JP4709040B2 - Drilling device, drilling method and pile construction method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a drilling device, a drilling method, and a pile construction method that are suitable for use in pile construction in mountainous areas and narrow areas, or pile construction for existing foundation reinforcement.

  Conventionally, a small diameter pile (micropile) having a pile diameter of approximately 400 mm or less has been put to practical use as a steel tower foundation pile or a steel tower foundation reinforcing pile constructed in a mountainous area or a narrow area. In the construction of this pile, drilling is generally performed by using a rotary packer or a down-the-hole hammer instead of a conventional large pile driver.

  The rotary packation is a machine in which bits are provided at the tip of the casing and the tip of the inner rod, and holes are drilled by rotation and impact. A down-the-hole hammer is a machine that has a piston structure at the tip of the hammer, and attaches a bit to the tip of the hammer to drill holes by striking and rotating.

  Patent Document 1 describes a technique of a dura foam type excavation method for collecting a high-quality formation (ground) sample. In this technique, as shown in FIG. 9, a sampler composed of an inner tube 101 and an outer tube 102 is fixed to the tip of a rod 100, and a plurality of bits (rotating excavation blades) 103 are attached to the tip of the outer tube 102. A foam-like dural foam in which bubbles having a hard film are connected to the gap between the inner pipe 101 and the outer pipe 102 is sent (indicated by an arrow in the figure), and this dura foam is bit together with slime (excavated waste). 103 is sent out from the flow path 104 formed in the gap between the holes 103 and is discharged to the outside of the hole through the gap between the hole wall 105 and the outer tube 102.

In this technique, the fine bubbles to be fed to the excavation surface are made into an aerosol, so that the fine bubbles can be sent constantly at high speed. Further, the fine bubbles ejected from between the bits 103 expand greatly without rupturing while being covered with the surface active micelles, and can form a dural foam and exhibit an excellent slime discharging ability. In addition, the bit can be cooled by an adiabatic change that occurs when the microbubbles expand, thereby improving the working efficiency.
JP 2003-120165 A

Among the above, the rotary packing and down-the-hole hammer are originally developed for anchors and rock drilling, and there are individual suitability and common problems as follows.
<Rotary packing>
(1) Cannot be used in mountainous areas due to water (muddy water) circulation.
(2) When the pile diameter is increased, the construction machine becomes larger (heavy).

<Down the hole hammer>
(1) Since the construction method is essentially a casing-less construction method, the construction capacity of the general earth and sand using the casing is extremely reduced.
(2) Special technology is required for the construction of slant piles.
(3) It is difficult to obtain pile accuracy.

<Common issues>
(1) Temporary land where heavy machinery can move and cargo handling equipment are required. In particular, if there are restrictions such as reinforcement of existing foundations and mountainous areas, construction may not be possible.
(2) When hitting an obstacle such as an existing foundation or steel, it is difficult to drill or it takes a considerable amount of time. (3) A single type of drilling machine cannot be applied to all geology.
(4) A relatively large noise (or vibration) is generated.
(5) There are many incidental facilities such as water tanks and compressors, which are often problematic in terms of transportation and temporary installation.
(6) When the reinforcement symmetry of the existing foundation is a small steel tower foundation, it is difficult to construct a pile in the steel tower because the drilling machine is large.

On the other hand, the technique described in Patent Document 1 has the following problems.
(1) A technique for passing a dura foam using a narrow portion of the inner tube 101 and the outer tube 102 which are double tubes and triple tubes is required.
(2) Because the gap between the inner tube 101 and the outer tube 102 through which the dura mater bubbles pass and the flow path 104 formed in the gap between the bits 103 are narrow, slime (digging waste) entering the gap Clogging is likely to occur and countermeasures are required.
(3) That is, the bubble passage area is decisively narrow. Considering the excavation efficiency when the excavation depth becomes deep, it becomes a method of cutting with carbide or diamond bit, but in that case, the rotation peripheral speed of the bit is required, so the balance with slime discharge becomes worse, Clogging occurs.
(4) In order to prevent clogging due to the ground properties exhibiting a strong tendency of disintegration and crushing properties, it is necessary to devise mixing of bubble liquid and chemical reaction.

  Therefore, the present invention is a lightweight, compact, applicable to any geology including obstacles such as steel, and construction of a drilling device, a drilling method, and a pile that can secure construction accuracy more than conventional. It is an object to provide a method.

In order to solve the above-mentioned problems, the present invention employs the following means.
The present invention relates to a drilling device for drilling the ground while sending bubbles into the drilling tube, the driving means for rotating the drilling tube about its axis, and the drilling tube in its axial direction. Elevating and lowering means for moving up and down, foam supply means for sending foam generated in the hole making tube, and pressure control means for controlling the pressure in the hole making tube due to the foam, It was set as the structure which has the single casing tube rotated by a drive means, and the diamond bit provided in the front-end | tip part of the single casing tube.

  According to the hole drilling device of the present invention, the hole drilling tube is configured as a single casing tube having a diamond bit at the tip, so that bubbles (fine bubbles) bubbled into the hole drilling tube are fed. The bubble passage area is the entire drilling tube, and the foam pressure can be applied to the entire excavation surface surrounded by the drilling tube. Thereby, excavation waste is discharged smoothly without clogging. In addition, since the pressure of the foam acts on the entire hole hole tube and the hole wall, this bubble protects the hole wall, prevents the bit tip from being seized, prevents the core from rotating around the hole tube, etc. Demonstrate.

  In addition, the hole drilling tube is a single casing tube with a diamond bit at the tip, and foam is sent into the inside, so it can be applied to any geology including obstacles such as steel. The accuracy can be ensured more than before, and the entire device can be made lighter and more compact.

In the present invention, the diamond bit is provided at a distal end portion of a cylindrical bit body at a cutting diamond segment disposed at intervals in the circumferential direction of the bit body, and on an inner peripheral surface side of the bit body. It is desirable to have a configuration having an inner diamond segment and an outer diamond segment provided on the outer peripheral surface side of the bit body.

  When configured in this manner, not only can the inner diamond segment have a stirring action and the outer diamond segment can have a hole wall self-supporting action, but the straightness improving action of the hole drilling tube can also be exhibited. In particular, regarding the hole wall self-supporting action, the fact that it is a rotary excavation using a diamond bit that does not exert impact or vibration on the hole wall also greatly contributes.

  Here, it is preferable that the inner diamond segment and the outer diamond segment extend from the cutting diamond segment in the axial direction of the bit body along the inner peripheral surface and the outer peripheral surface of the bit main body, respectively. By comprising in this way, both the stirring effect | action by bit rotation and the hole wall self-supporting effect | action can be exhibited more notably in the ground whose hole is drilled especially in relatively soft ground such as earth and sand.

  In the present invention, the protruding dimension of the outer diamond segment from the outer peripheral surface of the bit body can be made larger than the protruding dimension of the inner diamond segment from the inner peripheral surface of the bit body. In this way, if the outer dimension of the outer diamond segment is increased from the outer peripheral surface of the bit body, the extra drilling area of the hole wall by the outer diamond segment can be increased, so that the drainage effect is particularly effective in viscous ground that is easily clogged. Can be increased.

  In the present invention, it is desirable that the interval between the cutting diamond segments is set to be larger than the protruding dimension of the outer diamond segment from the outer peripheral surface of the bit body. When set in this way, a large gap (forming outer way) can be formed between the cutting diamond segments to discharge the cutting waste in the hole drilling tube to the outside (hole wall side) together with the foam.

  That is, by setting the gap between the cutting diamond segments to a gap larger than the gap between the outer peripheral surface of the casing tube and the hole wall (the outer wall dimension of the hole wall by the outer diamond segment), cutting by foam The waste discharging action can be performed smoothly without clogging.

  On the other hand, the present invention is a drilling method using the above-described drilling device, in which the foam generated by the foam supply means is fed into the drilling tube in which the diamond bit portion enters the ground and is made airtight. Including a foam supply step, and a drilling step of drilling the ground by rotating up and down in the axial direction while rotating the drilling tube around its axis by the driving means and the lifting means. Controls the pressure of the foam in the drilling tube and the rotation speed of the drilling tube so that low-grained material is pushed out of the drilled swarf with the foam from between the drilling tube and the hole wall. The method of drilling was adopted.

  According to the drilling method of the present invention, drilling is performed while controlling the pressure of bubbles in the drilling tube and the rotation speed of the diamond bit, so that the effect of extruding the low-graded material and the effect of fixing the internal residue can be improved. Can be demonstrated well. In addition, it adopts the rotary excavation method with diamond bit while feeding foam, so it can respond to drilling to topsoil, cobblestone, cohesive soil, hard rock without worrying about clogging, baking etc. It is.

Here, it is desirable to further include a remaining material discharging step of taking out undischarged material remaining in the hole drilling tube with a core lifter, a core basket or the like that is used by being mounted on the single casing tube. When this process is adopted, this drilling device can be used effectively even for the ground which is easily clogged such as cohesive soil. However, this remaining material discharge process may not be able to be lifted if the remaining material increases and the weight is increased. desirable.

  The present invention is a method for constructing a pile using the above-described drilling device, in which the foam generated by the foam supply means is fed into a drilling tube in which the diamond bit portion is made to enter the ground to be airtight. The foam supply step, the drilling step of drilling the ground by rotating up and down in the axial direction while rotating the drilling tube around its axis by the driving means and the lifting means, and the roughening of the wall surface of the drilled pile hole And a step of inserting a reinforcing bar into the pile hole and placing concrete, and in the drilling step, among the drilling waste excavated by the diamond bit, a low-graded material and the drilling tube It is characterized by drilling while controlling the pressure of foam in the drilling tube and the rotation speed of the drilling tube so as to be pushed out from between the hole walls.

  According to the pile construction method of the present invention, a rotary excavation method using a diamond bit while feeding bubbles is adopted, so it can be applied to any geology, and the construction accuracy of the pile as well as the construction of the diagonal pile is conventional. The above can be secured. Moreover, since obstacles, such as steel materials, can be constructed without problems, it can be effectively used for reinforcing steel tower foundation piles, for example.

  According to the present invention, a drilling device, a drilling method, and a pile that are lightweight and compact as a whole, can be applied to any geology including obstacles such as steel materials, and can ensure construction accuracy more than conventional. The construction method can be obtained.

Preferred embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a drilling device according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional perspective view of the drilling tube of the drilling device according to the embodiment, and FIG. 3 is an explanatory diagram of the operation of the drilling tube. 4A and 4B are a plan view and a perspective view showing a diamond bit. 5A and 5B are a perspective view and a cross-sectional view showing the core basket. 6A and 6B are a perspective view and a partial sectional view showing the core lifter, and FIG. 6C is a sectional view showing the lifter case.

  As shown in FIGS. 1 to 3, the hole drilling device according to the first embodiment has a driving means 2 for rotating the hole drilling tube 1 around its axis and the hole drilling tube 1 is moved up and down in the axial direction. Elevating and lowering means 3, foam supplying means 4 for sending bubbles (fine bubbles) 4 a bubbled into the hole making tube 1, and pressure control means 5 for controlling the pressure in the hole making tube 1 by the bubbles 4 a It has.

  Next, these details will be described. A fixed plate 6 is laid as necessary on the ground G to be drilled, and a hole for passing the drilling tube 1 up and down is provided in the fixed plate 6 as needed. The hole drilling tube 1 has a single casing tube 11 that is rotated by the driving means 2 and a diamond bit 7 provided at the tip of the single casing tube 11.

  The single casing tube (hereinafter referred to as a casing) 11 is made of, for example, a metal cylindrical tube, and is used by being connected to each other in the axial direction by screw connection. The uppermost casing tube 11 is coaxially connected to a casing connection head 13 provided on the output shaft of the driving means 2.

The drive means 2 includes a hydraulic motor 21 that is rotationally driven by pressure oil supplied from the hydraulic unit 22 via the hydraulic hose 23. The elevating means 3 includes an elevating arm 32 that can move up and down along a stand 31 erected on the fixed plate 6. The lifting arm 32 is equipped with a hydraulic motor 21, whereby the drilling tube 1 can be moved up and down together with the hydraulic motor 21.

  The foam supply means 4 includes an air compressor 41, a foaming device 42 that forcibly ejects foam liquid into an air supply fluid by compressed air supplied from the air compressor 41, and bubbles 4 a generated by the foaming device 42. And a pressure hose 43 for supplying the pressure into the casing 11 via the connection head 13.

  As shown in FIG. 3, the pressure control means 5 for controlling the pressure in the drilling tube 1 by the bubbles 4 a can also be configured by a valve 52 with an adjustment lever 51 provided at the tip of the pressure hose 43. However, it is basically configured by a control unit (a compressed air supply amount adjustment unit or a foam liquid ejection amount adjustment unit) (not shown) provided in the foaming device 42.

  As the foam liquid, Lipolane (trade name) commercially available as a foaming agent for foam drilling is preferably used. This foaming agent (foaming agent) is a foaming agent comprising a special anionic surfactant and exhibits excellent properties such as high foaming property, hard water resistance, heat resistance, low toxicity, and the like. Of course, other foaming agents can be used.

  The diamond bit 7 includes a cutting diamond segment 71 disposed at an interval in the circumferential direction of the bit main body 70 with respect to a tip portion of the cylindrical metal bit main body 70, and an inner peripheral surface side of the bit main body 70. An inner diamond segment 72 extending in the axial direction of the bit body 70 from the cutting diamond segment 71 and an outer ring provided on the outer peripheral surface side of the bit body 70 and extending in the axial direction of the bit body 70 from the cutting diamond segment 71. And a diamond segment 73. A female screw 74 is formed on the upper inner peripheral surface of the bit body 70 to be engaged with a male screw (not shown) provided on the lower outer peripheral surface of the casing 11. As the casing 11 and the bit body 70, those having a relatively small diameter of about 200 mm in outer diameter are employed in this embodiment.

  The inner diamond segment 72 protrudes from the inner peripheral surface of the bit body 70 and is configured to exhibit the excavation scraps stirring action. The outer diamond segment 73 protrudes from the outer peripheral surface of the bit body 70 and is configured to contribute to the extra moat action of the hole wall and the self-standing action of the hole wall. Thereby, consideration is given so that the straightness improving effect of the tube 1 for hole drilling can also be exhibited.

  In particular, the inner diamond segment 72 and the outer diamond segment 73 extend from the cutting diamond segment 71 in the axial direction of the bit body along the inner peripheral surface and outer peripheral surface of the bit main body 70, respectively. Both the stirring action and the hole wall self-supporting action due to the bit rotation in the relatively soft ground such as earth and sand can be exhibited more significantly.

  The protruding dimension of the outer diamond segment 73 from the outer peripheral surface of the bit body 70 is set to about 1/100 to 10/100 of the diameter of the bit body 70. If this protruding dimension of the outer diamond segment 73 is increased more than necessary, the excavation resistance increases, and if it is decreased more than necessary, the excavation waste may not be discharged smoothly. A more preferable range obtained from the experimental results is a projecting dimension of about 2/100 to 6/100, although it depends on the properties of the ground. When the diameter of the bit body 70 is 200 mm, it is 4 to 12 mm.

The protruding dimension of the inner diamond segment 72 from the inner peripheral surface of the bit body 70 is set to about 1/100 to 8/100 of the diameter of the bit body 70. If this protrusion dimension of the inner diamond segment 72 is increased more than necessary, the excavation resistance is increased in addition to the agitation resistance, and if it is decreased more than necessary, the agitation action of the excavation waste may not be performed smoothly. A more preferable range obtained from the experimental results is a projecting dimension of about 2/100 to 5/100, although it depends on the properties of the ground.

  In the embodiment, the protruding dimension of the outer diamond segment 73 is larger than the protruding dimension of the inner diamond segment. This is because the projecting dimension of the outer diamond segment 73 is increased, and the extra moat area of the hole wall by the outer segment 73 is increased, so that the discharge effect can be enhanced particularly in the viscous ground that is easily clogged. Is.

  The interval between the cutting diamond segments 71 is set to be larger than the protruding dimension of the outer segment 73 from the outer peripheral surface of the bit body 71. By setting in this way, a large gap (forming outer way) f is formed between the cutting diamond segments 71 to discharge the cutting waste in the drilling tube 1 to the outside (hole wall side) together with bubbles. be able to.

  That is, by setting the gap f between the cutting diamond segments 71 to a gap larger than the gap between the outer peripheral surface of the casing 11 and the hole wall (excavation dimension of the hole wall by the outer diamond segment 73), Consideration is given so that the cutting dust can be discharged smoothly by the bubbles 4a without clogging. Further, since the gap f communicates directly with the space in the bit body 70 in which no double pipe or the like is present, that is, the gap f in which a back area is secured, this point is also prevented from clogging. It greatly contributes to the action. The relationship between the forming outer way f and the back area greatly contributes to the fact that the inner diamond segment 72 and the outer diamond segment 73 are arranged on the rear side in the rotational direction of the cutting diamond segment 71.

  From the viewpoint of enhancing the excavation action of excavated waste, the larger the gap f, the better. However, if it is too large, the cutting action by the cutting diamond segment 71 is lowered. This cutting action is also reduced by wear of the cutting diamond segment 71. Therefore, the gap f is determined in consideration of these points in advance. Of course, with respect to the wear of the diamond segment, the inner diamond segment 72 and the outer diamond segment 73 are similarly considered.

  FIGS. 5A and 5B are a perspective view and a cross-sectional view showing the core basket 8. The core basket 8 is mounted between the bit body 70 and the casing 11 or between the casings 11 and used for discharging the remaining material in the drilling hole. The core basket 8 in the illustrated example includes a cylindrical portion 80 that is formed in a cylindrical shape that is shorter than the casing 11, and a female screw 81 provided on each of the upper inner peripheral surface and the lower inner peripheral surface of the cylindrical portion 80. , 82 and a plurality of bent pieces 83 projecting from the inner peripheral surface of the cylindrical portion 80.

  The bent piece 83 is formed by bending one end of a strip-shaped metal plate fixed to the inner peripheral surface between the female screws 81 and 82 of the cylindrical portion 80 around 45 degrees, and is spaced from the inner peripheral direction of the cylindrical portion 80. Many are provided. These bent pieces 83 receive a resistance of a remaining material or the like when the core basket 8 is pushed in, and the deformation occurs slowly (the angle of the bent piece 83 becomes loose), and the resistance against the pulling up of the core basket 8 is increased. It is designed to return moderately in response.

  Furthermore, it is designed so that it can be used repeatedly or at least several times, with the deformation corrected when re-inserted. Such a function can be imparted by considering the material and thickness of the plate material forming the bent piece 83, elasticity, the length and area of the bent piece 83 portion, and the like. In order to make the bending piece 83 replaceable or easy to replace, the fixing portion 84 of the bending piece 83 may be fixed to the cylindrical portion 80 by screwing (screwing).

  FIG. 6A is a perspective view showing a single type core lifter 9, and FIG. 6B is a sectional view thereof. (C) is a sectional view of a lifter case 90 that houses the core lifter 9. The core lifter 9 has a peripheral wall separating portion 9a obtained by cutting a part of a cylindrical peripheral wall, and is configured so that the outer diameter of the split cylindrical portion 9b can be changed by the peripheral wall separating portion 9a.

  Thick portions 9c and thin portions 9d are alternately formed on the inner peripheral surface of the split cylindrical portion 9b. These thick portions 9c and thin portions 9d extend in the axial direction of the split cylindrical portion 9b and are alternately formed in the circumferential direction of the split cylindrical portion 9b. The lower end edge of the split cylindrical portion 9b is formed with a tapered surface 9e for gradually reducing the thickness of the peripheral wall to make an acute angle.

  The lifter case 90 is attached to the casing 11 instead of the diamond bit 7 and has a cylindrical portion 91 having the same diameter as the outer diameter of the casing 11. An internal thread 92 is formed on the inner peripheral surface of the cylindrical portion 91 so as to be engaged with a male thread (not shown) of the casing 11. A housing portion 93 that houses the core lifter 9 is formed under the female screw 92. The inner wall surface of the accommodating portion 93 is formed on a tapered inner surface 94 whose inner diameter becomes smaller toward the lower end.

  The inner diameter A at the lower end of the accommodating portion 93 is formed to be slightly smaller than the outer diameter of the split cylindrical portion 9b in a state where the peripheral wall separating portion 9a is closed. Thereby, it is considered that the core lifter 9 inserted from the upper opening of the lifter case 90 and accommodated in the accommodating portion 93 does not come out of the accommodating portion 93.

  Further, when the core lifter 9 is used, when it is pulled up together with the casing 11, the split cylindrical portion 9 b has a smaller inner diameter due to the influence of the weight of the inner core (not shown) and the action of the tapered inner surface 94. Considered to be narrowed down. Thereby, it becomes the structure which can extract the core in the casing 11 containing a core lifter.

  FIG. 7 is a functional block diagram of the drilling device. This drilling device is an example in which the drilling device is divided into two systems in consideration of the efficiency and miniaturization of the entire system. In this example, two foaming devices 42, 42 are connected to one compressor 41, and power is supplied from a generator 45 to each foaming device 42, 42 and the compressor 41.

  The two hydraulic units 22, 22 are connected to a single hydraulic cooling device 24, and are supplied with electric power from a generator 45. Stands 31, 31 of two types of drilling devices are installed and used on one fixed plate 6. These drilling devices are configured in consideration of reduction in size and weight as shown in FIGS.

  In the drilling method using the drilling device having such a configuration, first, the bubble device 42 of the bubble supplying means 4 is inserted into the drilling tube 1 in which the diamond bit 7 portion is slightly entered into the ground G to make it airtight. The foam 4a generated by the above is sent through the pressure hose 43 (foam supply process).

  Then, the ground motor G is sequentially drilled by rotating up and down in the axial direction while rotating the drilling tube 1 around its axis by the hydraulic motor 21 and the lifting unit 3 of the driving unit 2 (drilling step).

  In this drilling process, as shown in FIG. 2 and FIG. 3, among the drilling waste drilled by the diamond bit 7, the low-gradient material 4b is pushed out together with the bubbles 4a from between the drilling tube 1 and the hole wall G1. Thus, drilling is performed while controlling the pressure of the bubbles 4a in the drilling tube 1 and the rotation speed of the drilling tube 1. In the action explanatory diagram of FIG. 3, 4c indicates a cobblestone or the like pressed by the bubbles (bubbles) 4a, and 4d indicates a cut rock pressed by the bubbles.

  In this drilling step, drilling is performed while controlling the pressure of the bubbles 4a in the drilling tube 1 and the rotational speed of the diamond bit 7, so that the extrusion effect of the low-graded material 4b and the internal residue (as residual material) Of cobblestone 4c, cutting rock 4d, etc.) can be efficiently exhibited. Here, the fixing effect of the remaining material means an effect of pressing the remaining material so that it does not travel with the casing 11 in the casing 11.

  This drilling method employs a rotary excavation method with diamond bit 7 while feeding bubbles 4a, so it can be used for topsoil, cobblestone, cohesive soil, and hard rocks without worrying about clogging or burning. It is possible to cope with other drilling holes.

  Here, when the remaining material (undischarged material) such as the cobblestone 4c and the cut rock 4d remains in the drilling tube 1, the lifter case 90 or the core in which the core lifter 9 is accommodated in the casing 11 A process of attaching the basket 8 and discharging the remaining material is performed. When this process is adopted, this drilling device can be used effectively even for the ground which is easily clogged such as cohesive soil.

  In addition, when constructing a pile using the above-described drilling device, although not particularly illustrated, after the above-described drilling process, a roughening process for roughening the wall surface of the drilled pile hole, It is possible to easily construct a relatively small-diameter pile by inserting a reinforcing bar or a reinforcing bar into the concrete and placing concrete. The reason for roughening the wall is to increase the adhesion between the hole wall and the concrete.

  According to this pile construction method, a rotary excavation method using a diamond bit while feeding bubbles is adopted, so it can be applied to any geology, as well as construction of slant piles, and the construction accuracy can be secured more than conventional. . Moreover, since obstacles, such as steel materials, can be constructed without problems, it can be effectively used for reinforcing steel tower foundation piles, for example.

It is a schematic block diagram of the drilling apparatus which concerns on the Example of this invention. It is a partial cross section perspective view of the tube for hole drilling of the hole drilling device which concerns on the Example of this invention. It is action | operation explanatory drawing of the tube for hole drilling which concerns on the Example of this invention. The diamond bit which concerns on the Example of this invention is shown, (a) is a top view, (b) is a perspective view. The core basket which concerns on the Example of this invention is shown, (a) is a perspective view, (b) is sectional drawing. The core lifter which concerns on the Example of this invention is shown, (a) is a perspective view, (b) is a fragmentary sectional view, (c) is sectional drawing which shows a lifter case. It is a functional block diagram which shows the example which equipped two drilling apparatuses which concern on the Example of this invention. It is explanatory drawing which shows the usage example of 2 systems of the drilling apparatus which concerns on the Example of this invention. It is explanatory drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tube for drilling 2 Drive means 3 Elevating means 4 Foam supply means 4a Foam 4b Low particle size 4c Cobblestone 4d Cutting rock 5 Pressure control means 6 Fixed plate 7 Diamond bit 8 Core basket 9 Core lifter 11 Single casing tube (casing)
90 Lifter case 70 Bit body 71 Diamond segment 72 for cutting Inner diamond segment 73 Outer diamond segment f Gap G Ground G1 Hole wall

Claims (6)

A drilling device that drills the ground while sending bubbles into the drilling tube,
Drive means for rotating the hole drilling tube around its axis;
Elevating means for elevating and moving the hole drilling tube in its axial direction;
A foam supply means for feeding the foamed foam into the hole drilling tube;
Pressure control means for controlling the pressure in the hole drilling tube due to the foam,
The hole drilling tube has a single casing tube that is rotated by the driving means, and a diamond bit provided at the tip of the single casing tube ,
The diamond bit has a plurality of cutting diamond segments arranged at intervals in the circumferential direction of the bit body at a distal end portion of the bit body, which is a cylindrical opening end, and an inner peripheral surface side of the bit body. A plurality of inner diamond segments provided, and a plurality of outer diamond segments provided on the outer peripheral surface side of the bit body,
The inner diamond segment protrudes from the inner peripheral surface of the bit body, and extends in the axial direction of the bit body along the inner peripheral surface of the bit body from the rear end side in the rotation direction of the cutting diamond segment,
The outer diamond segment protrudes from the outer peripheral surface of the bit body and extends in the axial direction of the bit body from the rear end side in the rotation direction of the cutting diamond segment along the outer peripheral surface of the bit body. . Wherein the outer diamond segments, protruding dimension from the outer peripheral surface of the bit body, the inner diamond segments, larger than the projection dimension from the inner peripheral surface of the bit body, drilling apparatus according to claim 1. The hole drilling device according to claim 1 or 2 , wherein an interval between the cutting diamond segments is set to be larger than a protruding dimension of the outer diamond segment from an outer peripheral surface of the bit body. A drilling method using the drilling device according to any one of claims 1 to 3 ,
A foam supply step of sending the foam generated by the foam supply means into the hole making tube which has been made airtight by allowing the diamond bit portion to enter the ground, and
A drilling step of drilling the ground by moving up and down in the axial direction while rotating the drilling tube around its axis by the driving means and the lifting means,
In the drilling step, the pressure of the foam in the drilling tube is such that, among the drilling waste excavated by the diamond bit, low-graded material is pushed out from between the drilling tube and the hole wall. Drilling method for drilling while controlling the rotation speed of the tube for drilling. Not Emissions, core lifter for use by mounting the single casing tube, further having a more retrieve residual material discharge step Koabasuke' DOO, drilling method according to claim 4 remaining in the drilling for the tube. A pile construction method using the drilling device according to any one of claims 1 to 3 ,
A foam supply step of sending the foam generated by the foam supply means into the hole making tube which has been made airtight by allowing the diamond bit portion to enter the ground, and
A drilling step of drilling the ground by moving up and down in the axial direction while rotating the drilling tube around its axis by the driving means and the lifting means;
A roughening step for roughening the wall surface of the drilled pile hole;
Including inserting a reinforcing bar into the pile hole and placing concrete.
In the drilling step, the pressure of the foam in the drilling tube is such that, among the drilling waste excavated by the diamond bit, low-graded material is pushed out from between the drilling tube and the hole wall. A pile construction method that drills while controlling the rotation speed of the drilling tube.

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