JP5253963B2 - Excavation method and pile construction method - Google Patents

Description

  The present invention relates to an excavation method and a pile-shaped object construction method for forming a hole by excavating a drilled surface vertically downward using a drill of an excavator.

  It is widely performed to form a hole in the vertical direction on the ground using a drill of an excavator. The outer shape of a drill (drill bit) is generally a conical shape that tapers toward the lower end (tip). By using a drill having such an outer shape, it is possible to excavate even on hard ground at the top of the tip, and to excavate the earth and sand generated by excavation upward.

  And a pile-shaped thing can be created by arrange | positioning H steel pile as a core material in the formed hole, and placing hardening materials, such as a solidification material and a filler, in the circumference | surroundings. Such piles are used as support piles for buildings. In addition, when using as a support pile of a building, in order to raise support strength, it is preferable that the lower surface of a support pile contacts the strongest ground in the ground.

  However, when the drill bit having the above-described outer shape is used, the bottom surface of the hole formed by the drill has a conical shape. And it is difficult to drive the hardening material to such a conical top. When the core material is an H steel pile, the H steel pile stays before reaching the top of the conical shape and hinders subsequent filling of the hardened material. For these reasons, a pile-shaped object created in such a hole cannot secure a sufficient contact area with the strongest ground in the ground. In addition, since the shape of the lower part of the pile-like object is also close to a conical shape, there is a problem that it cannot be said that the stability is sufficiently excellent.

  By the way, when forming a hole along the vertical direction on the ground, it has been proposed to excavate while supplying a stabilizing liquid (see, for example, Japanese Patent No. 3471742 (Patent Document 1 below)). By supplying the stable liquid, earth and sand (slime) generated by excavation can be recovered together with the stable liquid. The recovered stable solution is reused by removing slime.

  After completion of excavation, the stable liquid filled in the hole formed by excavation is recovered as much as possible, but it is difficult to recover all of it, so it is usually left before placing hardened material. Time is secured. Depending on the length of this standing time, the amount of the stable liquid that cannot be recovered and remains in the hole will decrease.

However, when the stabilizer is reused, it cannot be completely removed even if slime is removed from the recovered stabilizer. In particular, it is almost impossible to remove minute earth and sand. In other words, the reused stabilizing liquid contains residual slime. When such a stabilizing liquid is used, during the standing time before placing the curable material, the residual slime contained in the stabilizing liquid settles toward the bottom of the hole, or on the wall of the hole. Or reattach. As a result, the surface of the hole becomes mud (clay). For this reason, there is a problem that the surface of the hole and the pile-like object are difficult to be fixed even if a hardening material is placed in such a hole. In addition, the cause of mud on the surface of the hole is not limited to the stable liquid, and, for example, the earth and sand carried along with the groundwater and rainwater can be considered. And if the pile and the surface of the hole (particularly the wall surface) are not well established, it will not be suitable for use as a friction pile for buildings. Especially when friction piles are made by filling H steel piles into circular holes and then filling with hardened material, hardened materials are hard to penetrate between the flanges of H steel piles and the holes and harden. The fixing property between the material and the H steel pile cannot be sufficiently secured.
Japanese Patent No. 3471742

  Then, this invention sets it as the 1st objective to provide the excavation method which can level the bottom face of the hole formed. Furthermore, the pile-shaped construction method which can improve the stability of the lower part of a pile-shaped thing by creating a pile-like thing in the hole formed by this excavation method is provided.

  Moreover, this invention makes it the 2nd objective to provide the excavation method which can drop off the mud adhering to the wall surface of the formed hole. Furthermore, the pile-shaped construction method which can improve the fixability with respect to the wall surface of a hole is provided by creating a pile-shaped thing in the hole formed by this excavation method.

  The first aspect of the present invention basically relates to an excavation method in which a hole is formed by excavating a surface to be excavated vertically downward using the drill 20 of the excavator 10. Here, the drill 20 includes a drill bit 21 that hits a surface to be excavated. The drill bit 21 is configured such that the outer shape can be changed between a first outer shape that tapers toward the lower end and a second outer shape that forms a horizontal surface at the lower end. In the excavation method of the present invention, the first excavation step (S14), the outer shape changing step (S16), and the second excavation step (S18) are performed.

  In the first excavation step (S14), the drill bit 21 is used to excavate the surface to be excavated when the drill bit 21 takes the first outer shape. As a result, a hole having a conical bottom surface is formed. In the outer shape changing step (S16) after the first excavation step (S14), the outer shape of the drill bit 21 is changed from the first outer shape to the second outer shape. In the second excavation step (S18), when the drill bit 21 takes the second outer shape, the drill bit 21 is used to form the excavation surface (that is, the bottom surface of the hole) formed in the first excavation step (S14). Further drilling. This changes the bottom of the hole from a conical shape to a horizontal surface. Therefore, the bottom of the hole becomes flat.

  For this reason, when a pile-shaped object is created by placing a hardening material such as a solidified material in this hole, the stability of the lower part of the pile-shaped object is higher than when the bottom surface of the hole is conical. It will be. In particular, when creating a support pile for a building, a core material (for example, an H steel pile) is embedded in the hardened material after the hardened material is placed and before the hardened material is completely hardened. By creating support piles in this way, the building can be firmly supported.

  In the excavation method, it is preferable that the outer shape changing step (S16) includes a step of switching the rotation direction of the drill 20 from the normal rotation direction to the reverse rotation direction. In this case, in the first excavation step (S14), the drill 20 is rotated in the forward rotation direction.

  In order to achieve this, the excavator 10 includes a rotating means 30 that rotates the drill 20. The rotating means 30 includes a rotation direction switching mechanism 32 that switches the rotation direction of the drill 20 between the normal rotation direction and the reverse rotation direction. The drill bit 21 also includes an outer shape changing mechanism 23 that changes the outer shape in conjunction with the switching of the rotation direction of the drill 20 by the rotation direction switching mechanism 32. Alternatively, the outer shape changing mechanism 23 may change the outer shape according to the magnitude and direction of the pressure generated due to the manner in which the drill 20 hits the surface to be drilled depending on the rotation direction. By this outer shape changing mechanism 23, the outer shape of the drill 20 is changed from the first outer shape to the second outer shape. Therefore, according to this excavation method, the outer shape of the drill bit 21 can be easily changed.

  Further, another aspect of the present invention basically relates to a pile-like material construction method. In the pile-like material construction method, a pile-like material is created by filling a hole formed by the excavation method described above with a curable material having curability. In addition, when producing the support pile of a building, a core material (for example, H steel pile) is embed | buried in a hardening material.

And in the pile-shaped article construction method of the present invention, each step of the excavation method according to the first aspect, a liquid circulation step (S12), a hardening material filling step (S30), a hardening step (S3 6 ), Is further done. In order to perform the liquid circulation step (S12), a through passage 28 is provided in the drill 20 to connect the upper end to the lower end.

  In the liquid circulation step (S12), the liquid is circulated between the hole formed by the drill 20 and the outside of the hole during the excavation in the first excavation step (S14) and the second excavation step (S18). . For this reason, in this liquid circulation step (S12), a liquid supply step and a liquid recovery step are performed. In the liquid supply step, the liquid is supplied toward the bottom surface of the hole formed by the drill 20 using the through passage 28 of the drill 20. In the liquid recovery step, the liquid supplied to the bottom surface of the hole is recovered from between the outer peripheral surface of the drill 20 and the wall surface of the hole formed by the drill 20. In this way, the hole formed by the drill 20 is cleaned.

In the hardener filling step (S30), after the second excavation step (S18), the hardened material having curability is discharged from the lower end of the drill 20, so that the hardened material is put into the hole formed by the drill 20. Fill. Thereby, filling of the curable material can be performed from the bottom surface of the cleaned hole. The hardened material is discharged using the through passage 28 of the drill 20. Further, the cured material is discharged while the drill 20 is pulled up vertically. In the curing step (S3 6 ), the curing material filled in the holes in the curing material filling step (S30) is cured and cured. This creates a pile. According to this pile-like material construction method, since the filling of the hardening material is performed after the hole is washed, the pile-like material has an improved fixability to the bottom surface and the wall surface of the hole. In particular, when piles are used as building support piles, the core material (for example, H steel pile) is embedded in the hardened material after the hardened material is placed and before the hardened material is completely hardened. . By creating support piles in this way, the building can be firmly supported.

  Moreover, in the said pile-shaped article construction method, it is preferable that a bag injection | throwing-in step (S28) and a pumping step (S30) are further performed in the said hardening material filling step (S30). Here, in the bag charging step (S <b> 28), a bag-shaped object 40 having a size that satisfies the cross section of the through channel 28 is input to the through channel 28 from the upper end of the through channel 28. In the pressure feeding step (S30), the bag-shaped object 40 is pressure-fed in the through passage 28 together with the cured material by feeding the cured material above the charged bag-shaped object 40. When the bag-shaped object 40 is discharged from the lower end of the through-passage 28, the curable material is filled from the bottom surface of the hole formed by the drill 20.

  By doing in this way, even if the penetration path 28 is filled with liquid, the liquid can be discharged from the lower end of the penetration path 28 using the bag-shaped object 40. That is, the curable material can be filled immediately after the liquid filled in the through passage 28 is removed. For this reason, it can prevent that the curable material mixes with the liquid with which the penetration path 28 is filled. For this reason, the pile-shaped thing created in this hole will further improve the fixing property to the bottom face and wall surface of the hole.

  Furthermore, in the pile-like material construction method, a bag breakage step is performed in the pressure feeding step (S30). For this purpose, a protrusion 29 exposed to the through passage 28 is provided at the lower end of the through passage 28 of the drill 20. In the bag breakage step, the bag-shaped object 40 fed by pressure in the through passage 28 is broken by the protrusion 29. That is, since the bag-shaped object 40 is easily damaged by the projection 29 only by being pumped, it does not take time. Here, the inside of the bag-shaped object 40 is filled in advance with the same curable material as the curable material or a curable material having higher curability than the curable material. By doing so, when the bag-shaped object 40 is damaged, the cured material filled in the bag-shaped object 40 is diffused in the vicinity of the bottom surface of the hole formed by the drill 20. Thereby, it can utilize effectively, without wasting the volume of the bag-shaped object 40. FIG.

  The second aspect of the present invention basically relates to an excavation method for forming a hole by excavating a surface to be excavated vertically downward using the drill 20 of the excavator 10. Here, the excavator 10 includes a rotating means 30 that rotates the drill 20 around a central axis along the longitudinal direction thereof. The drill 20 includes a drill body 31 that is rotated by the rotating means 30, and a guide pipe 35 that is provided integrally with the drill body 31 outside the drill body 31 and rotates together with the drill body 31. Yes. A plurality of rounded up cones 36 are attached to the upper edge of the guide pipe 35. The rounded up cone 36 will be described later.

  In this excavation method, an excavation step (S12) and a recovery step (S32) are performed. In the excavation step (S12), the drill 20 is rotated by the rotating means 30, thereby forming a hole. In the recovery step (S32), the drill 20 at the bottom of the hole formed in the excavation step (S12) is recovered. Thereby, the guide pipe 35 moves along the wall surface of the formed hole.

  However, this recovery step (S32) includes a rounded-up cone rotating step in which the rotary means 30 rotates the drill 20 to rotate the rounded-up cones 36. As a result, the wall surface of the hole is cut by the plurality of rotated round cones 36. The operation of scraping the wall surface of the hole is performed as the guide pipe 35 moves. And the earth and sand reattached to the wall surface of the hole is also scraped off, and as a result, it falls off. Therefore, when a pile-like material is created by placing a hardened material such as concrete in this hole, the pile-like material will be more fixable to the wall of the hole. Especially when building support piles and friction piles for buildings, the core material (for example, H steel piles) should be turned into a hardened material after placing the hardened material and before the hardened material is completely hardened. Buried. By creating support piles and friction piles in this way, the building can be firmly supported.

  Further, another aspect of the present invention basically relates to a pile-like material construction method. In the pile-like material construction method, a pile-like material is created by filling a hole formed by the excavation method described above with a curable material having curability. In addition, you may further use a core material (for example, H steel pile) as needed.

And in the pile-shaped article construction method of the present invention, each step of the excavation method according to the second aspect, a liquid circulation step (S12), a hardening material filling step (S30), a hardening step (S3 6 ), Is further done. In order to perform the liquid circulation step (S12), a through passage 28 is provided in the drill 20 to connect the upper end to the lower end.

  In the liquid circulation step (S12), the liquid is circulated between the hole formed by the drill 20 and the outside of the hole during the excavation in the excavation step (S12) described above. For this reason, in this liquid circulation step (S12), a liquid supply step and a liquid recovery step are performed. In the liquid supply step, the liquid is supplied toward the bottom surface of the hole formed by the drill 20 using the through passage 28 of the drill 20. In the liquid recovery step, the liquid supplied to the bottom surface of the hole is recovered from between the outer peripheral surface of the drill 20 and the wall surface of the hole formed by the drill 20. In this way, the hole formed by the drill 20 is cleaned.

In the hardener filling step (S30), after the excavation step (S12), the hardened material having curability is discharged from the lower end of the drill 20 to fill the hole formed by the drill 20 with the hardened material. . Thereby, filling of the curable material can be performed from the bottom surface of the cleaned hole. The hardened material is discharged using the through passage 28 of the drill 20. Further, the cured material is discharged while the drill 20 is pulled up vertically. In the curing step (S3 6 ), the curing material filled in the holes in the curing material filling step (S30) is cured and cured. This creates a pile. According to this pile-like material construction method, since the filling of the hardening material is performed after the hole is washed, the pile-like material has an improved fixability to the bottom surface and the wall surface of the hole. In particular, when a pile-shaped object is a support pile or a friction pile of a building, the core material (for example, H steel pile) is hardened after the hardened material is placed and before the hardened material is completely hardened. Buried in By creating support piles and friction piles in this way, the building can be firmly supported.

  Moreover, in the said pile-shaped article construction method, it is preferable that a bag injection | throwing-in step (S28) and a pumping step (S30) are further performed in the said hardening material filling step (S30). Here, in the bag charging step (S <b> 28), a bag-shaped object 40 having a size that satisfies the cross section of the through channel 28 is input to the through channel 28 from the upper end of the through channel 28. In the pressure feeding step (S30), the bag-shaped object 40 is pressure-fed in the through passage 28 together with the cured material by feeding the cured material above the charged bag-shaped object 40. When the bag-shaped object 40 is discharged from the lower end of the through-passage 28, the curable material is filled from the bottom surface of the hole formed by the drill 20.

  By doing so, the liquid can be discharged from the lower end of the through-passage 28 using the bag-shaped object 40 even if the through-passage 28 is filled with liquid. That is, the curable material can be filled immediately after the liquid filled in the through passage 28 is removed. For this reason, it can prevent that the curable material mixes with the liquid with which the penetration path 28 is filled. For this reason, the pile-shaped thing created in this hole will further improve the fixing property to the bottom face and wall surface of the hole.

  Furthermore, in the pile-like material construction method, a bag breakage step is performed in the pressure feeding step (S30). For this purpose, a protrusion 29 exposed to the through passage 28 is provided at the lower end of the through passage 28 of the drill 20. In the bag breakage step, the bag-shaped object 40 fed by pressure in the through passage 28 is broken by the protrusion 29. That is, since the bag-shaped object 40 is easily damaged by the projection 29 only by being pumped, it does not take time. Here, the inside of the bag-shaped object 40 is filled in advance with the same curable material as the curable material or a curable material having higher curability than the curable material. By doing so, when the bag-shaped object 40 is damaged, the cured material filled in the bag-shaped object 40 is diffused in the vicinity of the bottom surface of the hole formed by the drill 20. Thereby, it can utilize effectively, without wasting the volume of the bag-shaped object 40. FIG.

  According to the excavation method according to the first aspect of the present invention, since the bottom surface of the hole is changed from a conical shape to a horizontal surface, the bottom surface of the hole becomes flat. In addition, according to the method for constructing a pile-like object of the present invention, since the pile-like object is created in a hole having a flat bottom surface, the stability of the lower part of the pile-like object is higher than that in the case where the bottom surface of the hole is conical. , Will increase. Such a pile-like object can be suitably used as a support pile for a building.

  According to the excavation method of the second aspect of the present invention, the earth and sand reattached to the wall surface of the hole are dropped off from the wall surface by rotating the plurality of raised cones 36 to cut the wall surface of the hole. Moreover, according to the pile-like material construction method of the present invention, since the pile-like material is created in the hole in which earth and sand are dropped from the wall surface, the pile-like material has improved fixability to the wall surface of the hole. Such a pile-like object can be suitably used as a support pile or a friction pile of a building.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. However, the form described below is an example, and can be appropriately modified within a range obvious to those skilled in the art.

  FIG. 1 is a process diagram (flow chart) showing a procedure of a pile-like material construction method including the excavation method of the present invention. FIG. 2 is a diagram showing a state of the excavation site when the drilled surface of the excavation apparatus (boring machine) 10 is drilled vertically downward to form a hole. FIG. 3 is a diagram showing a configuration of the drill 20 shown in FIG.

  In this aspect, a support pile or friction pile of a building is created by a pile-like construction method. As shown in FIG. 1, the pile construction method according to this aspect includes an excavator installation step (S10), a liquid circulation start step (S12), a first excavation step (S14), and a rotation direction reverse step (S16). ), A second excavation step (S18), a liquid circulation stop step (S20), a liquid recovery step (S22), a liquid circulation device removal step (S24), a hardening material pumping device installation step (S26), A bag-shaped article input step (S28), a pumping / filling step (S30) of a hardened material, a third excavation step (S32), a core material building step (S34), and a hardener curing step (S36); And a hardened material pumping device / digging device removal step (S38). Here, the excavation method according to the first aspect of the present invention includes at least a first excavation step (S14), a rotation direction reverse step (S16), and a second excavation step (S18). The excavation method according to the second aspect of the present invention includes at least a first excavation step (S14) and a third excavation step (S32).

  First, in the excavator installation step (S10), the excavator 10 is installed as shown in FIG. Specifically, the ground is the surface to be excavated, and the rotating means 30 is fixed to the crane 1. The rotating means 30 may be installed on the ground. Subsequently, the drill holding mechanism 3 is installed above the rotating means 30. As the drill holding mechanism 3, there is a swivel joint 3b. Subsequently, the drill 20 is fixed to the drill holding mechanism 3 so as to be suspended. The drill 20 is attached to the rotating means 30 by passing the suspended drill 20 through a through hole provided in the center of the rotating means 30. The liquid supply mechanism 5 is connected to the upper end of the drill 20, and one end of the recovery hose 8 of the liquid recovery mechanism 7 is disposed at a corresponding position so as to be inserted into a hole formed by the drill 20.

  Here, the drill 20 includes a drill body 31, a drill bit 21, and a guide pipe 35, as shown in FIG. The drill body 31 is, for example, a cylindrical member having a diameter of 90 mm, and a through passage 28 is formed inside. The drill bit 21 is a plate-like member that is attached to the lower end of the drill main body 31, and is attached so as to excavate in the range of 300 mm to 800 mm in diameter when, for example, turning. In this embodiment, the drill bit 21 includes two plate-like wing bits 21a and 21b as shown in the bottom view of FIG. The drill bit 21 may include three (three wings) or more wing bits. Each wing bit includes an outer shape deformation mechanism 23 described later. A plurality of metal bits (metal teeth) 22 and 22 'are embedded in the wing bits 21a and 21b, for example, through sheaths. The metal bit 22 and the metal bit 23 are provided at different locations. As will be described in detail later, at least one of the metal bit 22 and the metal bit 23 comes into contact with the surface to be excavated according to the operation of the outer shape deformation mechanism 23. The metal bit may not be embedded through the sheath, and may be formed directly on the wing bit by, for example, metal welding. The guide pipe 35 is fixed to the drill body 31 in a state of being disposed between the outer peripheral surface of the drill body 31 and the wall surface of the hole formed by the drill 20. Therefore, when the drill body 31 is rotated by the rotating means 30, the guide pipe 35 and the drill bit 21 are rotated together with the drill body 31.

  The rotating means 30 is for rotating the drill body 31 of the drill 20. In this aspect, the rotation means 30 further includes a rotation direction switching mechanism 32 for switching the rotation direction of the drill 20 between the normal rotation direction and the reverse rotation direction. The rotation direction switching mechanism 32 will be described in detail later.

  The drill holding mechanism 3 is a mechanism for receiving the load of the drill 20 from above. Specifically, it has a vertical movement mechanism 3a for moving the drill 20 up and down in the vertical direction, and a swivel joint 3b fixed to the vertical movement mechanism 3a for suspending the drill 20. The swivel joint 3b may be fixed to the vertical movement mechanism 3a via a hanging tool. The swivel joint 3b has a hose connection portion 3c having a through passage connected to the through passage 28 of the drill body 31.

  The liquid supply mechanism 5 includes a stabilizing liquid tank 5a for storing a stabilizing liquid, a high-lift sand pump 5b for taking out the stabilizing liquid from the stabilizing liquid tank 5a, a hose connection part 3c of the sand pump 5b and the swivel joint 3b, And a supply hose 5c connected to the. Here, the stabilizing liquid is a liquid, for example, easily available water. This stabilizing liquid is used to perform excavation smoothly and to clean the hole formed by the drill 20. The liquid recovery mechanism 7 includes at least a recovery hose 8 and a suction pump (sand pump) 7 a connected to one end of the recovery hose 8. The liquid recovery mechanism 7 may further include a solid-liquid separator (for example, a mud screen) and a precipitation tank (not shown). In this case, the solid-liquid separator is connected to the suction pump 7a, and removes the slime flowing together with the liquid from the liquid collected by the suction pump 7a as waste soil, thereby taking out the liquid. The liquid taken out by the solid-liquid separator or the liquid recovered by the suction pump 7a flows into the settling tank, and here, the solid that flows in with the liquid is precipitated. The liquid recovered by the supernatant of the sedimentation tank and the suction pump 7 a finally flows into the stable liquid tank 5 a of the liquid supply mechanism 5.

  Subsequently, in the liquid circulation start step (S12), first, the stabilizing liquid is supplied to the through passage 28 of the drill main body 31 through the hose connection portion 3c at the upper end of the drill 20. Thereby, the stabilizing liquid is discharged from the lower end of the drill 20. Also, the stabilizing liquid discharged from the lower end of the drill 20 moves between the side surface of the drill body 31 and the wall surface of the hole and moves toward the outside of the hole by the discharged force (flow velocity outside the tube). At this time, earth and sand (slime) generated by excavation moves with the stabilizing liquid. Subsequently, the liquid containing the slime is recovered by the suction pump through the recovery hose 8 inserted into the hole. Thereafter, the stable liquid containing slime is separated into liquid (stabilized liquid) and solid (slime) in the liquid recovery mechanism 7 or in the stable liquid tank 5a, and the stable liquid is taken out. This stabilizing liquid is reused by the liquid supply mechanism 5. That is, the stabilizing liquid circulates through the through passage 28 of the drill body 31 and between the drill body 31 and the hole (normal circulation system).

  When the circulation of the stable liquid is started in the liquid circulation start step (S12), excavation using the drill 20 is performed (first excavation step: S14). As shown in FIG. 3, the outer shape of the drill bit 21 at this time has a conical shape (first outer shape) that tapers toward the lower end. At this time, the metal bit 22 is exposed so as to hit the surface to be excavated. By using the drill bit 21 having such an outer shape, it is possible to excavate even on hard ground at the top of the tip, and to excavate the earth and sand generated by excavation upward. And the shape of the bottom face of the hole formed at this time also becomes a conical shape. Then, when the tip of the drill bit 21 reaches the target depth, the rotation of the drill 20 is stopped. The target depth is set to the distance from the ground to a solid ground, for example, when building support piles for buildings.

  When the rotation of the drill 20 is stopped, the rotation direction switching mechanism 32 of the rotation means 30 changes the rotation direction of the drill 20 from the normal rotation direction to the reverse rotation direction (rotation direction reverse rotation step: S16). In this embodiment, the outer shape of the drill bit 21 is changed from the conical shape shown in FIG. 3 to the outer shape (second outer shape) shown in FIG. 5 as the drill 20 rotates in the reverse direction. It is like that. As shown in FIG. 5, the lower end of the modified outer shape forms a horizontal surface (flat bottom bit).

  Such a change in the outer shape of the drill bit 21 is realized by an outer shape changing mechanism 23 provided in the drill bit 21. The outer shape changing mechanism 23 changes the outer shape in conjunction with, for example, switching of the rotation direction of the drill 20 by the rotation direction switching mechanism 32 of the rotating means 30. That is, the drill bit 21 is provided with at least an interlocking member that interlocks with the operation of the rotation direction switching mechanism 32. The interlocking member is, for example, a hinge, and this hinge connects the upper part and the lower part constituting each wing bit of the drill bit 21 so as to be rotatable. Here, since the upper part of the wing bit is fixed to the drill body 31, the outer shape is changed by rotating the lower part around the hinge. FIG. 5 shows a state after the wing bits 21a and 21b are rotated until the lower portions thereof are substantially horizontal. Thus, each wing bit rotates, so that at least a part of the plurality of metal bits 22 moves so as not to hit the surface to be excavated, and the plurality of metal bits 22 ′ are excavated. It will be exposed to hit the surface. As shown in FIG. 5, the plurality of metal bits 22 'are provided on the lower side surfaces of the wing bits 21a and 21b. Thereby, the drill 20 can excavate the surface to be excavated so as to be a horizontal surface.

  In the above embodiment, the outer shape changing mechanism 23 of the drill bit 21 changes the outer shape in conjunction with the switching of the rotation direction of the drill 20 by the rotation direction switching mechanism 32 of the rotating means 30. It may operate according to the magnitude and direction of the pressure generated due to the manner in which it hits the excavated surface depending on the rotation direction. This also allows the drill bit 21 to change its outer shape.

  Then, excavation is performed using the metal bit 22 'exposed on the surface to be excavated when the lower portions of the wing bits 21a and 21b are substantially horizontal (second excavation step: S18). Here, in order to excavate, the rotating means 30 rotates the drill 20 in the reverse direction. Moreover, since the lower part of each wing bit 21a, 21b is substantially horizontal, the external shape of the drill bit 21 has a horizontal surface at least at the lower end. For this reason, the drill bit 21 is drilled so that the conical bottom surface becomes a horizontal surface (flat).

  When the second excavation step is completed, the rotation of the drill 20 is stopped and the circulation of the stable liquid is stopped (liquid circulation stop step: S20). Specifically, the supply of the stabilizing liquid is stopped. Then, the stable liquid filled in the side surface of the drill 20 and the wall surface of the hole is recovered as much as possible by the recovery hose 8 using the liquid recovery mechanism 7 (liquid recovery step: S22). Here, the stabilizing liquid may remain in the through passage 28 of the drill body 31 or between the drill body 31 and the wall surface of the hole. Thereafter, a part of the liquid circulation device is removed (liquid circulation device removal step: S24). Specifically, the supply hose 5c is removed from the hose connection portion 3c, or the recovery hose 8 is pulled up from the hole.

  Next, the curing material pumping device 41 shown in FIG. 6 is installed (curing material pumping device installation step: S26). FIG. 6 is a diagram for explaining the relationship between the hardened material pumping device 41 and the drill main body 31.

  As shown in FIG. 6, the curing material pumping device 41 includes a solidification material plant 42 that holds a curing material (for example, a solidification material) so as not to be cured, a pressurization pump 44 connected to the solidification material plant 42, and a pressurization. It has a high-pressure hose 46 that connects between the pump 44 and the hose connection part 3c. And if the high pressure hose 46 of the hardening material pumping apparatus 41 is connected to the hose connection part 3c, the preparation for supplying a hardening material will be completed.

  Here, prior to the start of the supply of the curable material, first, the bag-shaped object 40 shown in FIG. 6 is introduced from the upper end of the through path of the hose connection portion 3c to the through path 28 of the drill body 31 (bag shape). Material input step: S28). Here, the bag-shaped object 40 has a size that satisfies the cross section of the through-passage 28 of the drill body 31, and can be created by, for example, forming a resilient material into a cylindrical shape. In this embodiment, the bag-shaped object 40 is filled with the same curable material as the curable material or a curable material having a higher curability than the curable material.

  Subsequently, the high-pressure hose 46 of the curing material pumping device 41 is connected to the hose connection portion 3c, and the curing material is fed above the bag-shaped object 40 introduced in the bag-shaped object charging step (S28). The bag-shaped object 40 is pumped in the through passage 28 of the drill main body 31 (step of feeding and filling hardened material: S30). By doing so, the bag-shaped object 40 discharges the stabilizing liquid filled in the through passage 28 of the drill body 31 from the lower end of the through passage 28 of the drill body 31. When the bag-shaped object 40 is discharged from the lower end of the through passage 28 of the drill main body 31 following the stabilizing liquid, the hardened material from the hardener feeding device 41 is also discharged from the lower end of the through passage 28 of the drill main body 31. It will be. Thereby, the curable material can be filled without a gap from the bottom surface of the hole formed by the drill 20.

  Here, a protrusion 29 is provided at the lower end of the through passage 28 of the drill body 31 so as to be exposed to the through passage 28 (see FIG. 6). For this reason, when the bag-shaped object 40 reaches the lower end of the through-passage 28 of the drill body 31 as a result of being fed, the bag-shaped object 40 is broken by the protrusion 29, and the cured material filled in the bag-shaped object 40 is removed by the drill 20. It diffuses in the vicinity of the bottom of the formed hole. Thereby, it can utilize effectively, without wasting the volume of the bag-shaped object 40. FIG. Further, since the bag-shaped object 40 is easily broken by the protrusion 29 only by being pressure-fed, it does not take time and effort.

  After that, by continuing to pump the cured material, the cured material fills the holes sequentially from the bottom. In particular, in this aspect, since the bottom surface of the hole is flattened in the second excavation step (S18), the hardening material is reliably filled. The filling of the curable material is performed while collecting (pulling up) the drill 20 according to the filling amount (injection amount) of the curable material. Thereby, it is possible to prevent the drill 20 from being filled with the hardened material. At this time, in this embodiment, the recovered drill 20 is rotated as necessary, and a plurality of rounded up cones (crown bits) 36 are rotated. The rounded-up cone 36 is attached to the upper edge of the guide pipe 35 (see FIG. 3). Since the guide pipe 35 moves along the wall surface of the hole, the wall surface of the hole is scraped off when the rounding cone 36 rotates (third excavation step: S32).

  In this way, the hardened material is filled while scraping the wall surface of the hole, and when the filling of the hardened material is completed, the core material is built before the hardened material is completely cured (core material building step: S34). ). As a core material, an H steel pile or a reinforcing bar can be used. Here, since the core material is built after filling with the curable material, the surface of the core material tends to come into contact with the curable material. For this reason, fixing between the core material and the curable material is more reliably performed after the filling than when the curable material is filled. Also, if the core material is built before filling with the hardened material, there may be a dead space between the core material and the wall surface or bottom surface of the hole that is not filled with the hardened material. Such a possibility can be eliminated. When a plurality of holes are formed, it is not necessary to build the core material in all the holes, and the core material may be built at a predetermined interval.

  Then, when the construction of the core material is completed, the feeding of the cured material by the cured material pumping device 41 is stopped. Thereafter, the cured material is cured by curing (curing material curing step: S36), and the curing material pumping device 41 and the excavating device 10 which are no longer necessary are removed (the curing material pumping device / digging device removing step: S38). When the cured material is cured, the wall surface and bottom surface of the hole, the cured material, and the core material are fixed to each other, and a desired pile-shaped object is created.

  As described above in detail, in this aspect, in the second excavation step, the bottom surface of the hole is changed from a conical shape to a horizontal surface (step S18), so that the bottom surface of the hole becomes flat. And since a pile-shaped object is created by filling a hole with a flat bottom surface (step S30), the stability of the lower part of the pile-shaped object is higher than when the bottom surface of the hole is conical. Will increase. Such a pile-like object can be suitably used as a support pile for a building. And when a pile-like thing is used as a support pile of a building, all the loads from a building can be received with the solid ground in the ground through the bottom of a hole. That is, it is possible to provide a highly reliable support pile. Further, since the hardening material is filled after the bottom surface of the hole is flattened, and further, the core material is built after filling the hardening material (step S34), so that the hardening material is placed in the dead space at the bottom of the hole. The possibility of not being filled can be eliminated.

  Further, in the above-described aspect, after forming the hole, in the third excavation step, by rotating the plurality of rounded up cones 36 to cut the wall surface of the hole (step S32), the earth and sand reattached to the wall surface of the hole Can be removed from the wall. And since the hardened material is filled in the hole from which the earth and sand are dropped from the wall surface (step S30) and the pile-shaped object is created, the fixability of the hole-shaped wall to the wall surface is enhanced. Such a pile-like object can be suitably used as a support pile or a friction pile of a building. Further, since the core material is built (step S34) after the hardening material is filled, the possibility that the hard material is not filled in the dead space between the previously built core material and the wall surface of the hole is eliminated. Can do.

  In addition, since the bottom surface of the hole is leveled and the wall surface of the hole is scraped off in separate steps, as described in the above-described embodiment, both methods are performed in a single pile construction method. Can be implemented. That is, the excavation method according to the first aspect of the present invention and the excavation method according to the second aspect of the present invention can be implemented in combination. Here, in the above-described embodiment, since the hardening material is filled from the bottom surface of the hole, even if the wall surface of the hole is scraped, it does not fall down to the bottom surface of the hole. In this case, it is possible to provide a pile-shaped object that has both the stability of the lower part of the pile-shaped object and the fixing property of the pile-shaped object to the wall surface of the hole.

  In addition, according to this aspect, when a solidifying material is used as the hardening material, since the solidifying material does not contain earth and sand, it is possible to build the core material after injecting the solidifying material into the hole. . Here, conventionally, it was necessary to inject the mortar into the hole after the core material was built, but in the present invention, the procedure can be reversed. In other words, the problem that the core material gets in the way of mortar injection is solved. In addition, muddy water accumulates in the dead space between the core material and the hole, and even if the solidified material is injected, the muddy water cannot be pushed out from the bottom of the hole one after another, and the solidified material and muddy water are mixed together. As a result, the problem that the reliability of the pile-like object is lowered is also solved. In addition, in the conventional method, there is a problem that the time for which the stable liquid (muddy water) filled in the hole is left is prolonged, and slime is likely to settle or adhere to the bottom surface or wall surface of the hole. Since the hardened material can be filled quickly and the wall surface of the hole is shaved in the third excavation step (S32), the conventional problem can be solved. Therefore, according to this invention, what has a high reliability can be provided as a support pile for buildings rather than the conventional construction method.

  In the above-described embodiment, the stable liquid is circulated. However, if there is no need to clean the through-passage 28 and the hole of the drill 20, the stable liquid need not be circulated. That is, in the present invention, even if the stable liquid is not circulated, sufficient effects can be obtained.

  In the above-described aspect, the outer shape of the drill bit 21 can be changed between the first outer shape and the second outer shape. Here, the lower part of the drill bit 21 may be configured to be removable from the upper part. In this case, the metal bit 22 'is exposed when the lower part is removed. In addition, you may enable it to collect | recover the removed lower part with a wire etc. Or you may enable it to return the removed front-end | tip part to an original position remotely using a wire etc.

  The excavation method according to the present invention can be used in the technical field of forming a hole by excavating a drilled surface vertically downward using the drill 20 of the excavator 10. Moreover, the pile-like material construction method according to the present invention forms a hole by excavating the drilled surface vertically downward using the drill 20 of the excavator 10, and fills the formed hole with a hardening material to form a pile. It can be used in the technical field of creating objects.

FIG. 1 is a process diagram showing the procedure of a pile-like material construction method including the excavation method of the present invention. FIG. 2 is a diagram illustrating a state of the excavation site when the drilled surface of the excavation apparatus 10 is excavated vertically downward to form a hole. FIG. 3 is a side view showing the configuration of the drill 20 shown in FIG. FIG. 4 is a bottom view of the drill bit 21 shown in FIG. FIG. 5 is a side view of the drill bit 21 for explaining a case where the outer shape of the drill bit 21 shown in FIG. 3 is changed. FIG. 6 is a diagram for explaining the relationship between the hardened material pumping device 41 and the drill main body 31.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crane 3 Drill holding | maintenance mechanism 3a Vertical movement mechanism 3b Swivel joint 3c Hose connection part 5 Liquid supply mechanism 5a Stabilizing liquid tank 5b Sand pump 5c Supply hose 7 Liquid recovery mechanism 7a Suction pump (sand pump)
8 Recovery hose 10 Excavator (boring machine)
20 drill 21 drill bit 21a, 21b wing bit 22, 22 'metal bit (metal tooth)
23 Outline changing mechanism 28 Through-path 29 Protrusion 30 Rotating means 31 Drill body 32 Rotation direction switching mechanism 35 Guide pipe 36 Round-up cone 40 Bag-shaped object 41 Curing material pumping device 42 Solidifying material plant 44 Pressurizing pump 46 High-pressure hose

Claims (5)

A drilling method for forming a hole by drilling a drilled surface vertically downward using a drill (20) of a drilling device (10),
The drill (20) includes a drill bit (21) that hits the drilled surface,
The drill bit (21) is configured such that the outer shape can be changed between a first outer shape having a taper shape toward the lower end and a second outer shape in which the lower end forms a horizontal surface,
Said method is:
A first excavation step (S14) for excavating the drilled surface using the drill bit (21) when the drill bit (21) takes the first outer shape;
After the first excavation step (S14), an external shape changing step (S16) for changing the external shape of the drill bit (21) from the first external shape to the second external shape;
When the drill bit (21) takes the second outer shape, the drill bit (21) is used to further excavate the excavation surface formed in the first excavation step (S14) (S18). And
Accordingly, a conical hole is formed in the bottom surface in the first excavation step (S14), and the bottom surface of the hole formed in the first excavation step (S14) is horizontally formed in the second excavation step (S18). Do,
Excavation method. The excavator (10) includes rotating means (30) for rotating the drill (20),
The rotating means (30) includes a rotation direction switching mechanism (32) for switching the rotation direction of the drill (20) between a normal rotation direction and a reverse rotation direction,
The drill bit (21) includes an outer shape changing mechanism (23) that changes the outer shape in conjunction with the rotation direction switching of the drill (20) by the rotation direction switching mechanism (32), or the drill (20) An external shape changing mechanism (23) for changing the external shape according to the magnitude and direction of the pressure generated due to a change in the manner of hitting the excavated surface depending on the rotation direction;
In the first excavation step (S14), the rotating means (30) rotates the drill (20) in the normal rotation direction,
The outer shape changing step (S16) includes a step in which the rotation direction switching mechanism (32) switches the rotation direction of the drill (20) from the normal rotation direction to the reverse rotation direction, whereby the drill (20) The external shape is changed from the first external shape to the second external shape,
The excavation method according to claim 1. A pile construction method for creating a pile by filling a hole formed by the excavation method according to claim 1 or 2 with a curing material having curability,
The drill (20) has a through-passage (28) connected from the upper end to the lower end inside,
Said method is:
During the excavation in the first excavation step (S14) and the second excavation step (S18), a liquid circulation step (S12) for circulating liquid between the hole formed by the drill (20) and the outside of the hole. )When,
After the second excavation step (S18), the hardened material filling the hole formed by the drill (20) by discharging the hardened material having curability from the lower end of the drill (20). Filling step (S30);
A curing step (S3 6 ) that cures and cures the curing material filled in the holes in the curing material filling step (S30),
The liquid circulation step (S12)
A liquid supply step of supplying a liquid toward a bottom surface of a hole formed by the drill (20) using the through passage (28) of the drill (20);
A liquid recovery step for recovering the liquid supplied to the bottom surface of the hole from between the outer peripheral surface of the drill (20) and the wall surface of the hole formed by the drill (20);
Thereby, in the liquid circulation step (S12), the hole formed by the drill (20) is washed,
In the curing material filling step (S30),
While pulling up the drill (20) vertically upward, the cured material is discharged from the lower end of the drill (20) using the through passage (28) of the drill (20), so that the filling of the cured material is performed. From the bottom of the cleaned hole,
Pile construction method. The curing material filling step (S30) includes:
A bag charging step (S28) for charging a bag-shaped object (40) having a size satisfying the cross section of the through channel (28) from the upper end of the through channel (28);
By feeding the cured material above the bag-shaped object (40) charged in the bag charging step (S28), the bag-shaped object (40) is pumped together with the cured material in the through passage (28). A pressure feeding step (S30)
As a result, in the pressure feeding step (S30), the bag-shaped object (40) is used to discharge the liquid filled in the through passage (28) from the lower end of the through passage (28), and the penetration The bag-shaped object (40) is discharged from the lower end of the path (28), thereby filling the curable material from the bottom surface of the hole formed by the drill (20).
The pile construction method according to claim 3. The drill (20) has a protrusion (29) provided at a lower end of the through passage (28) and exposed to the through passage (28),
The bag-shaped object (40) is filled with the same curable material as the curable material or a curable material having a higher curable property than the curable material,
The pressure feeding step (S30)
A bag breakage step of breaking the bag-shaped object (40) pumped in the through passage (28) by the protrusion (29);
Thereby, the hardened material filled in the bag-shaped object (40) is diffused in the vicinity of the bottom surface of the hole formed by the drill (20).
The pile construction method according to claim 4.

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