JP2013019260A - Drilling equipment and construction method for sheet pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide drilling equipment capable of rapidly and reliably performing construction of a sheet pile in hard soil.SOLUTION: Drilling equipment 1 has a hammer bit 14 attached to a rod, which is supported in such a rotatively driveable manner, via a down-the-hole hammer 12, and drills a hole by applying an impact on soil while making the hammer bit 14 rotated by an operation of the down-the-hole hammer 12. The plurality of hammer bits 14 are provided. Each of the hammer bits 14 has its center of gravity positioned on a rotational axis. The hammer bits are arranged in different height positions so that the adjacent hammer bits cannot overlap each other and interfere with each other in a plan view.

Description

  The present invention relates to a drilling device for drilling a ground and a sheet pile construction method.

  A drilling device having a down-the-hole hammer is known for drilling hard ground such as rock. For example, Patent Document 1 discloses a drilling device that can attach a drill bit to a down-the-hole hammer provided on a main shaft, and can build a sheet pile while drilling by a rotary hitting action of the drill bit. Patent Document 1 also discloses a configuration in which a plurality of excavation bits are provided, and is capable of handling sheet piles of various shapes and sizes.

Since the excavation apparatus disclosed in Patent Document 1 is configured to excavate by engaging a driving sheet pile with the preceding sheet pile so that a previously installed sheet pile can be drilled as a guide, In order to prevent interference with a sheet pile when the excavation bit is pulled out after being built, it is an essential constituent requirement that the bit body of the excavation bit be eccentric. However, the excavator provided with such an eccentric excavation bit has a problem of strength and durability of the excavation bit and a problem that a sufficient excavation speed cannot be obtained due to vibration or the like. In particular, in a configuration including a plurality of down-the-hole hammers, since each down-the-hole hammer has a bit body that is eccentric, stable excavation is difficult.
On the other hand, Patent Document 2 discloses an excavator including an abutting portion that abuts on an existing pile so that the existing pile can be digged with two excavation drills using the existing pile as a guide. However, since this excavator drills only by rotating the drill, it is not suitable for drilling hard ground, and since the abutting portion is fixed, this abutting portion There was a risk that this could hinder excavation work.

JP-A-9-31980 JP-A-8-27776

  Then, this invention aims at provision of the drilling apparatus and the construction method of a sheet pile which can perform the construction of a sheet pile with respect to a hard ground quickly and reliably.

  The object of the present invention is that a hammer bit is attached to a rod supported so as to be capable of rotational drive via a down-the-hole hammer, and the hammer bit rotates to impact the ground and drill a hole while the hammer bit is rotated by the operation of the down-the-hole hammer. A plurality of hammer bits are provided, and each hammer bit has a different height so that the center of gravity of each hammer bit is located on the rotation axis, adjacent ones overlap in plan view and do not interfere with each other. This is achieved by a drilling device arranged in the vertical position.

  Preferably, the drilling device further includes a casing that houses the down-the-hole hammer and a base member that is detachably supported by the casing, and the base member engages with a section portion of an existing sheet pile. It is preferable that an engaging member is provided. In this configuration, the base member preferably includes a pair of halves that are coupled so as to cover the periphery of the casing, and the engagement member is provided only on one of the halves. Is preferred.

  Alternatively, it is preferable that the drilling device further includes a casing that houses the down-the-hole hammer, and the casing includes an engaging member that engages with a section portion of an existing sheet pile between an engaging position and a retracted position. It is preferable to support it so as to be movable. In this configuration, it is preferable that a plurality of the engaging members are provided, and it is preferable that the engaging member to be engaged is selectable depending on the direction of the existing sheet pile.

  Further, the object of the present invention is a method of constructing a sheet pile using the above-described drilling device, the step of applying a rotational impact to the ground by each of the hammer bits, and forming a continuous hole continuous with the preceding hole; And a step of building a sheet pile in the continuous hole by engaging a section section of a sheet pile newly provided to a section section of an existing sheet pile arranged in the preceding hole. .

  ADVANTAGE OF THE INVENTION According to this invention, the drilling apparatus and construction method of a sheet pile which can perform the construction of a sheet pile with respect to a hard ground quickly and reliably can be provided.

1 is an overall configuration diagram of a drilling device according to an embodiment of the present invention. It is a principal part side view of the hole drilling apparatus shown in FIG. It is AA sectional drawing of FIG. It is process drawing for demonstrating the construction method of the sheet pile using the drilling apparatus shown in FIG. It is principal part sectional drawing of the drilling apparatus which concerns on other embodiment of this invention. It is a top view which shows the sheet pile constructed by the drilling apparatus which concerns on other embodiment of this invention. It is principal part sectional drawing of the hole drilling apparatus which concerns on other embodiment of this invention. It is principal part sectional drawing which shows the other usage example of the hole drilling apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram of a drilling device according to an embodiment of the present invention. As shown in FIG. 1, the hole drilling device 1 is suspended and supported at the tip of a boom 4 of a mobile crane 2 so that an earth auger 6 can be raised and lowered. A multi-axis reduction gear 8 with a built-in gear is attached to the lower portion of the earth auger 6. The multi-axis speed reducer 8 is provided with a casing 10 made of a steel pipe that individually accommodates a plurality of rods (not shown) so as to hang down. The casings 10 can be fixed to each other by connecting blocks (not shown) arranged at appropriate intervals along the axial direction.

  A hammer bit 14 is attached to the lower end of the rod accommodated in each casing 10 via a down-the-hole hammer 12. The down-the-hole hammer 12 has a known configuration in which a hammer (not shown) built-in moves up and down when a fluid pressure such as compressed air is supplied to repeatedly hit the hammer bit 14. The casing 10 of the present embodiment is configured so as to cover most of the rod along the axis, but may be configured to accommodate the down-the-hole hammer 12 at the lower end of the rod, and is configured to expose most of the rod. May be.

  In the drilling device 1 having the above-described configuration, the rod in each casing 10 is rotated via the multi-axis speed reducer 8 by the operation of the auger motor of the earth auger 6, and the down-the-hole hammer 12 connected to each rod is rotated. . The hammer bit 14 rotates while receiving repeated impact force from the down-the-hole hammer 12 as the down-the-hole hammer 12 rotates. In this way, a hard ground such as a rock can be drilled by applying a rotational impact.

  FIG. 2 is a side view of the main part showing the hammer bit 14 of the drilling device 1 shown in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. The drilling device 1 according to the present embodiment includes five hammer bits 14. 2 and 3, in order to distinguish and display each hammer bit 14, subscripts a to e are attached to the respective symbols (how to add the subscripts a to e are different configurations in other drawings). The same applies to elements).

  As shown in FIGS. 2 and 3, each hammer bit 14 a to 14 e is formed in a cylindrical shape on the outer periphery and has substantially the same shape and size, and the outer diameter is larger than the outer diameter of the casings 10 a to 10 e. Largely formed. The gravity center positions of the hammer bits 14a to 14e coincide with the rotation axis that is the center of the casings 10a to 10e, and the hammer bits 14a to 14e are rotationally driven so as not to be eccentric.

  Each of the hammer bits 14a to 14e is provided so that adjacent ones overlap in plan view so as to form a continuous hole corresponding to the shape of the sheet pile to be built. The U-shaped steel sheet pile having Moreover, each hammer bit 14a-14e is arrange | positioned in a different height position, in order to prevent adjacent interference. The arrangement of the hammer bits 14a to 14e in the height direction is not particularly limited, but in the present embodiment, the heights of adjacent ones are alternately changed to form an upper and lower two-stage arrangement, and the two hammer bits 14a, 14c is arranged in the upper stage, and three hammer bits 14b, 14d, 14e are arranged in the lower stage.

  Each hammer bit 14a-14e is comprised so that each may rotate synchronously with the multi-axis reduction gear 8. FIG. In the present embodiment, the two hammer bits 14a, 14c arranged in the upper stage rotate in the same direction, whereas the three hammer bits 14b, 14d, 14e arranged in the lower stage rotate in the opposite direction. The adjacent hammer bits 14a to 14e are configured so as to alternately rotate in the forward / reverse synchronous manner.

  According to the drilling device 1 having the above configuration, the plurality of hammer bits 14a to 14e are different from each other so that the respective centers of gravity are located on the rotation axis, the adjacent portions overlap in plan view, and do not interfere with each other. Since it arrange | positions in a height position, the continuous hole with which the hole formed by each hammer bit 14a-14e was continued can be accurately formed in a desired shape in a desired position. Therefore, by pre-determining the arrangement of the hammer bits 14a to 14e in accordance with the shape of the sheet pile to be built, it becomes possible to build the sheet pile by a single drilling operation, and to speed up the work. Can increase the performance and certainty.

  In the present embodiment, each of the hammer bits 14a to 14e rotates in the opposite direction between the upper and lower stages, and the lower hammer bits 14b, 14d, and 14e that come into contact with the ground first at the time of drilling are More than the upper hammer bits 14a and 14c having lower excavation resistance than the upper hammer bits 14a and 14c, the rotational reaction force received by each of the hammer bits 14a to 14e can be easily balanced between the upper and lower stages. Formation can be performed reliably. The arrangement of the hammer bits in the height direction may be three or more stages, and it is preferable to increase the number of hammer bits arranged in the lower stage. However, it is possible to adopt a configuration in which the number of lower hammer bits is smaller than that of the upper hammer bits.

  FIG. 4 is a process diagram for explaining a sheet pile construction method using the above-described hole drilling device 1. As shown to Fig.4 (a), the continuous hole SH1 which consists of a some hole is formed in the ground, and the drilling apparatus 1 of this embodiment is in the state in which the existing U-shaped steel sheet pile 50a exists in this continuous hole SH1. 4 (b), a new continuous hole is formed so as to be adjacent to the preceding hole Hd (a part of the continuous hole SH1) where the section (joint) 54a of the U-shaped steel sheet pile 50a is located. SH2 is formed. The continuous hole SH2 is formed by connecting a plurality of holes Ha to He, and the holes Ha to He are formed by hammer bits 14a to 14e, respectively.

  Next, as shown in FIG. 4C, the U-shaped steel sheet pile 50b is built into the formed continuous hole SH2. The newly provided U-shaped steel sheet pile 50b is disposed so as to be opposite to the existing U-shaped steel sheet pile 50a in the vertical direction in the figure, and a new U-shaped steel sheet is provided on the section portion 54a of the existing U-shaped steel sheet pile 50a. One section 52b of the sheet pile 50b is engaged and driven by a known method.

  Thereafter, as shown in FIG. 4D, a new continuous hole SH3 is formed so as to be adjacent to the preceding hole He where the other section portion 54b of the built sheet pile 50b is located. And as shown in FIG.4 (e), the new U-shaped steel sheet pile 50c is arrange | positioned so that it may become reverse direction with the existing U-shaped steel sheet pile 50b, and the section part 54b of the existing U-shaped steel sheet pile 50b. Then, driving is performed by engaging one section 52c of a new U-shaped steel sheet pile 50c.

  Thus, according to the construction method of the sheet pile of this embodiment, since each hammer bit 14a-14e is arrange | positioned so that the continuous hole along the shape of a U-shaped steel sheet pile may be formed, drilling area is reduced. It can be suppressed to the minimum necessary, and work efficiency can be improved. In addition, regardless of the orientation of the U-shaped steel sheet pile, the section portion of the U-shaped steel sheet pile can be accommodated in either the hole Hd or He that constitutes a part of the continuous hole. In this respect, the workability can be improved.

  As shown in FIG. 5, the hole drilling device 1 of the present embodiment is a casing that houses the down-the-hole hammer 12 a for the hammer bit 14 a (see FIGS. 2 and 3) that forms a hole Ha adjacent to the preceding hole when drilling. The engaging members 20a and 20b may be provided in the lower part of 10a. The two engaging members 20a and 20b shown in FIG. 5 are supported on the casing 10a by the rotating shafts 22a and 22b on the base end side, and hook portions 24a and 24b engageable with the section portion of the sheet pile on the distal end side. It is provided and is rotatable in the direction of arrow B. Further, thick reinforcing portions 26a and 26b are formed at the centers of the engaging members 20a and 20b. Notches are formed on the outer surfaces of the casings 10a and 10b. When the engaging members 20a and 20b are in the retracted position shown in FIG. 5, the contours of the holes Ha and Hb (that is, the hammer bits 14a and 14b) The whole of the engaging members 20a and 20b is accommodated inside the outer periphery), thereby avoiding an obstacle to the drilling operation. Then, when the engaging members 20a and 20b are rotated to the engaging position (indicated by the broken line for one engaging member 20b in FIG. 5), the hook portions 24a and 24b are engaged with the section portions of the existing sheet piles. Can do.

  According to the configuration shown in FIG. 5, when performing the drilling operation using the section portion of the existing sheet pile as a guide, the engagement members 20 a and 20 b to be engaged with the section portion can be appropriately selected, so that it is quick and reliable. Work becomes possible. For example, when the continuous hole SH2 shown in FIG. 4B is formed, one engagement member 20a shown in FIG. 5 is arranged at the retracted position, and the other engagement member 20b is rotated to the engagement position. Let Thereby, the hook part 24b of the other engagement member 20b can be engaged with the section part (joint) 54a of the U-shaped steel sheet pile 50a to perform the drilling operation, and the one engagement member 20a includes the holes Ha, It can be contained inside Hb.

  When the continuous hole SH3 shown in FIG. 4D is formed, one engagement member 20a shown in FIG. 5 is rotated to the engagement position, and the other engagement member 20b is arranged at the retracted position. By doing so, the hook part 24a of one engagement member 20a can be engaged with the section part (joint) 54b of the U-shaped steel sheet pile 50b, and a hole drilling operation can be performed. As described above, the engagement member to be engaged with the section portion of the sheet pile can be selected according to the direction of the sheet pile so that the drilling operation can be performed smoothly. In the present embodiment, the engagement members 20a and 20b are rotatably supported, so that the engagement member can be moved between the engagement position and the retracted position. The structure which can advance / retreat between may be sufficient. Further, the number of engaging members may be three or more according to the shape of the sheet pile, or even if it is a single member, there is an advantage that it can be retracted when not in use.

  The sheet pile to be constructed may have any shape other than the U-shaped steel sheet pile of this embodiment, and the plurality of hammer bits can be arranged with a high degree of freedom according to the shape of the sheet pile. For example, as shown in FIG. 6, when constructing a steel pipe sheet pile 60 having section portions 62 and 64 on the left and right sides of the steel pipe main body 61, a large-diameter hole Hx and a small-diameter hole Hy adjacent to the hole Hx. Then, a continuous hole SH can be formed by combining two medium-diameter holes Hz1 and Hz2 adjacent to the hole Hy. In the continuous hole SH, the steel pipe main body 61 is accommodated in the large-diameter hole Hx, and one section portion 62 is accommodated in the small-diameter hole Hy. Further, in the medium-diameter holes Hz1 and Hz2, a new continuous hole (not shown) is formed so as to be continuous therewith, so that a section portion of a new steel pipe sheet pile that engages with the accommodated section portion 62. Is housed.

  As shown in FIG. 7, the hole drilling device 1 of the present embodiment is a casing that houses the down-the-hole hammer 12 a for the hammer bit 14 a (see FIGS. 2 and 3) that forms a hole Ha adjacent to the preceding hole when drilling. The base member 40 may be configured to be detachably supported at the lower portion of 10a. In the configuration shown in FIG. 7, the same components as those in FIG. The casings 10a to 10e are integrated and reinforced by a hammer case 30 that is externally fitted so as to cover them.

  The base member 40 includes a pair of halves 41 and 42 having a semicircular inner peripheral surface. One end side of the pair of halves 41 and 42 is connected via a hinge 43 so as to be opened and closed. The other end sides of the pair of halves 41 and 42 are detachably attached to the hammer case 30 by means of connecting members 44 and 45 such as bolts, whereby the pair of halves 41 and 42 has the entire inner surface of the hammer case. It adhere | attaches on the surface of 30 and is couple | bonded so that the circumference | surroundings of the casing 10a may be covered. In the configuration shown in FIG. 7, the base member 40 is supported by the casing 10 a via the hammer case 30, but the base member 40 may be configured to be directly attached to the thick part of the casing 10 a or the like. .

  In the base member 40, the engaging member 46 is provided only in one half body 41. The engaging member 46 is formed so as to protrude from the outer surface of the half body 41, and has an abutting surface 47 that matches the outer surface shape of the section portion 54 of the U-shaped steel sheet pile 50 shown by a broken line in FIG. ing.

  According to the configuration shown in FIG. 7, when the engaging member 46 is unnecessary, such as when a continuous hole is newly provided, the engaging member 46 hinders the drilling operation by removing the base member 40 from the casing 10a. Can be prevented. And when forming the continuous hole SH2 shown in FIG.4 (b), as shown in FIG. 7, by attaching the base member 40 to the casing 10a, in the section part 54 of the existing U-shaped steel sheet pile 50, The abutting surface 47 of the engaging member 46 can be brought into contact with each other and engaged, and a drilling operation can be performed using the U-shaped steel sheet pile 50 as a guide. On the other hand, when the continuous hole SH3 shown in FIG. 4D is formed, as shown in FIG. 8, the base member 40 is reversed and attached to the casing 10a, so that the hole drilling operation is performed in the same manner as described above. It can be carried out. Thus, the base member 40 provided with the engaging member 46 is configured to be detachably supported by the casing 10a, so that the engaging member 46 can be reliably disposed at a desired position with respect to the casing 10a. Therefore, an accurate drilling operation can be performed.

DESCRIPTION OF SYMBOLS 1 Drilling apparatus 10 Casing 12 Down-the-hole hammer 14 Hammer bit 20 Engagement member 40 Base member 41, 42 Half split body 46 Engagement member 50 Sheet pile 52, 54 Section part SH Continuous hole

Claims (6)

A drilling device in which a hammer bit is attached to a rod supported so as to be rotationally driven through a down-the-hole hammer, and the hammer bit is rotated by impacting the ground while rotating by the operation of the down-the-hole hammer,
A plurality of the hammer bits are provided,
Each said hammer bit is a drilling apparatus by which each gravity center is located on a rotating shaft, adjacent each other overlaps by planar view, and is arrange | positioned in a different height position so that it may not mutually interfere. A casing that houses the down-the-hole hammer, and a base member that is detachably supported by the casing;
The drilling device according to claim 1, wherein the base member is provided with an engaging member that engages with a section portion of an existing sheet pile. The base member includes a pair of halves that are coupled so as to cover the periphery of the casing;
The drilling device according to claim 2, wherein the engagement member is provided only on one side of the half body. A casing for accommodating the down-the-hole hammer;
The said casing is a drilling apparatus of Claim 1 which supports the engaging member engaged with the section part of the existing sheet pile so that a movement is possible between an engagement position and a retracted position. A plurality of the engaging members are provided,
The drilling device according to claim 4, wherein the engaging member to be engaged is selectable depending on the direction of an existing sheet pile. A method of constructing a sheet pile using the drilling device according to claim 1,
Applying a rotational impact to the ground by each of the hammer bits to form a continuous hole continuous with the preceding hole;
A method for constructing a sheet pile comprising: engaging a section portion of a sheet pile newly provided to a section portion of an existing sheet pile disposed in the preceding hole to build the sheet pile into the continuous hole.

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