JP5380142B2 - Expanded bucket, casing, and expanded pile construction method - Google Patents

Description

  The present invention relates to a bottom-up bucket for forming a bottom-enlarged portion that is larger than a shaft portion at a bottom portion of a pile, a casing used with the bottom-up bucket, and construction of a bottom-up pile using these bottom-up bucket and casing. It is about the method.

  Conventionally, an all casing method has been used to construct a high-quality pile regardless of the properties of the ground.

  In this all-casing method, a cylindrical casing is rotationally press-fitted over the entire length of the excavation hole with an all-around rotating machine, and the earth and sand in the casing is excavated and discharged with a hammer grab to reach the ground of a predetermined depth. Perform hole bottom treatment. And it is a construction method which constructs a pile by driving in concrete by treme after building a reinforcing bar and pulling out and collecting a casing and treme with this concrete driving.

  Moreover, in this all casing construction method, when making a supporting force larger, the bottom expanded pile which formed the expanded bottom part expanded rather than the axial part in the part used as the bottom part of a pile is made | formed.

  Furthermore, in order to form a widened part that is larger than the shaft part in the part that becomes the bottom part of the pile, the bottomed bucket is attached to the lower part of the casing, and this widened bucket is rotated together with the casing to excavate the surrounding ground. (See Patent Document 1 and the like).

JP 2005-61205 A

  However, in the conventional bottomed bucket as described above, a hydraulic grip is provided on the upper part in order to take a reaction force necessary for excavation from the casing, and this hydraulic grip is hydraulically connected through a long hydraulic hose. It has a complicated configuration in which a hydraulic unit that performs control is connected.

  For this reason, there is a problem that it takes time just to attach the bottomed bucket to the lower part of the casing and the workability is poor.

  In addition, because of the complicated configuration, there is a high possibility of failure, and there is also a problem that it becomes expensive.

  Therefore, the present invention has an improved workability, a low possibility of failure, and a bottom expansion bucket that can be implemented at low cost, a casing used together with the bottom expansion bucket, and these bottom expansion buckets, as compared with the prior art. The purpose is to provide a method for constructing an expanded pile using a casing.

  In order to achieve the above object, a bottom expansion bucket according to the present invention is a bottom expansion bucket that is attached to a lower portion of a cylindrical casing having a cutting edge formed at a lower end portion and a locking portion, and is cylindrical. A main body portion, a widened wing portion that can be opened so as to increase the diameter of the main body portion, and when the widened wing portion is opened so as to expand, the engaging portion is engaged with the locking portion. A stopper portion provided at an upper portion of the main body portion, which is disengaged from the engaging portion when being pulled out from the casing, is provided.

  Here, the first bottom expanded bucket of the present invention is provided with a hanging portion connected to the hanging means on the upper portion of the stopper portion, and when the stopper portion is engaged with the locking portion. A stationary part that does not cause relative displacement with respect to the casing, a slide part that is provided on the suspension part and is slidable in the axial direction of the casing, and is movable in the axial direction with respect to the stationary part and A pin portion that can project toward the locking portion; a cam portion that connects the slide portion and the pin portion; and the cam portion is activated when the suspension portion is moved in the axial direction of the casing. It is characterized by.

  In the second widened bucket of the present invention, the lower end portion of the inner kelly bar of the kelly bar device in which the inner kelly bar is retractably accommodated in the outer kelly bar is connected to the upper portion of the main body, A suspension part connected to suspension means is provided at the upper end part of the inner kelly bar in the hollow part, and the stopper part is an outer periphery of the outer kelly bar of the kelly bar device engaged with the locking part of the casing. A stopper bar is provided so as to protrude from the surface in the radial direction.

  In addition, a transmission shaft portion that receives the force from the casing via the stopper portion is disposed inside the main body portion so as to be movable in the vertical direction of the main body portion, and is bent to the transmission shaft portion. It is preferable that the lower end of the coupling member coupled freely is connected to the widened wing portion.

  Further, the transmission shaft portion is slidably accommodated in a guide tube attached inside the main body portion, and a slide groove inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide tube. It is preferable that the connecting portion between the transmission shaft portion and the connecting member is protruded from the slide groove, and the transmission shaft portion is moved in the vertical direction using the connecting portion as a guide.

  Moreover, it is good for the protrusion part to be formed in the lower end of the said main-body part below the said widening wing | blade part.

  A first casing according to the present invention is a casing in which the above-described first bottomed bucket according to the present invention is attached to a lower portion thereof, and is formed at a cylindrical tubular body portion and a lower end portion of the tubular body portion. And a locking portion formed on the inner side surface in the vicinity of the lower end portion of the tubular body portion.

  Here, it is preferable that a guide protrusion that is tapered from above toward the locking portion is formed on the inner surface of the tubular body portion.

  The second casing of the present invention is a casing to which the above-described second bottom-enlarged bucket of the present invention is mounted at the upper part thereof, and has a cylindrical tubular body portion and an upper end portion of the tubular body portion. And a locking portion that protrudes in a hook shape.

  The construction method of the first expanded bottom pile of the present invention is a construction method of the expanded bottom pile that constructs the expanded bottom pile by using the first expanded bottom bucket of the present invention and the first casing of the present invention described above. A step of removing earth and sand in the casing while excavating the ground by the casing; a step of inserting the expanded bottom bucket into the casing by suspending it from an upper portion of the casing by a suspension means; The step of engaging the stopper portion with the locking portion of the casing that has been pulled up and mounting the bottom expansion bucket to the lower portion of the casing, and the widening wing portion of the bottom expansion bucket while rotationally press-fitting the casing Excavating the surrounding ground of the space not surrounded by the casing while opening the main body to increase the diameter of the main body, and from within the casing Serial 拡底 by lifting the bucket the hanging means, characterized in that it comprises a step of taking out the 拡底 bucket from the top of the casing.

  The construction method of the second expanded bottom pile of the present invention is a construction method of the expanded bottom pile that constructs the expanded bottom pile by using the second expanded bottom bucket of the present invention and the second casing of the present invention described above. A step of removing earth and sand in the casing while excavating the ground by the casing; a step of inserting the expanded bottom bucket into the casing by suspending it from an upper portion of the casing by a suspension means; While rotating and press-fitting the casing pulled up long, the stopper portion is engaged with the locking portion of the casing, and the widened wing portion of the bottomed bucket mounted on the upper portion of the casing is changed to the diameter of the main body portion. Excavating the surrounding ground in the space not surrounded by the casing while opening it so as to expand, and extending the bottomed bucket from the casing And lifting by means, characterized by comprising a step of taking out the 拡底 bucket from the top of the casing.

  Such a widened bucket of the present invention is a widened bucket that is attached to the lower part of a cylindrical casing having a cutting edge formed at the lower end portion and a locking portion, and a cylindrical main body portion and When the widening wing is formed so as to be openable so as to increase the diameter of the main body, and when the widening wing is opened so as to expand, the engaging portion is engaged. The stopper portion is provided on the upper portion of the main body portion from which the engagement with the locking portion is released.

  Because of this structure, it is possible to take the reaction force required for excavation to form the expanded base part from the casing without requiring a complicated structure such as hydraulic control. The possibility of failure is low, and furthermore, it can be implemented inexpensively.

  Here, as for the 1st bottom expansion bucket of this invention, the suspension part connected to a suspension means is provided in the upper part of the stopper part.

  The stopper portion is provided on the stationary portion that does not cause relative displacement with respect to the casing when engaged with the locking portion, the sliding portion that is slidable in the axial direction of the casing, and the stationary portion. On the other hand, it has a pin part that can move in the axial direction and can protrude toward the locking part, and a cam part that connects the slide part and the pin part, and the suspension part is moved in the axial direction of the casing. The cam portion is configured to operate.

  For this reason, the structure which can take the reaction force required for the excavation for forming an expanded bottom part from a casing can be implement | achieved simply and cheaply, without requiring complicated structures, such as hydraulic control.

  Further, the second bottom expanded bucket of the present invention is connected to the upper portion of the main body portion at the lower end portion of the inner kelly bar of the kelly bar device in which the inner kelly bar is retractably accommodated in the outer kelly bar, and in the hollow portion of the kelly bar device. A suspending portion connected to the suspending means is provided at the upper end portion of the inner kelly bar.

  And the stopper part is set as the structure provided with the stopper bar projected in the radial direction from the outer peripheral surface of the outer kelly bar of the kelly bar apparatus engaged with the latching | locking part of a casing.

  For this reason, the structure which can take the reaction force required for excavation for forming a bottom expanded part from a casing, without requiring complicated composition, such as hydraulic control, like the 1st bottom expanded bucket of the present invention, It can be realized simply and inexpensively.

  In addition, a transmission shaft portion that receives a force from the casing via the stopper portion is disposed inside the main body portion so as to be movable in the vertical direction of the main body portion, and is flexibly connected to the transmission shaft portion. When the lower end of the connecting member is connected to the widened wing, the structure that opens to widen the widened wing can be simplified and inexpensive without requiring a complicated configuration such as hydraulic control. .

  Further, the transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion, and a slide groove inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide tube. When the connecting portion between the transmission shaft portion and the connecting member is protruded from the slide groove and the transmission shaft portion is moved in the vertical direction using it as a guide, the widened wing portion can be opened and closed smoothly without difficulty.

  In addition, when a protruding part is formed at the lower end of the main body part below the widened wing part, when the widened wing part is opened to expand, the reaction force of the ground acts on the main body part greatly. However, since the position of the lower end is not displaced by being constrained by the ground by the projecting portion, the widened portion can be formed in a desired accurate shape without being shifted to one side.

  Such a first casing of the present invention is a casing in which the above-mentioned first bottomed bucket of the present invention is attached to the lower part thereof, and is formed in a cylindrical tube portion and a lower end portion of the tube portion. It is set as the structure provided with the cutting blade formed and the latching | locking part formed in the inner surface near the lower end part of a tubular-body part.

  With such a configuration, the bottom expansion bucket can take a reaction force required for excavation for forming the bottom expansion portion by engaging the stopper portion with the locking portion.

  Here, when a guide projection that tapers from the upper side toward the locking portion is formed on the inner side surface of the tubular body portion, the position of the stopper portion of the bottom expansion bucket is engaged with the locking portion. Even if a special operation for matching is not performed, the stopper portion can be engaged with the locking portion by being guided by the guide protrusion.

  Such a second casing of the present invention is a casing to which the above-described second bottom expansion bucket of the present invention is mounted at the upper part thereof, and has a cylindrical tube portion and an upper end portion of the tube portion. And a locking portion formed so as to protrude upward in a bowl shape.

  Since it is such a structure, a bottom expansion bucket can take the reaction force required for excavation for forming a bottom expansion part by engaging a stopper part with a latching | locking part like the 1st casing of this invention.

  Such a construction method of the first expanded bottom pile of the present invention is a method of constructing an expanded bottom pile using the above described first expanded bottom bucket of the present invention and the above described first casing of the present invention. It is a construction method, the step of removing earth and sand in the casing while excavating the ground with the casing, the step of inserting the expanded bucket into the casing by suspending it from the upper part of the casing by the suspension means, and raising the required length Engaging the stopper with the locking portion of the casing and attaching the bottom expansion bucket to the lower portion of the casing; and rotating and press-fitting the casing while expanding the diameter of the main body portion of the widening wing of the bottom expansion bucket Excavating the surrounding ground in the space not surrounded by the casing while being opened, and lifting the expanded bucket from the casing by the suspension means, It has a configuration in which a step of taking out the 拡底 bucket from above.

  Since it is such a structure, since the above-described first bottom expansion bucket of the present invention and the above-described first casing of the present invention are used, a high-quality bottom expansion is achieved in a shorter construction period and at a lower cost than in the prior art. Pile can be built.

  Such a construction method of the second expanded bottom pile of the present invention is a method of constructing an expanded pile using the above-described second expanded bottom bucket of the present invention and the above-described second casing of the present invention. In the construction method, while rotating and press-fitting a casing whose length has been increased, a stopper portion is engaged with a locking portion of the casing, and the widened wing portion of the bottomed bucket mounted on the upper portion of the casing is changed to the diameter of the main body portion. It is set as the structure provided with the process of excavating the surrounding ground of the space part which is not enclosed with a casing, making it open | release so that may be expanded.

  With such a configuration, the above-described second bottom expansion bucket of the present invention and the above-described second casing of the present invention are used. Therefore, compared with the prior art, the bottom expansion can be performed in a short period of time and at a low cost with a high quality. Pile can be built.

It is a longitudinal cross-sectional view which shows schematic structure of the construction apparatus of the bottom expanded pile in Example 1. FIG. In Example 1, it is explanatory drawing which shows the step which built the casing in the ground. FIG. 3 is an enlarged sectional view taken along line B-B in FIG. 2. It is a perspective view which shows schematic structure of the upper part of the bottom expansion bucket of Example 1. FIG. It is a top view of the construction apparatus of the bottom expanded pile of FIG. In Example 1, it is explanatory drawing which shows the step which suspends and inserts a bottom expansion bucket in a casing. In Example 1, it is explanatory drawing which shows the step which fitted the pin part of the stopper part in the latching hole of a casing. In Example 1, it is explanatory drawing which shows the step which pulls up a bottom expansion bucket after excavating a bottom expansion part. It is explanatory drawing for demonstrating the widening range of the widening wing | blade part in Example 1. FIG. (A) is an enlarged detailed view for demonstrating the excavation shape of a roller bit, (b) is an enlarged detailed view for demonstrating the excavation shape of a cutting-plate blade part. It is an AA arrow expanded sectional view in FIG. It is a figure explaining the structure of the guide cylinder of the bottom expansion bucket in Example 2, Comprising: (a) is DD sectional view taken on the line of (b), (b) is C- of (a). FIG. It is a longitudinal cross-sectional view which shows schematic structure of the construction apparatus of the bottom expanded pile in Example 3. FIG. In Example 3, it is explanatory drawing which shows the step which built the casing in the ground. It is a top view of the construction apparatus of the bottom expanded pile of FIG. In Example 3, it is explanatory drawing which shows the step which fitted the stopper bar of the stopper part in the latching notch of a casing. In Example 3, it is explanatory drawing which shows the step which pulls up a bottom expansion bucket, after excavating a bottom expansion part.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on Examples 1-3 shown in drawing.

  First, the structure of the construction apparatus of the expanded pile of Example 1 is demonstrated.

  As shown in FIG. 1, the construction apparatus for a bottomed pile according to the first embodiment is mainly configured by a cylindrical casing 2 and a bottomed bucket 1 attached to a lower portion of the casing 2.

  This casing 2 is rotationally press-fitted into the ground by an all-round rotating machine (not shown) connected in the vicinity of the upper end of the casing 2 and connected to a plurality of axial directions, and the length of the excavation hole necessary for constructing a bottomed pile Used as is.

  Here, as shown in FIG. 2, the casing 2 includes a cylindrical tube portion 2A, cutting edges 2a formed at the lower end of the tube portion 2A, and a lower end of the tube portion 2A. And a locking hole 2b as a locking portion formed so as to penetrate from the inner side surface near the portion to the outer side surface.

  Moreover, in this Example 1, the three locking holes 2b are provided at equal intervals in the circumferential direction of 2 A of pipe parts of the casing 2. As shown in FIG.

  Furthermore, as shown in FIG. 3, guide protrusions 2 c that taper from the upper side toward the respective locking holes 2 b are formed on the inner surface of the tubular body portion 2 </ b> A of the casing 2.

  The bottomed bucket 1 expands the cylindrical main body 1A, the two widened wings 12 and 12 formed so as to be openable so as to increase the diameter of the main body 1A, and the widened wings 12 and 12. The main body is engaged with the three locking holes 2b serving as the locking portions of the casing 2 when being opened, and is released from the engagement with the locking holes 2b when being pulled out from the casing 2. The stopper part 3 provided in the upper part of 1A and the suspension part 7 provided in the upper part of the stopper part 3 connected to the wire W as a suspension means are provided.

  First, as shown in FIG. 4, the stopper portion 3 constitutes a stationary sheath tube 31 as a stationary portion that does not relatively displace in the horizontal direction when the bottom expansion bucket 1 is inserted into the casing 2, and a suspension portion 7. A slide cylinder 71 serving as a slide portion slidable in the axial direction of the casing 2 and the inside of the fixed sheath tube 31 are movable in the axial direction and can protrude toward the locking hole 2 b of the casing 2. The pin part 32 and the cam part 33 which connects the slide cylinder 71 and the pin part 32 are provided.

  Further, the three stationary end portions of the stationary sheath tube 31 are fixed at equal intervals in the circumferential direction around the cylindrical support portion 34 in plan view, and the pin portions 32 protrude from the respective front end portions. It is possible (see also FIG. 5).

  Further, the slide cylinder 71 is formed by integrating an upper reduced diameter portion 71b in which a suspension means connection portion 71c to which a wire W is connected is formed on an upper surface and a lower enlarged diameter portion 71a.

  In addition, an accommodating cylinder 72 having a donut-shaped flange portion 72a formed on the upper side is provided on the upper portion of the support portion 34.

  The inside of the housing cylinder 72 accommodates the enlarged diameter portion 71a of the slide cylinder 71, the slide cylinder 71 can be slid in the axial direction of the casing 2, and the slide width is limited by the flange portion 72a. Has been.

  Further, around the enlarged diameter portion 71 a of the slide cylinder 71, three upper cam plates 71 d are provided so as to protrude in the horizontal direction corresponding to the stationary sheath pipe 31. Guide holes 72b for allowing the upper cam plate 71d to follow the slide of the slide cylinder 71 are provided.

  Further, a lower cam plate 32 a is provided on the upper portion of the pin portion 32 so as to protrude in the vertical direction, and the lower cam plate 32 a is provided on the pin portion 32 on each upper portion of the stationary sheath tube 31. Each of the guide holes 31a is provided so as to be able to follow this movement.

  A donut-shaped support plate 35 that supports the bottom of the stationary sheath tube 31 is provided around the support portion 34.

  Further, a pair of chevron-shaped support plates 36, 36 are provided on the upper surface of the support plate 35 so as to be vertically raised with the stationary sheath tube 31 interposed therebetween, and in the vicinity of the top portion between the pair of support plates 36, 36. Thus, an L-shaped cam 37 composed of an inward portion 371 facing inward and a downward portion 372 facing downward is rotatably supported by a shaft 38.

  A notch 37a that is slightly wider than the upper cam plate 71d is formed in the inward portion 371 of the cam 37, and the upper cam plate 71d is fitted in the notch 37a. A notch 37b that is slightly wider than the lower cam plate 32a is formed, and the lower cam plate 32a is fitted into the notch 37b to form the cam portion 33.

  The lower end portion of the support portion 34 and the upper end portion of the transmission shaft portion 14 extending from above the main body portion 1A are connected and fixed by fastening the connecting flange 16 with bolts and nuts.

  Furthermore, the space between the support plate 35 and the connecting flange 16 is reinforced by reinforcing plates 17A and 17B.

  On the outer surface of the support plate 36, as shown in FIG. 5, a guide roller 18 having a suspension 18a is provided so that the bottomed bucket 1 can be smoothly inserted into the casing 2 and pulled out from the casing 2. Are provided.

  In FIG. 4, the description of the guide roller 18 is omitted for easy understanding of the description of the cam portion 33.

  In this way, as shown in FIG. 2, while the casing 2 is rotationally press-fitted into the ground, the earth and sand in the casing 2 is excavated and removed by a hammer grab (not shown), and the casing 2 is built to a predetermined depth.

  Then, after raising the casing 2 to the required length, when the bottomed bucket 1 is suspended and inserted into the casing 2 by the wire W as shown in FIG. 6, as shown in FIG. The tip is guided to the tapered portion by the guide protrusion 2c, the tension of the wire W is lost, the cam portion 33 is operated, and the pin portion 32 protrudes and fits toward the locking hole 2b. Is attached to the lower part of the casing 2.

  Thereafter, when the bottom-extended portion of the bottom-extended pile has been excavated and the bottom-extended bucket 1 is lifted from the casing 2 by the wire W as shown in FIG. 8, the cam portion 33 is activated and the locking hole 2b. The pin portion 32 fitted to the inner wall of the fixed sheath tube 31 is accommodated in the fixed sheath tube 31, so that the bottomed bucket 1 can be easily lifted smoothly from the casing 2.

  On the other hand, as shown in FIG. 6, the main body 1 </ b> A of the bottomed bucket 1 is formed to have a diameter that can be inserted into the casing 2, and an annular stabilizer 4 is disposed on the top.

  Further, as shown in FIGS. 6 and 7, the widening wing parts 12 and 12 are closed to form a part of the side surface of the cylindrical main body 1 </ b> A when the bottomed bucket 1 is suspended. As shown in FIG. 1, the casing 2 is opened when the rotary press-fitting is performed again, and the excavation wall surface 6 is cut and widened.

  Furthermore, the widening wings 12 and 12 are closed to form part of the side surface of the cylindrical main body 1A as shown in FIG.

  As shown in FIG. 1, the widened wing portion 12 is formed with a constant width portion 12a having a substantially constant width near the lower end, and a triangular portion 12b having a tapered shape at the upper portion thereof. As shown in FIG. 9, it is formed in a circular arc shape in plan view.

  The uniform width portion 12a is formed to a height of, for example, about 500 mm, and a portion cut by the uniform width portion 12a becomes a bottom plate of an expanded pile having a thickness of about 500 mm.

  Further, as shown in FIG. 1, a plurality of roller bits 121,... Are provided at the side end portion of the widened wing portion 12 at intervals in the extending direction of the side end portion.

  As shown in FIG. 10A, the roller bit 121 is attached so that the bead-shaped bit portion 121a of the abacus rotates around a shaft 121b fixed to the side end portion.

  Furthermore, the excavation wall surface 6 cut by the roller bits 121,... And the fixed bit 122 may be uneven as shown in FIG. When the formation is desired, the bottomed bucket 1 is once lifted to remove the excavating blade to which the roller bits 121,... Are fixed from the attaching / detaching portion 124, and instead, a plate-shaped cutting plate blade as shown in FIG. The excavation wall surface 6 is excavated again by fixing the portion 123 to the side end portion of the widened wing portion 12 via the attaching / detaching portion 124.

  In addition, a plurality of fixed bits 122 having a smaller amount of lateral protrusion than the roller bit 121 are fixed between the roller bit 121 and the roller bit 121.

  That is, the roller bit 121 protrudes outward from the fixed bit 122, and the roller bit 121 comes into contact with the excavation wall surface 6 first to cut the ground into a groove shape.

  Further, since the roller bit 121 rotates around the shaft 121b, the generation of excessive stress can be suppressed by rotating when the roller bit 121 is in contact with the hard ground.

  As shown in FIG. 1, the main body 1 </ b> A has a notch 11 a that can accommodate the roller bits 121,... And the fixed bits 122,. Is formed.

  And the lower end of the connection member 141 is being fixed to the inner surface below this widening blade part 12, and the widening blade part 12 opens and closes by the force which acts via the connection member 141.

  That is, as shown in FIGS. 1 and 4, the transmission shaft portion 14 to which the lower end portion of the support portion 34 is connected is accommodated in the main body portion 1 </ b> A, and is connected to the lower end of the transmission shaft portion 14. The upper end of the member 141 is connected to be bent by a universal joint structure.

  Further, the transmission shaft portion 14 is accommodated in a cylindrical guide tube 15 having an open upper end, and is configured to be movable in the vertical direction (axial direction) of the main body portion 1A.

  .. Are fixed to the upper and lower portions of the outer peripheral surface of the guide cylinder 15 by welding or the like, and the other side of the mounting plate 151 is fixed to the inner surface of the main body 1A. Has been.

  Further, oval slide grooves 152, 152 extend in the longitudinal direction of the guide cylinder 15 on the opposing peripheral surface portions of the guide cylinder 15, and are connected to the transmission shaft portion 14 from the slide grooves 152, 152. A connecting bar 142 as a connecting portion for connecting the member 141 is projected.

  As shown in FIG. 11 (an enlarged cross-sectional view taken along line AA in FIG. 1), the connecting bar 142 is fitted into a hole that penetrates in a direction orthogonal to the axis near the lower end of the cylindrical transmission shaft portion 14. The reinforcing tube 14a is inserted.

  Both ends of the connecting bar 142 are projected from the slide grooves 152, 152, and cylindrical reinforcing covers 142a, 142a are attached to the projected both ends, respectively.

  Then, when the casing 2 is rotated in the R direction in FIG. 11, the rotational force is transmitted to the transmission shaft portion 14 to rotate the transmission shaft portion 14, and the reinforcing covers 142 a and 142 a attached to the connecting bar 142 that rotates accordingly. Pushes and rotates the guide cylinder 15, and the main body 1 </ b> A is rotated by the rotational force transmitted through the mounting plates 151 attached to the guide cylinder 15.

  The upper ends of connecting members 141 and 141 extending in opposite directions are fixed to the reinforcing covers 142a and 142a, respectively, so as to be freely bent.

  Further, as shown in FIG. 1, the lower end of the connecting member 141 is flexibly connected to a fixing portion 141 a attached to the inner surface of the widened wing portion 12.

  As shown in FIGS. 6 to 8, the widened bucket 1 configured as described above has the reinforcing cover 142 a of the connecting bar 142 in the slide groove when the transmission shaft portion 14 is pulled up with respect to the main body portion 1 </ b> A. Positioned at the upper end of 152, the connecting member 141 stands up and the widened wings 12, 12 are closed.

  When the transmission shaft portion 14 moves downward from this state, the reinforcing cover 142a is lowered along the slide groove 152, and the upper and lower universal joints of the connecting member 141 are bent, so that the connecting member 141 is inclined and the widened blades are bent. The parts 12, 12 are pushed sideways and opened (see FIG. 1).

  FIG. 9 is a plan view showing a state in which one widened blade 12 is opened and the other widened blade 12 is closed in order to explain the movement of the widened blades 12, 12. However, the widened wings 12 and 12 open and close at the same time.

  As shown in FIG. 9, the widened wing portion 12 can form an annular widened portion having a width substantially the same as the diameter before widening, in other words, the maximum widened portion 120 having a diameter nearly three times larger.

  Further, a closed blade stopper 125 is provided inside the main body 1A so as not to enter the inside of the widened wing 12 when the widened wing 12 is closed. The widened wing part 12 is stopped at a predetermined position by contacting the inner peripheral surface near the part.

  Furthermore, the lower end of the connecting member 141 is connected to the fixed portion 141a attached to the inner peripheral surface of the widened wing portion 12 so as to be freely bent. As shown in FIG. The extending direction of the connecting member 141 changes between when it is open and when it is closed.

  Further, as shown in FIG. 1, a projecting portion 13 is formed at the lower end of the main body portion 1 </ b> A below the widened wing portions 12, 12. For example, the protruding portion 13 having a height of about 200 mm to 600 mm is provided for the bottomed bucket 1 having a height of about 3 m.

  Further, a conical lid portion 131 is attached to the protruding portion 13 so as to be openable and closable. By opening the lid portion 131, the excavated earth and sand accumulated in the main body portion 1A can be discharged.

  Next, the construction method of the bottom expanded pile of Example 1 is demonstrated.

  First, as shown in FIG. 2, as shown in FIG. 2, the earth and sand in the casing 2 is removed by a hammer grab (not shown) while being rotationally pressed into the ground by an all-round rotating machine (not shown) connected in the vicinity of the upper end of the casing 2. Excavate, evacuate, and connect to multiple shafts, and build to the length of the excavation hole necessary to construct the expanded pile.

  Subsequently, the casing 2 is pulled up to the required length, and when the bottomed bucket 1 is inserted into the casing 2 by being suspended by the wire W as shown in FIG. 6, the casing 2 is locked as shown in FIG. The pin portion 32 of the stopper portion 3 is fitted into the hole 2 b, and the bottom expansion bucket 1 is attached to the lower portion of the casing 2.

  Subsequently, as shown in FIG. 1, the casing 2 is surrounded by the casing 2 while being rotationally press-fitted and opening the widened wings 12 and 12 of the bottomed bucket 1 so as to increase the diameter of the main body 1A. The surrounding ground is excavated from the excavation wall surface 6 of the empty space to form a space of the expanded portion of the expanded pile.

  Subsequently, as shown in FIG. 8, the widened bucket 1 is lifted from the casing 2 by the wire W, and the widened bucket 1 is taken out from the upper part of the casing 2.

  Finally, although not shown in the figure, after the reinforcing bar is built, concrete is driven by treme, and the casing 2 and treme are pulled out and collected as the concrete is driven.

  And the expanded pile is constructed by curing and solidifying the concrete.

  Next, the function and effect of the first embodiment will be described.

  The bottomed bucket 1 according to the first embodiment has a cylindrical casing 2 in which a cutting edge 2a is formed at the lower end and an engagement hole 2b as an engagement portion is formed on the inner surface near the lower end. It is the bottom expansion bucket with which the lower part is mounted | worn.

  When opening the cylindrical main body 1A, the widening wings 12 and 12 formed so as to be openable so as to increase the diameter of the main body 1A, and the widening wings 12 and 12, And a stopper portion 3 provided at the upper portion of the main body portion 1A that is engaged with the locking hole 2b of the casing 2 and is released from the engagement of the locking hole 2b when pulled out from the casing 2. It is configured.

  Because of such a configuration, the reaction force necessary for excavation for forming the expanded bottom portion can be taken from the casing 2 without requiring a complicated configuration such as hydraulic control. It is good, has a low possibility of failure, and can be implemented inexpensively.

  Here, an upper portion of the stopper portion 3 is provided with a suspension portion 7 to be connected to the wire W as a suspension means. When the stopper portion 3 is engaged with the engagement hole 2b as the engagement portion. An immovable sheath tube 31 as an immovable portion that does not cause relative displacement with respect to the casing 2, a slide cylinder 71 as a slide portion provided in the suspension portion 7 and slidable in the axial direction of the casing 2, and an immovable sheath tube 31 On the other hand, it is provided with a pin portion 32 that can move in the axial direction and can protrude toward the locking hole 2b, and a cam portion 33 that connects the slide cylinder 71 and the pin portion 32. When it is moved in the axial direction, the cam portion 33 operates.

  For this reason, the structure which can take the reaction force required for the excavation for forming an expanded bottom part from the casing 2 without requiring complicated structures, such as hydraulic control, can be implement | achieved simply and cheaply.

  A transmission shaft portion 14 that receives the force from the casing 2 via the stopper portion 3 is disposed in the main body portion 1A so as to be movable in the vertical direction of the main body portion 1A. The lower end of the connecting member 141 that is connected so as to be bent is connected to the widened wings 12 and 12.

  For this reason, also about the structure opened so that the wide wing | blade part 12 and 12 may be expanded, it can be made simple and cheap which does not require complicated structures, such as hydraulic control.

  Further, a protruding portion 13 is formed at the lower end of the main body portion 1 </ b> A below the widened wing portions 12, 12.

  For this reason, when the widened wings 12 and 12 are opened so as to expand, even if the reaction force of the ground acts greatly on the main body 1A, the lower end position is not displaced by being constrained by the ground by the protrusion 13. Thus, it is possible to form the widened portion in a desired accurate shape without shifting to one side.

  The casing 2 according to the first embodiment is a casing in which the above-described widened bucket 1 is attached to the lower part thereof.

  Then, a cylindrical tubular body portion 2A, a cutting edge 2a formed at the lower end portion of the tubular body portion 2A, and an engagement hole as an engagement portion formed on the inner surface near the lower end portion of the tubular body portion 2A 2b.

  With such a configuration, the bottom expanding bucket 1 can take a reaction force necessary for excavation for forming the bottom expanded portion by engaging the stopper portion 3 with the locking hole 2b.

  Here, a guide projection 2c that tapers from above to a locking hole 2b as a locking portion is formed on the inner surface of the tubular body portion 2A.

  For this reason, the stopper portion 3 is guided by the guide protrusion 2c without any special operation for aligning the stopper portion 3 of the bottomed bucket 1 so as to be engaged with the locking hole 2b. It can be made to engage with the stop hole 2b.

  In addition, since a plurality of casings 2 are connected and used, only the lowermost part needs to have such a configuration. Therefore, the entire casing 2 contributes to the cost reduction of the construction of the expanded pile.

  Such a method for constructing a bottomed pile according to Example 1 is a method for constructing a bottomed pile that constructs a bottomed pile using the above-described bottomed bucket 1 and the above-described casing 2.

  And the process of removing the earth and sand in the casing 2 while excavating the ground with the casing 2, and the process of suspending and inserting the bottom expansion bucket 1 into the casing 2 from the upper part of the casing 2 with the wire W as a suspension means And a step of engaging the stopper portion 3 with a locking hole 2b as a locking portion of the casing 2 which has been pulled up by a required length, and mounting the bottom expansion bucket 1 on the lower portion of the casing 2, while rotating and press-fitting the casing 2 The step of excavating the ground surrounding the space not surrounded by the casing 2 while opening the widened wings 12 and 12 of the bottomed bucket 1 so as to increase the diameter of the main body 1A, and the bottomed bucket 1 from within the casing 2 And a step of taking out the bottomed bucket 1 from the upper part of the casing 2.

  Since it is such a structure, since the above-described widened bucket 1 and the above-described casing 2 are used, a high-quality widened pile can be constructed in a shorter construction period and at a lower cost than in the prior art.

  Next, Example 2 will be described. In addition, the same code | symbol is attached | subjected and demonstrated about the description of the part same or equivalent to the content demonstrated in the said Example 1. FIG.

  In the second embodiment, as shown in FIG. 12, a case where a guide cylinder 15A having a slide groove 152A obliquely provided on the peripheral surface is used will be described.

  The guide tube 15A is a cylindrical tube member that is open at least at the top, and is fixed to the inner surface of the main body 11A via mounting plates 151A and 151B fixed to the upper and lower portions of the outer peripheral surface.

  Further, as shown in FIGS. 12A and 12B, a slide groove 152A inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide cylinder 15A.

  Cylindrical reinforcing pipes 153 and 153 are disposed and reinforced on both sides of the slide groove 152A.

  The guide tube 15A accommodates the transmission shaft portion 14 such that the reinforcing cover 142a of the connecting bar 142 provided at the lower end of the transmission shaft portion 14 protrudes from the slide groove 152A.

  When the transmission shaft portion 14 moves in the vertical direction while rotating, the protruding reinforcing cover 142a moves up and down while changing the direction. That is, as shown in FIG. 12B, the reinforcing cover 142a protrudes to the left in the drawing when it is in contact with the upper end of the slide groove 152A, and protrudes in the direction perpendicular to the paper surface when it is in contact with the lower end. To do.

  By configuring the reinforcing cover 142a to be connected to the connecting member 141 in this manner so as to move up and down while rotating around the guide cylinder 15A, it is possible to cancel the torsion that occurs when the widened wings 12 and 12 are opened and closed. The widened wings 12 and 12 can be smoothly opened and closed without generating excessive stress on the connecting member 141 or the universal joint.

  Other configurations and functions and effects are substantially the same as those of the first embodiment, and thus description thereof is omitted.

  Next, Example 3 will be described. In addition, the same code | symbol is attached | subjected and demonstrated about the description of the part same or equivalent to the content demonstrated in the said Example 1. FIG.

  First, the structure of the construction apparatus of the expanded pile of Example 3 is demonstrated.

  As shown in FIG. 13, the apparatus for constructing a bottomed pile according to the third embodiment is mainly configured by a cylindrical casing 20 and a bottomed bucket 10 mounted on an upper portion of the casing 20.

  The casing 20 is rotationally press-fitted into the ground by an all-around rotating machine (not shown) connected in the vicinity of the upper end of the casing 20 and connected to a plurality of shafts in the axial direction, and the length of the excavation hole necessary for the construction of the bottomed pile. Used as is.

  Here, as shown in FIG. 14, the casing 20 includes a cylindrical tubular body portion 20A, cutting edges 2a formed at the lower end of the tubular body portion 20A, and an upper end of the tubular body portion 20A. And a locking notch 20b as a locking portion formed so as to protrude upward in a bowl shape by an L-shaped member 20a fixed to the portion.

  Further, in the third embodiment, as shown in FIG. 15, the four locking notches 20b are provided at equal intervals in the circumferential direction of the tubular body portion 20A of the casing 20.

  As shown in FIG. 16, the bottomed bucket 10 includes a cylindrical main body 1 </ b> A, two widened wing parts 12, 12 that can be opened so as to increase the diameter of the main body 1 </ b> A, When the wings 12 and 12 are opened so as to expand, they are engaged with the four locking notches 20b of the casing 20, and when pulled out from the casing 20, the engagement with the locking notches 20b is performed. And a stopper portion 30 provided in the kelly bar device 19 above the main body portion 1A to be released.

  First, as shown in FIGS. 15 and 16, the stopper portion 30 is a kelly bar in which the upper end portion of the transmission shaft portion 14 extending from above the main body portion 1 </ b> A and the lower end portion of the inner kelly bar 19 </ b> A are detachably connected by the pin 21. A stopper bar 30A is provided which can be engaged with a locking notch 20b of the casing 20 projecting in the radial direction from the outer peripheral surface near the upper end of the outer kelly bar 19B of the device 19.

  Here, in the kelly bar apparatus 19, an inner kelly bar 19A is accommodated in an outer kelly bar 19B so as to be extendable and contractible.

  Further, the top bar 30A is projected in the radial direction at four circumferentially spaced positions on the outer peripheral surface in the vicinity of the upper end of the outer kelly bar 19B so as to face the radial direction in plan view. Each can be engaged with the locking notch 20b (see FIG. 15).

  Further, in the hollow portion of the kelly bar device 19, as shown in FIG. 16, a hanger 70 connected to the wire W as a hanger is provided at the upper end of the inner kelly bar 19 </ b> A. By lowering, the length of the kelly bar device 19 can be expanded and contracted, and the main body portion 1A connected to the lower end portion of the inner kelly bar 19A follows this, and is lifted and hung.

  In this way, first, as shown in FIG. 14, while the casing 20 is rotationally press-fitted into the ground, the earth and sand in the casing 20 is excavated by a hammer grab (not shown) and discharged, and the casing 20 is built to a predetermined depth. .

  Then, after raising the casing 20 to the required length, when the bottomed bucket 10 is suspended and inserted into the casing 20 by the wire W as shown in FIG. 16, the stopper bar 30 </ b> A is placed on the upper end of the casing 20. The

  When the casing 20 is rotated in this state, the tip of the stopper bar 30A is fitted into the locking notch 20b, and the bottomed bucket 10 is mounted on the upper part of the casing 20.

  Further, when the casing 20 is being rotationally press-fitted, the inner kelly bar 19 </ b> A and the outer kelly bar 19 </ b> B of the kelly bar device 19 are in a fixed state by the uneven frictional force of the joint portion. It is possible to transmit a pressing force to.

  The locking notch 20b is sized so that a slight gap of about 100 mm, for example, is formed on the upper side when the tip of the stopper bar 30A is fitted. Here, when the casing 20 is rotated in a state where the bottom expansion bucket 10 reaches the bottom of the excavation hole, only the casing 20 is press-fitted, and the tip of the stopper bar 30A is lifted in the locking notch 20b. appear. If it will be in this state, it can confirm that the main-body part 1A of the bottom expansion bucket 10 has reached the hole bottom of the excavation hole.

  Further, when the casing 20 is rotationally press-fitted, the stopper bar 30A is pushed down by the L-shaped member 20a, and the pressing force is transmitted to the transmission shaft portion 14 via the kelly bar device 19, so that the main body portion 1A of the bottom expansion bucket 10 is widened. The wing parts 12 and 12 are enlarged, and the bottom part of the bottom pile is excavated.

  Then, when the bottom expansion portion of the bottom expansion pile has been excavated and the bottom expansion bucket 10 is lifted from the casing 20 by the wire W as shown in FIG. 17, the inner kelly bar 19A is stored in the outer kelly bar 19B. Thus, the bottomed bucket 10 is in a compact state that can be easily lifted smoothly from the inside of the casing 20.

  Next, the construction method of the expanded bottom pile of Example 3 is demonstrated.

  First, as shown in FIG. 14, the earth and sand in the casing 20 is removed by a hammer grab (not shown) while the casing 20 is rotationally pressed into the ground by an all-round rotating machine (not shown) connected in the vicinity of the upper end of the casing 20 as shown in FIG. Excavate, evacuate, and connect to multiple shafts, and build to the length of the excavation hole necessary to construct the expanded pile.

  Subsequently, the casing 20 is pulled up to a required length, and the bottomed bucket 10 is inserted into the casing 20 by being suspended by the wire W as shown in FIG. The stopper bar 30 </ b> A is fitted, and the bottom expansion bucket 10 is mounted on the upper part of the casing 20.

  Subsequently, as shown in FIG. 13, the casing 20 is surrounded by the casing 20 while being rotationally press-fitted and opening the widened wings 12 and 12 of the bottomed bucket 10 so as to increase the diameter of the main body 1A. The surrounding ground is excavated from the excavation wall surface 6 of the empty space to form a space of the expanded portion of the expanded pile.

  Subsequently, as shown in FIG. 17, the widened bucket 10 is lifted by the wire W from the inside of the casing 20, and the widened bucket 10 is taken out from the upper part of the casing 20.

  Finally, although illustration is omitted, after the reinforcing bar is built, concrete is driven by treme, and the casing 20 and treme are pulled out and collected along with the concrete driving.

  And the expanded pile is constructed by curing and solidifying the concrete.

  Next, the effect of this Example 3 is demonstrated.

  The bottomed bucket 10 according to the third embodiment has an upper portion of a cylindrical casing 20 in which a cutting edge 2a is formed at a lower end portion and a locking notch 20b as a locking portion is formed at an upper end portion. It is an expanded bottom bucket to be attached.

  When opening the cylindrical main body 1A, the widening wings 12 and 12 formed so as to be openable so as to increase the diameter of the main body 1A, and the widening wings 12 and 12, When the stopper 20 is engaged with the locking notch 20b of the casing 20 and pulled out from the casing 20, the stopper 30 provided on the upper portion of the main body 1A is released from the engagement with the locking notch 20b. It is set as the structure provided.

  Since it is such a configuration, the reaction force necessary for excavation for forming the expanded bottom portion can be taken from the casing 2 without requiring a complicated configuration such as hydraulic control, like the expanded bottom bucket 1 of the first embodiment. Compared with the prior art, the workability is good, the possibility of failure is low, and furthermore, it can be carried out at low cost.

  Here, the lower end portion of the inner kelly bar 19A of the kelly bar device 19 in which the inner kelly bar 19A is retractably accommodated in the outer kelly bar 19B is connected to the upper portion of the main body 1A. A suspending portion 70 to be connected to a wire W as a suspending means is provided at the upper end portion of the.

  And the stopper part 30 is provided with the stopper bar 30A which protruded in the radial direction from the outer peripheral surface of the outer kelly bar 19B of the kelly bar apparatus 19 engaged with the latching notch 20b of the casing 20.

  For this reason, the structure which can take the reaction force required for the excavation for forming an expanded bottom part from the casing 20 without requiring complicated structures, such as hydraulic control, can be implement | achieved simply and cheaply.

  Such a casing 20 of Example 3 is a casing in which the above-described bottom expansion bucket 10 is mounted on the upper part thereof.

  And the structure provided with 2 C of cylindrical tube parts, and the latching notch 20b as a latching part formed by the L-shaped member 20a which protruded upward at the upper end part of 2 A of tube bodies, and Has been.

  With such a configuration, the bottom expansion bucket 10 can take a reaction force necessary for excavation for forming the bottom expansion portion by engaging the stopper bar 30A of the stopper portion 30 with the locking notch 20b.

  Here, since a plurality of casings 20 are connected and used, only the uppermost part needs to have such a configuration, so that the whole contributes to the cost reduction of the construction of the expanded pile.

  Such a method for constructing a bottomed pile according to Example 3 is a method for constructing a bottomed pile that constructs a bottomed pile using the above-described bottomed bucket 10 and the above-described casing 20.

  And the process of removing the earth and sand in the casing 20 while excavating the ground with the casing 20, and the process of inserting the expanded bottom bucket 10 into the casing 20 by suspending it from the upper part of the casing 20 with the wire W as a suspension means. The stopper bar 30A of the stopper portion 30 is engaged with the locking notch 20b as the locking portion of the casing 20 while being rotationally press-fitted into the casing 20 that has been pulled up to the required length, and is mounted on the upper portion of the casing 20. The step of excavating the surrounding ground in the space not surrounded by the casing 20 while opening the widened wings 12 and 12 of the bottomed bucket 10 so as to increase the diameter of the main body 1A; A step of lifting the bottomed bucket 10 from the upper part of the casing 20 by lifting it with the wire W; It is configured to include.

  Since it is such a structure, since the above-described bottomed bucket 10 and the above-described casing 20 are used, a high-quality bottomed pile can be constructed in a shorter construction period and at a lower cost than in the prior art.

  Other configurations and functions and effects are substantially the same as those of the first embodiment, and thus description thereof is omitted.

  The embodiment for carrying out the present invention has been described in detail based on the first to third embodiments with reference to the drawings. However, the specific configuration is not limited to the first to third embodiments. Design changes that do not depart from the gist of the present invention are included in the present invention.

  For example, in the first and second embodiments, the locking portion provided in the casing 2 is implemented as the locking hole 2b. However, the present invention is not limited to this, and is implemented as a locking hole that does not penetrate to the outer surface of the casing 2. Also good. Specifically, since the casing 2 normally has a double structure composed of an inner tube and an outer tube, a through hole is provided only in the inner tube, and this locking hole may be formed.

  Moreover, in the said Examples 1-3, although the outer side inclination part of the widening wing | blade part 12 was implemented substantially linearly, it is not limited to this, You may implement by circular arc shape etc.

  Further, in the third embodiment, the L-shaped member 20a is used to provide the locking notch 20b as the locking portion that protrudes in a bowl shape above the casing 20, but the present invention is not limited to this. Instead, it may be carried out using a member having a shape capable of providing the locking notch 20b.

  Moreover, in the said Example 3, in order to simplify description, although the Keriba apparatus 19 was implemented using what consists only of the inner Keriba 19A and the outer Keriva 19B, it is not limited to this, The bottom-pile pile to the deeper In the case of constructing, one having a plurality of outer Kerivas is used.

  Furthermore, in the construction method of the expanded bottom pile of the first embodiment, the expanded bottom bucket 1 is attached to the lower part of the casing 2 by pulling up the casing 2 and then inserting the expanded bottom bucket 1 into the casing 2, but this is limited to this. Not.

  That is, the bottom expansion bucket 1 may be attached to the lower part of the casing 2 by inserting the bottom expansion bucket 1 into the casing 2 and pulling up the casing 2.

  Moreover, in the construction method of the bottom expanded pile of the said Example 3, after raising the casing 20, the bottom expanded bucket 10 was inserted in the casing 20 and the bottom expanded part was excavated, but it is not limited to this.

  That is, the bottom expansion bucket 10 may be inserted into the casing 20 and the casing 20 may be pulled up in this state before the bottom expansion portion is excavated.

W wire (hanging means)
DESCRIPTION OF SYMBOLS 1 Expanded bucket 10 Expanded bucket 1A, 11A Expanded bucket body 2 Casing 20 Casing 2A Casing tube 2a Cutting edge 2b Locking hole (locking part)
20b Locking notch (locking part)
2c Guide protrusion 3 Stopper part 31 Non-moving sheath (non-moving part)
32 Pin part 33 Cam part 30 Stopper part 30A Stopper bar 7 Suspension part 70 Suspension part 71 Slide cylinder (slide part)
12 Widening wing part 13 Projection part 14 Transmission shaft part 141 Connecting member 15, 15A Guide tube 152, 152A Slide groove 19 Keriba device 19A Inner kelly bar 19B Outer keriba

Claims (5)

A bottom expanding bucket that is attached to a cylindrical casing in which a cutting edge is formed at the lower end and a locking portion is formed,
A cylindrical main body, a widened wing formed to be openable so as to increase the diameter of the main body, and an engagement with the locking portion when opening the widened wing so as to expand And a stopper portion provided at the upper part of the main body portion that is disengaged from the locking portion when being pulled out from the casing .
On the upper part of the stopper part, a hanging part to be connected to the hanging means is provided,
The stopper portion is a stationary portion that does not cause relative displacement with respect to the casing when engaged with the locking portion, a slide portion that is provided on the suspension portion and is slidable in the axial direction of the casing, A pin portion that is movable in the axial direction with respect to the immovable portion and that can protrude toward the locking portion; and a cam portion that connects the slide portion and the pin portion; When the casing is moved in the axial direction, the cam portion operates,
A transmission shaft portion that receives the force from the casing via the stopper portion is disposed in the main body portion so as to be movable in the vertical direction of the main body portion, and bendable to the transmission shaft portion. A bottom expansion bucket, wherein a lower end of a connected connecting member is connected to the widening wing part . The transmission shaft portion is slidably accommodated in a guide tube attached to the inside of the main body portion, and a slide groove inclined in a direction intersecting the axial direction is formed on the peripheral surface of the guide tube. 2. The widened bucket according to claim 1 , wherein a connecting portion between the transmission shaft portion and the connecting member is protruded from the slide groove, and the transmission shaft portion is moved in the vertical direction using the connecting portion as a guide. 拡底bucket according to claim 1 or 2, characterized in that the projecting portion is formed at the lower end of the body portion below the said widening wings. The bottomed bucket according to any one of claims 1 to 3, wherein the bottomed bucket is a casing attached to a lower portion thereof.
A cylindrical tubular body part, a cutting blade formed at the lower end of the tubular body part, and a locking part formed on the inner surface near the lower end part of the tubular body part ,
The casing is characterized in that a guide protrusion is formed on the inner side surface of the tubular body portion so as to taper from above toward the locking portion . A method for constructing a bottomed pile using the bottomed bucket according to any one of claims 1 to 3 and the casing according to claim 4 to construct a bottomed pile,
Removing the earth and sand in the casing while excavating the ground by the casing;
In the casing, the step of inserting the widened bucket by suspending it from the upper part of the casing by a suspension means;
Engaging the stopper portion with the locking portion of the casing that has been pulled up by a required length, and mounting the bottomed bucket on the lower portion of the casing;
Excavating the surrounding ground of the space not surrounded by the casing while opening the widening wing of the bottom expansion bucket so as to increase the diameter of the main body while rotating and press-fitting the casing;
A method for constructing an expanded pile, comprising: lifting the expanded bucket from the casing by the suspension means and taking out the expanded bucket from the upper part of the casing.

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