JP2013249685A - Band-like blade member for steel pipe pile, steel pipe pile, and composite pile and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a band-like blade member which is turned into a member suitable for a composite pile functioning as a bearing pile, and a construction method for the composite pile, which enables a steel pipe to be correctly installed in the center of the composite pile by a simple method.SOLUTION: A band-like blade member 10f is wound around a hollow steel pipe for a steel pipe pile by one round. Both ends of a body part 11 being wound are extended out by a predetermined length (W) to the outside of the steel pipe. A pair of fastening parts 12 inclined with respect to an axial direction is formed. A third blade 17 elongated to the outside from the body part 11 is formed as needed.

Description

  The present invention is particularly constructed in the ground comprising a banded blade member made into a part to be attached to a steel pipe pile used for ground improvement of a low-rise building structure, a steel pipe pile equipped with the same, and the steel pipe pile. The present invention relates to a steel pipe soil cement composite pile and a method for producing the composite pile.

  A super mini drill (SMD) pile construction method is known as a steel pipe pile construction method suitable for ground improvement of medium- and low-rise buildings. The SMD pile construction method is a construction method in which a steel pipe pile having a spiral wing (outer wing) having a size of about 2 to 3 times the pile diameter is attached to the outer periphery of the rake tip by rotating clockwise. The penetration of the steel pipe pile is rotationally penetrating into the ground part in an undrained state because the outer wing receives a propulsive force from the ground by giving a rotational torque to the pile head. Moreover, the SMD pile construction method has a feature that cement milk is not used.

  Further, a deep layer mixing (CDM) method is known in which a cement-based solidifying material slurry and an in-situ soil are stirred and mixed in a soft ground using a processing machine and solidified to a predetermined strength. The improved piles formed by the CDM method are called column-solidified piles or soil cement columns, and are used for improving the foundation ground of various structures, as well as temporary structures such as retaining walls and securing ground stability during excavation. There are also uses.

  On the other hand, steel pipe piles have a problem that as the years pass, rust is generated on the steel pipe surface and the initial strength cannot be maintained. Moreover, the conventional steel pipe pile has the problem that the trajectory through which the spiral blade at the tip has passed remains a gap, and the frictional force around the circumference of the pile diameter is reduced, and a void is generated in the ground around the pile. On the other hand, columnar solidified piles are not as strong as steel pipe piles, and there is a problem that the pile diameter of the solidified piles is increased in order to impart strength. As a solution to such a problem, a steel pipe soil cement composite pile in which a soil cement is formed around the steel pipe pile is known. Since the composite pile has an alkaline cement around the steel pipe, it prevents rust on the surface of the steel pipe and maintains the initial pile strength. Moreover, since the core material of a composite pile is a steel pipe, since the whole pile strength becomes high, the whole pile diameter can be made small.

  As such a steel pipe soil cement composite pile, a steel pipe soil cement composite pile using a steel pipe in which concave grooves forming stripes at regular intervals on the outer periphery of the steel pipe as a core material of the soil cement pile is known ( JP 2007-191990 A). When constructing a composite pile disclosed in Japanese Patent Application Laid-Open No. 2007-191990, excavation and agitating rods are used to inject a solidifying agent such as cement milk from the tip, and the soil and the solidifying agent are mixed and stirred to form soil cement. Then, a steel pipe is inserted and embedded in the uncured soil cement.

JP 2007-191990 A (Claim 1, paragraph number 0010) Japanese Patent Application No. 2012-106429

  However, since the construction method of the composite pile described in JP 2007-191990A inserts and embeds the steel pipe in uncured soil cement, is it almost impossible to install the steel pipe at the center of the composite pile? In order to install in the center, many processes are required, and there is a problem that an increase in cost is inevitable. Moreover, the steel pipe at the center does not reach the tip of the composite pile, but stops and is buried in the middle. For this reason, since the conventional composite pile cannot be embedded in the hard ground of a steel pipe, there is a problem that it does not function as a support pile but only functions as a friction pile. In order to solve such a problem, the patent applicant previously developed a new steel pipe pile (Japanese Patent Application No. 2012-106429). In the prior application, there is a description that the blades of the steel pipe pile can be made into parts, but there is no disclosure about a specific form of making parts or a band-like blade member.

  Accordingly, an object of the present invention is to provide a banded blade member suitable for a composite pile functioning as a support pile, and to construct a composite pile capable of correctly installing a steel pipe at the center of the composite pile by a simple method. It is to provide a method, and to provide a steel pipe pile having a novel structure used for the method.

  In such a situation, as a result of intensive studies, the present inventors have found that if the tightening portions at both ends of the band are band-shaped blade members having a pair of tightening portions having a specific shape inclined with respect to the axial direction, It can be easily attached to steel pipe piles by bolting etc., and if it is a steel pipe pile equipped with this banded blade member, it can be embedded into hard ground, so that a support pile can be obtained, solidified The inventors have found that a steel pipe can be correctly installed at the center of a composite pile by a simple method of gravity flow of material, and have completed the present invention.

That is, the present invention is a band-shaped blade member wound around a hollow steel pipe for steel pipe piles by one turn, and both ends of the main body to be wound are outside the steel pipe by a predetermined length (W ₁ ) A band-shaped blade member for steel pipe piles that extends and forms a pair of tightening portions that are inclined with respect to the axial direction.

  Moreover, this invention provides the steel pipe pile characterized by mounting | wearing the steel pipe with the said band-shaped blade member for steel pipe piles.

  The present invention also provides a composite pile comprising the steel pipe pile and a soil cement formed around the outer peripheral surface of the steel pipe pile.

  Moreover, this invention provides the manufacturing method of the composite pile characterized by having the process of supplying the solidification material around the steel pipe of this steel pipe pile, penetrating the said steel pipe pile in the ground by normal rotation. is there.

  The banded blade member for steel pipe piles of the present invention (hereinafter also simply referred to as “banded blade member”) can be easily obtained by, for example, bolting the outer peripheral surface of a steel pipe pile having a spiral blade at a known tip. Can be installed. The steel pipe pile with the banded blade member attached can change the inclination angle of the tip blade and the attachment blade, so the track of the attachment blade enters the various directions different from the tip blade against the ground around the steel pipe, The ground can be greatly disturbed.

  Moreover, according to the composite pile of this invention, since the front-end | tip of a steel pipe can be rooted in hard ground, it has both functions of a friction pile and a support pile. Moreover, since a steel pipe pile is located in the center of a composite pile, stable support strength can be expressed. Moreover, since the steel pipe pile circumference is alkaline cement, the corrosion prevention effect of a steel pipe is high.

  Further, according to the composite pile manufacturing method of the present invention, in addition to the same effect as the steel pipe pile described above, a simple method of rotating the steel pipe pile while introducing the solidified material from the ground surface around the steel pipe, It is possible to manufacture composite piles in which steel pipes are correctly arranged.

It is a perspective view of the band-shaped blade member in the 1st embodiment of the present invention. It is a top view of the band-shaped blade member of FIG. It is a schematic diagram which shows an example of the steel pipe pile which mounted | wore with the band-shaped blade | wing member of FIG. It is the simplified view seen from the front of the steel pipe pile of FIG. (A)-(C) are some side views which show the modification of a fastening part. It is a top view of the band-shaped blade member divided into two. It is a top view of the band-shaped blade member divided into three. It is a top view of the band-shaped blade member divided into four. It is a perspective view of the band-shaped blade member in the 2nd embodiment of the present invention. It is a perspective view of the modification of the band-shaped blade member in 2nd Embodiment. It is a perspective view of the band-shaped blade member in the 3rd embodiment of the present invention. It is a perspective view of the modification of the band-shaped blade member in 3rd Embodiment. It is a figure explaining the manufacturing method of the composite pile in embodiment of this invention. It is a figure explaining the process following the process of FIG. It is a figure explaining the process following the process of FIG.

(Band-shaped blade member of the first embodiment)
Next, the band-shaped blade member and the steel pipe pile on which the band-shaped blade member according to the first embodiment of the present invention is mounted will be described with reference to FIGS. The band-shaped blade member 10 is wound around the hollow steel pipe 20 with one turn, and both ends on the tightening side of the main body 11 to be wound have a predetermined length (W ₁₎ outside the steel pipe 20. ) A pair of blade-like tightening portions 12 (12a, 12b) extending and inclined with respect to the axial direction are formed.

The band-shaped blade member 10 is formed, for example, by rolling a belt-shaped iron plate having a height H, a predetermined length, and a predetermined thickness t into a cylindrical shape, and both end portions are inclined with respect to the axial direction. It is bent outward. Since the tightening portion 12 has an inclination angle α ₁ with respect to the direction perpendicular to the axial direction and extends a predetermined length (W ₁ ) outward from the main body portion 11, after being wound around the steel pipe 20, By rotating the steel pipe 20, it is easy to bite into the ground and functions as a disturbing blade. The band-shaped blade member 10 may be a member obtained by joining a fastening portion 12, which is a member different from the cylindrical main body portion 11, to the main body portion 11 by welding.

  The pair of blade-like tightening portions 12 (12a, 12b) are formed with bolt holes 13 through which the bolt shaft passes in this example. By passing bolts through the bolt holes 13 and tightening them with nuts, the pair of blade-like tightening portions 12a and 12b become an integral body of a plate-like body having a thickness of 2t + β, and the main body portion 11 is tightly wound around the steel pipe 20. Is done. In addition, β is a tightening allowance and is a gap of about several mm.

The inclination of the tightening portion 12 with respect to the axial direction may be a linear inclination or a slightly curved inclination. Inclination angle alpha ₁ relative to the axial direction perpendicular is specifically suitably determined from the range of 30 to 52 degrees. Examples of the curve include an upward curve, a downward curve, or an irregular curve in which both are combined. In addition, when the tightening portion 12 has a slightly curved inclination, the inclination angles at all locations of the tightening portion 12 are preferably in the range of 30 to 52 degrees.

The extending length (W ₁ ) of the tightening portion 12 is preferably 20 to 60 mm. If (W ₁ ) is 20 mm, the diameter of the composite pile formed in the ground is the minimum steel pipe diameter +4 cm, and the steel pipe has sufficient support for corrosion prevention, and the composite pile 40 has a support function. The diameter is sufficient. That is, in the composite pile, the thickness of the coating of the soil cement is at least 2 cm, and the corrosion prevention of the steel pipe is sufficient. In the outer direction in which the tightening portion 12 protrudes, the center in the length direction of the tightening portion 12 is preferably the radial direction.

  The height H (band width) of the band-shaped blade member 10 varies depending on the steel pipe to be used, the number of band-shaped blade members 10 installed, and the inclination angle of the tightening portion 12, and is approximately 50 to 250 mm although it cannot be determined to one. . Thereby, both the fixing function to a steel pipe, the 2nd blade | wing support function, and a blade | wing function can be provided.

  The shape of the tightening portion 12 of the band-shaped blade member 10 is not limited to that shown in FIG. 1. For example, the length is larger than the height H of the main body portion 11 and the upper and lower portions protrude from the main body portion (FIG. 5). (A)), a side view in which the central portion in the length direction swells is an arched shape (FIG. 5B), the length is smaller than the height H of the main body 11, and the upper and lower sides are retracted from the main body. Examples include shapes (FIG. 5C) and irregular shapes. The bolt holes 13 in FIGS. 5A to 5C are simply indicated by “·”. Moreover, when the front-end | tip part of these clamping parts 12 is made into a saw blade shape or a wave shape, while the disturbance effect of a ground improves, the surface area of a composite pile improves and the ground support function improves, It is preferable. Even if the tightening portion 12 has such a deformed shape, it can provide a function of tightening the band-shaped main body portion 11 to the steel pipe 20, a second blade support function, and a function of disturbing the ground.

  In the band-shaped blade member of the present invention, the divided member divided into two or more in the circumferential direction is wound around the steel pipe, and at least a pair of all the pair of tightening portions is in the axial direction. May be inclined. In the band-shaped blade member 10a of FIG. 6, the divided members 11a and 11b divided into two in the circumferential direction are wound around a steel pipe, and two pairs of tightening portions 12A and 12B are axially arranged. It is inclined with respect to. In the band-shaped blade member 10b of FIG. 7, the divided members 11a to 11c divided into three in the circumferential direction are wound around a steel pipe, and the three pairs of tightening portions 12A to 12C are axially arranged. It is inclined with respect to. In the band-shaped blade member 10c of FIG. 8, the divided members 11a to 11d divided into four in the circumferential direction are wound around the steel pipe, and among the four pairs of tightening portions 12A to 12D, 2 The pair of tightening portions 12A and 12C are inclined with respect to the axial direction. In addition, in the band-shaped blade member of FIGS. 6 to 8, at least one tightening portion 12 that is inclined with respect to the axial direction is sufficient. Even one tightening part is sufficient as the function of the inclined blade. In the figure, reference numeral 15 denotes a bolt, which is normally used in all bolt holes regardless of the illustration.

(Band-shaped blade member of the second embodiment)
Next, a band-shaped blade member according to the second embodiment of the present invention will be described with reference to FIG. 9, the same components as those in FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described. In other words, the band-shaped blade member 10d of FIG. 9 is different from the band-shaped blade member 10 in that the second blade is installed in the tightening portion 12 by clamping. That is, the band-shaped blade member 10d further includes a second blade 16a sandwiched between the pair of tightening portions 12a and 12b. Thus, by suppressing the projecting length of the tightening portion 12 (W _1), it is possible to lengthen the overall projection length, it becomes suitable when thickening the coating layer is a soil cement. The second blade 16a is obtained by adding a twist 161 to a plate-shaped blade, and the inclination angle of the tip portion 163 of the second blade 16a with respect to the axial direction is different from the inclination angle of the tightening portion 12 with respect to the same direction. be able to. In addition, the 2nd blade | wing 16a may be a plate-shaped blade | wing without a twist. Reference numeral 162 denotes a bolt shaft hole through which the bolt shaft passes.

  The second blade sandwiched between the pair of tightening portions 12a and 12b is not limited to the twisted blade of FIG. 9, and may be a tapered plate blade 16b as shown in FIG. If the second blade is a tapered plate blade 16b, the stirring resistance at the tip can be reduced. Further, the tapered plate blade 16b may be twisted. Further, a through hole may be formed in the blade body 164 of the plate-like blade 16b.

  The second blade sandwiched between the pair of tightening portions 12a and 12b is not limited to the twisted blade shown in FIG. 9, but a handle-like blade provided with a through hole 164 in the plate-shaped blade as shown in FIG. 16c may be used. If the second blade has a handle-like blade 16c having a through-hole 164, the upward reaction force accompanying the digging agitation can be relaxed and the stirring force can be increased. Further, the handle portion 165 may be twisted.

  If it is a band-shaped blade member in the second embodiment, in addition to the same effect as the band-shaped blade member in the first embodiment, in addition to the demand for various thicknesses of the coating layer that is a soil cement, This can be easily handled by selecting the second blade. Further, inclined blades different from the blade shape of the tightening portion 12 can be easily created.

(Band-shaped blade member of the third embodiment)
Next, a band-shaped blade member according to a third embodiment of the present invention will be described with reference to FIG. In FIG. 11, the same components as those in FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described. In other words, the band-shaped blade member 10f of FIG. 11 is different from the band-shaped blade member 10 in that a third blade extending a predetermined length (W ₂ ) from the peripheral surface of the main body 11 is formed. is there. The third blade 17 is a pair of left and right horizontal blades 17a and 17b having a flat cross section. The horizontal blades 17 have zero inclination angle with respect to the direction perpendicular to the axial direction. Moreover, it is preferable that the predetermined length (W ₂ ) of the third blade 17 is the same as the protruding length (W ₁ ) of the tightening portion 12 from the viewpoint of increasing the stirring efficiency. The 3rd blade | wing 17 is joined to the main-body part 11 by welding. The shape of the third blade 17 is not limited to that shown in FIG. 11. For example, the third blade 17 may be an inclined blade, may be twisted, may be asymmetrical, and may be one or three other than a pair of blades. There may be more than one blade. In the left-right asymmetry, for example, one is a horizontal blade and the other is an inclined blade.

  If it is a band-shaped blade member in 3rd Embodiment, in addition to having the same effect as the band-shaped blade member in 1st Embodiment, stirring power can be raised.

As a modification of the band-shaped blade member according to the third embodiment, a band-shaped blade member according to the second embodiment in which third blades are formed may be mentioned. That is, with respect to the first embodiment, the second blade is installed in the tightening portion 12 by clamping, and the third blade is installed on the peripheral surface of the main body portion 11. An example is shown in FIG. In FIG. 12, the handle blade 16c is as described in the second embodiment, and the description thereof is omitted. The third blades 17c and 17d are a pair of left and right horizontal blades having a flat cross section, and the protrusion length (W ₂ ) is preferably the same as the protrusion length of the handle-like blade 16c, from the viewpoint of increasing the stirring efficiency. In addition, the third blades 17c and 17d having a flat cross section can be installed at a position facing the through hole of the handle-like blade 16c in a side view so that a lump that passes through the through hole can be crushed. preferable.

(Description of steel pipe pile)
The steel pipe pile 30 is formed by mounting band-shaped blade members 10, 10 a to 10 g (hereinafter also simply referred to as “band-shaped blade member 10”) on the steel pipe 20, and as shown in FIG. a steel pipe having a spiral blade 2, it is preferable that formed by attaching a spiral blade 2 tip dimensioned H _y height up. By making the blades at the tip part spiral, it is possible to bite into the ground and facilitate the penetration of the steel pipe pile into the ground. Moreover, in the steel pipe pile 30, the inclination | tilt angle (alpha) ₁ of the clamping part 12 of the band-shaped blade member 10 should just differ from the inclination | tilt angle (alpha) ₀ of the spiral blade 2 of the front-end | tip part of the steel pipe 20 with which it mounts | wears. The inclination angle alpha ₁ of the clamping portion 12, is be different from the inclination angle alpha ₀ of the spiral blade 2 of the tip, it is possible to increase the disturbance effect of the ground. In addition, the blade diameter of the band-shaped blade member 10 is the same as the blade diameter of the spiral blade 2 at the tip portion or smaller than the blade diameter of the spiral blade 2 at the tip portion.

In addition, in the steel pipe pile of this invention, it is not limited to the steel pipe used with the steel pipe pile of FIG. 4, The spiral blade | wing of the front-end | tip part may not be. In this case, it is preferable to mount the inclination angle alpha ₁ is two or more different band-like blade member 10 of the clamping portion 12 in the steel pipe. That is, among the inclination angles alpha ₁ is two or more different band-like blade member 10 of the clamping portion 12, using a single band-shaped blade member 10 as tip vanes. In addition, when the inclination angle of the tip blade is increased, the biting into the ground is deteriorated, but the ground stirring effect is sufficient.

The distance between the tip blade and the band-shaped blade member 10 or the distance between the upper blade and the lower blade in the plurality of band-shaped blade members 10 is appropriately determined depending on the number of blades installed, the length of the steel pipe pile, the soil quality, and the like. , Approximately 0 to 3H _y (H _y is the vertical length of the lower blade forming the interval, and is H ₀ in FIG. 4), preferably ₀ to 2H _y . Moreover, if the space | interval of a front blade | wing and the band-shaped blade member 10 immediately above this front blade | wing is taken large, preparation of a composite pile will be attained with respect to the ground near the ground surface, for example, groundwater with a high salt concentration in the depth direction This is a suitable method in the case where the

  A conventional SMD pile can be used as the steel pipe having a spiral blade at the tip. Examples of the spiral blade include a regular spiral blade and a non-regular spiral blade. A regular spiral blade is a spiral blade of one or more turns, and has the same inclination angle at all positions of the spiral blade. The non-regular spiral blade does not have the same inclination angle at all the positions of the spiral, but refers to a blade including a horizontal portion or a gentle inclination portion in part.

(Description of composite pile manufacturing method)
The manufacturing method of the composite pile of this invention has the process (I process) which supplies a solidification material to the surroundings of the steel pipe of this steel pipe pile, penetrating the said steel pipe pile in the ground by normal rotation. The method of supplying the solidified material around the steel pipe pile is preferably based on gravity flow from the solidified material storage tank. Examples of the solidifying material include powdery solidifying material or cement milk.

  Then, an example of the manufacturing method of the composite pile of this invention is demonstrated with reference to FIGS. In FIG. 13, reference numeral 71 denotes soft ground, and reference numeral 72 denotes hard ground (supporting ground). Prior to penetrating the steel pipe pile 30, a cylindrical can (solidified material storage tank) 4 including the penetrating portion and penetrating vertically is installed on the ground surface. The cylindrical can 4 can be simply placed on the ground surface. A steel pipe pile 30 is erected in the cylindrical can 4 (FIG. 13), and the solidified material 5 of the designed amount is put into the cylindrical can 4. In this example, the solidifying material 5 is cement milk. Next, a rotational torque is applied to the pile head, and the steel pipe pile 30 is penetrated into the ground 7 by normal rotation.

The ground disturbing action of the blades in the steel pipe pile 30 is as follows. The steel pipe pile 30 penetrates into the ground while rotating forward. The tip blade 2 is a spiral blade and penetrates into the ground for a depth H ₀ by one rotation of the steel pipe. Until a blade (hereinafter referred to as “second blade”) that is a tightening portion of the band-shaped blade member 10 enters the ground, the spiral-shaped track of the tip blade 2 is cut in the ground, and the track portion. Hollow out. Next, the second blade enters the ground. Since the ground through which the second blade 12 passes is the ground through which the tip blade 2 has passed, it is not a virgin ground. Therefore, the trajectory of the tip blade 2 becomes rate-limiting, the second blade, is stuck only H ₀ minutes at proceeding H ₁ minute per revolution if it alone blade. That is, the second blade does not rotate according to the spiral shape but proceeds while shifting in the lateral direction. At this time, the second blade cuts the passing ground and can disturb the ground. The second blade further exerts a pressing force in the downward and lateral directions, so that a consolidation effect on the lower ground and the surrounding ground appears.

  The steel pipe pile 30 is penetrated into the ground 7 by forward rotation, and the ground impingement of the steel pipe pile 30 and the second blade compresses the surrounding ground by the above-mentioned ground disturbing action, and the ground around the steel pipe 20 and within the blade diameter. Will be formed and voids will be formed in the ground. In the ground under disturbance, the cement milk 5 in the cylindrical can 4 flows down by gravity. That is, the cement milk 5 is filled in the ground around the steel pipe 11 with the penetration of the steel pipe pile 30 (step I). Since the cement milk 5 is filled in synchronism with the penetration of the steel pipe pile 30, it is sufficiently mixed with the disturbed earth and sand (FIG. 14).

In order to further accelerate the disturbance of the ground during the process I, an intrusion start point changing process (process II) for correcting the blade trajectory may be performed. Step II is performed as follows. That is, penetration of the steel pipe pile 30 is stopped in the middle of performing the I process. While the steel pipe pile 30 is stopped, the steel pipe pile 30 is pulled upward by a predetermined length, and then re-penetrating while rotating the steel pipe pile 30. The length to be pulled up is preferably, for example, an appropriate length not more than the vertical length H _{0 of} the tip blade 2. Particularly preferred is 1 / 3H ₀ to 1 / 5H ₀ . The starting point of penetration of the first blade 2 is changed by raising the predetermined length of the stopped steel pipe pile 30. That is, in re-penetration, a spiral trajectory different from the initial spiral trajectory is taken, and the disturbance of the ground is promoted. If the lifting length is the same as H ₀ , the re-penetration results in the same spiral trajectory as the first spiral trajectory, and does not promote ground disturbance. Further, when the steel pipe pile 30 is pulled up to a predetermined length, the ground can be further disturbed by the tip blade 2 and the second blade, and the ground and cement milk can be mixed. Step II can be performed one or more times, preferably about 2 to 5 times in the middle of Step I.

  In order to forcibly disturb the ground during the process I, the vertical movement process (process III) of the steel pipe pile 30 may be performed. In the process III, the steel pipe pile 30 is moved up and down with a large stroke while the penetration of the steel pipe pile 30 is stopped and the steel pipe pile 30 is stopped during the process I. The stroke to be pulled up is preferably the length from the tip of the steel pipe pile 30 to the uppermost blade. By moving the steel pipe pile 30 up and down and stirring the ground, the cement milk can easily flow down to the stirring ground. The re-penetration of the steel pipe pile 30 may be performed from any point. Step III can be performed one or more times, preferably about 2 to 5 times in the middle of Step I.

  In the manufacturing method of the present invention, the tip blade 2 may be embedded in the hard ground layer 72. By providing the piercing part 9 penetrating into the hard ground layer 72, the tip support force of the steel pipe pile 30 is improved. Although the solidifying material 5 penetrates into the rooting portion 9, the solidifying material 5 does not need to penetrate into the rooting portion 9. Moreover, the piercing process of the steel pipe pile 30 is an arbitrary process and may be omitted. I process is complete | finished by the penetration to the design length of the steel pipe pile 30, and supply of the cement milk 5 being complete | finished. Whether the cement milk 5 is sufficiently supplied or not can be determined by observing the decrease of the cement milk 5 in the cylindrical can 4 during the penetration of the steel pipe pile 30. When the supply of the cement milk 5 is insufficient, the II step or the III step may be performed in the middle of the I step. The penetration of the steel pipe pile 30 is completed, uncured soil cement is formed around the steel pipe 20, and the unhardened soil cement is hardened to form the steel pipe soil cement composite pile 40 (FIG. 15). The cylindrical can 4 is merely placed on the ground surface and can be easily removed. According to the manufacturing method of the composite pile 40 of this invention, the steel pipe 20 can be correctly arrange | positioned in the center by the simple method of rotating the steel pipe pile 30, gravity-flowing the solidification material from the ground surface around the steel pipe 20. FIG. .

  The steel pipe pile of the present invention is not limited to the above-described embodiment, and as the steel pipe pile 30, the inclination angle gradually increases and the inclination angle gradually increases as it goes upward. There may be no small form or regularity in which blades having different inclination angles are alternately or randomly formed. When there are a plurality of second blades, the distance (pitch) between adjacent blades may be the same or different between all the blades.

(Description of composite pile)
The composite pile of this invention consists of a steel pipe pile and the soil cement formed around the outer peripheral surface of the steel pipe of this steel pipe pile. Soil cement is a hardened mixture of ground soil and solidified material around steel pipes. Further, as shown in FIG. 15, in the soil cement 6, the tip blade 2 of the steel pipe pile 30 and the second blade that is a fastening portion of the band-shaped blade member are buried, and the steel pipe pile 30 and the soil cement 6 Increases adhesion. Further, the composite pile 40 may have a root portion 9 in the hard ground layer 72 as shown in FIG. 15, or a tip that does not reach the hard ground layer 72 and does not have the root portion 9. Good. The composite pile 30 having the embedded portion 9 in the hard ground layer 72 functions not only as a friction pile but also as a support pile.

  The pile diameter of the composite pile 40 is substantially the same as the blade diameter of the tip blade or the band-shaped blade member, and specifically, the maximum is 4 times the steel pipe diameter and the minimum is preferably the steel pipe diameter + (4 cm). If the thickness of the coating of the soil cement 6 is 2 cm, the steel pipe is sufficiently prevented from corrosion and has a supporting function, so that the pile diameter of the composite pile 40 is sufficient. Moreover, the composite ground 40 has the surrounding ground consolidated, and has a high support force as a friction pile.

  In the band-shaped blade member of the present invention, when the tip of the second blade or the third blade is made into a saw blade shape or a wave shape, the disturbance effect of the ground is improved, the surface area of the composite pile is improved, and the ground support function is improved. It is preferable in terms of improvement.

  The band-shaped blade member of the present invention is a component for steel pipe piles, and a steel pipe pile can be manufactured simply by newly attaching it to a conventional SMD pile despite its novel structure. Further, the composite pile only needs to supply the solidified material around the steel pipe under gravity flow while penetrating the steel pipe pile, and the solidified material supply means may be a half-cut drum. For this reason, the composite pile in which the steel pipe is correctly arranged at the center can be manufactured at a low cost by an extremely simple method. Moreover, the alkaline cement is coat | covered around the steel pipe, and the anticorrosion effect of a steel pipe is high. Moreover, the composite pile which functions as a support pile can provide the stable support force over a long period of time.

2 Tip blade 4 Cylindrical can (solidification material storage tank)
5 Solidifying material (cemented milk)
6 Soil cement 7 Ground 9 Rooting portion 10, 10 a to 10 g Band-shaped blade member 11 Main body portion 12 Tightening portion 13 Bolt shaft hole 15 Bolt 16a to 16c Second blade 17 Third blade 20 Steel pipe 30 Steel pipe pile 40 Composite pile

Claims (10)

A band-shaped blade member wound around a hollow steel pipe for steel pipe piles with one turn, and both ends of the main body to be wound extend to the outside of the steel pipe by a predetermined length (W ₁ ). A band-shaped blade member for steel pipe piles, wherein a pair of tightening portions inclined with respect to the axial direction is formed.   The split member divided into two or more in the circumferential direction is wound around a steel pipe, and at least one of the pair of tightening portions is inclined with respect to the axial direction. Item 2. A band-shaped blade member for steel pipe piles according to Item 1.   The band-like blade member for steel pipe piles according to claim 1 or 2, further comprising a second blade sandwiched between the pair of tightening portions.   The band-shaped blade member for steel pipe piles according to claim 3, wherein the second blade is a plate-shaped blade, a twisted blade formed by twisting the plate-shaped blade, or a handle-shaped blade having a through hole. . A predetermined length outwardly from the circumferential surface of the body portion (W ₂₎ in the third blade extending, steel pipe piles for band-type according to claim 1, characterized by further comprising Blade member.   The banded blade member for steel pipe piles according to claim 5, wherein the third blade is a horizontal blade or an inclined blade.   A steel pipe pile obtained by mounting the banded blade member for a steel pipe pile according to any one of claims 1 to 6 on a steel pipe.   A composite pile comprising the steel pipe pile according to claim 7 and a soil cement formed around the outer peripheral surface of the steel pipe of the steel pipe pile.   A method for producing a composite pile, comprising a step of supplying a solidified material around the steel pipe of the steel pipe pile while penetrating the steel pipe pile according to claim 7 into the ground at normal rotation.   The method for producing a composite pile according to claim 9, wherein a method of supplying the solidified material around the steel pipe pile is based on gravity flow from the solidified material storage tank.

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