JP3744031B2 - Drilling tools and methods - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the field of excavation work for the ground, in particular excavation work for setting up foundation piles. More particularly, the present invention is in the field of tools and methods that can fill the excavated hole with concrete without having to excavate the ground and then remove the earth and sand.
[0002]
[Prior art]
Today, the construction of building foundation piles in the ground at construction sites is carried out mainly by the following three methods.
(A) Steel pipe driving drilling method (b) Large drilling method (c) Auger drilling method
The steel pipe driving excavation method (a) is a method of performing excavation by driving a steel pipe into the ground. In other words, the bottom of the steel pipe is temporarily closed, and then it is struck and vibrated and driven into the ground. The operation of driving the tube brings the surrounding soil into a tight state, thus improving the mechanical properties of the soil, especially the holding strength. Next, a reinforcing material is inserted into the pipe, and further concrete is poured. After this, the tube is pulled out from the soil while shaking with vibration and vibration so that the concrete and the soil are in close contact.
[0004]
The large drill excavation method (b) is a method in which the soil is partially scraped using a rotating large excavation blade. During the construction, the excavating blade repeats the operation of pulling out from the hole, discarding the soil on the surface, and returning it to the hole. The soil around the hole loosens and tends to collapse, so you can temporarily surround the excavated area with a frame, or put water or special impervious slurry to support the excavated area using its buoyancy. You must take measures such as. However, because it is simpler than the method using a slurry, a dry method is usually employed if possible. After this, the reinforcing material is inserted into the pipe, and further using a hose, the concrete is poured from the bottom of the hole to avoid mixing with the slurry.
[0005]
Finally, in the auger excavation method (c), a spiral excavation blade (auger) having the same length as that of the hole to be excavated is screwed into the ground, and the excavated soil is removed. It is a method of scraping the part on the ground. In this method, the soil may become close or loose, and it cannot be generally stated. However, the collapse of the soil around the blade is generally supported by the soil entering the inside of the blade. On the other hand, the concrete is usually supplied via a passage provided by hollowing out the shaft portion of the excavating blade, and is simultaneously fed into the hole when the blade is extracted from the hole. Further, the reinforcing material is sequentially fed in the same manner.
[0006]
However, each of the above three methods has drawbacks. That is,
First, the method (a) generates very loud noise and vibration, and is not suitable for use in an urban area. For economic reasons, the rake diameter is limited to 1 meter and the length is limited to 25 meters. However, this method requires a very short period of time, and the mechanical equipment is not so complicated, so that the construction cost is relatively low.
[0007]
Next, the method (c) is similar in performance to the method (a), but the noise is considerably small and there is no vibration. However, the length of the reinforcing material is limited to 16 to 18 meters because it is difficult to insert it deeply into the concrete.
[0008]
The method (b) uses a telescopic excavation rod, which is impossible with the methods (a) and (c), to set up a pile with a thickness of 2 meters or more and a length of 80 meters. be able to. On the other hand, special machinery and specialized operators are required, and there is the inconvenience of having to use bentonite slurry at the end.
[0009]
[Problems to be solved by the invention]
Therefore, it is an object to eliminate many of the above-mentioned drawbacks in the prior art and provide a reliable, simple and low cost excavation tool and method.
[0010]
[Means for solving problems]
One object of the present invention is to excavate a vertical or inclined hole, and at the same time to compact the surrounding soil and to make the soil wall and the injecting material such as concrete adhere well, and the above existing method (a) or It is to solve the problem of limiting the diameter and depth of the excavation hole, which is a drawback of (c).
Another object of the present invention is to prevent environmental noise and vibration.
Yet another object of the present invention is to reduce the cost and time of foundation piling work by allowing the use of fewer workers and simple machinery.
Another object of the present invention is to reduce power consumption by using devices with increased efficiency.
[0011]
According to one aspect of the present invention as claimed, the above objects are attached to the lower end of a rod string that can rotate about and advance along its longitudinal axis. An excavation tool, especially for use in concrete foundation pile driving, which is mounted freely on the rod string and tilted at an angle with respect to the longitudinal axis And a drilling tool having at least one roller which is rotatable and has two ends of the roller located on either side of the longitudinal axis.
[0012]
In another embodiment of the present invention, a construction method for setting up a concrete foundation pile, which is performed using the excavation tool, is provided. This construction method is characterized in that the soil at the bottom of the hole is cut by cutting means to form a drilling hole in a substantially cylindrical shape, which further includes the following two steps.
i) Enlarge the side wall of the drilling hole by pressing the side of the drilling tool against the earth wall of the drilling hole and rolling
ii) While continuously injecting a small amount of binder (binder) into the part of the drilled hole above the drilling tool, press the side wall of the hole with the belly of the drilling tool to build a hard coating on the hole wall [0013]
In yet another aspect of the invention, the concrete is continuously poured into the hole while the hole is being dug so that the hole is always filled with concrete, thereby preventing the collapse of the side wall of the hole during construction. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
In FIG. 1, reference numeral 10 generally indicates a drilling tool according to the present invention. The excavation tool 10 is firmly fixed to the lower end of the excavation rod 11 whose axis is substantially vertical. A drive device for driving a rod string (not shown) according to the rotation / advance movement of the excavation tool 10 is installed on the ground. The rod 11 corresponds to the lowest part of the rod string coupled to this drive device. Since these driving devices and rod strings are well known in the prior art, a detailed description thereof will be omitted here.
[0015]
The excavation tool 10 has a spindle-shaped roller 12 rotatably mounted on a central cylindrical shaft 13, the geometric axis y of which is at a suitable angle with respect to the longitudinal axis x of the rod 11. It is inclined at. The inclination of the shaft 13 with respect to the shaft x is obtained by a crank member 14 that connects the lower end of the rod 11 to the shaft 13. The roller 12 has a barrel shape, and the central portion 12c is thick, and the upper portion 12a and the lower portion 12b are thin. The lowest part of the roller 12 forms a conical tip 15.
[0016]
As already mentioned, the roller 12 obliquely intersects the axis x. Therefore, when the rod 11 rotates, the roller 12 rotates about its own axis y and rolls while contacting the side wall of the excavation hole. At this time, the roller axis y moves so as to trace the surfaces of two cones whose vertices abut each other due to a so-called movement called “chunch”.
[0017]
As the roller 12 rotates, the tip 15 scrapes the soil, while the barrel-shaped surface of the roller rolls while contacting the wall 17 of the hole. Therefore, the drilling hole is progressively widened by the belly of the roller 12. That is, when the excavation roller 12 descends, the excavation hole is first widened by a circle drawn by the lower part 12b, and then the thicker central portion 12c hits the earth wall to further widen the hole. And as a result of these, the soil around the hole is hardened.
[0018]
The crank member 14 has a special shape with its end portions 14a and 14b facing the directions of the axis x and the axis y, respectively, in order to realize the following two things.
-Inclining the rotation axis y of the roller 12 by a desired angle-As described above, the upper portions of the shaft 13 and the roller 12 are separated from the axis x, and both ends of the roller 12 are positioned on the opposite sides of the axis x. The two ends of the roller 12 are positioned on the opposite sides of the axis x because the movement of the rotating roller and the reaction of the soil with it acquire the ideal balance, even if there is only one roller. is there.
As is apparent from the above, the excavation tool 10 has a very simple structure.
[0019]
Next, another embodiment of FIG. 2 will be described. In this embodiment, a substantially cylindrical second roller 16 is rotatably attached to the crank member, spaced from the crank member 14 '. As shown in the figure, the axis z of the separated second roller 16 is substantially parallel to the excavation axis x. The purpose of the second roller 16 is to further compress the wall 17 of the excavation hole and further increase the self-holding force of the hole. From FIG. 2, the effect of the excavation tool on the soil will be understood. That is, when the roller 12 rotates and descends, the tip 15 pierces the circular groove 18 at the bottom of the excavation hole, and then the circular groove 18 is widened by the central portion and the upper portion of the roller 12, and then the second roller 16 acts. Thus, the diameter of the excavation hole is finally determined.
[0020]
Although not shown, in another embodiment of the present invention, a plurality of second rollers are installed above the excavating roller. These rollers are preferably mounted at different angles around the excavation axis for balance.
[0021]
Next, FIG. 3 shows a roller provided with various attachment means such as a digging fin 19 and a protrusion 20. These equipments are intended to improve the adhesion of concrete to the side wall of the hole and to make the excavation of the soil at the bottom of the hole more efficient.
[0022]
4 and 5 show a fourth embodiment of the present invention. In this embodiment, the conical tip 15 is integrated with the shaft 13, and the roller 12 rotates freely about the shaft 13. The roller 12 has a structure that can slide in the length direction along the cylindrical shaft 13. The roller 12 is a hollow shell with openings 28 and 29 at the top and bottom of the shell, respectively, which both communicate with each other via the shell lumen. The shell 21 is firmly fixed to the central bushing 31 with a coupling member 30. The bushing 31 is rotatably coupled to the shaft 13 and can optionally slide between an upper stop mechanism 32 and a lower stop mechanism 33 on this shaft. The lower stop mechanism 33 is provided on the upper surface of the conical tip 15.
[0023]
A plurality of passages are formed in the shell by the coupling member 30, and the fluid enters the shell from the upper opening 28, passes through the shell through the plurality of passages, and exits from the lower opening 29. The structure of the coupling member 30 is merely conceptual. The ratio of the total cross-sectional area of the coupling member 30 to the cross-sectional area of the entire shell 21 is small.
[0024]
Since the shell 21 can slide on the axis x, when the tool is pushed down for excavation, the shell 21 is in the state shown in FIG. 4, and the roller is lifted to a position where it hits the upper stop mechanism 32. In the state, the lower opening 29 is closed by the upper surface of the distal end portion 15.
[0025]
On the other hand, when the excavation tool is pulled out, as shown in FIG. 5, the tip portion 15 is retracted into the shell and the lower opening 29 is opened. As a result, a substance such as concrete is moved from the region above the tool to below the tool. Can flow into the territory.
[0026]
6 and 7 show another embodiment of the present invention. In this embodiment, the distal end portion 15 is configured integrally with the roller 12, and one or a plurality of passages 23 are bored in the roller 12 in the vertical direction. The lower end of each passage communicates with the outside through the opening 24. During excavation, these openings 24 are closed by a conical cap 22 that covers the outside of the tip 15. When the excavation tool is pulled out, the cap 22 is left behind at the hole bottom as shown in FIG. 7, so that a fluid such as concrete flows from the region above the tool to the region below the tool through the passage 23. To do.
[0027]
Yet another embodiment of the present invention is shown in FIG. In this embodiment, a cover 25 is attached to each opening 24 below the passage 23. The upper end of the cover 25 is hinged to the main body of the roller 12. During excavation, the cover 25 closes the passage 23 as shown in the cross-sectional view of the left half of FIG. When pulling out the excavation tool, as shown in the right half of FIG. 8, the cover 25 opens by pivoting on the hinge 27 at the upper end thereof, so that the material flows into the hole. Is possible.
[0028]
In the embodiment shown in FIGS. 4 to 8, it will be apparent that the operation of extracting the excavating tool from the hole is easy because the passage is made in the tool.
[0029]
The outline of the excavation tool based on the present invention has been described above. Since these tools can be used in several desirable methods, a few examples will be described below.
[0030]
First, the first method is called “dry boring method”, and the tool 10 is driven at right angles to the soil while rotating. The tool pierces the bottom of the hole, rolls around the surrounding earth wall, and after the tool is dug, a cylindrical hole is formed. Since the soil is compacted and hardly collapses, this dry boring method is considered to be an effective and low-cost method for many soil types. In this method, it is possible to insert the reinforcing material into the drilling hole and lower the concrete, and the concrete placement should be carried out in the manner described in the explanation of (b) Large drilling method. Can do.
[0031]
As a second method instead of the above, there is a so-called “coated bowling method”. This is a system in which a small amount of binder is continuously charged and pressed against the earth wall one after another by a roller to be fixed. The wall of the hole is therefore covered with a concrete coating. At this time, if the concrete mixed with a solidification accelerator is used, the concrete can be quickly solidified, thereby further expanding the practicality of the dry boring method.
[0032]
Next, as a third method, there is a “concrete boring method” that is ideal for unstable soil quality. This is a method in which concrete is continuously poured into the excavation hole while the excavation proceeds, and the hole is always filled with concrete. Since the hydraulic pressure of the concrete is applied, the collapse of the earth wall is suppressed, and in the meantime, a part of the concrete is combined with the earth wall by rolling. As in the case of (c) auger excavation method, the reinforcing material is inserted into the hole when the tool is pulled out.
[0033]
Compared with a conventionally used machine, the roller type drilling tool according to the present invention has the following advantages.
B) Friction between the tool and the soil is significantly reduced compared to the type in which the tool slides, thus reducing power consumption and improving the efficiency. B) Since the roller rolls, The degree of contact between the tool and the soil is small, so the force (pressure) per unit area that presses the soil is large.
From the above, when using the tool of the present invention, the mechanical properties of the soil are improved, and softening of the soil does not occur as in the case of using a drill type tool. As in the case of using the (a) steel pipe driving excavation method, the soil quality becomes close. Moreover, in the steel pipe driving excavation method, the impact noise when driving the steel pipe is large, but when the tool of the present invention is used, vibration and noise are greatly reduced.
[0035]
Compared with the large drilling method of (b), the method of the present invention can eliminate the play time (the time required for lifting to the ground, dumping, and pulling to the bottom of the hole), which is economically advantageous. It is. In the case of cohesive soil that can use a large drilling method, the above play time currently exceeds 50% of the total work time.
[0036]
Although it is secondary, when the excavation tool of the present invention is used, there is no problem that the site is soiled with mud, and it is advantageous that the cleaning cost is reduced.
[0037]
Next, regarding the comparison with (a) the steel pipe driving excavation method and (b) the auger excavation method, the depth that can be excavated by both methods is usually limited to 20 to 30 meters. The drilling depth can be extended to 50-60 meters if the soil allows it. Compared to an auger excavation method in which a spiral excavation blade is screwed into the ground using a machine of the same size, the method according to the present invention can dig a hole three times as deep. The sliding friction is greatly reduced and the driving power is concentrated on the key part of scraping the soil, so even if the applied torque is the same, the diameter of the hole that can be excavated becomes much larger. In addition, since the “dry boring method” is possible, it is easy to add a reinforcing material.
[0038]
By using the “dry boring method” and the “coated boring method”, all the advantages of the excavation tool according to the present invention are realized. In other words, increased drilling depth by using telescopic drill rods, expanded drilling diameter by low friction, speeding up drilling, eliminating the need for drilling slurries and reducing costs by reducing auxiliary equipment and workers. Is done.
[0039]
Next, when the “concrete boring method” is performed, the following three advantages can be obtained.
1) No landslide in the excavation hole 2) No injection by the hose, so it is possible to save machinery and workers for that purpose 3) Since the concrete injection is performed in parallel with the excavation, further injection time is required And not [0040]
In addition, since the taper portion 12a at the upper part of the roller, the work of injecting the binder into the excavation hole and the work of pulling out the tool from the hole are easy.
[0041]
Finally, the excavation tool according to the present invention can be mounted on excavating machines used today without any special changes.
[0042]
【The invention's effect】
Since the excavation tool of the present invention is a method in which the roller 12 rolls on the surface of the excavation hole, the friction between the tool and the soil is remarkably reduced and energy efficiency is improved as compared with the conventional slide method. Also, for the same reason, the side wall of the excavation hole is less scraped with a tool, rather the earth wall is pressed and compacted with a roller, and the soil mechanical properties are improved.
[Brief description of the drawings]
FIG. 1 is a side view, partly in section, of a first embodiment of an excavation tool according to the present invention.
FIG. 2 is an enlarged side view showing a situation during excavation of a second embodiment of the excavating tool according to the present invention.
FIG. 3 is a side view showing a third embodiment according to the present invention.
FIG. 4 is a sectional view showing a situation when a passage is closed according to a fourth embodiment of the present invention.
FIG. 5 is a sectional view showing a situation when a passage is opened according to a fourth embodiment of the present invention.
FIG. 6 is a sectional view showing a situation when a cap is mounted according to a fifth embodiment of the present invention.
FIG. 7 is a side view showing a situation when a cap is removed according to a fifth embodiment of the present invention.
FIG. 8 is a side view, partly in section, of a sixth embodiment according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Excavation tool 11 Rod 12 Roller 13 Shaft 14 Crank member 15 Tip part 16 Second roller 17 Excavation hole wall 19 Excavation fin 21 Shell 22 Cap 23 Passage 24 Opening 25 Cover (when closed)
26 Cover (when opened)
27 Hinge 28 Upper Opening 29 Lower Opening 30 Connecting Member 31 Bushing 32 Upper Stop Mechanism 33 Lower Stop Mechanism

Claims (9)

An excavation tool (10) particularly used for concrete foundation pile driving work, which is attached to the lower end of a rod string (11) that rotates about its own longitudinal axis (x) and advances along the longitudinal axis. ,
The excavation tool (10) has a central axis (13) having an axis coinciding with an inclined axis (y) inclined with respect to the longitudinal axis (x), the rod string (11), and the central axis (13). Comprising at least one roller (12) rotatably mounted with respect to
The roller (12) is rotatable about the tilt axis (y), the side surface is spindle-shaped and becomes thinner toward the upper end (12a) and the lower end (12b), and is the thickest at the central portion (12c). It has a barrel shape, and the upper end (12a) and the lower end (12b) are positioned opposite to each other with respect to the longitudinal axis (x), and the lower end (12b) has a conical tip (15) for crushing the soil. Have
Furthermore, the excavation tool has a curved or crank-like member (14, 14 ′) arranged between the rod string (11) and the central shaft (13), and the crank-like member (14, 14 ′). 14 ') has an upper end (14a) coupled to the rod string (11) and a lower end (14b) coupled to the central axis, the upper end being arranged with respect to the longitudinal axis (x). The lower end (14b) is eccentric with respect to the longitudinal axis (x) and is arranged with respect to the inclined axis (y).   At least one second substantially cylindrical roller (16) is disposed on the crank-like member (14 ′), the second roller (16) being spaced apart from the longitudinal axis (x), and The excavation tool according to claim 1, having a longitudinal axis (z) parallel thereto.   In the roller (12), one or a plurality of longitudinal internal passages (34, 23) communicating with the hole portion above the excavation tool (10) and the hole portion below the excavation tool (10) are provided. Each of the passages is closed when the tool is operated for excavation and closed when the tool is withdrawn from the hole. Each of the passages is provided with at least one closing means (15, 22, 25). The excavation tool according to claim 1, characterized in that a fluid such as concrete can flow through the passage from a hole area above the tool to a hole area below the tool.   The roller (12) comprises an outer shell (21) slidably mounted on a central shaft (13) fixed to the lower portion of the rod string (11), and the axis of the central shaft (13) is the inclined shaft ( Drilling tool according to claim 3, characterized in that it corresponds to y) and the closing means is a tip (15) integral with the central shaft (13).   At least one of the internal passages (23) has an opening (24) formed in a conical tip (15) below the inner passage (23), and the closing means has a shape matching the tip (15). (22), the cap covers the opening (24) from the lower side only during excavation and closes it, and when the excavation tool is pulled out, the cap is left behind in the hole. The excavation tool according to claim 3, wherein:   At least one of the internal passages (23) has an opening (24) drilled in a conical tip (15) below it, and the closing means is a closing cover (25) fastened to the roller (12). And the cover occupies a first position for closing the opening (24) during excavation, and the cover occupies a second position for opening the opening (24) when the excavation tool is pulled out. The excavation tool according to claim 3. A concrete foundation pile driving method using the excavating tool (10) according to any one of claims 1 to 6, wherein the excavating tool (10) is set to its own longitudinal axis (x). It is attached to the lower end of the rod string (11) that can rotate and move forward along the longitudinal axis, and by operating this rod string , the soil at the bottom of the hole is scraped at the tip (15, 19). A method of forming a drilling hole in a substantially cylindrical shape, comprising the following two steps simultaneously or in this order.
-Enlarging the drilling hole by pressing the side surface of the roller (12) against the side wall (17) of the drilling hole and rolling, thereby solidifying the soil around the hole.
-Sequentially injecting a small amount of binder (binder) into the hole area of the drilled hole above the drilling tool, pressing the hole side wall sequentially with the belly of the drilling tool (10) to the hole wall The process of building a hard film.   The concrete is characterized in that the side wall of the hole is prevented from collapsing during construction by continuously putting concrete into the excavation hole during excavation and creating a state in which the hole is always filled with concrete. 8. The method according to 7.   By inserting a step of opening at least one passage (34, 23) through the tool (10) into the operation stage of pulling out the tool (10) from the drilling hole, the hole above the drilling tool (10) 8. A method according to claim 7, characterized in that the binder flows down from the region to the bottom.

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