilling head 28
Rotated around 2.

When the first excavating head 28 is rotated, a plurality of engaging pieces 118 provided on the inner peripheral surface of the first excavating head 28 are moved to a stopper provided on the outer peripheral surface of the second excavating head 30. 90 and thereby the second drilling head 30
Is rotated with the first excavation head 28. Engaging piece 1
18 connects the second digging head 30 to the first digging head 28
When the second digging head 30 is positioned at the first position, the second digging head 30 is positioned so that the opening 72 and the notch 92 face each other even if the second digging head 30 is slightly displaced with respect to the first digging head 28.
To the space of the excavating head 28.

When the engaging piece 118 and the stopper 90 come into contact with each other with the rotation of the first excavating head 28, a plurality of convex pieces 1 provided on the outer peripheral portion of the upper end of the second excavating head 30 are provided.
20 (see FIG. 1) is pushed downward by the first drilling head 28. As a result, the second drilling head 30 is releasably prevented from rising with respect to the first drilling head 28. The convex piece 120 has an inclined upper surface that becomes lower toward the front in the rotation direction of the first excavation head 28.

As shown in FIGS. 10 to 15, the moving mechanism 3
4 is a cylindrical frame 13 fitted to the upper outside of the main body 26.
0 is provided. The main body 26 and the frame body 130 are assembled so that relative displacement in the direction of the axis 22 is possible but rotation about the axis 22 is impossible by one or more detent means.

One example of such a detent means is shown in FIGS. In the illustrated example, the detent means includes a stopper 132 attached inside the lower end of the frame 130 so as to extend in the vertical direction, and a main body 2 extending in the vertical direction.
6 and a groove 134 formed on the upper outside. The stopper 132 and the groove 134 are fitted so as to be relatively slidable in the vertical direction.

The frame body 130 can be divided into a plurality of members in the circumferential direction of the frame body.
As shown in FIG. 1 and FIG. 12, the bolts 136 and the nuts 138 are connected so as to be separable.

The frame 130 is provided with a concave portion 14 which is open on the outer peripheral side.
0 is provided at a plurality of locations on the lower outer periphery. Each recess 140 has a groove 1
A portion slightly higher than the height position of 32 extends in the circumferential direction, and the concave portions 140 adjacent in the circumferential direction are separated by the connecting portions of the adjacent divided members of the frame 130.

Each recess 140 has a pressing member 142 for reaction force.
Is arranged. Each pressing body 142 has a corresponding recess 1
It is arcuately curved to fit 40 and has an arcuate surface extending around axis 22 on the outside. In the illustrated example, the width of the arc-shaped surface, that is, the outer surface, that is, the size in the direction of the axis 22 is large, and therefore, the outer surface of the pressing body 142 has a large area.

The pressing members 142 which are adjacent to each other in the circumferential direction are connected to each other by a group of reaction force jacks, that is, a first jack group, so that their circumferential ends are relatively displaced in directions in which the pressing members 142 are separated from each other. I have. Each first jack group includes a plurality of reaction force jacks, that is, first
Jack 144 is provided. Each first jack 144
Is a hydraulic jack such as a hydraulic jack, and a cylinder is pivotally connected to an end of one pressing body 142 by a plate-shaped connecting member 146, and a piston rod is connected to an end of the other pressing body 142. Part is pivotally connected.

Each connecting member 146 is connected to the corresponding pressing body 14
2 extend from the circumferential end to the inside of the frame body 130 through the opening 148 of the frame body 130. Each connecting member 146 and the pressing body 142 are connected integrally or by welding. A plurality of first jacks 144 and a plurality of connecting members 146 of each first jack group for displacing the same pressing body 142
Is to synchronize the expansion and contraction of the first jack 144,
They are connected by a common pivot 150 so as to be pivotable.

The main body 26 and the frame body 130 are pushed down at a plurality of positions around the axis 22 by a push-down jack, that is, a second
Are connected by a jack 152. The cylinder of each second jack 152 is pivotally connected to the bottom plate 38 by a connector 156 using pins, and the piston rod is pivotally connected to the frame 130 by a connector 155 using pins. The stroke of the second jack 152 is
As in the illustrated example, it is preferable that the vertical dimension (width dimension) of the outer surface of the pressing body 142 be equal to or smaller than that of the pressing body 142.
It may be larger than the vertical dimension (width dimension) of the outer side surface of 42.

In the moving mechanism 34, the first jack 1
When the pressure member 44 is contracted, the adjacent pressing members 142 are drawn, so that each pressing member 142 is configured as shown in FIGS.
1, are housed in corresponding recesses 140, as indicated by solid lines in FIGS.

On the other hand, when each of the first jacks 144 is extended, the adjacent pressing members 142 are separated from each other. Therefore, each pressing member 142 is shown by a solid line in FIGS. 1 and 12 and in FIGS. 13 and 14. As shown by a two-dot chain line in FIG.
Is moved outward in the radial direction, so that each pressing body 142
Is pressed against the surrounding ground by protruding a part thereof from the corresponding recess 140.

Therefore, the moving mechanism 34 is provided with the pressing body 14
The main body 26 is pressed downward by the second jack 152 in a state in which a reaction force is obtained on the surrounding ground by pressing the base 2 against the surrounding ground. As a result, the first excavating head 28 is pushed downward through the main body 26 by the moving mechanism 34, and the second excavating head 30 is connected to the main body 26 and the first excavating head 28.
It is pushed down through.

As shown in FIGS. 14 and 15, the receiving means 36 includes an annular casing receiver 160 arranged inside the upper portion of the frame 130 and receiving the casing 24, and the casing receiver via a second jack 152. And a plurality of connectors 162 connected to the main body 26.

The casing receiver 160 has an L-shaped cross-section, and can be divided into a plurality of arc-shaped members extending in an arc inside the upper portion of the frame 130. Adjacent arc-shaped members are separably connected by a plurality of screw members such as bolts and nuts so that the casing receiver 160 extends inside the upper part of the frame 130.

In the illustrated example, each connecting member 162 is a plurality of long members having a U-shaped cross section. Each connected body 1
Reference numeral 62 denotes an upper end portion which is detachably connected to the casing receiver 160 by a plurality of screw members 164 and a lower end portion which is connected to the cylinder of the second jack 152 by a plurality of screw members 166.

The casing 24 is detachably connected to the casing receiver 160 by a plurality of screw members 168 such as bolts. The operation of connecting the casing 24 to the casing receiver 160 is performed on the ground.

In the excavator 20, when the second excavating head 30 containing no excavated object is mounted on the first excavating head 28, the second excavating head 30
The notch 92 and the engaging piece 118 are positioned so that the notch 92 faces the opening 72. This operation is performed until the engaging pieces 118 of the first digging head 28 engage the stoppers 90 of the second digging head 30 with the first jacks 144 being extended. Is performed by rotating.

In a state where each first jack 144 is extended, each second jack 152 is extended in synchronization with each other.
The rotation source 114 of the drive mechanism 28 is rotated. As a result, the gear 66 is rotated, so that the ring 66 is
The first and second digging heads 28, 30 are rotated about the axis 22 with respect to the body 26.

The propulsion reaction force, that is, the pushing-down reaction force caused by the extension of the second jack 152 is transmitted to the surrounding ground via the frame 130, the first jack 144 and the pressing member 142. The rotational reaction force resulting from the rotation of the first and second excavating heads 28 and 30 is
2. Frame body 130, first jack 144 and pressing body 1
It is transmitted to the surrounding ground via 42.

While the first excavating head 28 is being rotated, the first excavating head 28 is pressed by the dead weight of the excavator 20 and the earth and sand below the first excavating head 28 by the second jack 152. The earth under the first excavation head 28 is excavated by the cutter assembly 50.

The excavated material from the cutter assembly 50 enters the chamber 70 through the opening 72 of the first excavating head 28 with the rotation of the first excavating head 28, and then enters the guide 7.
6 forcibly moves toward the notch 92. Thereby, the excavated matter in the chamber 70 is reliably pushed into the cylindrical portion 80 from the opening 72 of the first excavation head 28 through the cutout portion 92 of the second excavation head 30. For this reason, the excavated material by the cutter assembly 50 is
In the excavating head 30 of the vehicle.

When the first excavation head 28 is rotated, earth and sand around the first excavation head 28 are excavated by the cutter 52. The excavated material by the cutter 52 enters the chamber 70 through the opening 74 of the first excavation head 28 with the rotation of the first excavation head 28. Thereby, the frictional force acting on the outer peripheral surface of the first excavation head 28 during excavation is reduced.

While the first excavating head 28 is being rotated, the second excavating head 30 is pressed by the first excavating head 28 against the earth and sand below the second excavating head 30, so that the second The earth and sand under the excavation head 30 is excavated by the cutter assembly 84. The excavated material from the cutter assembly 84 is moved along with the rotation of the second
8 while opening 100 of second drilling head 30.
From the cylindrical part 80.

When the second excavating head 30 is rotated, the earth and sand around the lower end of the second excavating head 30
Excavated by The excavated material by the cutter 86 enters the cylindrical portion 80 from the opening 102 of the second excavation head 30 as the second excavation head 30 rotates. Thereby, the frictional force acting on the outer peripheral surface of the second excavation head 30 during excavation is reduced.

With the rotation of the second excavation head 30, earth and sand at the center of the lower surface of the second excavation head 30 are excavated by the cutter 110. With the rotation of the second drilling head 30, the excavated material of the cutter 110 and the excavated material of the cutter assembly 84 together with the second drilling head 3 are rotated.
0 enters the cylindrical portion 80 through the opening 100. Thus, it is possible to prevent the excavation direction from changing.

When each second jack 152 is extended, the cylinder of the second jack 152 moves downward, so that the main body 26 is lowered and the receiving means 34 is lowered. The casing 24 is lowered together with the receiving means 34 because it is connected to the receiving means 34. Body 2
6. When the receiving means 34 and the casing 24 are lowered, the receiving means 34 and the casing 24 are controlled to a predetermined lowering speed while adjusting the falling speed due to their own weight.

When each of the second jacks 152 is fully extended, each of the first jacks 144 is contracted, so that each of the pressing members 142 is separated from the surrounding ground. In this state, each second jack 152 is contracted. Thereby, the frame 130 obtains a reaction force to the weight of the main body 24 and the casing 24 and is lowered by its own weight.

Thereafter, while the first jacks 144 are extended, the first and second excavating heads 28 and 30 are rotated while the second jacks 152 are extended, so that the main body 24 is moved. The step of excavating the ground while lowering and lowering the casing 24 and the step of lowering the frame 130 by contracting each second jack 152 in a state where each first jack 144 is contracted. It is repeated a predetermined number of times. Thereby, the casing 24 is sequentially arranged in the vertical direction at the excavation mark, that is, the vertical hole.

While repeating such a process, the frame 130
Alternatively, a new casing 24 is detachably connected to the upper end of the uppermost casing 24 that has been laid. At this time, the work of connecting the new casing 24 to the laid casing 24 can be performed on the ground. Casing 24
May be performed by suspending the excavation work, may be performed in parallel with the excavation work, or may be performed in parallel with the excavation work.

When the cylindrical portion 80 contains a predetermined amount of excavation, the excavation work is temporarily stopped by first stopping the drive mechanism 28. Next, a hook of a lifting machine (not shown) is hooked on the ring 98 of the second excavating head 30,
The second excavating head 30 is lifted to the ground side by a lifting machine.

The second excavating head 3 suspended on the ground
The excavated matter in the area 0 is transferred to a dump truck (not shown). The pin 106 provided on the cylindrical portion 80 is hung on a support provided on the ground when the excavated material in the second excavation head 30 is transferred to the dump truck, and the second excavation head 30 is overturned. Make things easier.

When the transfer of the excavated material from the second excavating head 30 is completed, the second excavating head 30 is suspended in the vertical hole by the lifting machine, mounted on the first excavating head 28, and then excavated. Work resumes.

When the second digging head 30 is mounted on the first digging head 28, if the second digging head 30 is displaced in the radial direction with respect to the first digging head 28,
0 contacts the upper plate portion 42 of the first drilling head 28,
May not be able to be mounted in the space of the first drilling head 28. To prevent this, the axis of the second digging head 30 is
It is necessary to lower the second excavating head 30 in a state where the second excavating head 30 is aligned with the axis 8. However, it is troublesome to perform such work manually.

However, in the excavator 20, the second head 3
0 is lowered with the lower end of the cylindrical portion 80 abutting the engagement piece 118, so that the second excavation head 30 Even if the second excavation head 30 is slightly displaced with respect to the first excavation head 28, the lower end of the cylindrical portion 80 is guided by the engagement piece 118 toward the center of rotation, that is, the side of the axis 22. The second excavating head 3 can be formed by simply lowering the head 30.
0 can be mounted in the space of the first drilling head 28.

When the second excavating head 30 is mounted in the space of the first excavating head 28, the earth and sand around the cylindrical portion of the second excavating head 30 is excessively excavated by the cutter 86. The second digging head 30 can be easily attached to and detached from the hole formed by the second and fourth cutters 42 and 46, and as a result, the second digging head 30 for discharging the excavated material can be removed by the first digging. The work of attaching and detaching to and from the head 28 becomes easy.

When correcting the forward direction of the excavator 20,
The drive mechanism 28 is driven while at least one jack 152 is extended. Thereby, the forward direction of the excavator 20 with respect to the vertical line is gradually corrected. When at least one jack 152 has been extended by a predetermined amount, the direction of advance of the excavator 20 is corrected in the correct direction with respect to the vertical. Therefore, thereafter, the drive mechanism 28 is driven while all the jacks 152 are extended at the same speed in synchronization.

When a vertical hole having a predetermined depth is excavated, the excavator 20 and the casing 24 are removed.

When the excavation of the vertical hole by the excavator 20 is completed, the second jack 152 is generally extended with the casing 24 lowered. Therefore, at least the first and second drilling heads 28, 30 and the drive mechanism 36 are first removed for the casing removal operation.

Next, as shown in FIG. 18, an annular reaction force transmitting body 200 and a cylindrical cover 202 are detachably assembled to the lower side of the main body 26. The reaction force transmitting body 200
It is formed in the shape of a thick plate having substantially the same outer shape as the main body 26. The cover 202 extends upward inside the main body 26 from an inner portion of the reaction force transmitting body 200. These operations are performed by extending the first jack 144 of the moving mechanism 34 and pressing the pressing body 1.
The pressing is performed on the wall surface of the vertical hole so that the excavator 20 and the casing 24 are prevented from being displaced.

Next, a reinforcing bar basket 204 combining a plurality of reinforcing bars is placed in the vertical hole. The reinforced cage 204 is the main body 2
6, penetrates through the reaction force transmitting body 200 and the cover 202, and extends vertically in the vertical hole. Instead of using a reinforcing bar basket in which a plurality of reinforcing bars are combined, a plurality of reinforcing bars or steel frames may be arranged in the vertical hole.

Next, as shown in FIG.
In a state where the first jack 144 of FIG. 4 is extended, a fluid solidifying material such as concrete or mortar is poured into the vertical hole using the tremy tube 206. Tremy tube 206
Reaches the hole bottom through the inside of the reinforcing rod cage 204. The solidified material is cast until the height position of the solidified material 208 that has been cast becomes the height position of the reaction force transmitting body 200.

When the excavator 20 completes excavation of the vertical hole, if the second jack 152 is contracted, it is preferable that the first and second excavating heads 28, Before removing 30, each second jack 152 is contracted with each first jack 144 contracted.
The step of elevating the frame 130 is performed by extending the frame 130.

Next, the first jack 1 of the moving mechanism 34
With the 44 extended, the second jack 152 of the moving mechanism 34 is contracted. Thereby, in a state where a reaction force is obtained on the wall surface of the vertical hole by the pressing body of the moving mechanism 34,
The reaction force transmitting body 200 and the cover 202 are raised, and the receiving means 36 and the casing 24 are pushed up.

Next, the first jack 1 of the moving mechanism 34
The second jack 1 of the moving mechanism 34 is contracted while the reaction force transmitting body 200 is in contact with the upper surface of the
52 is extended. As a result, the moving mechanism 34 is pushed up in a state where the reaction force is transmitted to the solidified material 208 that has been driven by the reaction force transmitting body 200.

Next, with the first jack 144 of the moving mechanism 34 extended again, the second jack 152 of the moving mechanism 34 is contracted. Thereby, the moving mechanism 3
In a state where a reaction force is obtained on the wall surface of the vertical hole by the pressing body of No. 4, the main body 26, the reaction force transmitting body 200 and the cover 202 are pulled up, and the receiving means 36 and the casing 24 are pushed up.

Next, the solidified material is poured into the vertical hole via the tremy tube 206. The solidified material is the cast solidified material 20.
8 until it reaches the height position of the reaction force transmitting body 200.

Thereafter, the first jack 144 of the moving mechanism 34 is contracted and the reaction force transmitting body 200 is brought into contact with the upper surface of the solidified material 208 until the uppermost casing 24 projects to the ground. Elongating the second jack 152 of the moving mechanism 34;
The step of contracting the second jack 152 of the moving mechanism 34 and the step of placing the solidified material are repeated with the 4 extended. Thereby, the excavator 20, the reaction force transmitting body 2
00 and the cover 202 are gradually raised, and the casing 24 and the receiving means 36 are gradually raised.

When the uppermost casing projects above the ground,
The casing is separated from its lower casing,
Will be removed. This operation can be performed on the ground side and is safe.

Thereafter, by performing the same steps, the casings are sequentially removed from the uppermost casing. The excavator 20
Excavator 20 is disassembled and removed, and the reaction force transmitting body 200 and the cover 202 are removed. The work of removing the excavator 20, the reaction force transmitting body 200, and the cover 202 can be easily and safely performed on the ground side.

The height position of the lower end of the tremie tube 204 is gradually raised as the solidified material is poured. The operation of placing the solidified material may be performed in parallel with the operation of lifting the main body 26, the reaction force transmitting body 200, and the cover 202, and the operation of pushing up the receiving means 36 and the casing 24. That is, while the main body 26, the reaction force transmitting body 200, the cover 202, the receiving means 36, and the casing 24 are raised, a solidifying material may be poured in proportion to the amount of the lift.

According to the excavator 20, the excavated material by the cutter assembly 50 is received in the space above the lower plate portion 44. Therefore, the excavation resistance by the cutter assembly 50 is small, and The received excavation is likely to move toward the second excavation head 30. However, a head having a plurality of arms extending radially from the inner plate portion 48 may be used as the first head, and the cutter assembly 50 may be attached to one or more arms.

A plurality of rollers 6 having a V-shaped groove 62a
2 may be attached to the cutter head 26, and a ring 66 having an annular engaging portion 66a that engages with the groove 62a may be attached to the main body 26. As means for rotatably supporting the cutter head 26 on the main body 26, other means such as using a plurality of bearings may be used in addition to rollers and rings.

According to the excavator 20, the pair of adjacent pressing members 142 is displaced by the plurality of first jacks arranged in parallel at a distance from each other in the vertical direction. In addition to the fact that a small jack can be used as compared with the case where the jack is displaced by the jack, the space in the excavator can be effectively used.
However, a pair of adjacent pressing bodies may be displaced by one first jack. Further, the means for displacing the pressing body 142 in the radial direction of the cylindrical body includes a pressing body 142 adjacent to the cylindrical body.
Not only jacks for moving these in a direction in which they come close to each other but also means for directly displacing them in the radial direction may be used.

Instead of using the long connecting body 162 of the receiving means 34, as shown in FIG.
May be used as a link. Third jack 170
The casing receiver 160 includes a plurality of screw members 172.
Are connected to the frame 130 and the piston rod of the second jack 152 by connecting pins 166.

When the third jack 170 is used, the second jack 170 is used.
While contracting the second jack 152, the third jack 1
The extension and contraction of the third jack 170 may be acted upon in reverse to the contraction of the second jack 152 so as to retract the third jack 170 while extending the second jack 152 and extending the second jack 152. . Also, the third jack 170
May be extended while the first jack 144 is extended, independent of the expansion and contraction of the second jack 152.

The casing 24 is, as shown in FIG.
It has flange-like connecting portions 186 and 188 at the upper end and the lower end. The connecting portion 186 at the upper end is provided with a screw hole 190 for screwing a bolt connecting the upper casing.
Having. On the other hand, the connecting portion 188 at the lower end has a hole 192 through which a bolt connected to the lower casing or the casing receiver is inserted.

A groove 194 into which the hand of an operator can be inserted is formed on the outer periphery of the lower end of the casing 24. Groove 194
Has a U-shape that opens to the outer peripheral side. According to the casing 184, the vertically adjacent casings 24 can be connected and separated on the outside thereof.
The connecting operation and the separating operation of the casing 24 are facilitated.

However, the casing has an inward flange at each of an upper end and a lower end, a plurality of screw holes for screwing bolts are formed in the upper flange, and a plurality of holes for passing bolts are formed. It may be formed on the lower flange portion. In the case of a casing having an inward flange portion at the top and bottom, an external connection is provided near the connection portion of the flange portion, particularly on the lower side near the connection portion above the flange portion so that the connecting operation and the separating operation of the casing are performed outside the casing. It is preferable to form a plurality of holes through which a hand can be inserted to operate the connecting bolt.

[0100] Instead of bolts, other means such as bolts and nuts may be used as connecting tools. Also, when the diameter of the vertical hole to be excavated is small, when the working space is wide, etc., it is not necessary to use an excavator that can be divided into a plurality of members in the circumferential direction, such as the main body and the first excavation head. .

The receiving means for receiving the casing may be formed directly on the upper end of the cylindrical frame 130 as shown in FIG. In the example shown in FIG.
Reference numeral 09 denotes an inward flange formed at the upper end of the frame 130, and the casing 24 is connected to the flange 209 at a plurality of locations in the circumferential direction by bolts 168.

In the case of the embodiment shown in FIG.
While the first jack is extended and the pressing body 142 is pressed against the wall surface of the vertical hole, the second jack is extended to lower the main body 26 and the casing 24.
Is lowered, and the second jack is contracted with the first jack contracted.
The frame body 130 can be lowered by its own weight and the weight of the casing. Also, at the time of removal, the main body 26 was pulled up by contracting the second jack while the first jack was extended and the pressing body 142 was pressed against the wall surface of the vertical hole, and the first jack was contracted. In the state, the second jack is extended and the frame 13 is extended.
0 can be raised and the casing 24 can be pushed up.

Instead of obtaining the reaction force when pushing up the casing from the solidified material that has been cast, the casing may be supported or temporarily fixed on the ground side and may be obtained on the casing, or may be obtained on the wall surface of the vertical hole. Is also good.

When the excavated vertical hole is used as a foundation as in the above embodiment, the vertical hole is generally filled with a solidified material. When the vertical hole is used for other purposes such as a shaft, the solidified material is filled into the vertical hole. You don't have to. In this case, for example, an appropriate lining may be formed on the wall surface of the vertical hole, or the casing may be used as all or a part of the lining without removing the casing. Further, even when the excavated vertical hole is used as a foundation, the casing may be buried without removing the casing.

The casing used in the present invention can be made of either a metal material or a concrete material. However, depending on the diameter or depth of the vertical hole to be excavated, the properties of the ground, or the like, the casing is finally removed. For example, it may be made of another material such as industrial waste material or a combination thereof depending on the excavation conditions. Further, such a casing includes a casing formed in advance in a tubular shape, a casing formed by assembling a plurality of arc-shaped members into a casing in which the plurality of members are arranged, and a casing in which a plurality of liner plates are arranged. Any of the casings formed by assembling into a cylindrical shape may be used.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a vertical hole excavator of the present invention.

FIG. 2 is a plan view of the excavator shown in FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is an enlarged longitudinal sectional view showing a part of a main body and a first excavating head, and is a sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is an enlarged longitudinal sectional view showing another part of the joint between the main body and the first excavation head, and is a sectional view taken along line 5-5 in FIG. 2;

FIG. 6 is a plan view showing an example of a second excavation head.

FIG. 7 is a front view showing a part of the second excavation head shown in FIG.

FIG. 8 is a side view showing a part of the second excavation head shown in FIG.

FIG. 9 is an enlarged sectional view showing the vicinity of a cutter assembly of a second excavation head.

FIG. 10 is a sectional view taken along the line 10-10 in FIG. 1;

FIG. 11 is a cross-sectional view showing a state where the pressing body of the moving mechanism is retracted.

FIG. 12 is a cross-sectional view showing a state where the pressing body of the moving mechanism is protruded.

FIG. 13 is a longitudinal sectional view showing a relationship between the pressing body of the moving mechanism and the first jack, in a state where the first jack is contracted and the pressing body is retracted.

FIG. 14 is a longitudinal sectional view showing a relationship between a pressing body of the moving mechanism and a second jack, wherein the pressing body is retracted and the second jack is contracted.

FIG. 15 is a right side view of FIG.

FIG. 16 is a cross-sectional view showing one embodiment of a rotation stopping means.

FIG. 17 is a sectional view taken along the line 17-17 in FIG. 16;

FIG. 18 is a diagram for explaining a method of removing the casing.

FIG. 19 is a view showing another embodiment of the receiving means.

FIG. 20 is a view showing one embodiment of a casing used in the present invention.

FIG. 21 shows another embodiment of the receiving means for the casing.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 excavator 22 body axis 24 casing 26 body 28 first excavating head 30 second excavating head 32 drive mechanism 34 moving mechanism 36,209 receiving means 80 cylindrical part 82 bottom 200 reaction force transmitting body 202 cover 204 steel cage 206 Tremey tube 208 Solidified material

Claims (6)

[Claims] An excavator including a cylindrical main body, an excavating head disposed at a lower end of the main body, and a moving mechanism for moving the main body in a vertical direction, while excavating the ground, a plurality of holes are formed in the excavated vertical holes. A method of excavating a vertical hole in which casings are sequentially arranged in a vertical direction, wherein a step of lowering an arranged casing and a step of assembling the next casing on the arranged uppermost casing are performed a plurality of times. The drilling method of the vertical hole. 2. The method according to claim 1, wherein the step of lowering the disposed casing is performed by obtaining a reaction force on the wall surface of the vertical hole while adjusting a falling speed of the disposed casing by its own weight by the moving mechanism. Excavation method as described. 3. The casing according to claim 1, wherein each casing has a connecting portion connected to a casing disposed on an upper side or a lower side.
Or the excavation method according to 2. 4. Each of the casings is formed into a casing that is formed in a tubular shape in advance, a casing in which a plurality of arc-shaped members are assembled into a casing in which the plurality of members are arranged, and a casing in which a plurality of liner plates are arranged. The excavation method according to claim 1, 2, or 3, which is selected from a group of casings to be assembled. 5. The excavation method according to claim 1, wherein the step of assembling the next casing is performed once each time the step of lowering the disposed casing is performed one or more times. 6. The excavator according to claim 1, wherein each casing is made of a material selected from the group consisting of a metal material, a concrete material, and an industrial waste treatment material. Method.