JP4210297B2 - Expanded pipe with tip blade and steel pipe pile with tip blade provided with the same - Google Patents

Description

  The present invention includes a diameter-enlarged tube with a tip blade that can be constructed in a short time by being connected to the tip of a pile body buried in the ground, and can obtain a large tip support force after being buried, and the same. The present invention relates to a steel pipe pile with a tip blade.

Conventionally, various screwed piles have been proposed that are embedded in the ground by the action of the wing plate by attaching a wing plate to the tip and side of the pile and applying a rotational force using a construction machine installed on the ground. It can be constructed with low vibration, low noise and no soil, and after embedding, it can be put into practical use in the field of civil engineering and construction because it can obtain a large tip support force by utilizing the area of the wing plate.
For example, (Patent Document 1) discloses “a screwed pile having a diameter-increased portion provided at a tip portion of a pile body, and a wing provided at least at the tip portion of the diameter-expanded portion or in the vicinity thereof”. ing.
In addition, (Patent Document 2) states that “the pile is divided into a tip portion consisting of a steel pipe, a digging blade, and a blade, and a tip portion that is connected to the upper side of the tip portion, and the tip portion and the supplement portion of the tip portion are supplemented. An assembly-type steel pipe pile having a structure in which a steel pipe can be arbitrarily selected and connected by an appropriate means is disclosed.
JP 2002-348863 A JP 2004-316411 A

However, the above conventional techniques have the following problems.
(1) Since the screwed pile of (Patent Document 1) has a straight shape in which the tip surface of the wing extends straight in the radial direction, when the screwed pile is rotated, the entire surface (radial direction of the blade) Since the entire width) penetrates into the earth and sand at the same time, the resistance during construction is large, the torque required for screwing is also large, construction takes time, and deformation or breakage occurs at the tip of the wing due to the load. It had the subject that it was easy to do and lacked workability.
(2) Since the assembly type steel pipe pile of (Patent Document 2) has blades arranged only on the outer periphery of the steel pipe, the ground contact area is narrow and the tip support force is insufficient. The number had to be increased, and had the problem of lacking in resource saving and workability. Further, by providing a drilling blade at the tip of the steel pipe, the drillability can be improved, but the number of parts increases and the mass productivity is lacking, and the tip surface of the blade is straight in the radial direction as in (Patent Document 1). Due to the straight shape extending in the direction, the tip of the blade is likely to be loaded at the time of construction, and deformation and breakage are likely to occur. In addition, when reinforcing plates and struts are provided to reinforce the blades, the number of parts increases and mass productivity is lacking, the tip becomes larger, the shape becomes complicated, and it is easy to receive resistance in the soil. However, it had a problem of lacking in workability and workability.

  The present invention solves the above-mentioned conventional problems, has a simple structure, has a small number of parts, is excellent in mass productivity, and can be attached to the tip of the pile body to reduce the load during construction and prevent breakage and deformation. Providing a diameter expansion tube with a tip blade with excellent workability and reliability that can be embedded in a short time by providing a diameter expansion tube with a tip blade, providing excellent workability and a large tip support force after embedding Therefore, it is possible to reduce the pipe diameter of the pile body and reduce the number of pipes used. It is excellent in resource saving and handling, and is less likely to be displaced when buried, with low vibration, low noise, and no waste. The purpose is to provide a steel pipe pile with a tip blade with excellent reliability and environmental protection that can be constructed in soil.

In order to solve the above-described conventional problems, the expanded pipe with a tip blade of the present invention and the steel pipe pile with the tip blade having the same have the following configurations.
The diameter expansion tube with a tip blade according to claim 1 of the present invention is a diameter expansion tube with a tip blade continuously provided at a lower end portion of a pile body formed in a hollow cylindrical shape, from the upper end side to the lower end side. An enlarged diameter portion formed by expanding the diameter, a notch portion formed by spirally cutting a lower end portion of the enlarged diameter portion, and an outer diameter disposed on an end surface of the notch portion. A spiral blade having an inner diameter larger than the maximum diameter of the expanded portion and smaller than a minimum diameter of the expanded portion, a drilling blade formed in an arc shape at a tip portion on the lower end side of the spiral blade, and the expanded diameter The spiral opening is formed in a substantially crescent shape so that the central opening of the spiral blade is not blocked when viewed from the upper end side of the portion, and the spiral is connected to the inner upper surface of the spiral blade and the upper end on the inner peripheral side of the enlarged diameter portion. And a convex guide plate disposed in the same direction as the blades .
With this configuration, the following effects can be obtained.
(1) An enlarged diameter portion formed by expanding the diameter from the upper end side toward the lower end side, a notch portion formed by spirally cutting the lower end portion of the enlarged diameter portion, and an end face of the notch portion Since it has a spiral blade with an outer diameter larger than the maximum diameter of the expanded portion and an inner diameter smaller than the minimum diameter of the expanded portion, it is embedded by connecting the expanded portion to the lower end of the pile body. It is possible to obtain a large tip support force by enlarging the ground contact area later, to reduce the pipe diameter of the pile body, to reduce the number of pipes used, and to improve resource saving and workability.
(2) Since the spiral blades are arranged on the end face of the cutout part formed by cutting out the lower end part of the enlarged diameter part in a spiral shape, the construction is attached to the lower end part of the pile body and installed on the ground. By giving a rotational force using a machine, it can be easily embedded in the ground by the action of the spiral blades, and is excellent in workability.
(3) Since the diameter-expanded portion is formed by expanding from the upper end side toward the lower end side, the distance from the outer peripheral surface of the lower end of the diameter-expanded portion to the outer periphery of the spiral blade can be shortened. The bending moment generated by the external force during construction can be reduced, the deformation of the spiral blade can be effectively prevented, and the durability is excellent.
(4) By having the excavating blade formed in an arc shape at the tip portion on the lower end side of the spiral blade, the tip portion of the spiral blade easily enters the ground during rotation, and the earth and sand are formed in an arc shape. It is easy to flow to the rear of the spiral blade along the excavation blade, and the resistance applied to the spiral blade can be reduced, so that deformation and breakage of the spiral blade can be prevented, and the workability and reliability are excellent. .
(5) Since the inner diameter of the spiral blade is smaller than the minimum diameter of the expanded portion, the earth and sand loosened and fluidized by the spiral blade during construction moves along the upper surface of the spiral blade. In addition, it can easily enter the inside of the enlarged diameter portion, can shorten the construction time, and is excellent in workability.
(6) By having a convex guide plate portion arranged in a spiral shape connecting the upper surface of the spiral blade and the upper end of the enlarged diameter portion, loosen the earth and sand that has entered the inside of the enlarged diameter portion by the convex guide plate. Since it can be fluidized and earth and sand can be guided and moved from the upper surface of the spiral blade along the convex guide plate to the upper end of the enlarged diameter portion, the torque required for screwing can be reduced and construction can be performed. Time can be shortened and workability is excellent.
(7) Since most of the convex guide plate overlaps with the spiral blade and the central opening of the spiral blade is not blocked by the convex guide plate, an increase in resistance can be prevented, and Intrusion of earth and sand into the interior is not hindered, and workability is excellent.
(8) By arranging the convex guide plate in a spiral shape in the same direction as that of the spiral blade, the earth and sand that has entered the inside of the enlarged diameter portion smoothly flows from the upper surface of the spiral blade along the upper surface of the convex guide plate. And is reliably guided to the upper end of the enlarged diameter portion.

  Here, as the diameter-enlarged portion, it is only necessary to increase the diameter from the upper end side toward the lower end side, and the peripheral wall between the upper end portion and the lower end portion may be formed linearly or curved. You may form in. In particular, when a diameter-enlarged portion in which the peripheral wall between the upper end portion and the lower end portion is formed in a curved shape like a reducer used for connection of tubes having different tube diameters, the diameter can be enlarged at a short distance, It is possible to increase the rigidity by taking a large area of the large diameter portion, and it is excellent in durability and stability of the tip support force.

The cutout portion is formed for one turn at the lower end portion of the enlarged diameter portion so as to correspond to one turn of the spiral blade. The spiral blade can be easily formed by cutting one portion of a flat plate-like annular member in an arc shape in the radial direction. By forming an inclined rake face on the end face cut in an arc shape, the tip of the spiral blade becomes an excavating blade. If the cutting surface is inclined from the beginning when the annular member is cut, a spiral blade having an arcuate excavation blade can be formed by only one cutting process, which is easy to process and excellent in mass productivity.
Although the spiral blade is cut at the tip portion, it remains in an annular shape in a plan view, so that the ground contact area is not reduced and the tip support force can be ensured.
In addition, the outer diameter and inner diameter of the spiral blade can be appropriately selected according to the necessary tip support force, the diameter of the pile body, and the like.

It is preferable to form the convex guide plate so as to have a substantially crescent shape when viewed from the upper end side of the enlarged diameter portion. The wider the convex guide plate, the more soil can be scraped up, and the sand that has entered the inside of the enlarged diameter part can be cut finely. Since the torque increases, it is desirable that the position of the string is within the range of the spiral blade or slightly protrudes from the central opening. As a result, most of the convex guide plate overlaps with the spiral blade, and the central opening of the spiral blade is not blocked by the convex guide plate. Intrusion of earth and sand into the interior is not hindered, and workability is excellent.

The mounting angle of the convex guide plate is preferably larger than the inclination of the spiral blade. This is because the moving distance of the earth and sand can be shortened, and the earth and sand can be scraped up to the upper end side of the enlarged diameter portion in a short time, and the workability is excellent. Specifically, although depending on the inclination of the spiral blade, the mounting angle of the convex guide plate is preferably 30 to 50 degrees. As the mounting angle of the convex guide plate becomes smaller than 30 degrees, the total length of the convex guide plate becomes longer, the shape becomes complicated, and it becomes difficult to process and attach to the enlarged diameter part, so that mass productivity tends to decrease. There is a tendency, and as it becomes larger than 50 degrees, the earth and sand tend to slip on the convex guide plate, and it tends to be difficult to reliably guide the earth and sand to the upper end side of the enlarged diameter portion, which is not preferable.
The number of convex guide plates is preferably 1 to 3, although it depends on the size of the enlarged diameter portion and the mounting angle of the convex guide plates. As the number of the convex guide plates is more than 3, the convex guide plates are easily overlapped with each other, and it is difficult to reliably weld the convex guide plates to the enlarged diameter portion, and the productivity is lowered. There is a tendency that the internal resistance of the enlarged diameter part increases during burial work, and the workability tends to deteriorate.
There is not preferable.

The invention according to claim 2 is the expanded pipe with a tip blade according to claim 1, wherein the peripheral wall between the upper end portion and the lower end portion of the enlarged diameter portion is formed in a curved shape. is doing.
With this configuration, in addition to the operation obtained in the first aspect, the following operation can be obtained.
(1) When the diameter-enlarged portion in which the peripheral wall between the upper end portion and the lower end portion is formed in a curved shape is used, the diameter can be enlarged at a short distance, and the large-diameter portion area is widened to increase the rigidity. It can be increased and has excellent durability and stability of the tip support force.

A third aspect of the present invention is the diameter-enlarged tube with a tip blade according to the first or second aspect , and is disposed to be inclined toward the upper end side of the expanded-diameter portion so as to face the convex guide plate. It has the structure provided with the auxiliary convex guide part.
With this configuration, in addition to the operation obtained in the first or second aspect , the following operation can be obtained.
(1) By having an auxiliary convex guide portion that is opposed to the convex guide plate and is inclined to the upper end side of the enlarged diameter portion, the convex guide is provided without increasing the resistance inside the enlarged diameter portion. The earth and sand which penetrate | invaded the inside of the enlarged diameter part with the board can be efficiently moved to the upper end of the enlarged diameter part, and it is excellent in the efficiency at the time of construction.
(2) By placing the convex guide plate and the auxiliary convex guide portion facing each other, the load applied to the convex guide plate and the auxiliary convex guide portion can be dispersed. Deformation and breakage of the guide part can be prevented and the reliability is excellent.

Here, the direction of the inclination of the auxiliary convex guide portion is the same as the direction of the inclination of the convex guide plate, so that the earth and sand inside the enlarged diameter portion becomes convex with the rotation of the enlarged tube with the tip blade. It can move smoothly along the guide plate and the auxiliary convex guide part. In particular, by making the attachment angle of the auxiliary convex guide portion equal to the attachment angle of the convex guide plate, the earth and sand are inclined at a substantially constant angle along the convex guide plate and the auxiliary convex guide portion inside the enlarged diameter portion. As it rises while rotating, the flow of earth and sand is smooth and excellent in workability.
The width and length of the auxiliary convex guide portion can be appropriately selected in consideration of the load during rotation. In particular, as the width of the auxiliary convex guide portion is wider, a larger amount of earth and sand can be guided and scraped up, but if it extends to the central opening portion, resistance increases during rotation and torque increases, which is not preferable.

In addition, the attachment range of the auxiliary convex guide part depends on the shape of the enlarged diameter part and the attachment angle of the auxiliary convex guide part, but from 1/4 to 1/1 of the total length of the enlarged diameter part from the upper end side of the enlarged diameter part. It is preferable to arrange in the range of 3. As the attachment range of the auxiliary convex guide part becomes narrower than 1/4 of the total length of the enlarged diameter part, the moving distance of the earth and sand tends to be short, and it becomes difficult to sufficiently guide the earth and sand, from 1/3 As it becomes wider, it becomes difficult to attach the auxiliary convex guide portion along the inner peripheral surface of the enlarged diameter portion, and the productivity tends to decrease, which is not preferable.
In addition, when the auxiliary convex guide part is divided into a plurality of parts in the longitudinal direction and arranged also at the center part and the lower end part of the entire length of the enlarged diameter part, the earth and sand are reliably guided from the lower end side to the upper end side of the enlarged diameter part. Can do. Also, by dividing the auxiliary convex guide part, the auxiliary convex guide part can be easily attached along the shape of the inner peripheral surface of the enlarged diameter part, thus simplifying the shape of the auxiliary convex guide part It is possible to prevent deterioration of workability and productivity. In addition, you may arrange | position a some auxiliary | assistant convex guide part in parallel with respect to one convex guide plate.

Invention of Claim 4 is a diameter expansion pipe with a tip blade | wing of any one of Claim 1 thru | or 3, Comprising: The protruding item | line part arrange | positioned by the internal peripheral surface of the said diameter expansion part, and It has the structure provided with the projection part.
With this configuration, in addition to the action obtained in any one of claims 1 to 3, the following action is obtained.
(1) By having the ridges and / or protrusions disposed on the inner peripheral surface of the enlarged diameter portion, the earth and sand inside the enlarged diameter portion can be guided and scraped up to the upper end side of the enlarged diameter portion; It can be rotated while finely cutting the earth and sand in the vicinity of the inner peripheral surface of the enlarged diameter portion, the torque required for screwing can be reduced, and workability can be improved.
(2) By forming ridges and / or protrusions on the inner peripheral surface of the enlarged diameter portion, the surface area of the inner peripheral surface of the enlarged diameter portion can be increased to increase the contact area with the earth and sand. And the inner peripheral surface of the enlarged diameter part are improved, and the stability of the tip support force after embedding is excellent.

Here, the shape, number, and arrangement of the ridges and / or protrusions can be selected as appropriate. For example, one ridge may be arranged in a spiral shape, and a plurality of ridges and / or projections may be arranged regularly or irregularly. The wider the ridge, the greater the amount of earth and sand that can be guided and scraped, but if it protrudes far to the center opening, it will become a resistance during rotation and torque will increase, so it will fit within the spiral blade range. Preferably, it is formed so that it slightly protrudes from the central opening. Further, the length and inclination are determined in consideration of resistance and strength during rotation.
The protrusion can be formed in any shape such as a rod shape, a cone shape, or a pyramid shape. The longer the protrusion protrudes to the inside of the enlarged diameter part, the more the earth and sand inside the enlarged diameter part can be agitated and cut, but if it becomes too long, the resistance increases during rotation and the torque increases. Since it is easy for damage such as deformation to occur due to hard foreign matter such as concrete or a lump of concrete, it is preferable to form it to a length that fits within the range of the spiral blades or to protrude slightly to the central opening. The thickness is determined in consideration of resistance and strength during rotation.
If the slope of the ridge is inclined in the same direction as the spiral blade or the convex guide plate, the earth and sand inside the enlarged diameter part can easily move along the ridge, reducing the torque required for screwing. It is possible to improve the earth and sand scraping effect. In addition, when the slope of the ridge is inclined in the opposite direction to the spiral blades or the convex guide plate, the earth and sand inside the enlarged diameter part can be efficiently loosened and fluidized, The effect can be improved.

The steel pipe pile with a tip blade according to claim 5 of the present invention is a pile main body formed in a hollow cylindrical shape and any one of claims 1 to 4 continuously provided at a lower end portion of the pile main body. It has the structure provided with the diameter expansion pipe with a front-end | tip blade | blade of description.
With this configuration, the following effects can be obtained.
(1) An existing pile body can be embedded in a short time by connecting a diameter-expanded pipe with a tip blade to the lower end of the pile body formed in a hollow cylindrical shape. After that, a large tip support force can be obtained, so that the pipe diameter of the pile body can be reduced and the number of pipes used can be reduced, and resource saving and handling are excellent.

Here, the diameter expansion pipe with a tip blade can cope with the difference in the pipe diameter of the pile body by preparing a plurality of pipe diameters (minimum diameters) at the upper end of the diameter expansion portion. Prepare diameter expansion pipes with tip blades with different dimensions in advance, and fix them as many times as necessary to the bottom of the pile body by welding, greatly reducing the cost of materials procurement, storage and transportation it can.
Moreover, the combination of the pile body and the expanded pipe with the tip blade can be selected as appropriate and can be easily assembled on site, so the steel pipe pile with the tip blade can be supplied according to the progress of the work. It is easy to manage delivery times and inventory such as transportation, and has excellent handling.

As described above, according to the expanded pipe with a tip blade of the present invention and the steel pipe pile with a tip blade provided with the same, the following advantageous effects can be obtained.
According to the invention of claim 1,
(1) When the pile body is rotated during burial construction, the arc-shaped excavation blade formed at the tip on the lower end side of the spiral blade is likely to enter the ground, and the resistance applied to the spiral blade is reduced. Therefore, it is easy to flow the earth and sand to the rear of the spiral blade along the excavating blade, and it is possible to prevent the deformation and breakage of the spiral blade. Can be provided.
(2) Since the inner diameter of the spiral blade is smaller than the minimum diameter of the expanded portion, the earth and sand loosened and fluidized by the spiral blade during construction moves along the upper surface of the spiral blade. In addition, it is possible to provide a diameter-expanded pipe with a tip blade excellent in workability that can easily enter the inside of the diameter-expanded portion and can shorten the construction time.
(3) By the convex guide plate portion arranged in a spiral shape connecting the upper surface of the spiral blade and the upper end of the enlarged diameter portion, the earth and sand that has entered the enlarged diameter portion can be loosened and fluidized. Can be guided and moved from the upper surface of the blade to the upper end of the enlarged diameter section along the convex guide plate arranged in a spiral in the same direction as the inclination of the spiral blade, reducing the torque required for screwing Therefore, it is possible to provide a diameter-expanded tube with a tip blade excellent in workability that can shorten the construction time.
(4) Most of the convex guide plate overlaps with the spiral blade, and the central opening of the spiral blade is not blocked by the convex guide plate. Intrusion of earth and sand into the interior is not hindered, and workability is excellent.
(5) By arranging the convex guide plate in a spiral shape in the same direction as that of the spiral blade, the earth and sand that has entered the inside of the enlarged diameter portion smoothly flows from the upper surface of the spiral blade along the upper surface of the convex guide plate. And is reliably guided to the upper end of the enlarged diameter portion.

According to invention of Claim 2, in addition to the effect of Claim 1,
(1) When the diameter-enlarged portion in which the peripheral wall between the upper end portion and the lower end portion is formed in a curved shape is used, the diameter can be enlarged at a short distance, and the large-diameter portion area is widened to increase the rigidity. It can be increased and has excellent durability and stability of the tip support force.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2,
(1) By having an auxiliary convex guide portion that is opposed to the convex guide plate and is inclined to the upper end side of the enlarged diameter portion, the convex guide is provided without increasing the resistance inside the enlarged diameter portion. It is possible to provide a diameter-enlarged pipe with a tip blade excellent in efficiency at the time of construction capable of efficiently moving earth and sand that has entered the inside of the diameter-enlarged part together with the plate to the upper end of the diameter-enlarged part.
(2) By placing the convex guide plate and the auxiliary convex guide portion facing each other, the load applied to the convex guide plate and the auxiliary convex guide portion can be dispersed. It is possible to provide a diameter-expanded tube with a tip blade that can prevent deformation or breakage of the guide portion and has excellent reliability.

According to invention of Claim 4, in addition to the effect of any one of Claims 1 to 3,
(1) The ridges and / or protrusions disposed on the inner peripheral surface of the enlarged diameter portion guide the earth and sand inside the enlarged diameter portion and scrape it up to the upper end side of the enlarged diameter portion, It is possible to provide a diameter-enlarged pipe with a tip blade excellent in handleability that can be rotated while finely cutting the earth and sand near the inner peripheral surface and can reduce the torque required for screwing and improve workability. .
(2) The surface area of the inner peripheral surface of the enlarged diameter portion can be increased by the protruding ridges and / or protrusions formed on the inner peripheral surface of the enlarged diameter portion, and the contact area with the earth and sand can be increased. It is possible to provide a highly reliable diameter-expanded tube with a tip blade that can improve the biting with the inner peripheral surface of the diameter portion and improve the stability of the tip support force after embedding.

According to the invention of claim 5,
(1) It is possible to embed in a short time just by connecting the expanded pipe with the tip blade to the lower end of the existing pile body, and it has excellent workability and can obtain a large tip support force after burying. Further, it is possible to provide a diameter-expanded tube with a tip blade excellent in resource saving and handling properties that can reduce the pipe diameter of the pile body and reduce the number of pipes used.

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 (a) is a plan view of a diameter-expanded tube with a tip blade according to Embodiment 1 of the present invention, and FIG. 1 (b) is a front view of the diameter-expanded tube with a tip blade according to Embodiment 1 of the present invention. 2 is a side view of the expanded pipe with the tip blade according to the first embodiment of the present invention, and FIG. 3 is a bottom view of the expanded pipe with the tip blade according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1.
1 to 4, reference numeral 1 denotes a diameter-expanded pipe with a tip blade according to the first embodiment of the present invention. Reference numeral 2 denotes a diameter-expanded pipe with a tip blade formed by expanding from the upper end 2 a side toward the lower end 2 b side. The enlarged diameter portion 3 is formed by cutting out the lower end portion of the enlarged diameter portion 2 in a spiral shape. The notched portion of the enlarged tube 1 with a tip blade is provided on the end face of the notched portion 3 and has an outer diameter. The spiral blade of the diameter-expanded tube 1 with a tip blade larger than the maximum diameter of the expanded diameter portion 2 and smaller than the minimum diameter of the expanded diameter portion 2, 4 a is the upper surface of the spiral blade 4, and 4 b is the spiral blade 4. The central opening 5 of the enlarged tube 1 with a tip blade formed at the center is an excavation blade 5a of the expanded tube 1 with a tip blade formed in an arc shape at the tip of the lower end side of the spiral blade 4. It is a rake face formed in an inclined shape on the end face of the excavation blade 5.

A reducer in which the peripheral wall between the upper end 2a portion and the lower end 2b portion is formed in a curved shape is used as the enlarged diameter portion 2. As a result, the diameter can be increased at a short distance, and the large diameter region can be widened to increase the rigidity, and the durability and stability of the tip support force are excellent. Moreover, by using the standardized ready-made product as the enlarged diameter part 2, the alignment with the pile body is easy, and the handling property and the mass productivity are excellent.
In addition, the shape of the enlarged diameter part 2 is not limited to this, The surrounding wall between the upper end 2a part and the lower end 2b part may be formed linearly, and it is not shown in FIG.1 (b) It may be formed in a curved shape.

The cutout portion 3 was formed for one turn at the lower end 2b portion of the enlarged diameter portion 2 so as to correspond to the spiral blade 4 for one turn. The spiral blade 4 was formed by cutting one place of a flat plate-like annular member in an arc shape in the radial direction. By forming the inclined rake face 5a on the end face cut in the arc shape, the tip of the spiral blade 4 becomes the excavating blade 5. If the cutting surface is inclined from the beginning when the annular member is cut, the spiral blade 4 having the arcuate excavation blade 5 can be formed by only one cutting process, which is easy to process and excellent in mass productivity. .
Although the spiral blade 4 is cut by the excavating blade 5, as shown in FIGS. 1 and 3, since it remains annular in plan view, the ground contact area at the time of embedding is not reduced, and the tip Support force can be secured.

The steel pipe pile with the tip blades provided with the expanded pipe with the tip blades configured as described above will be described.
FIG. 5 is a front view showing a steel pipe pile with a tip blade provided with a diameter-enlarged tube with a tip blade according to Embodiment 1 of the present invention.
In FIG. 5, 10 is a steel pipe pile with a tip blade provided with a diameter-enlarged tube with a tip blade in the first embodiment, 11 is a hollow cylindrical shape and 11 is a diameter-expanded tube with a tip blade in the first embodiment at the lower end portion 11a. Is a steel pile body that is continuously provided.

The enlarged pipe 1 with the tip blade and the pile body 11 are fixed by welding. The diameter expansion pipe 1 with the tip blade can cope with the difference in the pipe diameter of the pile body 11 by preparing a plurality of pipe diameters (minimum diameters) at the upper end 2a of the diameter expansion part 2. Costs required for procurement, storage, and transportation of materials, since it is only necessary to prepare diameter-expanded pipes 1 with different blades in advance and weld them to the lower end 11a of the pile body 11 when necessary. Can be greatly reduced.
Moreover, since the combination of the pile main body 11 and the diameter expansion pipe 1 with a tip blade | wing can be selected suitably, and it is assembled easily on the site, the steel pipe pile 10 with a tip blade | wing can be supplied according to the progress of work. It is easy to handle due date and inventory management such as assembly and transportation, and is easy to handle.
In addition, the outer diameter and inner diameter of the spiral blade 4 can be appropriately selected according to the necessary tip support force, the diameter of the pile body 11, and the like.

About the steel pipe pile with a tip blade | wing provided with the diameter expansion tube with a tip blade | wing in Embodiment 1 of this invention comprised as mentioned above, the usage method is demonstrated below.
In FIG. 5, by applying a rotational force to the pile body 11 using a construction machine (not shown) installed on the ground, the steel pipe pile 10 with the tip blade provided with the enlarged pipe with the tip blade is buried in the ground. . At this time, since the arcuate excavation blade 5 is formed at the lower end side of the spiral blade 4, the spiral blade 4 easily enters the ground, so that the earth and sand are removed from the excavation blade 5 to the spiral blade 4. It flows smoothly along the upper surface 4a. Further, since the spiral blade 4 has a central opening 4 b and the inner diameter of the spiral blade 4 is smaller than the minimum diameter of the enlarged diameter portion 2, the spiral blade 4 moves along the upper surface 4 a of the spiral blade 4. The earth and sand can easily enter the inside of the enlarged diameter portion 2, and the resistance applied to the spiral blade 4 can be reduced. As a result, misalignment is unlikely to occur, construction can be performed with low vibration, low noise, no soil, and excellent in reliability and environmental protection.

As described above, since the diameter expansion tube with the tip blade in the first embodiment of the present invention is configured, the following operation is obtained.
(1) An enlarged diameter portion 2 formed by expanding the diameter from the upper end 2a side toward the lower end 2b side, and a notch portion 3 formed by helically cutting the lower end 2b portion of the enlarged diameter portion 2; Since it has the spiral blade | wing 4 arrange | positioned at the end surface of the notch part 3 and whose outer diameter is larger than the largest diameter of the enlarged diameter part 2, and whose inner diameter is smaller than the smallest diameter of the enlarged diameter part 2, the lower end part 11a of the pile main body 11 By connecting the enlarged diameter portion 2 continuously, it is possible to increase the ground contact area after embedment and obtain a large tip support force, to reduce the pipe diameter of the pile body 11 and to reduce the number of pipes used. Resource and workability can be improved.
(2) Since the spiral blade 4 is disposed on the end surface of the notch 3 formed by spirally cutting the lower end 2b of the enlarged diameter portion 2, it is attached to the lower end 11a of the pile body 11. By applying a rotational force using a construction machine installed on the ground, it can be easily embedded in the ground by the action of the spiral blade 4 and is excellent in workability.
(3) Since the diameter-expanded portion 2 is formed to increase in diameter from the upper end 2a side toward the lower end 2b side, the distance from the outer peripheral surface of the lower end 2b of the diameter-expanded portion 2 to the outer periphery of the spiral blade 4 is increased. Since it can be shortened, the bending moment generated by the external force during construction can be reduced, the deformation of the spiral blade 4 can be effectively prevented, and the durability is excellent.
(4) By having the excavation blade 5 formed in an arc shape at the tip portion on the lower end side of the spiral blade 4, the tip portion of the spiral blade 4 easily enters the ground during rotation, and the earth and sand are in an arc shape. Since it is easy to flow to the rear of the spiral blade 4 along the formed excavation blade 5 and the resistance applied to the spiral blade 4 can be reduced, deformation and breakage of the spiral blade 4 can be prevented, Excellent workability and reliability.
(5) Since the inner diameter of the spiral blade 4 is smaller than the minimum diameter of the enlarged diameter portion 2, the earth and sand loosened and fluidized by the spiral blade 4 during construction is applied to the upper surface 4 a of the spiral blade 4. When moving along, it is easy to enter the inside of the enlarged diameter portion 2, the construction time can be shortened, and the workability is excellent.

As mentioned above, since the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing in Embodiment 1 of this invention is comprised, the following effects are acquired.
(1) The existing pile main body 11 can be embedded in a short time by connecting the expanded pipe 1 with a tip blade to the lower end portion 11a of the pile main body 11 formed in a hollow cylindrical shape, thereby improving the workability. In addition to being excellent, a large tip support force can be obtained after embedding, so the pipe diameter of the pile body 11 can be reduced and the number of pipes used can be reduced, and resource saving and handling are excellent.

(Embodiment 2)
6 (a) is a plan view of a diameter-expanded tube with a tip blade according to Embodiment 2 of the present invention, and FIG. 6 (b) is a cross-sectional view taken along line BB in FIG. 6 (a). 6 (c) is a partial cross-sectional view taken along the line CC of FIG. 6 (a). In addition, the same thing as Embodiment 1 attaches | subjects the same code | symbol, and abbreviate | omits description.
In FIG. 6, the diameter expansion tube 1 a with the tip blade in the second embodiment is different from the first embodiment in that the lower end portion 6 a is in contact with the upper surface 4 a of the spiral blade 4 and the upper end portion 6 b is the upper end of the diameter expansion portion 2. The convex guide plate 6 having a substantially crescent shape arranged in a spiral shape so as to reach 2a, and the auxiliary convex shape arranged opposite to the convex guide plate 6 and inclined toward the upper end 2a side of the enlarged diameter portion 2 It is a point provided with the guide part 7.

When viewed from the upper end 2a side of the enlarged diameter portion 2, the convex guide plate 6 was formed so as to have a substantially crescent shape. As the width of the convex guide plate 6 is wider, a larger amount of earth and sand can be scraped up, and the earth and sand that has entered the inside of the enlarged diameter portion 2 can be cut finely. Since the torque sometimes increases due to resistance, it is preferable that the position of the string falls within the range of the spiral blade 4 or slightly protrudes from the central opening 4b. Since most of the convex guide plate 6 overlaps with the spiral blade 4 and the central opening 4b of the spiral blade 4 is not blocked by the convex guide plate 6, it is possible to prevent an increase in resistance and to expand the diameter. Intrusion of earth and sand into the inside of the part 2 is not hindered and the workability is excellent.
In addition, by arranging the convex guide plate 6 in a spiral shape in the same direction as the spiral blade 4, the earth and sand that has entered the inside of the enlarged diameter portion 2 can be removed from the upper surface 4 a of the spiral blade 4 by the convex guide plate 6. It moves smoothly along the upper surface and is reliably guided to the upper end 2a of the enlarged diameter portion 2.

The attachment angle of the convex guide plate 6 was selected in the range of 30 to 50 degrees so as to be larger than the inclination of the spiral blade 4. As the mounting angle of the convex guide plate 6 becomes smaller than 30 degrees, the total length of the convex guide plate 6 becomes longer, the shape becomes complicated, and it becomes difficult to process and attach to the enlarged diameter portion 2, thereby reducing mass productivity. As it becomes larger than 50 degrees, the earth and sand tend to slip on the convex guide plate 6 and it becomes difficult to reliably guide the earth and sand to the upper end 2a side of the enlarged diameter portion 2. It is because it was understood. Further, by making the mounting angle of the convex guide plate 6 larger than the inclination of the spiral blade 4, the moving distance of the earth and sand can be shortened, and the earth and sand are scraped up to the upper end 2a side of the enlarged diameter portion 2 in a short time. It can be used and has excellent workability.
In the present embodiment, only one convex guide plate 6 is disposed, but the number of the convex guide plates 6 is 1 to 3 depending on the size of the enlarged diameter portion 2 and the mounting angle of the convex guide plate 6. The range can be selected. As the number of the convex guide plates 6 exceeds 3, the convex guide plates 6 tend to overlap with each other, and it becomes difficult to reliably weld the convex guide plates 6 to the enlarged diameter portion 2, thereby increasing productivity. It is because it was found that the resistance inside the enlarged-diameter portion 2 was increased during burying construction, and the workability tends to be lowered.

By making the direction of the inclination of the auxiliary convex guide part 7 the same as the direction of the inclination of the convex guide plate 6, the earth and sand inside the enlarged diameter part 2 with the rotation of the enlarged diameter pipe 1a with the tip blades, It can move smoothly along the convex guide plate 6 and the auxiliary convex guide portion 7. In particular, by making the attachment angle of the auxiliary convex guide portion 7 equal to the attachment angle of the convex guide plate 6, the earth and sand follow the convex guide plate 4 and the auxiliary convex guide portion 6 inside the enlarged diameter portion 2. Therefore, the earth and sand flow is smooth and the workability is excellent.
In addition, the width | variety, length, etc. of the auxiliary | assistant convex guide part 7 can be suitably selected in consideration of the load at the time of rotation. In particular, as the width of the auxiliary convex guide portion 7 is wider, a larger amount of earth and sand can be guided and scraped up, but if it protrudes to the central opening portion 4b, it becomes undesirably increased in resistance and torque during rotation.

Moreover, although the attachment range of the auxiliary convex guide part 7 depends on the shape of the enlarged diameter part 2 and the attachment angle of the auxiliary convex guide part 7, the entire length of the enlarged diameter part 2 from the upper end 2a side of the enlarged diameter part 2 is increased. It arrange | positioned in the range of 1 / 4-1 / 3. As the attachment range of the auxiliary convex guide portion 7 becomes narrower than 1/4 of the total length of the enlarged diameter portion 2, the moving distance of the earth and sand tends to be short, and it becomes difficult to sufficiently guide the earth and sand. This is because as it becomes wider than 3, it becomes difficult to attach the auxiliary convex guide portion 7 along the inner peripheral surface of the enlarged diameter portion 2, and it has been found that the productivity tends to decrease. A plurality of auxiliary convex guide portions 7 may be arranged in parallel with respect to one convex guide plate 6.
The enlarged pipe 1a with the tip blade in the second embodiment can be fixed to the lower end portion 11a of the pile body 11 by welding as in the first embodiment and used as a steel pipe pile with the tip blade.
Moreover, since it is the same as that of Embodiment 1 about the usage method of the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing in Embodiment 2, description is abbreviate | omitted.

As described above, since the expanded pipe with the tip blade in the second embodiment of the present invention is configured, the following actions are obtained in addition to the actions obtained in the first embodiment.
(1) By having the convex guide plate portion 6 arranged in a spiral shape connecting the upper surface 4a of the spiral blade 4 and the upper end 2a of the enlarged diameter portion 2, the earth and sand that has entered the inside of the enlarged diameter portion 2 is projected. It is possible to loosen and fluidize by the guide plate 6 or to move the earth and sand from the upper surface 4a of the spiral blade 4 along the convex guide plate 6 to the upper end 2a of the enlarged diameter part 2 The torque required for the operation can be reduced, the construction time can be shortened, and the workability is excellent.
(2) Increasing the resistance inside the enlarged diameter portion 2 by having the auxiliary convex guide portion 7 that is opposed to the convex guide plate 6 and is inclined and arranged on the upper end 2a side of the enlarged diameter portion 2. In addition, the earth and sand inside the enlarged diameter portion 2 together with the convex guide plate 6 can be efficiently moved to the upper end 2a of the enlarged diameter portion 2, and the construction efficiency is excellent.
(3) By disposing the convex guide plate 6 and the auxiliary convex guide portion 7 so as to face each other, the load applied to the convex guide plate 6 and the auxiliary convex guide portion 7 can be dispersed. The deformation and breakage of the plate 6 and the auxiliary convex guide portion 7 can be prevented, and the reliability is excellent.

  As mentioned above, since the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe | tube with a tip blade | wing in Embodiment 2 of this invention is comprised, the effect | action similar to the effect | action obtained in Embodiment 1 is acquired.

(Embodiment 3)
FIG. 7 is a cross-sectional view of a diameter-expanded pipe with a tip blade according to Embodiment 3 of the present invention. In addition, the same thing as Embodiment 1 attaches | subjects the same code | symbol, and abbreviate | omits description.
In FIG. 7, the diameter expansion tube 1b with the tip blade in the third embodiment is different from that in the first embodiment in that it includes a plurality of ridges 7a disposed on the inner peripheral surface of the diameter expansion portion 2 so as to be inclined. It is a point.
The shape, number, and arrangement of the ridges 7a can be selected as appropriate. In addition, the angle of inclination of the ridge portion 7a is equal to the angle of the spiral blade 4 or is increased by about 10 to 20 degrees, so that the earth and sand inside the enlarged diameter portion 2 can easily move along the ridge portion 7a. Thus, the torque required for screwing can be reduced. In addition, as the width of the ridge 7a is wider, a larger amount of earth and sand can be guided and scraped up. However, if it protrudes to the center opening 4b, resistance increases during rotation and torque increases. It was formed in a width that fits within the range.

In the present embodiment, the plurality of ridges 7a are regularly arranged while being inclined. However, for example, one ridge may be arranged in a spiral shape, or the plurality of ridges may not be provided. You may arrange regularly.
In addition, the cross-sectional shape of the ridge portion 7a is not limited to the rectangular shape as in the present embodiment, and may be formed in a semi-cylindrical shape, a triangular prism shape, or a protruding shape. Moreover, when the protrusion part formed in arbitrary shapes, such as rod shape, a cone shape, and a pyramid shape, is provided instead of the protrusion part 7a, the earth and sand inside the enlarged diameter part 2 should be reliably stirred and fluidized. Can do. The longer the protrusion protrudes to the inside of the enlarged diameter portion 2, the more the earth and sand inside the enlarged diameter portion 2 can be agitated and cut finely. Since damage such as deformation is likely to occur due to hard foreign matter such as gravel or concrete lump, it is necessary to form the length within the range of the spiral blade 4 or to a length that slightly protrudes from the central opening 4b. is there.
The expanded pipe 1b with the tip blade in the third embodiment can be used as a steel pipe pile with the tip blade by fixing to the lower end portion 11a of the pile body 11 by welding as in the first embodiment.
Moreover, about the usage method of the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing in Embodiment 3, since it is the same as that of Embodiment 1, description is abbreviate | omitted.

As described above, since the expanded pipe with the tip blade in the second embodiment of the present invention is configured, the following actions are obtained in addition to the actions obtained in the first embodiment.
(1) By having the ridges 7a disposed on the inner peripheral surface of the enlarged diameter portion 2, the sand inside the enlarged diameter portion 2 is guided and scraped up to the upper end 2a side of the enlarged diameter portion 2; It is possible to rotate while finely cutting the earth and sand near the inner peripheral surface of the enlarged diameter portion 2, and it is possible to reduce the torque required for screwing and improve the workability.
(2) By forming the ridges 7a on the inner peripheral surface of the enlarged diameter portion 2, the surface area of the inner peripheral surface of the enlarged diameter portion 2 can be increased and the contact area with the earth and sand can be increased. The bite with the inner peripheral surface of the diameter portion 2 is improved, and the stability of the tip support force after embedding is excellent.

  As mentioned above, since the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing in Embodiment 3 of this invention is comprised, the effect | action similar to the effect | action obtained in Embodiment 1 is acquired.

Hereinafter, the present invention will be specifically described by way of examples.
Example 1
A pile driving test was carried out using the steel pipe pile with the tip blade provided with the expanded pipe 1a with the tip blade described in the second embodiment.
FIG. 8A is a front view showing a steel pipe pile with a tip blade provided with a diameter-expanded tube with a tip blade used in Example 1, and FIG. 8B is a diameter expansion with a tip blade used in Example 1. It is a bottom view which shows the steel pipe pile with a tip blade | wing provided with the pipe | tube.
In FIG. 8, the dimensions of each part are the pipe diameter d ₁ = 406.4 mm of the pile body 11, the maximum diameter d ₂ = 508 mm of the lower end 2b part of the expanded pipe 1a, the outer diameter d ₃ = 1016 mm of the spiral blade 4 and the spiral The inner diameter of the blade 4 (hole diameter of the central opening 4b) d ₄ = 250 mm, and the total length l of the steel pipe pile with the tip blade was 12.55 m.
First, a ground survey was conducted by boring, and it was confirmed that there was a support layer at a depth of 9.3 m.
Next, the pile driving of the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing was performed. For pile driving, a small pile driving machine DHJ-25 manufactured by Nippon Vehicle Co., Ltd. was used.
FIG. 9A is a diagram showing the relationship between construction time and depth, and FIG. 9B is a diagram showing the relationship between construction time and torque. In FIG. 9A, the vertical axis indicates the depth, and the horizontal axis indicates the elapsed time. Moreover, in FIG.9 (b), the vertical axis | shaft has shown the depth and the horizontal axis has shown the torque.
The maximum depth was 9.9 m, and it was possible to reliably embed up to the support layer. On the way, the torque increases (around 2.5 m in FIG. 9B) and the approach speed decreases (5 in FIG. 9A) due to the influence of obstacles such as boulders (pebbles) and concrete blocks contained in the ground. Although the rotation of the steel pipe pile did not stop, the work could be performed continuously, and the pile driving could be completed in a construction time of about 60 minutes.
(Example 2)
In FIG. 8, the pipe diameter d ₁ = 267.4 mm of the pile body 11, the maximum diameter d ₂ = 355.6 mm of the lower end 2b portion of the expanded pipe 1a, the outer diameter d ₃ = 711 mm of the spiral blade 4, and the spiral blade Except that the inner diameter of 4 (hole diameter of the central opening 4b) d ₄ = 200 mm, pile driving was performed with a steel pipe pile with a tip blade provided with a diameter-enlarged tube with a tip blade similar to that in Example 1.
In addition, the depth of the support layer at this time was 12 m.
FIG. 10A is a diagram showing the relationship between construction time and depth, and FIG. 10B is a diagram showing the relationship between construction time and torque. In FIG. 10A, the vertical axis indicates the depth, and the horizontal axis indicates the elapsed time. In FIG. 10B, the vertical axis indicates the depth and the horizontal axis indicates the torque.
The maximum depth was 12.6 m, and it was possible to reliably embed up to the support layer. On the way, torque increases (around 3.5m, around 7.5m in Fig. 10 (b), around 7.5m) and approach speed decreases (Fig. 10 (b) due to the influence of obstacles such as boulders (gravels) and concrete blocks contained in the ground. a) around 3.5m, around 7.5m, around 11m) was observed, but the steel pipe piles never stopped rotating and could be worked continuously, with a construction time of about 72 minutes I was able to complete the pile driving.

After completion of the test, when the inside of the pile main body 11 of (Example 1) and (Example 2) was confirmed, the earth and sand entered up to about half of the total length, and the convex guide plate 6 and the auxiliary convex guide part 7. It was found to be effective for scraping soil.
Moreover, although the steel pipe pile of (Example 1) and (Example 2) was pulled out and the damage condition was confirmed, all are deformed in the spiral blade 4, the convex guide plate 6, the auxiliary convex guide part 7, etc. No damage such as chipping was observed, and it was found that these shapes were not easily resisted in the soil and were excellent in workability.
As described above, by using the steel pipe pile with a tip blade provided with the expanded pipe with the tip blade of (Example 1) and (Example 2), it is difficult to be affected by obstacles in the soil, and continuous work. It is possible to embed in a short time, reduce the load during burial work, prevent damage and deformation of spiral blades, etc., and can improve the workability and reliability of pile driving work It was.

  The present invention has a simple structure, a small number of parts and excellent mass productivity, and it is excellent in workability and reliability that can reduce damage and deformation by reducing the load during construction by attaching it to the tip of the pile body. Providing a diameter expansion pipe with a tip blade and providing a diameter expansion tube with a tip blade can be embedded in a short time, providing excellent workability and providing a large tip support force after being embedded. Excellent in resource saving and handling that can reduce the diameter of pipes and reduce the number of pipes used, is less likely to be misaligned during burial, has low vibration, low noise, and can be installed without soil removal, environmental protection The purpose is to provide a steel pipe pile with a tip blade with excellent properties, and it can reduce the cost required for civil engineering and construction work, and contribute to resource saving and energy saving.

(A) Plan view of a diameter-expanded tube with a tip blade according to Embodiment 1 of the present invention (b) Front view of a diameter-expanded tube with a tip blade according to Embodiment 1 of the present invention Side view of diameter-expanded tube with tip blade in embodiment 1 of the present invention The bottom view of the diameter expansion pipe with a tip blade in Embodiment 1 of the present invention 1 is a cross-sectional view taken along line AA in FIG. The front view which shows the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing in Embodiment 1 of this invention. (A) Plan view of diameter-expanded tube with tip blade in embodiment 2 of the present invention (b) Cross-sectional view taken along line BB in FIG. 6 (a) (c) CC line in FIG. 6 (a) Arrow cross-sectional view Sectional drawing of the diameter expansion tube with a tip blade | wing in Embodiment 3 of this invention The front view which shows the steel pipe pile with a tip blade | wing provided with the diameter expansion pipe with a tip blade | wing used in Example 1. (A) Diagram showing relationship between construction time and depth (b) Diagram showing relationship between construction time and torque (A) Diagram showing relationship between construction time and depth (b) Diagram showing relationship between construction time and torque

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Diameter expansion pipe 2 with tip blade Expanded portion 2a Upper end 2b Lower end 3 Notch portion 4 Spiral blade 4a Upper surface 4b Central opening 5 Excavation blade 5a Rake face 6 Convex guide plate 6a Lower end portion 6b Upper end portion 7 Auxiliary Convex guide section 7a Convex section 10 Steel pipe pile with tip blade 11 Pile body 11a Lower end

Claims (5)

A diameter-enlarged pipe with a tip blade continuously provided at a lower end portion of a pile body formed in a hollow cylindrical shape, the diameter-enlarged portion formed by expanding from the upper end side toward the lower end side, and the diameter expansion A notch portion formed by spirally cutting the lower end of the portion, and an outer diameter larger than a maximum diameter of the enlarged diameter portion disposed on an end surface of the notched portion, and an inner diameter being the maximum of the enlarged diameter portion. The spiral blade smaller than the small diameter, the excavating blade formed in an arc shape at the tip of the lower end of the spiral blade, and the central opening of the spiral blade as viewed from the upper end side of the enlarged diameter portion are closed. A convex guide plate that is formed in a substantially crescent shape and is connected in the same direction as the spiral blade in a spiral shape that connects the inner upper surface of the spiral blade and the inner peripheral upper end of the enlarged diameter portion , A diameter-expanded tube with a tip vane characterized by comprising. The diameter expansion tube with a tip blade according to claim 1, wherein a peripheral wall between an upper end portion and a lower end portion of the diameter expansion portion is formed in a curved shape. The diameter-expanded tube with a tip blade according to claim 1 or 2 , further comprising an auxiliary convex-shaped guide portion that is opposed to the convex guide plate and is inclined and disposed on an upper end side of the diameter-expanded portion. . The diameter expansion tube with a tip blade according to any one of claims 1 to 3, further comprising a ridge and / or a protrusion disposed on an inner peripheral surface of the diameter expansion section. A pile main body formed in a hollow cylindrical shape, and a diameter-expanded tube with a tip blade according to any one of claims 1 to 4 connected to a lower end portion of the pile main body. A steel pipe pile with a tip blade.

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