JP2016075139A - Rotary penetration pile, and construction method for consolidated foundation using the rotary penetration pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary penetration pile and a construction method for a consolidated foundation that enhance load bearing capacity of the pile and enable confirmation on protrusion of an expanded excavation blade in a ground from a periphery of a spiral vane.SOLUTION: A rotary penetration pile includes: a pile body 10 having a steel outer tube 11 and a steel inner tube 12 fitted inside of the outer tube at a tip part, with an edge of the inner tube closed by a bottom cover 13 exposed from the outer tube; a spiral vane 20 wound almost once on a peripheral surface of the inner tube; two expanded excavation blades 30 fitted on the spiral vane, the expanded excavation blades being open by 180° in a circumferential direction of the spiral blade and protruding outward in a radial direction of the pile body; and an injection nozzle 40 for curable fluid disposed on the peripheral surface of the inner tube. Detection is made possible of protrusion of the expanded excavation blade in the radial direction of the pile body from the periphery of the spiral vane, by an upward movement in an axial direction of the outer tube while rotating when rotation of the pile body in a reverse direction starts underground.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary penetrating pile that has increased support force (push-in resistance force and pull-out resistance force) and a construction method for a rooted rotary penetrating pile that uses the rotary penetrating pile.

  In construction that employs a pile as a foundation for civil engineering and construction work, a method of forming an expanded root having a diameter larger than the pile diameter at the tip of the pile is employed in order to increase the bearing capacity of the pile. For example, a hole for a pile with the same hole diameter as the pile diameter is drilled in the ground using a dedicated drilling device, and then expanded so that the hole diameter near the pile tip is about twice the pile diameter. After pouring the soil and sand and mixing, the excavation equipment is pulled up from the hole for the pile, and before the curable fluid hardens, the pile is advanced into the hole for the pile, and the tip of the pile is set to the curable fluid. There is known an expanded root-setting method in which it is penetrated and fixed in a mixture of sand and earth.

  However, in the above-mentioned enlarged rooting method, it is divided into a drilling process for holes for piles and a pile embedding process for burying piles in the holes for piles, and it is difficult to shorten the construction time. There is a problem that a dedicated device is required.

  In order to solve the above-mentioned problem, for example, a rotary penetrating pile provided with a spiral blade having an outer diameter twice to three times the pile diameter on the outer periphery of the pile tip portion and provided with a discharge hole of a curable fluid is used. This rotary penetrating pile is rotated and penetrated from the ground surface into the ground, and when the tip reaches the support layer in the ground, the ejection of the curable fluid from the discharge hole of the rotary penetrating steel pipe pile is started, While rotating forwards and backwards repeatedly, moving up and down, stirring and mixing earth and sand and hardened fluid, it was rotated and penetrated to the final depth, forming a cylindrical shape with the same diameter as the spiral blade around the steel pipe pile body. An expanded rooting method for forming a solidified mixture has been proposed (see Patent Document 1). The spiral wing plays a role of propagating the rotation penetration into the ground and a role of transmitting the supporting force to the supporting ground. This construction method does not require a dedicated excavation device and can form an enlarged foundation in the process of rotating the pile into the ground, thereby shortening the construction time and lowering the construction cost.

  As another construction method, a plurality of auxiliary (enlarged) excavation blades that can protrude in the radial direction of the pile from the periphery at an appropriate interval along the circumferential direction of the peripheral edge of the spiral blade provided on the outer periphery of the tip portion of the pile Rotating penetrating piles are used, and this rotating penetrating pile is rotated into the ground from the ground surface.When the tip reaches the upper end of the support layer in the ground, Start the ejection of the curable fluid to the outside, move it up and down while repeating normal rotation and reverse rotation, rotate and penetrate to the final depth while stirring and mixing the earth and curable fluid, and around the steel pipe pile body An enlarged rooting method for forming a solidified mixture having a cylindrical shape with the same diameter as an enlarged excavating blade protruding from the periphery of a spiral blade has been proposed (see Patent Document 2). This construction method does not require a dedicated excavation device as in the construction method using the above-mentioned rotary penetrating pile, and it can form an expanded foundation in the process of rotating the pile into the ground, shortening construction time and construction cost. In addition, the ground excavation dimensions secured by the spiral blades are increased by the dimensions of the projections of the expanded excavation blades, making it possible to increase the size of the roots with a larger diameter than when only the spiral blades are used. It is possible to form.

JP 2013-57194 A JP2013-19249A

  In the former construction method, it is necessary to install a spiral blade with a larger diameter to increase the bearing capacity of the pile, but if this is done, it will be bulky when the pile is transported to the construction site, and will rotate at the initial stage of rotational penetration into the ground. There is a problem that penetration resistance increases.

  In the latter construction method, when the pile is rotated and penetrated into the ground, the enlarged excavation blade is pushed by the earth and sand around the ground and does not protrude from the periphery of the spiral wing, but fits into the spiral wing, and the rotary penetrating pile is reversed and moved upward. When moving, the expanded excavation blade is pushed out by the earth and sand around the ground and protrudes from the periphery of the spiral wing, so the initial resistance to rotation penetration into the ground is not much different from the case of only the spiral wing, There is a problem that it is not possible to confirm that the enlarged excavating blade protrudes from the periphery of the spiral blade in the ground.

  The present invention uses a rotating penetrating pile and the rotating penetrating pile that can increase the bearing capacity of the pile and confirm that the enlarged excavating blade protrudes from the peripheral edge of the spiral blade in the ground. The purpose is to provide a method for constructing foundations that are solidified.

  A rotary penetrating pile according to claim 1 of the present invention is a pile main body including an outer cylinder and an inner cylinder disposed in a distal end portion of the outer cylinder with a closed tip exposed from the outer cylinder. And a spiral blade provided along the peripheral surface near the tip of the inner cylinder exposed from the outer cylinder, and an enlarged excavation blade provided on the spiral blade so as to protrude radially outward of the pile body, A curable fluid jet provided on the peripheral surface of the inner cylinder, and the outer cylinder rotates the inner cylinder in a direction opposite to the direction in which the pile main body rotates and penetrates into the ground. The enlarged excavation blade is housed on the peripheral side of the spiral wing when the pile main body is rotated and penetrated into the ground, and the pile main body is The outer cylinder that rotates relative to the inner cylinder when rotating in a direction opposite to the direction of rotation penetration The outer cylinder is configured to protrude outward from the periphery of the spiral wing in the radial direction of the pile main body, and the outer cylinder is rotated with respect to the inner cylinder when the pile main body is rotated in a direction opposite to the rotation penetrating direction. It is characterized by detecting that the enlarged excavating blade protrudes from the peripheral edge of the spiral blade to the outside in the radial direction of the pile body by using a predetermined distance in the axial direction.

  According to a tenth aspect of the present invention, there is provided a method for constructing a solidified foundation using a rotary penetrating pile, wherein the outer cylinder and the closed tip are exposed from the outer cylinder, and the inside of the tip portion of the outer cylinder is exposed. A pile body provided with an inner cylinder disposed on the outer cylinder, a spiral wing provided along an outer peripheral surface near the tip of the inner cylinder exposed from the outer cylinder, and a radial outer side of the pile body on the spiral wing A digging blade provided in a projectable manner on the peripheral surface of the inner cylinder, and a jet of a curable fluid provided on the peripheral surface of the inner cylinder, wherein the outer cylinder rotates and penetrates the pile body into the ground When rotating in the opposite direction to the inner cylinder, it is configured to be movable by a predetermined distance in the axial direction while rotating with respect to the inner cylinder. The pile body is rotated in a direction opposite to the direction in which the pile body is rotated and penetrated. The outer cylinder that rotates with respect to the inner cylinder is configured to protrude radially outward of the pile body from the peripheral edge of the spiral wing, and the jet outlet rotates and penetrates the pile body into the ground The outer cylinder is covered with the outer cylinder, and the outer cylinder rotates with respect to the inner cylinder and is not covered with the outer cylinder when the pile main body is rotated in the direction opposite to the rotation penetration direction. A preparatory step using a rotating penetrating pile provided at a surface location, and placing a curable fluid supply pipe on the pile body, and rotating the pile body to a predetermined depth in the ground by the propulsive force of the spiral blade The outer cylinder moves a predetermined distance in the axial direction with respect to the inner cylinder at the initial stage of rotation of rotating the pile main body in a direction opposite to the direction of rotating and penetrating the pile body. Use A confirmation step of confirming that the enlarged excavation blade protrudes from the peripheral edge of the spiral blade to the radially outer side of the pile body by rotation of the outer cylinder with respect to the inner cylinder; and after the confirmation step, the pile body is rotated. While rotating in a direction opposite to the penetration direction and pulling up from the predetermined depth to a predetermined position, the curable fluid is removed from the curable fluid supply pipe through the jet nozzle that is no longer covered by the outer cylinder. A rotary pulling step of excavating the ground around the spiral blade with the enlarged excavating blade while spraying, and repeating the rotary penetration step and the rotary pulling step between the predetermined position and the predetermined depth In between, the earth and sand excavated by the spiral blade and the enlarged excavating blade and the curable fluid ejected from the ejection port are agitated and mixed.

  According to the present invention, the supporting force of the pile can be increased, and when the pile main body is rotated in a direction opposite to the direction in which the pile main body is rotated and penetrated, the outer cylinder is axially fixed with respect to the inner cylinder by a predetermined distance. It is configured to detect that the enlarged excavating blade protrudes from the peripheral edge of the spiral wing to the outside of the pile body in the radial direction by using the movement, so the protrusion of the enlarged excavating blade can be confirmed with a very simple configuration It is possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Example of the rotation penetration pile of this invention, (a) is a schematic perspective view which shows the state which the expansion excavation blade was settled in the periphery of the spiral wing, (b) is a periphery of the spiral wing It is a schematic perspective view which shows the state which protruded from the radial direction outer side of the pile main body. 1A is a detailed view of a rotary penetrating pile in the state shown in FIG. 1A, FIG. 1A is a partially cut half longitudinal sectional view, FIG. 1B is a partially omitted plan view, and FIG. It is a partial side view which shows the relationship with an exit. FIG. 1B is a detailed view of a rotating penetrating pile in the state shown in FIG. 1B, in which FIG. 1A is a partially cut half longitudinal sectional view, FIG. 1B is a partially omitted plan view, and FIG. It is a partial side view which shows the relationship with an exit. It is a figure which shows 2nd Example of the rotation penetration pile of this invention, (a) is a half cut longitudinal cross-sectional view in the state in which the expansion excavation blade was settled in the periphery of the spiral wing, (b) is a partly omission in the same state FIG. FIG. 4 is a diagram in a state in which the enlarged excavation blade of the rotary penetrating pile shown in FIG. 4 protrudes from the peripheral edge of the spiral blade to the outer side in the radial direction of the pile main body, and (a) is a partially cut longitudinal sectional view in the same state; b) is a plan view with a part omitted in the same state. It is process explanatory drawing which shows 1st Example of the construction method of the solidified foundation which uses the rotation penetration pile of this invention, (a) is before the front-end | tip part of a rotation penetration pile reaches the support layer in the ground. The figure which shows a state, (b) is a figure which shows the state which the front-end | tip of the rotation penetration pile reached | attained the bottom of the support layer in the ground, (c) is supported by rotating the rotation penetration pile in the direction opposite to the rotation penetration. The figure which shows the state which started pulling up from the layer bottom part, (d) is a figure which shows the state by which the rotation penetration pile was pulled up to the support layer upper part, (e) is the state which the front-end | tip of the rotation penetration pile returned to the support layer bottom part. FIG. It is a figure which shows 3rd Example of the rotation penetration pile of this invention, (a) is the top view which abbreviate | omitted partially in the state which the expansion excavation blade was settled in the peripheral side of the spiral blade, (b) is an expansion excavation blade It is the top view which abbreviate | omitted partially in the state protruded to the radial direction outer side of the pile main body from the periphery of a spiral wing | blade. FIG. 7 is a first modified example of the rotary penetrating pile of the present invention shown in FIG. 7, (a) is a partially omitted plan view in a state where the enlarged excavating blade is accommodated on the peripheral side of the spiral blade, and (b) is an enlarged excavating blade. It is the top view which abbreviate | omitted partially in the state which protruded to the radial direction outer side of the pile main body from the periphery of a spiral wing | blade. FIG. 7 is a second modification of the rotary penetrating pile of the present invention shown in FIG. 7, (a) is a partially omitted plan view in a state where the enlarged excavating blade is accommodated on the peripheral side of the spiral blade, and (b) is an enlarged excavating blade. It is the top view which abbreviate | omitted partially in the state which protruded to the radial direction outer side of the pile main body from the periphery of a spiral wing | blade. It is a figure which shows 4th Example of the rotation penetration pile of this invention, (a) is a top view which abbreviate | omitted partially in the state in which the expansion excavation blade was settled in the peripheral side of the spiral wing, and the penetration part was closed, b) is a partially omitted plan view of the enlarged excavating blade protruding from the peripheral edge of the spiral wing to the radially outer side of the pile main body while the penetrating portion is opened. It is a figure which shows 5th Example of the rotation penetration pile of this invention, (a) is the top view which abbreviate | omitted partially in the state which the expansion excavation blade was settled in the peripheral side of the spiral blade, (b) is an expansion excavation blade It is the top view which abbreviate | omitted partially in the state protruded to the radial direction outer side of the pile main body from the periphery of a spiral wing | blade. FIG. 11 is a modified example of the rotary penetrating pile of the present invention shown in FIG. It is the top view which abbreviate | omitted partially in the state protruded to the radial direction outer side of the pile main body from the peripheral edge of the wing | blade. It is a figure which shows 6th Example of the rotation penetration pile of this invention, (a) is a top view which abbreviate | omitted partially in the state where the enlarged excavation blade was settled in the peripheral side of the spiral wing, and the penetration part was closed, (b) ) Is a partially omitted plan view of the enlarged excavating blade protruding from the periphery of the spiral blade to the outside in the radial direction of the pile body while the penetrating portion is open. It is explanatory drawing explaining the state which the excavated earth and sand and a curable fluid flow through the penetration part from one surface side of a spiral blade to the other surface side or the other surface side to one surface side. ) Is an explanatory diagram of the flow state of the excavated earth and sand and the curable fluid in the penetrating portion shown in FIG. 7, FIG. 8, or FIG. 11, and (b) is the excavating portion in the penetrating portion shown in FIG. 9 or FIG. It is explanatory drawing of the fluid state of earth and sand and a curable fluid.

  About the 1st Example of the rotation penetration pile of this invention, the outline is demonstrated with reference to Fig.1 (a), (b). The rotary penetrating pile A of the present embodiment is made of a steel pipe that is disposed in the distal end portion of the outer cylinder 11 with the outer cylinder 11 made of steel pipe and the tip closed by the bottom lid 13 exposed from the outer cylinder 11. The pile main body 10 having the inner cylinder 12, the substantially one-turn spiral wing 20 provided along the outer peripheral surface near the tip of the inner cylinder 12 exposed from the outer cylinder 11, and the spiral wing 20 in the circumferential direction 180. Two enlarged excavation blades 30 that can be protruded radially outward of the pile body 10 and are arranged with an opening angle of °, and a curable fluid jet 40 provided on the peripheral surface of the inner cylinder 12 A tip excavation blade 50 disposed on the bottom lid 13. When the pile body 10 is rotated in the ground in a direction opposite to the direction in which the pile main body 10 is rotated and propelled (the direction in which the pile body 10 is pulled up from the ground), the outer cylinder 11 rotates at a predetermined angle with respect to the inner cylinder 12 at the initial stage of rotation. Move in the direction (up a predetermined distance). After the initial rotation in the direction opposite to the direction of propulsion into the ground, the outer cylinder 11 and the inner cylinder 12 rotate together. In the rotary penetrating pile A of the present embodiment, the diameter of the pile main body 10 is extended from the peripheral edge of the spiral blade 20 by utilizing the fact that the outer cylinder 11 rotates by a predetermined angle with respect to the inner cylinder 12 at the initial stage of the rotation. The enlarged excavating blade 30 is moved radially outward of the pile body 10 by utilizing the fact that the outer cylinder 11 is moved in the axial direction by a predetermined distance with respect to the inner cylinder 12 by pushing the outer cylinder 11 outward. It is intended to detect that it has protruded. In addition, the outer cylinder 11 is added according to the penetration depth in the ground of the rotation penetration pile A at the time of construction. A curable fluid has fluidity at the time of construction and hardens over time after construction. For example, a milk-like material in which cement or ground solidification material is dissolved in water, or a mortar with sand added thereto. Etc.

  As shown in FIG. 1 (a), the distal end of the outer cylinder 11 is notched in a substantially spiral shape, and the outer peripheral surface near the distal end of the inner cylinder 12 is separated from the outer cylinder 11 through the notch 14. Exposed. The cutout portion 14 is provided with a stepped portion 14a to which the one end portion 20a of the spiral blade 20 is locked in the state shown in FIG. Moreover, the recessed part 14b in which the inner end part 32a (refer FIG.2 (b)) of the support piece 32 which comprises the expansion excavation blade 30 is provided is provided.

  As shown in FIGS. 2 (a) and 3 (a), the inner cylinder 12 is partitioned into two upper and lower rooms 15a and 15b via a partition plate 15, and is formed on the peripheral wall of the lower room 15b. The jet port 40 is provided, and a receiving pipe 61 is provided in the upper chamber 15a to removably receive the distal end portion of the curable fluid supply pipe 60. The lower end of the receiving pipe 61 is connected to a hole 15 c provided in the central portion of the partition plate 15. The curable fluid is supplied from the curable fluid supply pipe 60 to the lower chamber 15b through the receiving pipe 61 and the hole 15c, and is ejected from the ejection port 40 toward the radially outer side of the pile body 10. A plurality of elastic rings 62 (three in FIG. 2 (a) and FIG. 3 (a)) are arranged on the inner peripheral surface of the receiving pipe 61 with an appropriate interval in the axial direction, and a curable fluid supply pipe. The curable fluid is prevented from leaking from the gap between 60 and the receiving pipe 61.

  As shown in FIGS. 2 (a) and 3 (a), the spiral blade 20 and the inner peripheral surface of the distal end portion of the outer cylinder 11 and the outer peripheral surface of the inner cylinder 12 covered by the inner peripheral surface A screw portion 16 and a screw portion 17 having the same pitch are provided, and the inner cylinder 12 is screwed into the distal end portion of the outer cylinder 11 via the screw portions 16 and 17. On the inner peripheral surface of the outer cylinder 11, a stopper 18 is provided in the vicinity of the screw portion 16. When the outer cylinder 11 moves in the axial direction as the outer cylinder 11 rotates with respect to the inner cylinder 12. The stopper stopper 18 hits the threaded portion 17 of the inner cylinder 12 so that the outer cylinder 11 does not move any further. In this embodiment, the stopper 18 is set so that the outer cylinder 11 is rotated once relative to the inner cylinder 12 and the outer cylinder 11 stops by one pitch when moved in the axial direction.

  The spiral blade 20 has an outer diameter that is two to three times the outer diameter of the outer cylinder 11. While the rotary penetrating pile A (pile main body 10) is rotating (forward rotating) in a direction to rotate and penetrate into the ground, the one end portion 20a of the spiral blade 20 and the stepped portion 14a of the notch portion 14 are related to each other. The stopped state is maintained (see FIG. 1A), and the outer cylinder 11 is prevented from rotating with respect to the inner cylinder 12. Therefore, the outer cylinder 11 and the inner cylinder 12 rotate together and penetrate into the ground while the pile body 10 is rotated forward and rotated into the ground.

  On the other hand, when the pile body 10 is rotated (reversely rotated) in a direction opposite to the direction in which the pile body 10 is rotated and penetrated into the ground, the outer cylinder 11 rotates once with respect to the inner cylinder 12 at the initial stage of the rotation, and the screw portion 16, screw The part 17 moves upward by one pitch in the axial direction, but the stopper 18 prevents the outer cylinder 11 from moving more than one pitch relative to the inner cylinder 12, and then the outer cylinder 11 and the inner cylinder 12 are integrated. Rotate and retreat from the ground (pulled up).

  As shown in FIG. 2A, FIG. 3A, etc., the enlarged excavation blade 30 includes an excavation blade piece 31 extending in the axial direction of the pile body 10 and the excavation blade piece 31 to the spiral blade 20. And a pair of support pieces 32 to be attached. The pair of support pieces 32 are slidably attached to the spiral blade 20 by a pivot 33 that sandwiches the surface portion of the spiral blade 20 and whose inner end near the inner cylinder 12 penetrates the surface portion of the spiral blade 20 in the axial direction. The excavation blade piece 31 is fixed (welded) to the outer end of the pair of support pieces 33 on the peripheral side of the spiral blade 20. The excavation blade piece 31 can swing (rotate) with respect to the spiral blade 20 with the pivot 33 as a fulcrum, and can protrude from the peripheral edge of the spiral blade 20 on the radially outer side of the pile body 10.

  When the pile main body 10 is rotated forward and penetrated into the ground, the ground friction force acting on the spiral blade 20 is the enlarged excavating blade 30 as shown by an arrow B in FIG. Acts on the peripheral side of the spiral blade 20. For this reason, as shown in FIGS. 2B and 2C, the enlarged excavation blade 30 has the inner end portion 32 a of the support piece 32 stopped in the recess 14 b provided in the notch portion 14 of the outer cylinder 11. The excavating blade piece 31 is accommodated on the peripheral side of the spiral blade 20. On the other hand, when the pile body 10 is reversely rotated and pulled up from the ground, the frictional force of the ground acting on the spiral blade 20 causes the enlarged excavation blade 30 to move the spiral blade as indicated by an arrow C in FIG. It acts in the direction which extrudes from the periphery of 20 to the radial direction outer side from the periphery of the pile main body 10. At the beginning of the reverse rotation, the outer cylinder 11 rotates with respect to the inner cylinder 12, and the support piece 32 has an inner end portion 32a as shown in FIGS. 1 (b) and 3 (b). It is pushed by the recess 14 b of the notch 14 of the cylinder 11 and rotates with the pivot 33 as a fulcrum, and the excavation blade piece 31 protrudes from the peripheral edge of the spiral blade 20 to the outside in the radial direction of the pile body 10. In other words, at the initial stage of reverse rotation, an extruding force from the outer cylinder 11 to the radially outer side of the pile body 10 acts on the enlarged excavation blade 30. The expanded excavating blade 30 is coupled with the frictional force from the ground and the pushing force from the outer cylinder 11, so that the excavating blade piece 31 reliably projects outward in the radial direction of the pile body 10.

  Since the enlarged excavating blade 30 is accommodated on the peripheral side of the spiral blade 20 when the pile main body 10 is rotated forward and rotated into the ground, it hardly causes rotational penetration resistance. Moreover, when the pile excavation blade 30 rotates the pile main body 10 reversely in the ground, the excavation blade piece 31 projects outward in the radial direction of the pile main body 10 to enlarge the excavation area. Therefore, when the pile main body 10 is moved up and down by repeating forward rotation and reverse rotation in the ground, the soil around the spiral blade 20 can be more excavated and softened than in the case of the spiral blade 20 alone.

  As shown in FIGS. 1A, 1B, etc., a mark 70 is marked with paint or the like on the outer peripheral surface of the curable fluid supply pipe 60 positioned at the upper end of the pile head of the outer cylinder 11. ing. When the outer cylinder 11 is moved upward in the axial direction by one pitch of the screw portions 16 and 17 with respect to the inner cylinder 11, the mark 70 is hidden in the pile head of the outer cylinder 11. This is a result of the outer cylinder 11 rotating once with respect to the inner cylinder 12, and as described above, the rotation of the outer excavating blade 30 causes the diameter of the pile main body 10 from the periphery of the spiral blade 20 by one rotation of the outer cylinder 11. Projects outward in the direction. Therefore, by observing that the mark 70 is hidden in the pile head of the outer cylinder 11, it is possible to detect that the enlarged excavation blade 30 protrudes radially outward of the pile body 10.

  In this embodiment, when the pile main body 10 is rotated in reverse in the ground, the outer cylinder 11 moves upward in the axial direction by one pitch of the screw portions 16 and 17 with respect to the inner cylinder 12 at the initial rotation. Thus, in order to detect that the enlarged excavating blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10, the case where the mark 70 is attached to the outer peripheral surface of the curable fluid supply pipe 60 is shown. However, the present invention is not limited to this. For example, it may be detected by measuring a change in the height of the pile head by applying a ruler or the like to the upper end of the pile head exposed from the ground.

  The spout 40 is composed of, for example, a check valve and the like, and the curable fluid can be ejected from the room 15b to the excavated soil in the ground. 15b has a function of preventing inflow. As shown in FIGS. 1B and 3C, the jet nozzle 40 is located between the one end 20 a and the other end 20 b of the spiral blade 20 on the peripheral surface of the inner cylinder 12. The spout 40 is covered and protected by the outer cylinder 11 (the outer cylinder 11 is closed) as shown in FIGS. 1 (a) and 2 (c) at the time of forward rotation in which the pile body 10 is rotated and penetrated into the ground. When the pile main body 10 is pulled up from the ground, it is not covered by the outer cylinder 11 (the outer cylinder 11 opens) as shown in FIGS. 1B and 3C, and the curable fluid can be ejected. It becomes.

  As described above, according to the rotary penetrating pile A of the first embodiment, the support force can be increased by the enlarged excavating blade 30, and the curable flow located at the upper end of the pile head of the outer cylinder 11 By attaching a mark 70 to the outer peripheral surface of the body supply pipe 60 and observing the mark 70, the enlarged excavation blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 in the ground. Can be detected. Further, the mark 70 as the detection means can be easily attached with paint or the like, so that it does not cost much. Further, when the pile body 10 is reversely rotated in the ground, the outer cylinder 11 is rotated with respect to the inner cylinder 12 at the initial stage of rotation, and the enlarged excavating blade 30 is moved outward from the periphery of the spiral blade 20 in the radial direction of the pile body 10. The pushing force acts, and the pushing force and the frictional force (see arrow C in FIG. 3B) acting on the spiral blade 20 from the ground combine to bring the excavating blade piece 31 outward in the radial direction of the pile body 10. It can be reliably projected. Further, the spout 40 is covered with the outer cylinder 11 and protected from the earth and sand around the spiral blade 20 when the pile main body 10 is rotated forward and inserted into the ground, so that the spout 40 is configured. A general-purpose product can be used as a check valve, and the cost can be reduced. Furthermore, when the pile body 10 is rotated in the reverse direction in the ground, the outer cylinder 11 is opened, and the curable fluid supplied from the curable fluid supply pipe 60 is excavated around the spiral blade 20 without any trouble. Can erupt towards

  4 (a), 4 (b), 5 (a), and 5 (b) show a second embodiment of the rotary penetrating pile of the present invention. 1 (a), (b), FIGS. 2 (a), (b), (c), and the same parts as those shown in FIGS. 3 (a), (b), (c). The detailed description is omitted.

  In the rotary penetrating pile Aa of the second embodiment, the mechanism for projecting the enlarged excavating blade 30 outward in the radial direction of the pile body 10 is different from the rotary penetrating pile A of the first embodiment described above, and the other parts Is the same. The projecting mechanism includes a pin 80 provided on the outer cylinder 11 side and a groove 81 provided on the enlarged excavation blade 30 side on which the pin 80 is slidably engaged. As the outer cylinder 11 rotates with respect to the inner cylinder 12 at the initial stage of reverse rotation, the pin 80 slides in the groove 81 to rotate the enlarged excavating blade 30 with the pivot 33 serving as a fulcrum. The main body 10 is protruded radially outward. The pins 80 are attached to substantially fan-shaped support protrusions 82 provided on the outer peripheral surface portions of the distal end portion of the outer cylinder 11 corresponding to the pair of enlarged excavating blades 30 so as to extend in the axial direction of the outer cylinder 11. It is done. The groove portion 81 is provided at the inner end portion of the support piece 32 on the surface (upper surface) side of the spiral blade 20 of the pair of support pieces 32 so as to extend in the direction of the pivot 33.

  When the pile main body 10 is rotated forward and penetrated into the ground, the ground friction force acting on the spiral blade 20 is the enlarged excavating blade 30 as shown by an arrow D in FIG. , And the enlarged excavating blade 30 has its excavating blade piece 31 located on the peripheral side of the spiral blade 20. On the other hand, when the pile body 10 is reversely rotated and pulled up from the ground, the ground frictional force acting on the spiral blade 20 causes the expanded excavation blade 30 to move the spiral blade as indicated by an arrow E in FIG. It acts in the direction which extrudes from the periphery of 20 to the radial direction outer side from the periphery of the pile body 10. At the initial stage of the reverse rotation, the outer cylinder 11 rotates with respect to the inner cylinder 12, and the pin 80 slides in the groove 81 along with this rotation, so that the enlarged excavating blade 30 is moved with the pivot 33 as a fulcrum. The force which rotates and makes it protrude to the radial direction outer side of the pile main body 10 acts. The enlarged excavating blade 30 is configured such that the friction force from the ground and the force from the outer cylinder 11 transmitted through the pin 80 and the groove 81 combine to ensure that the excavating blade piece 31 is radially outward of the pile body 10. Protrusively.

  Similarly to the rotary penetration pile A of the first embodiment described above, the rotary penetration pile Aa of the second embodiment can increase the supporting force by the enlarged excavating blade 30 and observe the mark 70. Thus, it is possible to detect that the enlarged excavating blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 in the ground. In addition, the enlarged excavation blade 30 can be reliably projected outward in the radial direction of the pile body 10 at the initial stage of rotation in which the pile body 10 is rotated in the reverse direction.

  In addition, at the initial stage of rotation for rotating the pile main body 10 in the reverse direction, the outer excavation blade 30 is rotated from the peripheral edge of the spiral blade 20 to the pile main body 10 by utilizing the rotation of the outer cylinder 11 with respect to the inner cylinder 12. The mechanism for projecting radially outward is not limited to the mechanisms of the two embodiments shown in FIGS. 1 (a), 1 (b) to 5 (a), (b).

  Next, an embodiment of a method for constructing a solidified foundation using the rotary penetrating pile of the present invention will be described with reference to FIGS. 6 (a) to 6 (e). In the construction method of the present embodiment, the rotary penetrating pile A of the first embodiment shown in FIGS. 1 (a), 1 (b) to 3 (a), (b), (c) is used. In the figure, the same parts as those shown in FIGS. 1 (a), 1 (b) to 3 (a), (b), (c) are denoted by the same reference numerals, and detailed description thereof is omitted.

  First, preparations are made such as inserting the distal end portion of the curable fluid supply pipe 60 into the receiving pipe 61 (see FIG. 2 (a), etc.) before the rotary penetrating pile A rotates and penetrates into the ground. After this preparatory step, the process proceeds to the rotary penetration step shown in FIGS. 6 (a) and 6 (b).

  Fig.6 (a) shows the state before the front-end | tip part of the rotation penetration pile A arrives at the support layer S in the ground in the rotation penetration process. As shown in the figure, the pile main body 10 is rotationally driven (forward rotation) by a ground pile driver (not shown) equipped with a rotational drive device, and utilizes the screwing action (propulsive force) of the spiral blade 20. Penetration into the ground. At the time of this rotation penetration, the pile main body 10 penetrates while the tip excavation blade 50 excavates the ground, so that the pile main body 10 can be smoothly penetrated even when the ground is hard. In addition, when the ground is not so hard, the pile main body 10 can be penetrated into the ground without any trouble without providing the tip excavation blade 50.

  In the rotational penetration step, as shown in FIG. 6 (b), the tip of the pile main body 10 is scheduled to be positioned at the lower end of the solidified body F (see FIGS. 6 (c) to (e)) in the support layer S. Continue until the depth of (the bottom of the support layer S) is reached. When the bottom of the support layer S is reached, the mark 70 is marked with paint or the like on the outer peripheral surface of the curable fluid supply pipe 60 located at the upper end of the pile head of the outer cylinder 11. In the rotary penetration process, the enlarged excavation blade 30 is accommodated on the peripheral side of the spiral blade 20 by the frictional force that acts on the spiral blade 20 from the earth and sand around the spiral blade 20, and the enlarged excavation blade 30 rotates and penetrates the pile body 10. There is no resistance.

  After the rotational penetration step, the outer cylinder 11 rotates relative to the inner cylinder 12 at the initial stage of rotation in which the pile body 10 is rotated (reversely rotated) in the opposite direction to that during rotational penetration. The excavating blade 30 is pushed out from the peripheral edge of the spiral blade 20 to the outside in the radial direction of the pile body 10, and the outer cylinder 11 moves in the axial direction with respect to the inner cylinder 12 along with this rotation. It is confirmed that the enlarged excavation blade 30 protrudes outward in the radial direction of the pile body 10. That is, in this confirmation step, the excavating blade 30 is moved from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 by utilizing the fact that the outer cylinder 11 rotates relative to the inner cylinder 12 and moves in the axial direction. While extruding, it is confirmed that the enlarged excavation blade 30 protrudes radially outward of the pile body 10. In this example, the mark 70 on the outer peripheral surface of the curable fluid supply pipe 60 located at the upper end of the pile head of the outer cylinder 11 located on the ground surface was hidden in the pile head of the outer cylinder 11. It is confirmed that the enlarged excavation blade 30 protrudes radially outward of the pile body 10 by observing (see FIG. 6C).

  In the above confirmation step, when the mark 70 on the outer peripheral surface of the curable fluid supply pipe 60 is hidden in the pile head of the outer cylinder 11, the enlarged excavation blade 30 is moved from the peripheral edge of the spiral blade 20 to the pile body by the outer cylinder 11. 10 indicates that the outer cylinder 11 has been projected outside and the opening 10 has been opened without covering the spout 40. Therefore, after this confirmation process, the pile body 10 is further rotated in the reverse direction and pulled up in the support layer S. Move on. In this rotational pulling step, as shown in FIG. 6C, the curable fluid is ejected from the ejection port 40 while the pile body 10 is rotated in the reverse direction. The pile main body 10 moves upward from the bottom of the support layer S, and the ground around the spiral blade 20 is excavated by the enlarged excavation blade 30 protruding outward in the radial direction of the pile main body 10 in the process of movement. That is, the excavated earth and sand and the ejected curable fluid are agitated and mixed while expanding and excavating.

  As shown in FIG. 6 (d), the rotary pulling process is performed until the tip portion of the pile body 10 reaches a depth (upper part of the support layer S) where the upper end of the root-solidified body F is located. When the front end portion of the pile body 10 reaches the upper part of the support layer S, the pile body 10 is rotated forward. However, since the forward rotation of the pile body 10 is performed at the location of the already-excavated support layer S, the expanded excavation is performed. The frictional force of the ground that presses the blade 30 against the peripheral edge of the spiral blade 20 is weak, and the enlarged excavating blade 30 remains protruding outward in the radial direction of the pile body 10. Enlarging excavation and agitation mixing are performed while the pile body 10 is rotated forward in the support layer S. This rotation penetration, expansion excavation, and stirring and mixing are performed until the tip of the pile body 10 reaches the bottom of the support layer S as shown in FIG.

  When the tip end portion of the pile body 10 reaches the bottom of the support layer S, the process moves from the rotation penetration step (see FIG. 6 (e)) to the rotation pulling step (see FIG. 6 (d)). After the rotation penetration step, the pile body 10 is moved up and down a plurality of times in the support layer S by repeating the rotation pulling step, the expansion excavation, and the stirring and mixing. Thereby, the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 are agitated and mixed by using the curable fluid ejected from the ejection port 40, the spiral blade 20 and the enlarged excavating blade 30. This agitation and mixing varies depending on the properties of the excavated earth and sand and the properties of the curable fluid to be used. For example, after the rotary penetration step, agitation and mixing by vertically moving the pile body 10 is repeated ten times.

  As described above, a solidified body F obtained by solidifying the excavated earth and sand in the ground with a curable fluid is completed in the support layer S.

  7 (a) and 7 (b) show a third embodiment of the rotary penetrating pile of the present invention. 1 (a), (b), FIGS. 2 (a), (b), (c), and the same parts as those shown in FIGS. 3 (a), (b), (c). The detailed description is omitted.

  In the rotary penetrating pile Ab of the third embodiment, a pair of rectangular through holes as penetrating portions that allow the one surface side (front surface side) and the other surface side (back surface side) to communicate with the spiral blade 20. 21 is provided, and this point is different from the rotary penetrating pile A of the first embodiment described above, and the other portions are the same. When rotating the rotary penetrating pile Ab forward / reversely and moving the tip of the pile body 10 up and down a plurality of times within the support layer S (see FIG. 6), as shown in FIG. 14 (a), The earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 through the through-hole 21 and the curable fluid ejected from the jet port 40 from the front side to the back side or from the back side to the front side of the spiral blade 20. To flow. The stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through-hole 21 is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30, so that the sand and the curable fluid are stirred and mixed. As a result, the root-solidified body F (see FIG. 6) in which the earth and sand and the curable fluid are uniformly mixed can be formed. In addition, in the rotary penetrating pile Ab of the third embodiment, as in the rotary penetrating pile A of the first embodiment described above, the support force can be increased by the enlarged excavating blade 30, and the mark 70 (FIG. 1 (a) and the like), it is possible to detect that the enlarged excavation blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 in the ground. In addition, the enlarged excavation blade 30 can be reliably projected outward in the radial direction of the pile body 10 at the initial stage of rotation in which the pile body 10 is rotated in the reverse direction.

  FIGS. 8A and 8B show a first modification of the rotary penetrating pile Ab of the third embodiment. 1 (a), (b), FIG. 2 (a), (b), (c), FIG. 3 (a), (b), (c), FIG. 7 (a), (b). The same reference numerals are given to the same parts as those shown in FIG.

  In the rotary penetrating pile Ac of the first modified example, a pair of cutout portions 21a in which a part of the peripheral edge of the spiral blade 20 is cut out is provided as the penetrating portion. Also in the rotation penetration pile Ac of this 1st modification, as shown to Fig.14 (a), it is ejected from the earth and sand excavated with the spiral blade 20 and the said enlarged excavation blade 30 via the notch part 21a, and the said jet nozzle 40. Further, the curable fluid flows from the surface side of the spiral blade 20 to the back surface side or from the back surface side to the surface side, and the stirring and mixing by this flow is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30. The stirring and mixing of the earth and sand and the curable fluid is further promoted, and the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed.

  FIGS. 9A and 9B show a second modification of the rotary penetrating pile Ab of the third embodiment. 1 (a), (b), FIG. 2 (a), (b), (c), FIG. 3 (a), (b), (c), FIG. 7 (a), (b). The same reference numerals are given to the same parts as those shown in FIG.

  In the rotary penetrating pile Ad of the second modified example, a pair of rectangular through holes 21b are provided as the penetrating parts in the spiral blade 20, and a guide part 22 is provided on one end side in the long side direction of the through holes 21b. Yes. The guide portion 22 is formed, for example, by bending a part of the cut and raised generated when forming the through hole 21b at an appropriate angle to the back surface side of the spiral blade 20. As shown in FIG. 14B, the guide portion 22 guides the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 and the curable fluid ejected from the ejection port 40 to the through hole 21b. The flow of the earth and sand and the curable fluid from the front surface side to the back surface side or the back surface side to the front surface side of the spiral blade 20 through the through hole 21b is made smooth. Even in the rotary penetration pile Ad of the second modified example, the stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through hole 21b is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30. The stirring and mixing of the earth and sand and the curable fluid is further promoted, and the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed.

  10 (a) and 10 (b) show a fourth embodiment of the rotary penetrating pile of the present invention. 1 (a), (b), FIGS. 2 (a), (b), (c), and the same parts as those shown in FIGS. 3 (a), (b), (c). The detailed description is omitted.

  In the rotary penetrating pile Ae of the fourth embodiment, the spiral blade 20 is provided with a pair of rectangular through holes 21c as penetrating portions that allow the front surface side and the back surface side to communicate with each other, and the support piece for the enlarged excavating blade 30 The pair of through holes 21c is configured to be openable and closable by 32, and this point is different from the rotary penetrating pile A of the first embodiment described above, and the other portions are the same. When the rotary penetration pile Ae is rotated forward / reversely and the tip portion of the pile body 10 is moved up and down a plurality of times in the support layer S, as shown in FIG. 14 (a), through the through hole 21c. Thus, the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 and the curable fluid ejected from the jet port 40 flow from the surface side of the spiral blade 20 to the back surface side or from the back surface side to the surface side. The stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through hole 21c is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30, whereby the earth and sand and the curable fluid are stirred and mixed. As a result, the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed. In the fourth embodiment, unlike the third embodiment in which the through hole 21 is also provided, the through hole 21c can be opened and closed by the support piece 32, and the rotary penetrating pile Ae is rotated in the forward direction by rotating forward. When penetrating, as shown in FIG. 10A, the through hole 21 c is closed by the support piece 32 of the enlarged excavating blade 30 that is accommodated on the peripheral side of the spiral blade 20. For this reason, it is possible to prevent the ground reaction force from leaking through the through hole 21c during the rotation penetration, and to prevent the rotation propulsion force from being lowered into the ground due to the provision of the through hole 21c. When the through-hole 21c is rotated in the reverse direction by rotating the rotary penetrating pile Ae from the ground, the through-hole 21c extends in the radial direction of the pile body 10 from the peripheral side of the spiral blade 20 as shown in FIG. It is opened by the support piece 32 of the extended digging blade 30 protruding. Note that, in the rotary penetrating pile Ae of the fourth embodiment, as in the rotary penetrating pile A of the first embodiment described above, the support force can be increased by the enlarged excavating blade 30, and the mark 70 (FIG. 1 (a) and the like), it is possible to detect that the enlarged excavation blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 in the ground. In addition, the enlarged excavation blade 30 can be reliably projected outward in the radial direction of the pile body 10 at the initial stage of rotation in which the pile body 10 is rotated in the reverse direction.

  Fig.11 (a), (b) has shown the 5th Example of the rotation penetration pile of this invention. In the figure, the same parts as those shown in FIGS. 4 (a), 4 (b), 5 (a) and 5 (b) are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the rotary penetrating pile Af of the fifth embodiment, the spiral blade 20 is provided with a pair of rectangular through holes 21d as penetrating portions that allow the front surface side and the back surface side to communicate with each other. Although it differs from the rotary penetration pile Aa of 2 Example, it is the same about other parts. The point of providing the through hole 21d is the same as the rotary penetrating pile Ab of the third embodiment described above. When the rotary penetrating pile Af is rotated forward and backward to move the tip of the pile body 10 up and down a plurality of times in the support layer S, as shown in FIG. Thus, the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 and the curable fluid ejected from the jet port 40 flow from the surface side of the spiral blade 20 to the back surface side or from the back surface side to the surface side. The stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through hole 21d is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30, so that the sand and the curable fluid are stirred and mixed. As a result, the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed. In addition, in the rotary penetrating pile Af of the fifth embodiment, the supporting force can be increased by the enlarged excavating blade 30 as in the case of the rotary penetrating pile A of the first embodiment described above, and the mark 70 (FIG. 1). Etc.) can be detected by projecting the enlarged excavating blade 30 from the peripheral edge of the spiral blade 20 to the outer side in the radial direction of the pile body 10. In addition, the enlarged excavation blade 30 can be reliably projected outward in the radial direction of the pile body 10 at the initial stage of rotation in which the pile body 10 is rotated in the reverse direction.

  12 (a) and 12 (b) show a modification of the rotary penetrating pile Af of the fifth embodiment. In the figure, the same parts as those shown in FIGS. 4A, 4B, 5A, 5B, FIG. Is omitted.

  In the rotary penetrating pile Ag of this modification, a pair of rectangular through holes 21e are provided in the spiral blade 20 as the through parts, and a guide part 22a is provided on one end side in the long side direction of the through holes 21e. Like the guide portion 22 (see FIG. 9), for example, the guide portion 22a bends a part of the cut and raised generated when forming the through hole 21e at an appropriate angle to the back side of the spiral blade 20. It is formed by. As shown in FIG. 14B, the guide portion 22a guides the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 and the curable fluid ejected from the ejection port 40 to the through hole 21e. The flow of the earth and sand and the curable fluid from the front surface side to the back surface side or the back surface side to the front surface side of the spiral blade 20 through the through hole 21e is made smooth. Also in the rotary penetration pile Ag of this modification, the stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through hole 21e is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30, so that The stirring and mixing with the curable fluid is further promoted, and the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed.

  13 (a) and 13 (b) show a sixth embodiment of the rotary penetrating pile of the present invention. In the figure, the same parts as those shown in FIGS. 4 (a), 4 (b), 5 (a) and 5 (b) are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the rotary penetrating pile Ah of the sixth embodiment, a pair of cutout portions 21f that are cut out in a substantially circular shape are provided as penetrating portions that allow the front surface side and the back surface side of the spiral blade 20 to communicate with each other. The pair of cutout portions 21f are configured to be openable and closable by 30 support pieces 32. This point is different from the rotary penetration pile Aa of the second embodiment described above, and the other portions are the same. It is the same as the rotary penetrating pile Ae of the fourth embodiment described above in that the notch 21f can be opened and closed by the support piece 32. When the rotary penetration pile Ah is rotated forward / reversely and the tip portion of the pile body 10 is moved up and down a plurality of times in the support layer S, as shown in FIG. Thus, the earth and sand excavated by the spiral blade 20 and the enlarged excavating blade 30 and the curable fluid ejected from the jet port 40 flow from the surface side of the spiral blade 20 to the back surface side or from the back surface side to the surface side. The stirring and mixing by the flow of the earth and sand and the curable fluid performed through the notch 21f is added to the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30, whereby the sand and the curable fluid are stirred and mixed. As a result, the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed. In the sixth embodiment, unlike the fifth embodiment in which the through hole 21d is also provided, the notch portion 21f can be opened and closed by the support piece 32, and the rotary penetrating pile Ah is rotated forward to rotate in the ground. When penetrating, as shown in FIG. 13A, the notch portion 21 f is closed by the support piece 32 of the enlarged excavating blade 30 that is accommodated on the peripheral side of the spiral blade 20. For this reason, it is possible to prevent the ground reaction force from leaking through the notch 21f during the rotation penetration, and to prevent the rotation propulsion force from being lowered into the ground due to the provision of the notch 21f. When the notched portion 21f rotates the rotary penetrating pile Ah in the reverse direction and pulls it up from the ground, the notched portion 21f is formed in the radial direction of the pile main body 10 from the peripheral side of the spiral blade 20 as shown in FIG. It is opened by the support piece 32 of the extended digging blade 30 protruding. In addition, in the rotary penetrating pile Ah of the sixth embodiment, as in the rotary penetrating pile A of the first embodiment described above, the support force can be increased by the enlarged excavating blade 30, and the mark 70 (FIG. 1 (a) and the like), it is possible to detect that the enlarged excavation blade 30 protrudes from the peripheral edge of the spiral blade 20 to the radially outer side of the pile body 10 in the ground. In addition, the enlarged excavation blade 30 can be reliably projected outward in the radial direction of the pile body 10 at the initial stage of rotation in which the pile body 10 is rotated in the reverse direction.

  The rotating penetrating pile of the present invention includes a rotating penetrating pile A shown in FIG. 1 (a), the rotating penetrating pile Aa shown in FIG. 4 (a), the rotating penetrating pile Ab shown in FIG. a) a rotary penetrating pile Ac shown in FIG. 9 (a), a rotary penetrating pile Ae shown in FIG. 10 (a), a rotary penetrating pile Af shown in FIG. 11 (a), FIG. It is not limited to the rotation penetration pile Ag shown to (a) etc., the rotation penetration pile Ah etc. shown to FIG.

  Moreover, in the construction method of the solidified foundation using the rotation penetration pile of this invention, when the rotation penetration pile A shown to FIG. 1 (a), (b) etc. is used (FIG. 6 (a) thru | or (e). However, the present invention is not limited to this. For example, the rotary penetrating pile Aa shown in FIG. 4 (a), the rotary penetrating pile Ab shown in FIG. 7 (a), FIG. 8 (a), etc. Rotating penetrating pile Ac shown in FIG. 9 (a), rotating penetrating pile Ad shown in FIG. 10 (a), rotating penetrating pile Af shown in FIG. 11 (a), FIG. 12 (a). A rotary penetrating pile Ag shown in FIG. 13 or a rotary penetrating pile Ah shown in FIG.

  For example, when the rotary penetrating pile Ab shown in FIG. 7 (a) or the like is used, the tip portion of the pile body 10 is moved up and down within the support layer S (between a predetermined position and a predetermined depth) (the rotation). During the repetition of the penetration step and the rotary pulling step), the stirring and mixing by the flow of the earth and sand and the curable fluid performed through the through hole 21 is performed by the stirring and mixing using the spiral blade 20 and the enlarged excavating blade 30. In addition, the stirring and mixing of the earth and sand and the curable fluid is further promoted, and the root-solidified body F in which the earth and sand and the curable fluid are uniformly mixed can be formed.

  The rotary penetration pile of the present invention and the method for constructing the foundation using the rotary penetration pile are applied when the push-in support force and the pull-out support force are improved without increasing the outer diameter of the spiral blade. .

A, Aa Rotating penetration pile Ab, Ac Rotating penetration pile Ad, Ae Rotating penetration pile Af, Ag Rotating penetration pile Ah Rotating penetration pile S Support layer F Rooting body 10 Pile body 11 Outer cylinder 12 Inner cylinder 13 Bottom lid 20 Spiral wing 21 through hole 21a cutout portion 21b through hole 21c through hole 21d through hole 21e through hole 21f cutout portion 22 guide portion 22a guide portion 30 enlarged excavation blade 40 jet outlet 60 curable fluid supply pipe 70 mark 80 pin 81 groove portion

Claims (11)

A pile body comprising an outer cylinder, and an inner cylinder disposed in the distal end portion of the outer cylinder with the closed tip exposed from the outer cylinder;
A spiral wing provided along an outer peripheral surface near the tip of the inner cylinder exposed from the outer cylinder;
An enlarged excavation blade provided on the spiral wing so as to protrude radially outward of the pile body;
A curable fluid jet port provided at a peripheral surface portion of the inner cylinder that is covered with the outer cylinder so as to be opened and closed;
The outer cylinder is movable a predetermined distance in the axial direction while rotating a predetermined angle with respect to the inner cylinder when rotating the pile main body in a direction opposite to the direction of rotating and penetrating into the ground.
The enlarged excavation blade is accommodated on the peripheral side of the spiral blade when the pile body is rotated and penetrated into the ground, and is rotated into the inner cylinder when the pile body is rotated in a direction opposite to the direction of the rotation penetration. Projecting radially outward of the pile body from the periphery of the spiral wing by the outer cylinder rotating against,
When the pile main body is rotated in a direction opposite to the direction in which the rotation is inserted, the enlarged excavating blade moves to a peripheral edge of the spiral blade by utilizing the fact that the outer cylinder moves a predetermined distance in the axial direction with respect to the inner cylinder. It detects that it protruded to the radial direction outer side of the said pile main body from the rotation penetration pile characterized by the above-mentioned. In the rotation penetration pile according to claim 1,
Screw portions having the same pitch as the pitch of the spiral blades are provided on the inner peripheral surface of the tip portion of the outer tube and the outer peripheral surface of the inner tube, and the inner tube is placed in the tip portion of the outer tube through these screw portions. Rotating penetrating pile characterized by being screwed onto. In the rotation penetration pile of the foundation pile according to claim 1 or 2,
The spout is provided between the end portions of the spiral wing on the peripheral surface of the inner cylinder, and when the pile main body is rotated and penetrated into the ground, it is covered by the outer cylinder and the pile main body is rotated and penetrated. When rotating in a direction opposite to the direction, the outer cylinder rotates relative to the inner cylinder and is not covered by the outer cylinder. In the rotation penetration pile according to claim 2 or 3,
When the outer cylinder rotates relative to the inner cylinder and moves in the axial direction by a predetermined pitch when the pile main body is rotated in a direction opposite to the direction in which the pile body rotates and penetrates into the ground, the outer cylinder is moved relative to the inner cylinder. A rotary penetrating pile provided with a stopper for stopping movement. In the rotation penetration pile as described in any one of Claims 1 thru | or 4,
The rotary excavation pile, wherein the enlarged excavation blade is provided so as to be capable of swinging with respect to the spiral blade. In the rotation penetration pile according to claim 5,
The enlarged excavating blade is rotated by being pushed by the outer cylinder rotating with respect to the inner cylinder when rotating the pile main body in a direction opposite to the direction in which the pile main body is rotated and penetrated, from the periphery of the spiral blade A rotary penetrating pile characterized by projecting radially outward of the pile body. In the rotation penetration pile according to claim 5,
A pin is provided in the outer cylinder in parallel with the axial direction of the outer cylinder, and a groove part is provided at the end of the enlarged excavation blade so that the pin is slidably engaged.
When the enlarged excavating blade rotates the pile main body in a direction opposite to the direction of the rotation penetration, the pin moves in the groove portion with the outer cylinder rotating with respect to the inner cylinder. A rotary penetrating pile that rotates and protrudes radially outward from the periphery of the spiral wing. In the rotation penetration pile according to claim 5,
A rotary penetrating pile characterized in that the spiral blade is provided with a penetrating portion for communicating one surface side with the other surface side. In the rotation penetration pile according to claim 8,
The enlarged excavation blade includes a support piece provided so as to be swingable with respect to the spiral blade, and an excavation blade piece provided at an outer end portion of the support piece and extending in the axial direction of the pile body,
The penetration part is closed by the support piece when the pile body is rotated and penetrated into the ground, and is opened by the support piece when the pile body is rotated in a direction opposite to the direction of the rotation penetration. Thus, it is comprised so that opening and closing is possible using the said support piece, The rotation penetration pile characterized by the above-mentioned. A construction method for a solidified foundation that uses a rotating intrusion pile,
A pile body comprising an outer cylinder, and an inner cylinder disposed in the distal end portion of the outer cylinder with the closed tip exposed from the outer cylinder;
A spiral wing provided along an outer peripheral surface near the tip of the inner cylinder exposed from the outer cylinder;
An enlarged excavation blade provided on the spiral wing so as to protrude radially outward of the pile body;
A curable fluid jet port provided at a peripheral surface portion of the inner cylinder that is covered with the outer cylinder so as to be opened and closed;
The outer cylinder moves a predetermined distance in the axial direction while rotating a predetermined angle with respect to the inner cylinder when rotating the pile body in a direction opposite to the direction of rotating and penetrating into the ground,
The enlarged excavation blade is accommodated on the peripheral side of the spiral blade when the pile body is rotated and penetrated into the ground, and is rotated into the inner cylinder when the pile body is rotated in a direction opposite to the direction of the rotation penetration. Projecting radially outward of the pile body from the periphery of the spiral wing by the outer cylinder rotating against,
The spout is covered with the outer cylinder when the pile body is rotated and penetrated into the ground, and the outer cylinder is rotated with respect to the inner cylinder when the pile body is rotated in a direction opposite to the direction of the rotation penetration. And use a rotating intrusion pile,
A preparation step of disposing a curable fluid supply pipe on the pile body;
Rotating penetration step of rotating the pile main body and rotating and penetrating to a predetermined depth in the ground by the propulsive force of the spiral wing,
Using the fact that the outer cylinder moves a predetermined distance in the axial direction while rotating with respect to the inner cylinder at the initial stage of rotation in which the pile main body is rotated in a direction opposite to the direction of the rotation penetration, the enlarged excavation A confirmation step for confirming that the blade protrudes radially outward of the pile body from the periphery of the spiral blade;
After the confirmation step, the pile main body is not covered by the outer cylinder from the curable fluid supply pipe while rotating in the direction opposite to the direction in which the pile body is rotated and pulled up from the predetermined depth to a predetermined position. A rotary pulling step of excavating the ground around the spiral wing with the enlarged excavating blade while ejecting the curable fluid through an ejection port, and
During the repetition of the rotary penetration step and the rotary pulling step between the predetermined position and the predetermined depth, the hardened material ejected from the earth and sand excavated by the spiral blade and the enlarged excavation blade and the ejection port A construction method for a solidified foundation using a rotating penetrating pile, characterized by stirring and mixing with a fluid. A construction method for a solidified foundation that uses a rotating intrusion pile,
A pile body comprising an outer cylinder, and an inner cylinder disposed in the distal end portion of the outer cylinder with the closed tip exposed from the outer cylinder;
A spiral wing provided along an outer peripheral surface near the tip of the inner cylinder exposed from the outer cylinder;
A penetrating portion for communicating one surface side and the other surface side of the spiral blade;
An enlarged excavation blade provided on the spiral wing so as to protrude radially outward of the pile body;
A curable fluid jet port provided at a peripheral surface portion of the inner cylinder that is covered with the outer cylinder so as to be opened and closed;
The outer cylinder moves a predetermined distance in the axial direction while rotating a predetermined angle with respect to the inner cylinder when rotating the pile body in a direction opposite to the direction of rotating and penetrating into the ground,
The enlarged excavation blade is accommodated on the peripheral side of the spiral blade when the pile body is rotated and penetrated into the ground, and is rotated into the inner cylinder when the pile body is rotated in a direction opposite to the direction of the rotation penetration. Projecting radially outward of the pile body from the periphery of the spiral wing by the outer cylinder rotating against,
The spout is covered with the outer cylinder when the pile body is rotated and penetrated into the ground, and the outer cylinder is rotated with respect to the inner cylinder when the pile body is rotated in a direction opposite to the direction of the rotation penetration. And use a rotating intrusion pile,
A preparation step of disposing a curable fluid supply pipe on the pile body;
Rotating penetration step of rotating the pile main body and rotating and penetrating to a predetermined depth in the ground by the propulsive force of the spiral wing,
Using the fact that the outer cylinder moves a predetermined distance in the axial direction while rotating with respect to the inner cylinder at the initial stage of rotation in which the pile main body is rotated in a direction opposite to the direction of the rotation penetration, the enlarged excavation A confirmation step for confirming that the blade protrudes radially outward of the pile body from the periphery of the spiral blade;
After the confirmation step, the pile main body is not covered by the outer cylinder from the curable fluid supply pipe while rotating in the direction opposite to the direction in which the pile body is rotated and pulled up from the predetermined depth to a predetermined position. A rotary pulling step of excavating the ground around the spiral wing with the enlarged excavating blade while ejecting the curable fluid through an ejection port, and
During the repetition of the rotary penetration step and the rotary pulling step between the predetermined position and the predetermined depth, the hardened material ejected from the earth and sand excavated by the spiral blade and the enlarged excavation blade and the ejection port The fluid is stirred and mixed, and is excavated by the spiral blade and the expansion excavation blade from the one surface side of the spiral blade to the other surface side or the other surface side to the one surface side through the penetration portion. A method for constructing a solidified foundation using a rotating intrusion pile, wherein the earth and sand and the curable fluid are fluidized and mixed with stirring.