JP2018100568A - Method and device for inspecting pile hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for inspecting a pile hole, capable of obtaining reliable inspection results whether the hole bottom or hole wall of the pile hole has reached a bearing stratum or not.SOLUTION: A method for inspecting a pile hole inspects whether the hole bottom or hole wall of a pile hole formed in a foundation has reached a bearing stratum or not, including determining whether the hole bottom or hole wall of the pile hole has reached a bearing stratum or not based on the force received by a scratch member 41 from the foundation of the hole bottom or hole wall of the pile hole when scratched by the scratch member 41.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a pile hole inspection method and a pile hole inspection apparatus for inspecting whether or not a hole bottom or a hole wall of a pile hole has reached a support layer that can secure a support force of the pile.

When building cast-in-place piles or ready-made piles in a pile hole drilled in the ground, it is confirmed whether the bottom of the pile hole has reached a support layer that can secure the support capacity of the pile. (See Patent Document 1).
Moreover, the hole wall on the bottom side of the pile hole supports the pile using a PS logging probe (PS logging device) for judging the hardness of the hole wall of the pile hole using the elastic wave velocity. It is also known to inspect whether or not a support layer that can secure force is reached (see Patent Document 2).

Japanese Patent No. 5619263 Japanese Patent Laying-Open No. 2015-7321

In the method for inspecting the bottom of a pile hole, which is disclosed in Patent Document 1 and inspects whether or not the bottom of the pile hole has reached the support layer, whether or not the center of the hole bottom has reached the support layer is determined. I am inspecting. However, when the ground layer is complex, for example, in one pile hole, the supporting force may be different between the ground at the center of the hole bottom and the ground at the periphery of the hole bottom. For example, when the hole hole diameter is relatively large, the result is that the center of the hole reaches the support layer, but the periphery of the hole does not reach the support layer. There is a case.
Moreover, in the method of inspecting whether the hole wall of the hole bottom side of a pile hole has reached the support layer using the PS logging probe disclosed in Patent Document 2, the PS logging probe and the hole wall are Since the accuracy of the obtained test result (shear wave waveform) differs depending on the difference in the distance between them and the orientation of the PS logging probe, there is a problem that a highly reliable test result cannot be obtained.
The present invention provides a pile hole inspection method and a pile hole inspection apparatus capable of obtaining a highly reliable inspection result indicating whether or not a hole bottom or a hole wall of a pile hole has reached a support layer. .

A pile hole inspection method according to the present invention is a pile hole inspection method for inspecting whether or not a hole bottom or a hole wall of a pile hole formed in the ground has reached a support layer, It is characterized by determining whether the hole bottom or hole wall of the pile hole reaches the support layer based on the force that the scratching member receives from the ground when the ground of the ground or the hole wall is scratched by the scratching member Therefore, based on the force directly received from the ground at the periphery of the hole bottom, it can be determined whether the periphery of the hole bottom has reached the support layer, and whether the hole bottom has reached the support layer. It is possible to obtain a reliable test result indicating whether or not the hole wall has reached the support layer based on the force directly received from the ground of the hole wall, and the hole wall is supported. A highly reliable test result indicating whether or not the layer has been reached can be obtained. In addition, since the inspection is performed based on the force directly received from the ground of the hole wall, deposits such as slime do not become an obstacle, and a highly reliable inspection can be performed. In addition, since it becomes possible to inspect the entire hole wall of the pile hole, the depth position of the hole wall reaching the support layer can be understood, and the depth of penetration of the pile hole is obtained from the depth position. And the position of the pile bottom can be determined appropriately.
In addition, a scratching member is provided in a drilling bucket or a bottom-up bucket for excavating the ground to form a pile hole, and by rotating the drilling bucket or the bottom-up bucket in the pile hole, Since it is characterized by scratching the ground of the hole wall, the existing drilling or drilling bucket is used to indicate whether the hole bottom or wall of the pile hole has reached the support layer. Highly accurate test results can be obtained.
A pile hole inspection apparatus according to the present invention is a pile hole inspection apparatus for inspecting whether or not a hole bottom or a hole wall of a pile hole formed in the ground has reached a support layer, A pile member having a scratching member for scratching the ground or the ground of the hole wall, and a measuring instrument for measuring the force that the scratching member receives from the ground when the scratch is scratched by the scratching member. Based on the force directly received from the ground around the bottom of the hole, it can be determined whether the periphery of the bottom of the pile hole has reached the support layer, and the bottom of the pile hole has reached the support layer It is possible to obtain a reliable test result indicating whether or not the hole wall of the pile hole has reached the support layer based on the force directly received from the ground of the hole wall of the pile hole Thus, a highly reliable test result indicating whether or not the hole wall of the pile hole has reached the support layer can be obtained. Further, since the inspection can be performed based on the force directly received from the ground of the hole wall, the deposit such as slime does not become an obstacle, and the highly reliable inspection can be performed.
In addition, since it becomes possible to inspect the entire hole wall of the pile hole, the depth position of the hole wall reaching the support layer can be understood, and the depth of penetration of the pile hole is obtained from the depth position. And the position of the pile bottom can be determined appropriately.
In addition, since a scraping member is provided in a drilling bucket or a bottom expansion bucket for excavating the ground to form a pile hole, a drilling bucket or a bottom expansion bucket which is an existing excavator is used, A highly reliable test result indicating whether the hole bottom or the wall of the hole has reached the support layer can be obtained.
In addition, the scratching member is provided so as to scratch the ground when the drilling bucket or the bottom expansion bucket is rotated in the direction opposite to the rotation direction during excavation. Therefore, the drilling bucket or the bottom expansion bucket is used. Then, after the pile hole is formed, it is possible to inspect the ground state of the hole bottom or hole wall of the pile hole by reversely rotating the drilling bucket or the bottom expansion bucket. That is, it is possible to continuously perform the pile hole formation work and the ground condition inspection work of the hole bottom or hole wall of the pile hole, and efficiently perform the ground condition inspection work of the hole bottom or hole wall of the pile hole. Is possible.
In addition, the scratching member can be inspected to be able to scratch the ground of the hole bottom of the pile hole or the ground of the hole wall, and the retracted state not to be able to scratch the ground of the hole bottom of the pile hole or the ground of the hole wall. Since the setting means for setting is provided, the pile hole is formed by using the drilling bucket or the bottomed bucket, and then the scratching member is set to the inspectable state by the setting means. It is possible to inspect the bottom of the pile hole or the ground state of the hole wall by rotating the bottom expansion bucket in the same direction as the rotation direction during excavation. That is, it is possible to continuously perform the pile hole formation work and the ground condition inspection work of the hole bottom or hole wall of the pile hole, and efficiently perform the ground condition inspection work of the hole bottom or hole wall of the pile hole. Is possible.

Schematic which shows a pile hole inspection apparatus. The drilling bucket provided with the measurement means is shown, (a) is a side view (partial cross section), (b) is a bottom view. (A) is a perspective view which shows the lying state of a measurement means, (b) is a perspective view which shows the state which the measurement means stood up. (A) is a bottom view showing the state of the measuring means at the time of normal rotation (drilling) of the drilling bucket, (b) is a bottom view showing the state of the measuring means at the time of reverse rotation (during inspection) of the drilling bucket. (A) is a plan view of the measuring means, (b) is a bottom view showing the state of the measuring means during the normal rotation of the drilling bucket (during excavation), and (c) is the measurement means during the reverse rotation of the drilling bucket (during inspection). The bottom view which shows a state. The bottom view which shows the state of the measurement means at the time of drilling bucket reverse rotation (at the time of test | inspection). (A) is sectional drawing which shows the state of the measuring means of a retracted state, (b) is sectional drawing which shows the state of the measuring means of an inspection possible state. The bottom expanded bucket provided with the measurement means is shown, (a) is a perspective view which shows the state at the time of normal time (at the time of non-widening), (b) is a perspective view which shows a widened state.

Embodiment 1
In the pile hole inspection method according to the first embodiment, in order to inspect whether the hole wall on the pile hole bottom side of the pile hole formed in the ground has reached the support layer, It is a method for inspecting whether the ground of the hole wall on the bottom side of the pile hole has reached the support layer based on the force received by the scratching member from the ground when the ground is scratched with the scratching member, and hereinafter the method A pile hole inspection apparatus according to the first embodiment for realizing the above will be described.

  As shown in FIG. 1, the pile hole inspection device 1 is a drilling unit that is detachably attached to an excavator 2 such as an earth drill machine and a tip (lower end) of a kelly bar 23 that serves as an excavation rotating shaft of the excavator 2. A bucket 3 and a measuring means 4 provided in the drilling bucket 3 are provided.

As shown in FIG. 1, in the excavator 2, the drilling bucket 3 is detachably attached to a tip portion (lower end portion) of a kelly bar 23 that is a drilling rotation shaft suspended from the tip of a wire 22 that is fed out or wound up from a main body 21. Mounted on.
The drilling bucket 3 can be moved up and down by unwinding or winding the wire 22 with a winch (not shown) provided in the main body 21, and the rotational drive is arranged at the tip of the arm 24 supported by the main body 21. By rotating the kelly bar 23 while being pushed downward by the device 25, the drilling bucket 3 rotates around the central axis of the kelly bar 23 to excavate the ground. The rotation driving device 25 is configured to be able to perform forward rotation driving for rotating the drilling bucket 3 in one direction and reverse rotation driving for rotating the drilling bucket 3 in the other direction during excavation.

  As shown in FIG. 2, the drilling bucket 3 includes a cylindrical bucket body 31, a bottom lid 32 attached to the bottom of the bucket body 31 so as to be openable and closable, and a cutter bit 33 provided on an outer surface 32 f of the bottom lid 32. And a side cutter 34 provided on the outer peripheral surface 36 on the bottom side of the bucket body 31, and earth and sand formed on the bottom lid 32 for taking the earth and sand cut by the cutter bit 33 and the side cutter 34 into the bucket body 31. The intake hole 35 is provided.

  As shown in FIG. 3, the measuring unit 4 includes a scratching member 41 formed of, for example, a plate material or a bar, an attachment member 42 that rotatably attaches the scratching member 41 to the outer peripheral surface 36 of the drilling bucket 3, and a scratching member 41. Is provided with a measuring device 43 for detecting the force that the scratching member 41 receives from the ground when the drilling bucket 3 is rotated in a state in which it is in contact with the ground of the hole wall on the pile hole bottom side.

  As shown in FIGS. 3A and 4A, the scratching member 41 is configured so that, when the drilling bucket 3 is rotated forward (in the direction in which the drilling bucket 3 is rotated when excavating a pile hole), as shown in FIGS. When the drilling bucket 3 rotates in the reverse direction, it collides with the hole wall on the bottom side of the pile hole as shown in FIGS. 3 (b) and 4 (b). It is rotatably attached to the outer peripheral surface 36 of the drilling bucket 3 via the attachment member 42 so that it can be lifted up.

That is, as shown in FIG. 3, the attachment member 42 includes a shaft rotation support portion 44 attached to the outer peripheral surface 36 of the drilling bucket 3 and a rotation shaft 45 rotatably attached to the shaft rotation support portion 44. And a torsion coil spring 46. Then, the torsion coil spring 46 is wound around the outer periphery of the rotating shaft 45, and one end of the torsion coil spring 46 is fixed to the scratching member 41 provided at one end of the rotating shaft 45 and the other torsion coil spring 46 is provided. When the end is fixed to the shaft rotation support portion 44 or the outer peripheral surface 36 of the drilling bucket 3, the torsion coil spring 46 does not become a resistance when the rotation shaft 45 rotates in one direction, and the rotation shaft 45 moves in the other direction. When rotating, the spring force of the torsion coil spring 46 becomes a resistance.
That is, the torsion coil spring 46 is provided so that a biasing force that causes the scratching member 41 to fall along the outer peripheral surface 36 of the drilling bucket 3 is applied to the rotating shaft 45.
The scratching member 41 and the rotating shaft 45 may be integrally formed.

When the measuring means 4 rotates the drilling bucket 3 forward and excavates the ground to construct the pile hole, the portion other than the tip 41t of the scratching member 41 contacts the hole wall of the pile hole being constructed. It is provided in the outer peripheral surface 36 of the drilling bucket 3 so that it may not.
By doing so, during pile hole construction (when the drilling bucket 3 is rotating forward), the tip 41t of the lying scratching member 41 comes into contact with the hole wall of the pile hole being constructed, and the torsion coil spring 46 It will be in the state urged | biased by the outer peripheral surface 36 side of the drilling bucket 3 (refer Fig.4 (a)). When the drilling bucket 3 is rotated reversely on the bottom side of the pile hole after the construction of the pile hole, the tip 41t of the scratching member 41 in contact with the hole wall of the pile hole is pushed against the hole wall, and the scratching member 41 is turned into a torsion coil. It rises from the lying down state against the spring force of the spring 46 (see the scratching member 41 shown by a two-dot chain line in FIG. 4B). That is, when the tip 41t of the scratching member 41 operates so as to scratch the hole wall, the scratching member 41 rises from the lying down state. The amount by which the scratching member 41 rises differs depending on the ground condition of the hole wall. Therefore, the amount of rising, that is, the amount of rotation of the rotary shaft 45 is used as the force that the scratching member 41 receives from the ground. The ground state of the hole wall on the bottom side of the pile hole can be determined according to the magnitude of the rotation angle θ).
Note that one measuring means 4 may be provided on the outer peripheral surface 36 of the drilling bucket 3.

  The measuring device 43 uses, for example, a rotation angle sensor that detects the rotation angle θ (rotation amount) of the rotation shaft 45 when the scratching member 41 rises from the state where it is lying down along the outer peripheral surface 36 of the drilling bucket 3.

A pile hole inspection method using the pile hole inspection apparatus 1 of the first embodiment will be described.
The drilling bucket 3 provided with the measuring means 4 is attached to the tip of the kelly bar 23 of the excavator 2, and the drilling bucket 3 is rotated forward to excavate the ground to form a pile hole. During the forward rotation of the drilling bucket 3, a force for rotating the scratching member 41 in a direction away from the outer peripheral surface 36 of the drilling bucket 3 is not applied to the tip 41 t of the lying scratching member 41. And after forming a pile hole, the said drilling bucket 3 is reversely rotated in the state which located the drilling bucket 3 in the hole bottom side of a pile hole. During the reverse rotation of the drilling bucket 3, the tip 41 t of the lying scratching member 41 is caught by the hole wall on the bottom side of the pile hole, and the scratching member 41 resists the spring force of the torsion coil spring 46. A force is applied to rotate the scratching member 41 in a direction away from the outer peripheral surface 36 of the drilling bucket 3.

  Therefore, in the first embodiment, the rotation angle θ of the rotating shaft 45 when a force to rotate the scratching member 41 in the direction away from the outer peripheral surface 36 of the drilling bucket 3 is applied as an evaluation value, and the pile hole bottom side It is determined whether the ground of the perforated wall reaches the support layer. That is, when the drilling bucket 3 is rotated in the reverse direction and the scratching member 41 scratches the hole wall on the hole bottom side, the initial state of the rotary shaft 45 depends on the ground state of the hole wall on the hole bottom side (such as the hardness of the ground). Therefore, the rotation angle θ of the rotation shaft 45 is detected and used as an evaluation value.

In the first embodiment, for example, when the ground of the hole wall on the bottom side of the pile hole has reached the support layer, the drilling bucket 3 is reversely rotated to move the scratching member 41 away from the outer peripheral surface 36 of the drilling bucket 3. The rotation angle θ of the rotating shaft 45 at the time of rotation is obtained by experiments, and the rotation angle θ is used as a reference evaluation value, and the rotating shaft 45 measured at the hole wall on the bottom side of the pile hole currently being constructed is measured. The rotation angle θ is compared with a reference evaluation value as an evaluation value.
If the measured evaluation value reaches the reference evaluation value (that is, when the measured evaluation value (rotation angle θ) is equal to or greater than the reference evaluation value (rotation angle θ)), the hole wall on the bottom side of the hole It is judged that the ground resistance of the hole is large and the hole wall on the bottom side of the hole reaches the support layer, and the measured evaluation value does not reach the reference evaluation value (that is, the measured evaluation value (rotation angle θ)) Is smaller than the standard evaluation value (rotation angle θ)), the bottom of the pile hole is further excavated to increase the depth of the pile hole, and the measurement is performed again. The measured evaluation value reaches the standard evaluation value. Until the depth of the pile hole is increased. And after the evaluation value of the ground of the hole wall on the bottom side of the pile hole reaches the standard evaluation value, rebar rods are inserted into the pile hole, mud water in the pile hole is replaced with concrete, and the cast-in-place concrete pile is By performing construction, it is possible to construct a highly reliable cast-in-place concrete pile in which the circumferential surface on the pile bottom side of the pile hole is reliably supported by the support layer.

  For example, after forming the pile hole, with the drilling bucket 3 positioned on the hole bottom side of the pile hole, the scratching member 41 moves the hole wall on the hole bottom side by rotating the drilling bucket 3 once in the reverse rotation direction. The rotation angle θ of the rotating shaft 45 at the time of scratching is continuously detected as an evaluation value, and it is determined whether or not the ground of the hole wall on the hole bottom side reaches the support layer. In this case, since the scratching member 41 makes one round around the hole wall, the rotation angle θ of the rotation shaft 45 at each position along the circumferential direction of the hole wall from the position of the hole wall serving as a rotation reference position for starting rotation. By recording the above, the state of the ground at each position along the circumferential direction of the hole wall can be understood in detail. Therefore, the entire ground around the hole wall reaches the support layer, or a certain part of the ground around the hole wall reaches the support layer, but a part of the ground around the hole wall becomes the support layer. For example, it can be seen that the boundary of the support layer is slanted around the pile hole. If the entire ground around the hole wall does not reach the support layer, the bottom of the pile hole is further drilled until the entire ground around the hole wall reaches the support layer, and the entire ground around the hole wall reaches the support layer. Then, by further excavating the bottom of the pile hole until the desired depth of penetration is reached, it is possible to form a pile hole that can reliably support the pile on the support layer.

According to the first embodiment, it is possible to determine whether the hole wall on the pile hole bottom side has reached the support layer based on the force directly received by the scratching member 41 from the ground of the hole wall on the pile hole bottom side. A highly reliable test result indicating whether or not the hole wall on the pile hole bottom side has reached the support layer can be obtained.
Moreover, in order to determine whether the hole wall on the pile hole bottom side reaches the support layer based on the force directly received by the scratching member 41 from the ground of the hole wall on the pile hole bottom side, sediments such as slime are obstructed. Therefore, a highly reliable inspection can be performed. That is, the measuring means 4 is not pressed against the hole bottom where the deposit such as slime is accumulated, but is pressed against the hole wall to perform the inspection. It can be performed.
In addition, by using the drilling bucket 3 that is an existing excavator, it is possible to obtain a highly reliable inspection result indicating whether or not the hole wall on the pile hole bottom side has reached the support layer.
Moreover, after forming a pile hole using the drilling bucket 3, it becomes possible to reversely rotate the drilling bucket 3 and inspect the ground condition on the bottom side of the pile hole. That is, the pile hole forming work and the ground condition inspection work on the bottom side of the pile hole can be continuously performed, and the ground condition inspection work on the bottom side of the pile hole can be efficiently performed.

Embodiment 2
In the first embodiment, it may be determined whether or not the ground of the hole wall on the bottom side of the hole reaches the support layer using the rotational torque when the drilling bucket 3 is rotated in the reverse direction as an evaluation value.
That is, when the drilling bucket 3 is rotated in the reverse direction and the scratching member 41 scratches the hole wall on the bottom side, the rotational torque of the drilling bucket 3 depends on the ground condition (such as the hardness of the ground) of the hole wall on the bottom side. Since they are different, the rotational torque of the drilling bucket 3 is detected and used as an evaluation value.
In this case, the measuring device may use, for example, a torque sensor that measures the rotational torque when the drilling bucket 3 is rotated.

Embodiment 3
In the first embodiment, a strain gauge as a measuring instrument is provided on the base side of the scratching member 41, the strain applied to the scratching member 41 during reverse rotation of the drilling bucket 3 is measured, and the measured value is used as an evaluation value. You may make it determine whether the ground of the hole wall of the side has reached the support layer.
That is, when the scratching member 41 scratches the hole wall on the hole bottom side by rotating the drilling bucket 3 in the reverse direction, depending on the ground condition (such as the hardness of the ground) of the hole wall on the hole bottom side, Since the strain amount is different, this strain amount is measured and used as an evaluation value.

Embodiment 4
As shown in FIG. 5, the scratching member 41 is attached to a displacement spring 51 that is displaced along the circumferential direction of the outer peripheral surface 36 of the drilling bucket 3, and the drilling bucket 3 is rotated in the reverse direction so that the scratching member 41 is a hole on the bottom side of the hole. As the measuring device 43 that detects the amount of displacement of the displacement spring 51 when the wall is scratched, for example, the measuring means 4 having a displacement sensor may be used.
In this case, the rotating body composed of the scratching member 41, the rotating shaft 45, and the torsion coil spring 46 is attached to the installation board 53 via the shaft rotation support portion 44 described above, and the installation board 53 is moved to the support frame 54. The mounting substrate 53 is connected to each other, and one end 53a in the moving direction of the installation substrate 53 is connected to one end-side inner surface 54a of the support frame 54 facing the one end 53a by a plurality of displacement springs 51, 51. 53, the other end 53b in the moving direction of 53 and the inner surface 54b of the other end side of the support frame 54 facing the other end 53b are connected by a plurality of displacement springs 51, 51,. The support frame 54 is configured to be attached to the outer peripheral surface 36 of the drilling bucket 3. For example, the support frame 54 is formed of a rectangular frame, the installation substrate 53 is attached to the support frame 54 so as to be movable along the longitudinal direction of the support frame 54, and the length of the support frame 54 is Since the support frame 54 is attached to the outer peripheral surface 36 of the drilling bucket 3 so that the direction extends along the rotation direction of the drilling bucket 3, the scratching member 41 extends along the circumferential direction of the outer peripheral surface 36 of the drilling bucket 3. It is provided to be movable.
That is, when the scraping member 41 scratches the hole wall on the hole bottom side by rotating the drilling bucket 3 in the reverse direction, depending on the ground condition (such as the hardness of the ground) of the hole wall on the hole bottom side, as shown in FIG. As described above, the amount of movement of the installation board 53 due to the difference in the amount of displacement of the displacement springs 51, 51...

Embodiment 5
As shown in FIG. 6, when the scratching member 41 scratches the hole wall on the hole bottom side, the measuring means 4 having a configuration in which a soil pressure gauge as a measuring device 43 for detecting the pressure received from the hole wall is provided on the scratching member 41 is used. May be.
That is, when the scraping member 41 scratches the hole wall on the hole bottom side by rotating the drilling bucket 3 in the reverse direction, the scratching member 41 receives from the ground depending on the ground state of the hole wall on the hole bottom side (such as the hardness of the ground). Since the pressure is different, this pressure is measured and used as an evaluation value.

Embodiment 6
When the scratching member 41 is rotated as in the first to fifth embodiments, if the tip 41t side of the scratching member 41 is bent away from the outer peripheral surface 36 of the drilling bucket 3, the drilling is performed. It is preferable because the tip 41t of the scratching member 41 is easily caught on the hole wall on the hole bottom side and the scratching member 41 is easily rotated when the bucket 3 rotates in the reverse direction.

Embodiment 7
The scratchable member 41 can be inspected to be able to scratch the ground of the pile hole bottom of the pile hole or the ground of the hole wall on the bottom side of the pile hole, and the ground of the pile hole bottom of the pile hole or the hole wall on the bottom side of the pile hole For example, a hydraulic cylinder may be used as setting means for setting the retracted state incapable of scratching the ground.
For example, as shown in FIG. 7, the scratch member 41 is attached to, for example, the tip of a piston rod 57 of the hydraulic cylinder 56, the hydraulic cylinder 56 having the scratch member 41 is attached to the bucket body 31, and the piston rod of the hydraulic cylinder 56 is By controlling the expansion and contraction of 57, as shown in FIG. 7A, the scratching member 41 is retracted inside the bucket body 31, or as shown in FIG. It is good also as the measurement means 4 comprised so that it might be in the state which protruded from the outer peripheral surface 36 of the drilling bucket 3. FIG.
For example, the through hole 37 is formed in the peripheral wall 38 of the bucket body 31, and the scratching member 41 attached to the tip of the piston rod 57 of the hydraulic cylinder 56 is disposed outside the outer peripheral surface 36 of the bucket body 31 through the through hole 37. What is necessary is just to set it as the structure by which the said hydraulic cylinder 56 was attached to the surrounding wall 38 of the bucket main body 31 via the attachment member 59 so that it might not protrude outside the outer peripheral surface 36 of the bucket main body 31.
In the case of the seventh embodiment, the scratching member 41 may be the scratching member 41 configured to rotate as in the first to sixth embodiments, or as shown in FIG. A scratching member 41 configured to move forward and backward by moving straight in the moving direction of the piston rod 57 may be used. When using the scratching member 41 configured to move straight forward and back, it is preferable to use one having a sharp tip formed so as to easily penetrate into the ground (see FIG. 7).
According to the seventh embodiment, the drilling bucket 3 is excavated by forming the pile hole using the drilling bucket 3 and then setting the scratching member 41 in an inspectable state by operating the hydraulic cylinder 56 as the setting means. It is possible to inspect the ground condition on the bottom side of the pile hole by rotating in the same direction as the rotation direction at the time. That is, the pile hole forming work and the ground condition inspection work on the bottom side of the pile hole can be continuously performed, and the ground condition inspection work on the bottom side of the pile hole can be efficiently performed.

Embodiment 8
The measuring means 4 described in the first to seventh embodiments may be provided on the outer surface 32f (see FIG. 2B) of the bottom cover 32 of the drilling bucket 3. For example, one of the cutter bits 33 and the measuring means 4 are attached so as to be exchanged.
According to the eighth embodiment, it is possible to determine the state of the ground around the hole bottom of the pile hole.
That is, according to the eighth embodiment, at the time of measurement, the drilling bucket 3 is rotated in a state where the scratching member 4 is in contact with or penetrating the ground around the bottom of the pile hole, and the scratching member 41 scratches the ground. Based on the force received from the ground at the bottom, the state of the ground around the bottom of the hole of the pile hole can be determined, and the conventional inspection method only inspects whether the center of the bottom of the hole has reached the support layer Compared with the inspection device, it is possible to obtain a highly reliable inspection result indicating whether or not the bottom of the pile hole has reached the support layer.

Embodiment 9
In each of the above-described embodiments, the inspection device configured by providing the measuring unit 4 in the drilling bucket 3 is illustrated, but the inspection device configured by providing the measuring unit 4 in the bottomed bucket 7 may be used.
For example, as shown in FIG. 8, the bottom expansion bucket 7 includes a column 70 that is connected to the tip of the kelly bar 23 and serves as a rotation center axis of the bottom expansion bucket 7, a base 72 that is connected to the column 70 by a connection plate 71, and a widening Wings 80 and widening means for widening the widened wings 80 are provided.
The base 72 is formed, for example, by a pair of arcuate walls that face each other via the support 70 so as to form a part of a virtual cylinder centered on the support 70.
A plurality of, for example, two widening blades 80 are provided around the support post 70 at equal intervals in the circumferential direction. For example, as shown in FIG. 8, widening blades 80 and 80 are provided around the support post 70 at positions separated by 180 ° in the circumferential direction.
Each of the widened blades 80 and 80 includes an upper widened blade 81 and a lower widened blade 82, respectively.
Each of the lower widened wings 82 and 82 is rotatably connected to the circumferential end of the arc wall forming the base 72 via a hinge 85.
Under normal conditions (when not widened), the lower widened wings 82 and 82 of the widened wings 80 and 80 face each other via the support 70 so as to form a part of a virtual cylinder centered on the support 70. A pair of arcuate walls are formed, and the upper widening blades 81 and 81 of the widening blades 80 and 80 are mutually connected via the column 70 so as to form a part of a virtual conical hollow body centered on the column 70. It is formed by a pair of opposing curved walls. The curved wall is formed by, for example, an elongated curved wall extending along the column 70 at a position 180 degrees apart in the circumferential direction of the virtual conical hollow body with the column 70 as the center.
Further, at the time of widening, the upper widened blades 81 and 81 and the lower widened blades 82 and 82 of the widened blades 80 and 80 are configured to move away from the support column 70.
In the state where the widening blades 80 and 80 are widened, outermost edges 87 of the widening blades 80 and 80 extending along the extending direction of the support column 70 are arranged at predetermined intervals along the extending direction of the support column 70. A plurality of excavation claws 88, 88... Are provided.
Therefore, the bottom expansion bucket 7 is configured such that the column 70 is rotated to the bottom side of the pile hole by rotating the column 70 while expanding the upper wide blades 81 and 81 and the lower wide blades 82 and 82 of the wide blades 80 and 80 at the bottom of the pile hole. The lower cylindrical upper conical bottom expansion hole having a radius from the center of 70 to the outermost peripheral position of the upper widening blade 81 and the lower widening blade 82 of the widening blade 80 can be excavated.
The widening means includes, for example, a hydraulic cylinder 95 having one end connected to the support column 70 via a hinge 92 and the other end connected to the inner surface of the lower widening blade 82 via a hinge 94. , The piston rod 96 of the hydraulic cylinder 95 is extended, and the upper widening blade 81 and the lower widening blade 82 of the widening blade 80 are moved away from the support column 70.
The hinges 92 and 94 are constituted by hinges that are rotatable in the horizontal direction.
The measuring means 4 is attached to, for example, the outermost portions 89 and 89 when the lower widened blades 82 and 82 of the widened blades 80 and 80 are opened, or the lower ends of the lower widened blades 82 and 82.

A measurement method using the measurement apparatus of Embodiment 9 will be described.
A drilling bucket (not shown) is attached to the tip of the kelly bar 23 of the excavator 2, and after drilling the ground using the drilling bucket to form a pile hole, the drilling bucket is replaced with the expanded bucket 7 and the expanded bucket 7 is installed on the bottom side of the pile hole. Thereafter, the hydraulic cylinder 95 of the bottom expansion bucket 7 is operated to widen the widening blades 80 and 80, and then the bottom expansion bucket 7 is rotated forward to form a bottom expansion portion. After forming the widened portion, by rotating the widened bucket 7 in reverse, the scratching member 41 scratches the ground of the hole wall of the widened portion and the ground of the peripheral portion of the pile hole bottom so that the state of the ground can be determined. become.

  In addition, as long as the bottom expansion bucket is comprised so that a widening blade can be widened, you may use bottom expansion buckets other than the structure mentioned above. For example, a widened bucket as disclosed in Japanese Patent Application Laid-Open No. 2008-14007, that is, a widening means is formed in a cylindrical shape of an upper opening and is positioned 180 degrees apart from each other on the circumferential surface of the cylinder. It is connected to the tip of a support with a long pair of guide grooves and the top of the Kerry bar inserted into the support through the upper opening of the support, and both ends are provided to protrude outside the support through the pair of guide grooves. One widening operation shaft (link) having one end connected to one end of the transmission shaft through a universal joint and the other end connected to the lower inner surface of one widening blade through a universal joint And the other widening operation shaft (link) having one end connected to the other end of the transmission shaft portion via a universal joint and the other end connected to the lower inner surface of the other widening blade via a universal joint, Even if you use a bottomed bucket with a configuration There.

Embodiment 10
In the case where the inspection is performed by rotating the drilling bucket 3 or the bottom expansion bucket 7 in the reverse direction at the time of inspection, when excavating the ground by rotating the drilling bucket 3 or the bottom expansion bucket 7 forward, the hydraulic cylinder as the setting means, The scratching member 41 is set in a retracted state in which it is impossible to scratch the ground at the bottom of the pile hole or the hole wall at the bottom of the pile hole, and the drilling bucket 3 or the bottom expansion bucket 7 is reversely rotated for inspection. When performing, the tip 41t of the scratching member 41 is moved in the direction away from the drilling bucket 3 or the bottom expansion bucket 7 by the hydraulic cylinder as the setting means so that the tip can be inspected. You may comprise so that the ground can be scratched in 41t.

  In the above description, the scratching member 41 can be inspected to be able to scratch the ground of the pile hole bottom of the pile hole or the ground of the hole wall on the bottom side of the pile hole, and the ground or pile hole of the pile hole bottom of the pile hole. Although an example in which a hydraulic cylinder is used as the setting means for setting the retracted state incapable of scratching the ground of the hole wall on the bottom side, means other than the hydraulic cylinder may be used as the setting means. For example, as the setting means, a mechanism that rotates the scratching member to set in an inspectable state and a retracted state may be used.

Moreover, although the example which test | inspects the hole wall of the pile hole bottom side was shown above, according to the pile hole inspection apparatus 1 and the pile hole inspection method of this invention, it is also possible to test | inspect the whole hole wall of a pile hole. It becomes.
For example, the drilling bucket 3 provided with the measuring means 4 on the outer peripheral surface 36 is rotated forward to excavate the ground little by little, and the state of the hole wall of the hole after excavation is checked by rotating the drilling bucket 3 in reverse. Thus, the state of the hole wall of the pile hole can be inspected in order from the ground side, and the entire hole wall of the pile hole can be inspected. In this case, since the depth position of the hole wall that has reached the support layer can be known, the depth of the pile hole can be determined from the depth position, and the position of the pile bottom is appropriately determined. Will be able to.

  Further, for example, after the drilling bucket 3 is rotated forward to form a pile hole or a part of the pile hole, the drilling bucket 3 is moved to the opening side of the pile hole that is the ground side, and the pile is rotated while the drilling bucket 3 is rotated in the reverse direction. By lowering to the bottom side of the hole, it becomes possible to continuously inspect the entire hole wall.

  Further, in the above, the inspection device in which the measuring means 4 is attached to the drilling bucket 3 or the bottomed bucket 7 is illustrated. However, after the pile hole is formed, for example, the excavation function is excluded from the above-described drilling bucket or the bottomed bucket. You may use the pile hole inspection apparatus 1 of the structure provided with the measuring means 4 mentioned above in the apparatus. That is, since the excavation function is not required for the inspection apparatus, a dedicated pile hole inspection apparatus 1 in which the measurement means 4 is provided on a base body that does not have the excavation function may be used.

1 Pile hole inspection device, 3 drilling bucket, 4 measuring means,
7 Expanded bucket, 41 Scratch member, 43 Measuring instrument,
56 Hydraulic cylinder (setting means).

Claims (6)

A pile hole inspection method for inspecting whether a hole bottom or a hole wall of a pile hole formed in the ground has reached a support layer,
Whether the bottom or hole wall of the pile hole reaches the support layer based on the force that the scratching member receives from the ground when the ground of the hole bottom of the pile hole or the ground of the hole wall is scratched by the scratching member. The pile hole inspection method characterized by determining. A scratching member is provided in a drilling bucket or a bottom expansion bucket for excavating the ground to form a pile hole,
2. The pile hole inspection method according to claim 1, wherein the ground of the hole bottom of the pile hole or the ground of the hole wall is scratched by a scratching member by rotating the drilling bucket or the expanded bucket in the pile hole. A pile hole inspection device for inspecting whether the hole bottom or hole wall of a pile hole formed in the ground has reached the support layer,
A scratching member that scratches the ground at the bottom of the hole of the pile hole or the ground of the hole wall, and a measuring device that measures the force that the scratching member receives from the ground when the scratching member scratches the ground. Pile hole inspection device.   The pile hole inspection apparatus according to claim 3, wherein a scratching member is provided on a drilling bucket or a bottom-up bucket for excavating the ground to form a pile hole.   The pile hole inspection apparatus according to claim 4, wherein the scratching member is provided so as to scratch the ground when the drilling bucket or the bottom expansion bucket is rotated in the direction opposite to the rotation direction during excavation.   The scratching member is in an inspectable state in which the ground at the bottom of the pile hole or the ground in the hole wall can be scratched, and in a retracted state in which the ground at the bottom of the pile hole or the ground of the hole wall cannot be scratched. The pile hole inspection apparatus according to any one of claims 3 to 5, further comprising setting means for setting.

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