JP2005097936A - Boring execution method and its device excavating gravel layer or obstacle layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boring method and its device capable of easily excavating a ground of a gravel layer including cobble stones or a ground in which obstacles or the like are embedded. <P>SOLUTION: A double steel pipe type core tube 7 is connected to a drilling rod 1, a stabilizing liquid is ejected to the vicinity of a bit 9 attached to the tip end of a core tube during excavation, the double tube clearance of the core tube is used for a passage 8 of the stabilizing liquid. A crown bit 9 with an opening/closing arm hinge in which one or more hinges are pivoted so as to freely rise and fall is provided on the upper face of the spiral auger bit attached to the bottom of the inside of the core tube 7 by excavation is pushed up the cobble stones or obstacles 17 during the excavation by the boring machine together with the stabilizing liquid from the downward to the upward in the opened condition of the arm 11 in the core tube, after completion of excavation, the arm 11 is pushed down almost horizontally to a closed state and cobble stones or obstacles 17 in the excavated earth are filled and then the tube is pulled out, obstacles in the core tube are taken out and removed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a boring method and apparatus for excavating a gravel layer or an obstacle layer.

  The cast-in-place pile method is a method of drilling holes using a special excavating machine at the construction site, and placing concrete bars or mortar in a reinforcing bar or core, such as the Benoto method, earth drill method, reverse method, etc. There is. The Benoto method is to press-fit a casing tube (steel pipe) while vibrating, excavate the earth and sand in the tube with a hammer mag, etc., excavate it to a predetermined depth, and then lay a rebar cage and place concrete. This is a construction method that is unsuitable for construction in urban areas because the casing tube is press-fitted while vibrating on a large scale. In the earth drill method, a rotating bucket is attached with a blade and excavated, and the earth is pulled up to the ground using the bucket. In the reverse method, drilling is performed with a reverse circulation drill, and the produced slime is sucked up from the tip of the bit together with the muddy water and eliminated.

Under the construction conditions in a narrow construction place and restricted space height, the top drive reverse construction method (TBH construction method) is actively adopted as an improvement of the rotary boring construction method (BH construction method) and the reverse construction method.
The rotary boring method is also called a BH (Boring Hole) method, which uses a boring machine having a power of 22 kw or higher and rotates an excavating bit attached to the tip of the boring rod for excavation. For excavation, the stable liquid is sent to the tip of the bit by a grout pump, the excavated sediment is carried to the hole by the rising water flow by the normal circulation, and discharged by the side pump installed at the hole. After excavation is completed, slime treatment is performed, and cast-in-place concrete piles are built with reinforcing steel, and concrete is cast to build the piles. In addition, concrete piles, steel pipe piles, and H steel are built, and mortar is injected to create embedded piles.
This construction method is characterized by the fact that the construction machine is small and can be constructed on a small site, and is the most compact of the existing pile excavation methods. Furthermore, a. Construction in a small site is possible. B. Construction is possible even when the work height is low, such as indoors. C. Because the machine is light and small, it can be loaded even on narrow roads. D. Large heavy machinery is not required for assembly and disassembly of the machine. E. There is an advantage that noise and vibration during construction is very low.

  Depending on the target geological conditions, circulating a stable liquid mixed with bentonite clay to prevent hole wall collapse when excavating the ground where gravel layers containing obstacles or obstacles are buried with a boring machine The type of bit is selected, and the excavation is carried out while applying the necessary bit load to the bit and rotating, but under such geological conditions, the work is difficult and the excavation takes a long time, and the construction cost is extremely high. In some cases, the construction becomes impossible and the design may be changed. Therefore, it is desired to develop a boring method and an apparatus capable of easily excavating a gravel layer or an obstacle layer.

In order to achieve the above object, claim 1 of the present invention uses a boring machine to rotate a drilling core tube with a metal crown bit at the tip while circulating a stabilizing liquid through a drilling rod. , Drilling holes while discharging the stable liquid pumped from the double pipe gap of the core tube made of double steel pipe from the vicinity of the tip of the core tube, and circulating the discharged stable liquid into the core tube It is a boring method for excavating a gravel layer or an obstacle layer, characterized in that cobblestone or gravel stays in the core tube by returning it up from the top of the slab.
The second aspect of the present invention provides a crown bit in which one or more arms or inclined iron plates are pivotally attached to a helical auger bit attached to the bottom of a core tube by excavation, and a cobblestone or obstacle during excavation by a boring machine. After pushing up the object together with a stable liquid flow that circulates upward from below in the core tube, after the excavation is completed, the arm or the inclined iron plate is brought down and closed to hold the cobblestone or obstacle in the core tube, It is characterized by removing the obstacle in the core tube by removing the tube.
Claim 3 connects the double steel pipe type core tube to the drilling rod, and makes the double tube gap of the core tube a stable liquid passage in order to discharge the stable liquid near the tar crown bit attached to the tip of the core tube at the time of excavation, A spiral auger bit on the lower inner side of the core tube is provided with a plurality of inclined iron plates or movable arms, and cobblestones or obstacles in the excavated soil are sprinkled up by the water flow in the core tube and held in the core tube. A boring device for excavating a characteristic gravel layer or obstacle layer.

In the present invention, by using a core tube metal crown bit with a special auger (or inclined steel plate with teeth), even when using a generally used large-diameter boring machine, it is possible to construct while circulating a stable liquid. Even under such severe geological conditions as described above, safe construction can be performed with a small-scale facility.
That is, the advantages of the present invention are listed as follows.
(1) Since construction is possible with small-scale equipment, construction is possible even in narrow location conditions.
(2) Since the digging is carried out while rotating the special bit while circulating the stabilizing liquid in the normal circulation, construction without vibration and noise is possible.
(3) Since the cylindrical metal crown bit is dug only to the minimum instead of the entire borehole construction, there is less excavation consumable material, the excavation efficiency is high, and super large boring is not required, so construction costs However, it is extremely cheap compared to other construction methods.
(4) Since the core tube can be used for various geological conditions in which obstacles such as pine piles and concrete are buried, excavation can be easily performed.
(5) Since the bit type is a core tube type, even under severe geological conditions, construction can be expected under high precision conditions with little hole bending.
(6) Even if a large amount of stabilizing liquid is used during excavation, the stabilizing liquid is pushed upward from the bottom in the core tube, so the resistance during rotation between the outside of the core tube and the hole wall is small, and slime Since it can be collected in the core tube, excavation is possible as long as the upper hole wall does not collapse.

When carrying out the present invention, when using a boring machine to rotate and drill a drilling rod with a metal crown bit attached to the tip, it is pumped from the double pipe gap of the core tube as a double steel pipe type drilling rod. By drilling a hole while discharging the stabilized liquid near the tip of the core tube, the discharged stable liquid is circulated upward in the core tube so that cobbles or gravel stays in the core tube.
Also, drilling a crown bit with an open / close hinge, which has one or more hinges pivotally mounted on the top surface of a helical auger bit attached to the inner bottom of the core tube by excavation. The cobblestone or obstacle is opened inside the core tube and the hinge is opened with the water flow upward from below. After excavation, the hinge is tilted downward and closed, and the cobblestone or obstacle is filled in the core tube. After caulking, the tube is extracted and the obstacle in the core tube is taken out and removed.
In addition, a double steel pipe core tube is used as the drilling rod, and a double pipe gap is formed in the vicinity of the tall crown bit attached to the tip of the core tube at the time of excavation. Alternatively, a gravel layer or obstacle layer characterized in that a plurality of movable hinges made of inclined iron plates are provided, and cobblestones or obstacles in the excavated soil are swollen by water flow in the core tube and held in the core tube. A boring device for excavation.

Next, a construction method and an apparatus for excavating a gravel layer containing cobblestone of the present invention or a ground containing an obstacle with a boring machine will be described in detail.
A drilling core tube 7 is connected under the drilling rod 1 provided with the stable liquid supply path 2. The core tube 7 is a double tube of an outer tube 7a and an inner tube 7b, and a stabilizing liquid passage 8 is formed between them, and a water discharge port 7c is formed at the lowermost end. The upper coupling of the core tube 7 has an upper plate 3 and a lower plate 4, and a communication path 5 that leads to the stabilizing liquid supply path 2 is provided therebetween. Further, several water discharge return holes 6 are provided through the upper plate 3 and the lower plate 4.
A helical auger bit 9 and several metal crown bits (metal chips) 10 are fixed to the lower portion of the core tube 7. As shown in FIGS. 1 and 2, brackets 13 are provided at several locations inside the core tube 7. An inclined iron plate or a movable arm 11 is rotatably attached to the long hole 14 through a hinge (shaft) 12, and a rubber cushion 15 is provided at the rotating end of the arm. Further, triangular cutters 16 and 16 are arranged between the movable arms 11 and 11.
A metal crown bit with an auger bit as shown in FIG. 1 is used, a metal crown bit 10 is attached to the tip of the core tube 7, and a helical auger bit (toothed inclined iron plate) is placed inside the lower portion of the core tube. A movable arm 11 that is mounted in a plurality of rows at two or more positions at a target position, and is pivotally supported so as to be movable up and down at the center of the upper surface of the auger bit installed at the lower stage of the core tube 1. Install.

With the core tube crown bit 9 attached to the tip of the drilling rod 7, the present invention provides the following operational effects during excavation.
(1) Stabilizing liquid is discharged from the vicinity of the metal crown bit and auger bit by piping, and the stabilizing liquid is circulated in the direction of pushing up from the bottom to the top in the core tube (Fig. 1). The object 17 is pushed upward by the circulating action of the stable liquid having viscosity and specific gravity, and easily flows into the core tube 7.
(2) By attaching a helical auger bit to the inner lower part of the core tube 7, cobblestones or obstacles are dug up by the action of mechanical rotational force, and are easily rolled up and pushed into the core tube 7. To do.
(3) In order to reliably collect cobblestones or obstacles that have been excavated in the core tube, gravel moves from bottom to top during excavation by the movable arm 11 attached to the lower upper surface of the helical auger bit. Since it is pushed up, the excavation is stopped when the core tube is completely filled.
During excavation, the movable arm is in an open state (Fig. 1). When excavating and excavating the tube, if the stable liquid circulation and the rotation of the boring machine are stopped, gravel and obstacles in the core tube will be lowered. Since it is about to fall, it becomes a closed state, and the object filled in the core tube is fully collected. In this way, the material clogged in the excavation core tube 1 is pulled up and taken out. Similarly, using the boring machine again, rotating the core tube metal crown bit with auger, digging while circulating the stabilizing liquid in the normal circulation system,

  As described above, the core tube metal crown bit with an auger for boulder collection using the BH / R bit of the present invention uses a large-diameter boring machine and a crown bit with a composite metal welded on a metal tip at the tip of the core tube. Auger bit blades are attached to the inside of the tip of the core tube, and a hinge is attached so that large gravel such as cobbles clogged in the core tube can be collected when excavation is completed and the tube is extracted. The method is the same principle as a general BH method. If the depth is relatively shallow, it is possible to dig a gravel layer mixed with some cobblestone. However, it cannot be applied to hard strata that cannot be drilled, or to gravel layers that contain harsh cobbles that are too large to enter the core tube. Drilling is possible even under severe geological conditions by welding composite metal to a metal crown bit.

As a feature of the core tube metal crown bit with auger for collecting cobblestone of the present invention,
(1) Using a large-diameter boring machine, feed the stabilizing liquid through the drilling rod to the bottom of the hole, rotate the bit attached to the tip of the drilling rod while circulating, and dig. In that case, the stabilizing liquid pumped from the drilling rod is piped into the core tube and discharged at the tip of the metal crown bit. Also, as another contrivance, a hole is made in the head of the core tube, and the stable liquid discharged from the tip is circulated from the bottom to the top through the core tube instead of the outer tube, and the cobblestone is the core tube. It is easy to float up inside.
(2) A metal crown bit is attached to the tip of the core tube, but two helical auger bits are attached to the target position at the lower part inside the core tube. Thus, the cobblestone is mechanically devised so as to be caught in the core tube.
(3) If the bit is rotated and drilled and cobblestone is filled in the core tube, stop the rotation of the boring machine, stop the circulation of the stable liquid, extract the drilling rod, and collect the cobblestone in the core tube. However, the hinge is attached so that the cobblestone in the cylindrical core tube does not fall out of the core tube. This hinge is in a released state so that the cobbles can easily enter the core tube when drilling, and is closed so that the cobbles in the core tube do not fall during extubation.
(4) Since the gravel layer mixed with cobblestone, which is a harsh geological condition, is dug, a special device has been devised for the tip of the metal crown bit that drills cobblestone. Composite metal is welded to the top surface of the metal crown bit, and the teeth overlap in two layers. Thereby, it can withstand drilling holes such as cobblestones and can effectively dig, and the bit life is increased.

During excavation, the movable arm 11 is in a substantially horizontal open state as shown in FIG. The stabilizing liquid is discharged from the spout 7c at the lower end of the core tube and pushed up. At the same time, the cobblestone and gravel 17 are lifted up by the auger bit in the core tube, and easily enter the core tube.
The stabilizing liquid pumped through the drilling rod 1 passes through the inside of the core tube passage 8 and is discharged from the tip of the metal crown bit 9, and the excavated soil containing cobblestone is pushed up from the bottom to the top in the core tube. Due to the rotation of the metal crown bit 10 attached to the tip and the built-in auger bit, gravel and obstacles are easily swept into the core tube and collected. When the circulation of the stabilizing liquid is stopped at the time of extubation after the completion of excavation, the movable arm 11 in the core tube falls down (substantially horizontal) and closes, so that the foreign matter such as cobblestones 17 is collected and removed by pulling up the core tube. The

  In the excavation work, an appropriate bit load is applied while circulating the stabilizing liquid by a normal circulation method, and the bit is rotated to excavate. First, the stabilizing liquid stored in the stabilizing liquid tank passes through the delivery hose by the slush pump, passes through the rod, is pumped to the tip of the bit, and is discharged. The slime produced by the rotation of the bit is carried out of the hole by the flow velocity outside the tube of the stable liquid having viscosity and appropriate specific gravity. The stabilizer containing the slime is pumped to the mud screen in the stabilizer plant by a sand pump installed at the hole. The mud screen separates coarse grain slime. The fine-grained slime that has passed through the wire mesh is precipitated and separated in a stable liquid tank. A good quality stabilizer that does not contain slime is again pumped into the hole by a slush pump and circulates in the same path.

An example of stabilizing liquid management is as follows.
Bentonite concentration 12-15% during stable liquid production
(In the case of 15%, when mud is generated)
Management target Specific gravity at the time of mud 1.06-1.08
Specific gravity at the time of digging 1.30-1.50

Sectional drawing which shows the boring construction method which excavates the gravel layer or obstacle layer of this invention. The bottom view of FIG. The enlarged side view of a movable arm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drilling rod 2 Stabilizing liquid supply path 3 Upper plate 4 Lower plate 5 Communication path 6 Water discharge return hole 7 Drilling core tube 7a Outer tube 7b Inner tube 7c Water outlet 8 Stabilizing liquid passage 9 Helical auger bit 10 Metal tip 11 Inclined iron plate (Movable arm)
12 Hinge 13 Bracket 14 Slot 15 Rubber cushion 16 Triangular cutter 17 Cobblestone

Claims (3)

  When using a boring machine to circulate the drilling core tube with a metal crown bit at the tip while circulating the stabilizing liquid through the drilling rod, the double tube gap of the core tube made of a double steel pipe type is used. Drilling holes while discharging the pumped stable liquid from the vicinity of the tip of the core tube, circulating the discharged stable liquid through the core tube, and then returning the cobblestone or gravel into the core tube by returning it from the top of the core tube. A boring method for excavating a gravel layer or an obstacle layer characterized by being retained in the ground.   A crown bit, which is a spiral auger bit attached to the bottom of the core tube by excavation, and one or more arms or tilted iron plates pivoted in a undulating manner, and cobblestones or obstacles inside the core tube during excavation by a boring machine It is pushed up together with a stable liquid flow that circulates upward from below, and after the excavation is completed, the arm or the inclined iron plate is brought down to a closed state to hold cobbles or obstacles in the core tube, and then the tube is extracted to remove the core tube. 2. The boring method according to claim 1, wherein the obstacle is taken out and removed.   A double steel pipe type core tube is connected to the drilling rod, and when digging, the stable liquid is discharged near the crown crown bit attached to the tip of the core tube. A gravel layer characterized in that a spiral auger bit is provided with a plurality of inclined iron plates or movable arms, and cobblestones or obstacles in the excavated soil are sprinkled up by water flow in the core tube and held in the core tube Or a boring device that excavates obstacle layers.

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