WO2009091041A1 - Steel pipe for reinforcing foundation, method of reinforcing foundation using the same, and method of reinforcing structure - Google Patents

Steel pipe for reinforcing foundation, method of reinforcing foundation using the same, and method of reinforcing structure Download PDF

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Publication number
WO2009091041A1
WO2009091041A1 PCT/JP2009/050568 JP2009050568W WO2009091041A1 WO 2009091041 A1 WO2009091041 A1 WO 2009091041A1 JP 2009050568 W JP2009050568 W JP 2009050568W WO 2009091041 A1 WO2009091041 A1 WO 2009091041A1
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WIPO (PCT)
Prior art keywords
steel pipe
ground
recess
concave portion
reinforcing steel
Prior art date
Application number
PCT/JP2009/050568
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French (fr)
Japanese (ja)
Inventor
Tomohiro Nakaji
Yuki Motegi
Tatsuya Yamamoto
Tetsu Satoh
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Nippon Steel Corporation
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Filing date
Publication date
Application filed by Nippon Steel Corporation filed Critical Nippon Steel Corporation
Priority to CN2009801015105A priority Critical patent/CN101910560A/en
Publication of WO2009091041A1 publication Critical patent/WO2009091041A1/en

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D35/00—Straightening, lifting, or lowering of foundation structures or of constructions erected on foundations

Definitions

  • the present invention relates to a steel pipe for ground reinforcement suitable for use in a leading construction method in tunnel construction or the like, a reinforcement method for a drilling wall surface, a ground reinforcement method using the same, and a method for reinforcing a structure such as a concrete foundation. .
  • This application claims priority based on Japanese Patent Application No. 2008-009570 filed in Japan on January 18, 2008, the contents of which are incorporated herein by reference.
  • the steel pipe used for the above-mentioned prior receiving method is buried in the natural ground. Therefore, a steel pipe made of a material that is relatively inexpensive and has high strength is used.
  • a steel pipe made of a material that is relatively inexpensive and has high strength is used.
  • the injection material flowing out through the through hole sufficiently penetrates into the natural ground and is tightly filled in the gap between the natural mountain and the steel pipe.
  • the steel pipe disclosed in Patent Document 3 has a convex portion on the outer peripheral surface of the steel pipe, which obstructs the placement of the steel pipe. Moreover, when discharging earth and sand from the outer surface side of a steel pipe, this convex part becomes an obstacle. For this reason, the convex portion cannot be formed into a large shape, and it is difficult to ensure sufficient adhesion. Moreover, in order to give a convex part to the outer peripheral surface of a steel pipe, after manufacturing a steel pipe, the process which provides a convex part by another process is needed. Therefore, there are problems that productivity is inferior and costs are increased.
  • An object of the present invention is to provide a steel pipe for ground reinforcement that adheres closely to the ground, a ground strengthening method using the steel pipe, and a method for strengthening a structure.
  • the present invention employs the following means in order to solve the above problems and achieve the object.
  • the steel pipe for ground reinforcement of the present invention is a steel pipe for ground reinforcement for pouring an injection material into the ground, and is provided with a concave portion and a smooth portion disposed on the outer peripheral surface thereof. And a plurality of through holes in the concave portion or the smooth portion that communicate with the inside and outside of the steel pipe for ground reinforcement.
  • the cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D.
  • B / H 3 to 20 when the cross-sectional shape of the concave portion is triangular, the width of the concave portion is (B), and the depth of the concave portion is (H).
  • a plurality of the concave portions are provided in the circumferential direction of the steel pipe, and at least the concave portions facing each other are provided so as to avoid the same circumference of the steel pipe.
  • a plurality of the recesses are provided in an oblique direction with respect to the axis of the steel pipe.
  • a plurality of the recesses are provided in parallel to the axis of the steel pipe.
  • a plurality of the recesses are provided in a circular shape when the recess is viewed from the front.
  • plating or resin coating is provided on the surface of the steel pipe.
  • the ground number strengthening method of the present invention is the ground reinforcement steel pipe as set forth in (1) above while excavating the ground, and after this ground reinforcement steel pipe is placed, An injection material is injected from the inside of the steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes.
  • a minimum inner diameter of the steel pipe for ground reinforcement is larger than an outer diameter of an inner bit used when excavating the ground.
  • the maximum outer diameter of the steel pipe for ground reinforcement is smaller than the outer diameter of an outer bit used for excavation of the ground.
  • the ground reinforcing steel pipe according to claim 1 is placed while excavating the structure, and the ground reinforcing steel pipe is used. After the placement, an injection material is injected from the inside of the ground reinforcing steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes.
  • the concave portion is formed on the outer peripheral surface of the steel pipe, the concave portion does not become a resistance when embedded in the ground. Further, when the injection material is poured into the outer peripheral surface of the steel pipe, the injection material is also filled in the concave portion, and the adhesion with the ground is improved. As a result, it is possible to reduce the number of burials at the time of construction, and it is possible to shorten the construction cost and the construction period. Moreover, since the steel pipe for ground reinforcement
  • the production efficiency is not lowered, and the manufacturing cost can be reduced as compared with the conventional method.
  • strengthening as described in said (1) it can apply similarly to reinforcement of structures, such as a concrete foundation of a building, for example, and a strong reinforcement is possible at low cost.
  • FIG. 1 is a front view showing an example of a steel pipe for ground reinforcement according to the present invention.
  • FIG. 2A is a diagram showing an example of a steel pipe for ground reinforcement according to the present invention.
  • FIG. 2B is a diagram showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2C is a diagram showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2D is a view showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2E is a view showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2F is a diagram showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2G is a diagram showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2H is a view showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2I is a view showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2J is a view showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 2K is a diagram showing a modification of the ground reinforcing steel pipe of the present invention.
  • FIG. 3A is a diagram showing a specific example of a concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 3A is a diagram showing a specific example of a concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 3B is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 3C is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 3D is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 4 is a view showing the relationship between the width and depth of the concave portion of the ground reinforcing steel pipe of the present invention.
  • FIG. 5 is a view showing a production line of a normal forged steel pipe.
  • FIG. 6 is a diagram showing an embodiment of a forged steel pipe production line for producing the ground reinforcing steel pipe of the present invention.
  • FIG. 7A is a conceptual diagram of a roll used for manufacturing the steel pipe of the present invention.
  • FIG. 7B is a conceptual diagram of a roll used for manufacturing the steel pipe of the present invention.
  • FIG. 8 is a diagram showing another embodiment of a forged steel pipe production line for producing the ground reinforcing steel pipe of the present invention.
  • FIG. 9 is a partial cross-sectional view of the tip portion of the ground reinforcing steel pipe into which a drill rod with a bit is inserted.
  • FIG. 10A is a diagram illustrating a method for evaluating the adhesion strength in Examples.
  • FIG. 10B is a diagram illustrating a method for evaluating adhesion in a comparative example.
  • FIG. 11 is a diagram comparing the effects of the examples.
  • FIG. 1 schematically shows a steel pipe 5 for ground reinforcement according to the present invention.
  • the steel pipe 5 for ground reinforcement is provided with recesses 2 on the outer periphery of the steel pipe 1 at regular intervals.
  • the concave portion 2 can increase the frictional force between the steel pipe 1 and the ground or concrete.
  • a plurality of through holes 3 that pass through the inside and the outside of the steel pipe 1 are arranged on the entire peripheral surface of the steel pipe 1.
  • the injected material injected into the steel pipe 1 flows out to the outer surface of the steel pipe through these through holes 3. A part of the injection material is filled between the natural ground and the steel pipe 1 to fix the natural ground and the steel pipe 1.
  • the other part penetrates into the ground and solidifies, strengthening this ground.
  • the recess 2 is embedded in the solidified injection material layer, and both are firmly integrated. For this reason, even if an axial force acts on the steel pipe 1, the engagement between the recess 2 and the injection material layer causes a catching resistance and prevents the steel pipe 1 from moving. From the above, in the ground reinforcement steel pipe 5 of the injection material according to the present embodiment, the adhesion between the steel pipe 1 and the natural ground can be improved, and the steel pipe 1 and the natural ground can be fixed more firmly.
  • reference numeral 4 indicates an outer bit.
  • 2A to 2K show specific examples showing other shapes of the recess 2.
  • 2A, 2B, and 2C have recesses 2A to 2C in the circumferential direction of any steel pipe 1, and a plurality of recesses 2A to 2C are formed at regular intervals in the axial direction.
  • the ground strengthening steel pipe 5 in FIG. 2A is an example in which a plurality of recesses 2A are provided on the same circumference of the steel pipe 1 (two facing each other in the figure).
  • the recess 2 is formed not by a rolling roll but by a reciprocating pressing device that can approach and retract from the steel pipe 1A.
  • the recess 2 ⁇ / b> B has substantially the same depth on the circumference of the steel pipe 1.
  • the steel pipe 5 for ground reinforcement of FIG. 2C is an example in which a plurality of recesses 2C are provided in the circumferential direction of the steel pipe 1, and at least the facing recesses 2C do not exist on the same circumference.
  • the strength of the steel pipe 1 at the position where the concave portion 2C is disposed is made by staggering so that the concave portions 2C facing each other do not exist on the same circumference. Can be improved.
  • the 2C is suitable when the strength of the ground reinforcing steel pipe 5, particularly the strength of the portion where the recess 2 is disposed, is required to be higher. In the example of the staggered arrangement of the recesses 2C, it is desirable to form the entire width of the opposing portions of the recesses 2C so as not to wrap.
  • 2D to 2G are views showing the steel pipe 1 in which concave portions 2D to 2G having long sides in an oblique direction with respect to the axis of the steel pipe 1 are formed.
  • 2H and 2I are views showing the steel pipe 1 in which concave portions 2H and 2I having long sides in a direction parallel to the axis of the steel pipe 1 are formed.
  • 2J and 2K are views showing the steel pipe 1 in which round spot-like (circular) recesses 2J and 2K are formed.
  • the spot-like recesses 2J and 2K can be freely selected from ellipses and polygons because of their ease of formation.
  • the recesses 2D to 2G are arranged on the same circumference or alternately arranged in a staggered manner.
  • the shape is limited only by the height of the recesses 2D to 2G, and it is only necessary to secure a space that allows the excavation bid to pass through the inner surface of the steel pipe 1.
  • the steel pipe 5 for ground reinforcement of the present invention forms the recess 2 hot or warm. Therefore, for example, the steel pipe 1 can be easily manufactured even if the thickness is 2 mm or more. Therefore, when the steel pipe 5 for ground reinforcement 5 is manufactured and this steel pipe 5 for ground reinforcement is driven into the ground while being rotated, for example, the torsional force acts on the steel pipe 5 for ground reinforcement, and the tip is bent. It won't be crushed. Moreover, the outer diameter 50mm or more which can be practically used as the steel pipe 5 for ground reinforcement
  • the surface of the steel pipe 1 constituting the recess 2 as described above is plated or coated with a resin, so that it is good. It is desirable to exhibit corrosion resistance.
  • the concave portion 2 of the steel pipe 1 As shown in FIGS. 3A to 3D, there are basically a case where the cross-sectional shape is a triangular shape and a case where the cross-sectional shape is a square shape. In the case of a semicircular shape and a trapezoidal shape, it may be considered substantially equal to a triangle. In any case, the depth H of the concave portion 2 (which indicates the depth of the deepest portion) is 0.005 ⁇ D (however, in order to obtain the frictional force between the peripheral surface of the steel pipe 1 and the ground or concrete) D: Steel pipe outer diameter) or more is necessary.
  • the depth H of the recess 2 is set to 0.005 ⁇ D to 0.2 ⁇ D.
  • the width B of the recess 2 needs to be 0.015 ⁇ D or more in order to obtain the above frictional force.
  • it exceeds 2 ⁇ D the effect of improving the frictional force is small, so it is necessary to set it to 2 ⁇ D or less.
  • width B of the recess 2 width B of the recess 2 and the soil cement inside the recess 2. It shall be determined by either bearing pressure strength. At this time, if any one of the destruction modes clearly precedes the other, the strength is determined by the destruction mode, and thus the strength is considered to decrease. Therefore, in considering the optimum shape of the concave portion 2, it is necessary to find a shape in which the above two destruction modes occur simultaneously.
  • the support pressure P that provides the support strength and the shear force S that provides the shear strength are required to satisfy the following balance condition formula (1).
  • S P cos ⁇ (1)
  • ⁇ is an angle formed by the surface of the steel pipe 1 and the entrance surface of the recess 2.
  • the shear force S is defined by the area where the shear force acts ⁇ shear force. Therefore, the shearing force S is formulated by the following formula (2).
  • the recess 2 is arranged around the entire circumference of the steel pipe 1.
  • the shear area is represented by the product of the circumferential length ⁇ D of the steel pipe 1 and the width B (the bottom portion of the triangle) of the recess 2.
  • Expression (4 ′) is a modification of the force balance conditional expression (1) for giving the optimum shape.
  • the angle ( ⁇ ) formed between the side surface of the recess 2, that is, the triangular slope of FIG. 4 and the surface of the steel pipe 1 is 45 degrees (hereinafter referred to as a triangular shape), and 90 degrees ( This is hereinafter referred to as a square shape).
  • ⁇ 90 ° (the concave portion 2 is a square shape)
  • B / H ⁇ b / ⁇ (5) It becomes.
  • FIG. 5 is a view showing a production line of a normal forged pipe.
  • a steel strip 10 slit to a desired width is formed into a circular cross section with a roll 21. Thereafter, both ends of the roll 22 are heated to high heat, pressed, and abutted.
  • the collided tube is narrowed to reduce the diameter to a predetermined size by the subsequent rolls 23-34.
  • the forged pipe 11 (steel pipe 1) is manufactured by cutting into a predetermined length by the cutting machine 38 and adjusting the shape with the subsequent rolls 35-37.
  • FIG. 6 is an example of a forged pipe manufacturing line. Only the final roll 34 of the squeeze roll before the cutting machine 38 is changed with respect to the conventional production line. As shown in FIGS. 7A and 7B, the roll 34 is provided with convex portions ⁇ on the circumferential surface of the roll 34 at one or a plurality of locations in the roll axis direction. This convex part ⁇ is used as a pressing means. The roll 34 provided with the convex portion ⁇ is used both vertically and on one side. In FIGS. 6 and 7A to 7B, two upper and lower rolls 34a and 34b are shown, but one set may be three or more rolls.
  • the concave portion 2 is easily formed in the portion of the forged welded tube 11 where the convex portion ⁇ hits. Moreover, the shape of the concave portion 2 is formed in a shape conforming to the shape of the convex portion ⁇ of the roll 34 as compared with the cold processing. Therefore, a more acute recess 2 is obtained. Thereafter, the steel pipe 5 for ground reinforcement according to the present invention is completed by being cut into a predetermined length, shaped, and provided with a recess 11a.
  • the shape and pitch of the convex portion ⁇ of the roll 34 may be changed.
  • the upper and lower rolls 34a and 34b are both provided with a convex portion ⁇ and the concave portion 2 on the forged pipe 11 is to be formed at the same position, the convex portions ⁇ of the upper and lower rolls 34a and 34b are initially aligned.
  • the upper and lower rolls 34a and 34b may be connected via one drive source and a universal joint, and the upper and lower rolls 34a and 34b may be driven in synchronization.
  • the shape of the convex portion ⁇ formed on the roll 34 is desirably made higher at the center of the roll 34 and lower toward the end of the roll 34.
  • the peripheral speed is different between the center portion and the end portion of the roll 34. For this reason, the end portion having a larger diameter has a higher peripheral speed. Accordingly, since the rotation of the roll 34 progresses faster than the passing pipe, an unnecessary force is applied to the forged pipe 11. As a result, the deformation and distortion more than necessary are given to the forged pipe 11.
  • FIG. 8 is an example of another forged pipe manufacturing line.
  • a pressurizing device (pressing means) 39 for the dedicated forged welding pipe 11 (steel pipe 1) is provided between the drawing roll 34 and the cutting machine 38.
  • the pressurizing device 39 may be the roll 34 having the above-described convex portion ⁇ , or may be a type that pressurizes the forging pipe 11 while being sandwiched from above and below.
  • the pressurizing device 39 preferably has a mechanism capable of moving back and forth with respect to the forged weld tube 11 or moving forward and backward in the direction of travel of the forged weld tube 11.
  • the pressurizing device 39 can be moved close to and retracted from the forged weld tube 11, the concave portion 2 can be formed at an arbitrary position of the forged weld tube 11. Even when it is desired to change the pitch of the recesses 2, the roll 34 need not be replaced. Furthermore, this function makes it possible for the control unit to recognize the cutting position of the forged tube 11 in advance, and to control so that the concave portion 2 is not positioned at this cutting position. If the recess 2 comes to the end of the forged pipe 11, the diameter and shape of the end face will be different for each forged pipe 11. In this case, for example, connection between the forged pipes 11 becomes difficult.
  • the reduced diameter portion forming device can be moved in synchronization with the progress of the forged weld tube 11.
  • the shape of the recess 2 can be freely formed without causing unnecessary distortion to the forged welded tube 11 due to the difference in the peripheral speed between the center portion and the end portion of the roll 34 as described above.
  • these functions may be applied to the roll 34 in which the existing final squeeze roll is provided with the convex portion ⁇ .
  • the pipe making method may be any one of a pipe making method by electric sewing, a pipe making method for hot or warm welding, a pipe making method by forging, and a seamless pipe making method. It is only necessary to heat the piped surface by a pressing means during or after pipe making and press the piped surface by a pressing means in a warm or hot state, and it is possible to manufacture the steel pipe 1 with the recess 2 online. And since the recessed part 2 is formed in the steel pipe 1 manufactured with these manufacturing methods, it can be easily manufactured even if the thickness of the steel pipe 1 is 2 mm or more.
  • the steel pipe 1 when the steel pipe 1 is driven into the ground while being rotated as a steel pipe pile, the steel pipe 1 is thick, so that a torsional force acts on the steel pipe 1 and the steel pipe 1 is not bent or the tip is not crushed.
  • a steel pipe having an outer diameter of 50 mm or more that can be practically used as the ground reinforcing steel pipe 5 can be easily manufactured.
  • the production efficiency is the same as when producing a normal forged steel pipe.
  • the concave portion 2 can be continuously provided simultaneously with the steel pipe manufacturing. Furthermore, by changing the shape of the protrusion ⁇ of the dedicated roll 34, the concave portions 2 having any shape, spacing, and arrangement can be given. Further, there is no need for processing in a separate process, and the steel pipe 1 with the recesses 2 can be provided at a very low cost.
  • the concave portion 2 is formed when the steel pipe 1 is placed by providing a convex shape (that is, the concave portion 2) on the inner surface side instead of the outer surface side of the steel pipe 1 in this way. It will not get in the way.
  • the several through-hole 3 is drilled in the steel pipe 1 which provided the recessed part 2. As shown in FIG.
  • the through hole 3 may be the concave portion 2 on the periphery of the steel pipe 1 or may be provided in a smooth portion other than the concave portion 2. Or you may provide in either.
  • the diameter and arrangement of the through-holes 3 are not particularly limited as long as the injection material spreads over the entire length and may be arbitrarily determined depending on the properties of the reinforcing agent to be injected and the state of the ground to be injected.
  • FIG. 9 is a view showing the positions of the excavating bits 4 and 7 and the ground reinforcing steel pipe 5.
  • the outer bit 4 excavates the ground or the like ahead while rotating by the power transmitted from the rod 6 and the inner bit 7.
  • the ground reinforcement steel pipe 5 of the present invention is disposed behind the outer bit 4. Therefore, the outer diameter of the steel pipe 5 for ground reinforcement should just be smaller than the outer diameter of the outer side bit 4.
  • the rod 6 and the inner bit 7 pass through the inside of the steel pipe 5 for ground reinforcement. Therefore, the minimum inner diameter of the steel pipe 1 needs to be larger than the maximum outer diameter of the inner bit 7. As long as the above conditions are satisfied, the depth of the recess 2 on the circumference of the steel pipe can be increased.
  • a drill rod 6 having an inner bit 7 attached to the tip is inserted into the steel pipe 1, and the inner bit 7 at the tip is inserted into the steel pipe 1.
  • the drill rod 6 and the rear end of the steel pipe 1 are connected to a drilling machine (not shown) so as to protrude from the outer bit 4 of the drill.
  • the drilling rod 6 and the steel pipe 1 are drilled while being hit, rotated and thrusted from the rock drill.
  • water or compressed air is supplied from the rock drill and discharged from the tip of the outer bit 4.
  • Most of the flour produced by the drilling is discharged through the inside of the steel pipe 1, but a part is discharged backward through the outside of the steel pipe 1.
  • the drill rod 6 is pulled out from the steel pipe 1 together with the inner bit 7 backward. Thereafter, an injection device (not shown) is attached to the rear end of the steel pipe 1, and the injected material is press-fitted into the steel pipe 1. The injected material fills the steel pipe 1 and flows out through a large number of through holes 3 provided in the steel pipe 1. Then, while flowing along the outer surface of the steel pipe 1, it penetrates into the ground and solidifies. Thereby, the natural ground is strengthened.
  • this steel pipe 1 has a concave portion 2 formed on the outer peripheral portion thereof, the concave portion 2 is embedded in a solidified injection material layer, and both are firmly integrated. For this reason, even if an axial force is applied to the steel pipe 1, the engagement between the recess 2 and the injection material layer causes a catching resistance and prevents the steel pipe 1 from moving. In this way, the steel pipe 1 is firmly fixed in the natural ground. Since the recess 2 has a predetermined cross-sectional shape, it is possible to improve both the fluidity of the pouring material and flour and the catching resistance for preventing deviation.
  • the concave portion 2 is usually formed by a rolling roll. Therefore, the cross-sectional shape is a gentle shape with no edge or corner. Therefore, the flour and the injected material flow smoothly and do not partially clog or void. For this reason, not only the discharge state of the flour is good, but the adhesion between the injection material and the steel pipe 1 is improved, and excellent ground reinforcement can be achieved.
  • the combination of the ring-shaped outer bit 4 fixed to the distal end portion of the steel pipe 1 and the inner bit 7 attached to the distal end portion of the drilled rod 6 is adopted as the bit.
  • the diameter is expanded so as to be larger than the outer diameter of the steel pipe 1, and at the end of the drilling, the diameter is contracted so as to be smaller than the inner diameter of the steel pipe 1, and the rear You may make it pull out. In this case, it is not necessary to fix the ring bit (outer bit) 4 to the tip of the steel pipe 1.
  • the levels are the three levels shown in Table 1. Size: 76.3mm ⁇ ⁇ 3.2mmt ⁇ 6mL, standard STK
  • FIGS. 10A and 10B the adhesion strength is evaluated by embedding a ground reinforcing steel pipe 5 in the soil cement 100 and applying a load from the upper portion 101 to measure the maximum load (the degree of adhesion is evaluated at the maximum load). did).
  • FIG. 10A is a diagram schematically showing an evaluation method when the ground reinforcing steel pipe 5 of the present invention is embedded.
  • FIG. 10B is a diagram schematically illustrating an evaluation method when a steel pipe 102 provided with a convex portion 103 is embedded as Comparative Example 2.
  • As the soil cement 100 a mixture of soil and a solidifying agent was used. At this time, the soil was carried out in two cases of clay and sandy soil.
  • the particle size of the cohesive soil is 0.001 to 0.005 mm, and the particle size of the sandy soil is 0.074 to 2.000 mm.
  • the present invention has a larger push-through load, that is, a higher adhesion force than the other comparative examples.
  • the manufacturing cost of the ground reinforcing steel pipe in which the concave portion of the present invention is formed is almost the same level as the manufacturing cost of the straight pipe of Comparative Example 1.
  • the convex steel pipe of the comparative example 2 adds the build-up welding cost for forming a convex part to the pipe making cost. Therefore, the cost is high. Thus, it can be seen that the present invention is superior in terms of cost.
  • the steel pipe for ground reinforcement according to the present invention has a concave portion formed on the outer peripheral surface of a conventional steel pipe, which reduces ground reinforcement in tunnel construction or the strengthening of structures such as concrete foundations. Effective at cost.

Abstract

Disclosed is a steel pipe for reinforcing the foundation driven in the foundation and usable for injecting an injection material into the foundation. The steel pipe comprises recessed parts and flat smooth parts disposed on the outer periphery of the pipe and a plurality of through holes that are formed in the recessed parts or the flat smooth parts and communicate with the inside and the outside of the steel pipe.

Description

地盤強化用鋼管、及びそれを使用した地盤強化方法、並びに構造体の強化方法Ground strengthening steel pipe, ground strengthening method using the same, and structure strengthening method
　本発明は、トンネル工事等における先受け工法や掘削壁面の補強工法等に使用するに適した地盤強化用鋼管、及びそれを使用した地盤強化方法、並びにコンクリート基礎などの構造体を補強する方法に関する。　
　本願は、２００８年０１月１８日に、日本国に出願された特願２００８－００９５７０号に基づき優先権を主張し、その内容をここに援用する。 TECHNICAL FIELD The present invention relates to a steel pipe for ground reinforcement suitable for use in a leading construction method in tunnel construction or the like, a reinforcement method for a drilling wall surface, a ground reinforcement method using the same, and a method for reinforcing a structure such as a concrete foundation. .
This application claims priority based on Japanese Patent Application No. 2008-009570 filed in Japan on January 18, 2008, the contents of which are incorporated herein by reference.
　例えば、軟弱な地山におけるトンネル工事では、地山を補強するために、鋼管を埋設する先受け工法が採用されることが多い。この工法では、先端部にビットを装着したさく孔ロッドに、鋼管を外嵌して穿孔を行う。そして、所定深さの穿孔を行ったら、鋼管をそのまま残してさく孔ロッドを引き抜き、鋼管の内部にモルタル等の注入材を注入する。鋼管の胴部には、内外に通ずる多数の通孔が穿孔されている。内部に注入された注入材は、その通孔を通って地山に浸透して固化する。これにより、軟弱な地山が強化される。先受け工法については、多数の特許出願がなされている（例えば、特許文献１及び特許文献２参照）。
　上記先受け工法に使用される鋼管は、地山に埋設される。そのため、比較的安価で強度が大きい材質の鋼管が使用される。注入材の注入時には、上記通孔を通して流出する注入材が地山に十分に浸透し、かつ地山と鋼管との隙間に密に充填される必要がある。また、埋設された鋼管が強固に固定されるためには、この鋼管とその外周部の注入材の層とが強固に一体化しているのが望ましい。 For example, in a tunnel construction in a soft ground, in order to reinforce the ground, a receiving construction method in which a steel pipe is buried is often adopted. In this construction method, a steel pipe is externally fitted to a drill rod with a bit attached to the tip. Then, after drilling at a predetermined depth, the drill rod is pulled out while leaving the steel pipe as it is, and an injection material such as mortar is injected into the steel pipe. A large number of through holes communicating with the inside and outside of the body of the steel pipe are drilled. The injection material injected into the inside penetrates into the natural ground through the through hole and solidifies. Thereby, a soft ground is strengthened. Many patent applications have been filed for the prior construction method (for example, see Patent Document 1 and Patent Document 2).
The steel pipe used for the above-mentioned prior receiving method is buried in the natural ground. Therefore, a steel pipe made of a material that is relatively inexpensive and has high strength is used. When injecting the injection material, it is necessary that the injection material flowing out through the through hole sufficiently penetrates into the natural ground and is tightly filled in the gap between the natural mountain and the steel pipe. Further, in order to firmly fix the embedded steel pipe, it is desirable that the steel pipe and the layer of the injection material on the outer periphery thereof are firmly integrated.
　しかしながら、従来の鋼管は、外面が平滑な面として形成されているので、外部の注入材の層との引っ掛かりがなく、両者がしっかりと固定されているとは言えなかった。これを改良するため、鋼管の外面にサンドブラスト処理等を施して、面を荒くする方法がある。しかしながら、この方法ではそれなりの密着効果が得られたが、鋼管を地山に強固に固定するという面では未だ満足できていない。
　また、特許文献３には、地盤強化用鋼管として、外周部に螺旋状の凸条が形成され、この螺旋状凸条の間隔部に、注入材を鋼管の外部に流出させるための内外に通ずる複数の通孔が設けられた地盤強化用鋼管が開示されている。
特開２０００－２０４８７０号公報 特開２００１－０２０６５７号公報 特開２００６－０２２５０１号公報 However, since the conventional steel pipe is formed with a smooth outer surface, it cannot be said that both are firmly fixed without being caught by an external injection material layer. In order to improve this, there is a method of roughening the surface by subjecting the outer surface of the steel pipe to sandblasting or the like. However, although this method has obtained a certain adhesion effect, it is not yet satisfactory in terms of firmly fixing the steel pipe to the natural ground.
Further, in Patent Document 3, as a steel pipe for ground reinforcement, spiral ridges are formed on the outer peripheral part, and the space between the spiral ridges leads to the inside and outside for allowing the injected material to flow out of the steel pipe. A steel pipe for ground reinforcement provided with a plurality of through holes is disclosed.
JP 2000-204870 A JP 2001-020657 A JP 2006-022501 A
　しかし、上記特許文献３に開示される鋼管では、鋼管の外周面に凸部があるので、鋼管を打設する時の邪魔になる。また、鋼管の外表面側から土砂を排出する際に、この凸部が邪魔となる。そのため、凸部を大きな形状にできず、十分な密着性が確保し難い。また、鋼管の外周面に凸部を付与するには、鋼管を製造した後に、別工程で凸部を付与する加工が必要となる。そのため、生産性が劣り、また、コストが高くなるとの問題がある。
　本発明は上記問題を解決するものであり、製造コストを高くすることなく、地盤に埋設するときは抵抗が小さく、且つ、補強材を流し込んだ際には、鋼管とその周辺とがしっかりと強固に密着する地盤強化用鋼管、及びそれを使用した地盤強化方法、並びに構造物の強化方法の提供を目的とする。 However, the steel pipe disclosed in Patent Document 3 has a convex portion on the outer peripheral surface of the steel pipe, which obstructs the placement of the steel pipe. Moreover, when discharging earth and sand from the outer surface side of a steel pipe, this convex part becomes an obstacle. For this reason, the convex portion cannot be formed into a large shape, and it is difficult to ensure sufficient adhesion. Moreover, in order to give a convex part to the outer peripheral surface of a steel pipe, after manufacturing a steel pipe, the process which provides a convex part by another process is needed. Therefore, there are problems that productivity is inferior and costs are increased.
The present invention solves the above problem, and without increasing the manufacturing cost, the resistance is small when embedded in the ground, and when the reinforcing material is poured, the steel pipe and its periphery are firmly and firmly fixed. An object of the present invention is to provide a steel pipe for ground reinforcement that adheres closely to the ground, a ground strengthening method using the steel pipe, and a method for strengthening a structure.
　本発明は、上記課題を解決して係る目的を達成するために以下の手段を採用した。
（１）本発明の地盤強化用鋼管は、地盤に打設され、この地盤の中に注入材を注入するための地盤強化用鋼管であって、その外周面に配された凹部及び平滑部と、前記凹部あるいは前記平滑部にあって、この地盤強化用鋼管の内外に通ずる複数の通孔と、を有する。
（２）前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；前記凹部の断面形状が三角形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、Ｂ／Ｈ＝３～２０である；のが好ましい。
（３）前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；前記凹部の断面形状が四角形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、Ｂ／Ｈ＝４～２０である；のが好ましい。
（４）前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；前記凹部の断面形状が半円状、あるいは台形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、Ｂ／Ｈ＝３～２０である；のが好ましい。　
（５）前記凹部が、前記鋼管の同一円周上に複数設けられているのが好ましい。
（６）前記凹部が、前記鋼管の円周方向に複数設けられ、少なくとも向かい合う前記凹部が、前記鋼管の同一円周上をさけて設けられているのが好ましい。　
（７）前記凹部が、前記鋼管の軸に対し、斜め方向に複数設けられているのが好ましい。
（８）前記凹部が、前記鋼管の軸に対し、平行に複数設けられているのが好ましい。
（９）前記凹部が、前記凹部を正面視した際に、円形状に複数設けられているのが好ましい。
（１０）前記鋼管の表面にめっき、あるいは、樹脂被覆が配されているのが好ましい。
（１１）本発明の地番強化方法は、地盤強化に際して、地盤を掘削しながら上記（１）に記載の地盤強化用鋼管を打設し、この地盤強化用鋼管を打設後、この地盤強化用鋼管の内部から前記複数の通孔を通して前記地盤強化用鋼管の外部に注入材を注入する。
（１２）前記地盤強化用鋼管の最小内径が、前記地盤を掘削する際に用いる内側ビットの外径よりも大きいのが好ましい。
（１３）前記地盤強化用鋼管の最大外径が、前記地盤の掘削に用いる外側ビットの外径よりも小さいのが好ましい。
（１４）本発明の構造体の強化方法は、コンクリートを含む構造体の強化に際して、この構造体を掘削しながら請求項１に記載の地盤強化用鋼管を打設し、この地盤強化用鋼管を打設後、この地盤強化用鋼管の内部から前記複数の通孔を通して前記地盤強化用鋼管の外部に注入材を注入する。 The present invention employs the following means in order to solve the above problems and achieve the object.
(1) The steel pipe for ground reinforcement of the present invention is a steel pipe for ground reinforcement for pouring an injection material into the ground, and is provided with a concave portion and a smooth portion disposed on the outer peripheral surface thereof. And a plurality of through holes in the concave portion or the smooth portion that communicate with the inside and outside of the steel pipe for ground reinforcement.
(2) The cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D. It is preferable that B / H = 3 to 20 when the cross-sectional shape of the concave portion is triangular, the width of the concave portion is (B), and the depth of the concave portion is (H).
(3) The cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D. Yes; It is preferable that B / H = 4 to 20 when the cross-sectional shape of the concave portion is a square shape, the width of the concave portion is (B), and the depth of the concave portion is (H).
(4) When the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D. Yes; B / H = 3 to 20 when the cross-sectional shape of the concave portion is semicircular or trapezoidal, the width of the concave portion is (B), and the depth of the concave portion is (H) Is preferred.
(5) It is preferable that a plurality of the concave portions are provided on the same circumference of the steel pipe.
(6) It is preferable that a plurality of the concave portions are provided in the circumferential direction of the steel pipe, and at least the concave portions facing each other are provided so as to avoid the same circumference of the steel pipe.
(7) It is preferable that a plurality of the recesses are provided in an oblique direction with respect to the axis of the steel pipe.
(8) It is preferable that a plurality of the recesses are provided in parallel to the axis of the steel pipe.
(9) It is preferable that a plurality of the recesses are provided in a circular shape when the recess is viewed from the front.
(10) It is preferable that plating or resin coating is provided on the surface of the steel pipe.
(11) The ground number strengthening method of the present invention is the ground reinforcement steel pipe as set forth in (1) above while excavating the ground, and after this ground reinforcement steel pipe is placed, An injection material is injected from the inside of the steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes.
(12) It is preferable that a minimum inner diameter of the steel pipe for ground reinforcement is larger than an outer diameter of an inner bit used when excavating the ground.
(13) It is preferable that the maximum outer diameter of the steel pipe for ground reinforcement is smaller than the outer diameter of an outer bit used for excavation of the ground.
(14) In the method for strengthening a structure according to the present invention, when reinforcing a structure including concrete, the ground reinforcing steel pipe according to claim 1 is placed while excavating the structure, and the ground reinforcing steel pipe is used. After the placement, an injection material is injected from the inside of the ground reinforcing steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes.
　上記（１）に記載の地盤強化用鋼管は、鋼管の外周面に凹部が形成されているので、地盤への埋設時にはこの凹部が抵抗にならない。また、鋼管の外周面に注入材を流し込んだ際には、凹部にも注入材が充填され、地盤との密着性が向上する。その結果、施工時の埋設本数の削減が可能となり、施工コストおよび施工工期の短縮が可能となる。
　また、上記（１）に記載の地盤強化用鋼管は、外周面に凹部を設けるのみなので、例えば、鋼管を造管後、そのまま凸部を有したロール間を通すだけで製造が可能である。そのため、生産能率も低下せず、製造コストも従来方法に比較して低減可能である。
　また、上記（１）に記載の地盤強化用鋼管を使用すれば、例えば建造物のコンクリート基礎などの構造物の補強にも同様に適用が可能で、低コストで強固な補強が可能である。 In the steel pipe for ground reinforcement described in (1) above, since the concave portion is formed on the outer peripheral surface of the steel pipe, the concave portion does not become a resistance when embedded in the ground. Further, when the injection material is poured into the outer peripheral surface of the steel pipe, the injection material is also filled in the concave portion, and the adhesion with the ground is improved. As a result, it is possible to reduce the number of burials at the time of construction, and it is possible to shorten the construction cost and the construction period.
Moreover, since the steel pipe for ground reinforcement | strengthening as described in said (1) only provides a recessed part in an outer peripheral surface, it can manufacture only by passing between the rolls which have a convex part as it is after forming a steel pipe, for example. Therefore, the production efficiency is not lowered, and the manufacturing cost can be reduced as compared with the conventional method.
Moreover, if the steel pipe for ground reinforcement | strengthening as described in said (1) is used, it can apply similarly to reinforcement of structures, such as a concrete foundation of a building, for example, and a strong reinforcement is possible at low cost.
図１は、本発明の地盤強化用鋼管の一例を示す正面図である。FIG. 1 is a front view showing an example of a steel pipe for ground reinforcement according to the present invention. 図２Ａは、本発明の地盤強化用鋼管の一例を示す図である。FIG. 2A is a diagram showing an example of a steel pipe for ground reinforcement according to the present invention. 図２Ｂは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2B is a diagram showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｃは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2C is a diagram showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｄは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2D is a view showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｅは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2E is a view showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｆは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2F is a diagram showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｇは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2G is a diagram showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｈは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2H is a view showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｉは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2I is a view showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｊは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2J is a view showing a modification of the ground reinforcing steel pipe of the present invention. 図２Ｋは、本発明の地盤強化用鋼管の変形例を示す図である。FIG. 2K is a diagram showing a modification of the ground reinforcing steel pipe of the present invention. 図３Ａは、本発明の地盤強化用鋼管の凹部の具体例を示す図である。FIG. 3A is a diagram showing a specific example of a concave portion of the ground reinforcing steel pipe of the present invention. 図３Ｂは、本発明の地盤強化用鋼管の凹部の、他の具体例を示す図である。FIG. 3B is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention. 図３Ｃは、本発明の地盤強化用鋼管の凹部の、他の具体例を示す図である。FIG. 3C is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention. 図３Ｄは、本発明の地盤強化用鋼管の凹部の、他の具体例を示す図である。FIG. 3D is a diagram showing another specific example of the concave portion of the ground reinforcing steel pipe of the present invention. 図４は、本発明の地盤強化用鋼管の凹部の幅と深さとの関係を示す図である。FIG. 4 is a view showing the relationship between the width and depth of the concave portion of the ground reinforcing steel pipe of the present invention. 図５は、通常の鍛接鋼管の製造ラインを示す図である。FIG. 5 is a view showing a production line of a normal forged steel pipe. 図６は、本発明の地盤強化用鋼管を製造する鍛接鋼管の製造ラインの一実施例を示す図である。FIG. 6 is a diagram showing an embodiment of a forged steel pipe production line for producing the ground reinforcing steel pipe of the present invention. 図７Ａは、本発明鋼管の製造に使用するロールの概念図である。FIG. 7A is a conceptual diagram of a roll used for manufacturing the steel pipe of the present invention. 図７Ｂは、本発明鋼管の製造に使用するロールの概念図である。FIG. 7B is a conceptual diagram of a roll used for manufacturing the steel pipe of the present invention. 図８は、本発明の地盤強化用鋼管を製造する鍛接鋼管の製造ラインの他の実施例を示す図である。FIG. 8 is a diagram showing another embodiment of a forged steel pipe production line for producing the ground reinforcing steel pipe of the present invention. 図９は、ビット付きのさく孔ロッドを挿入した、地盤強化用鋼管の先端部の一部断面図である。FIG. 9 is a partial cross-sectional view of the tip portion of the ground reinforcing steel pipe into which a drill rod with a bit is inserted. 図１０Ａは、実施例における密着力の評価方法を示す図である。FIG. 10A is a diagram illustrating a method for evaluating the adhesion strength in Examples. 図１０Ｂは、比較例における密着力の評価方法を示す図である。FIG. 10B is a diagram illustrating a method for evaluating adhesion in a comparative example. 図１１は、実施例における効果を比較した図である。FIG. 11 is a diagram comparing the effects of the examples.
符号の説明Explanation of symbols
　１　鋼管
　２　凹部
　３　通孔
　４　外側ビット
　５　地盤強化用鋼管 DESCRIPTION OF SYMBOLS 1 Steel pipe 2 Recessed part 3 Through-hole 4 Outer bit 5 Steel pipe for ground reinforcement
　以下、図面によって本発明を具体的に説明する。
　図１に、本発明に係る地盤強化用鋼管５を模式的に示す。この地盤強化用鋼管５は、鋼管１の外周部に、一定間隔で周状に凹部２が設けられている。この凹部２によって、鋼管１と地盤あるいはコンクリート等との摩擦力を高められる。
　また、鋼管１の周面全面に、鋼管１の内外を通ずる複数の通孔３が配されている。鋼管１の内部に注入された注入材は、これらの通孔３を通して鋼管外面に流出される。この注入材の一部は、地山と鋼管１との間に充填され、地山と鋼管１とを固定する。また、他の一部は地山に浸透して固化し、この地山を強化する。この際、凹部２は、固化した注入材の層に埋め込まれた状態となり、両者が強固に一体化する。このため、鋼管１に軸方向の力が作用しても、この凹部２と注入材層との係合によって引っ掛かり抵抗が生じ、鋼管１の移動が防止される。
　以上より、注入材本実施形態の地盤強化用鋼管５では、鋼管１と地山との密着性の向上が図れ、より強固に鋼管１と地山とを固定できる。図１中、符号４は外側ビットを示す。
　この地盤強化用鋼管５の製造方法は、鋼管製造ラインにて鋼管１を造管後、熱間あるいは温間で、押圧手段により鋼管１の表面に凹部２を付与するのみである。そのため、生産性は通常の造管工程と殆ど変わらない。 Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 schematically shows a steel pipe 5 for ground reinforcement according to the present invention. The steel pipe 5 for ground reinforcement is provided with recesses 2 on the outer periphery of the steel pipe 1 at regular intervals. The concave portion 2 can increase the frictional force between the steel pipe 1 and the ground or concrete.
In addition, a plurality of through holes 3 that pass through the inside and the outside of the steel pipe 1 are arranged on the entire peripheral surface of the steel pipe 1. The injected material injected into the steel pipe 1 flows out to the outer surface of the steel pipe through these through holes 3. A part of the injection material is filled between the natural ground and the steel pipe 1 to fix the natural ground and the steel pipe 1. In addition, the other part penetrates into the ground and solidifies, strengthening this ground. At this time, the recess 2 is embedded in the solidified injection material layer, and both are firmly integrated. For this reason, even if an axial force acts on the steel pipe 1, the engagement between the recess 2 and the injection material layer causes a catching resistance and prevents the steel pipe 1 from moving.
From the above, in the ground reinforcement steel pipe 5 of the injection material according to the present embodiment, the adhesion between the steel pipe 1 and the natural ground can be improved, and the steel pipe 1 and the natural ground can be fixed more firmly. In FIG. 1, reference numeral 4 indicates an outer bit.
In this method of manufacturing the steel pipe 5 for ground strengthening, after the steel pipe 1 is formed on the steel pipe production line, the concave portion 2 is only given to the surface of the steel pipe 1 by the pressing means in a hot or warm manner. Therefore, productivity is almost the same as that of a normal pipe making process.
　図２Ａ～２Ｋは、凹部２の他の形状を示した具体例を示す。
　図２Ａ、２Ｂ，２Ｃは、いずれの鋼管１の円周方向に凹部２Ａ～２Ｃを有し、この凹部２Ａ～２Ｃが軸方向に一定間隔で複数形成されている。図２Ａの地盤強化用鋼管５は、凹部２Ａを鋼管１の同一円周上に複数（図では対向して２個）設けた例である。図２Ｂの地盤強化用鋼管５は、凹部２を圧延ロールではなく、鋼管１Ａに対し、近接、退避可能な往復式の押圧装置により形成したものである。凹部２Ｂが、鋼管１の円周上でほぼ同一の深さとなっている。図２Ｃの地盤強化用鋼管５は、凹部２Ｃは鋼管１の円周方向に複数設けられ、これらのうち少なくとも向かい合う凹部２Ｃが同一円周上には存在しない例である。
　図２Ｃの鋼管１のように、向かい合う凹部２Ｃが同一円周上に存在しないように千鳥配置とすることで、図２Ａの鋼管１に比べて、凹部２Ｃが配された位置の鋼管１の強度を向上させられる。図２Ｃに示す鋼管１は、地盤強化用鋼管５の強度、特に凹部２が配された部分の強度がより高く要求される場合に適している。凹部２Ｃの千鳥配置の例では、凹部２Ｃの対向する部分の全幅がラップしないように形成することが望ましい。 2A to 2K show specific examples showing other shapes of the recess 2.
2A, 2B, and 2C have recesses 2A to 2C in the circumferential direction of any steel pipe 1, and a plurality of recesses 2A to 2C are formed at regular intervals in the axial direction. The ground strengthening steel pipe 5 in FIG. 2A is an example in which a plurality of recesses 2A are provided on the same circumference of the steel pipe 1 (two facing each other in the figure). In the steel pipe 5 for ground reinforcement shown in FIG. 2B, the recess 2 is formed not by a rolling roll but by a reciprocating pressing device that can approach and retract from the steel pipe 1A. The recess 2 </ b> B has substantially the same depth on the circumference of the steel pipe 1. The steel pipe 5 for ground reinforcement of FIG. 2C is an example in which a plurality of recesses 2C are provided in the circumferential direction of the steel pipe 1, and at least the facing recesses 2C do not exist on the same circumference.
As in the steel pipe 1 of FIG. 2C, the strength of the steel pipe 1 at the position where the concave portion 2C is disposed is made by staggering so that the concave portions 2C facing each other do not exist on the same circumference. Can be improved. The steel pipe 1 shown in FIG. 2C is suitable when the strength of the ground reinforcing steel pipe 5, particularly the strength of the portion where the recess 2 is disposed, is required to be higher. In the example of the staggered arrangement of the recesses 2C, it is desirable to form the entire width of the opposing portions of the recesses 2C so as not to wrap.
　図２Ｄ～２Ｇは、鋼管１の軸に対し、斜め方向に長辺を有する凹部２Ｄ～２Ｇを形成した鋼管１を示した図である。図２Ｈ及び図２Ｉは、鋼管１の軸に平行な方向に長辺を有する凹部２Ｈ，２Ｉを形成した鋼管１を示した図である。図２Ｊ及び図２Ｋは、丸いスポット状（円形状）の凹部２Ｊ，２Ｋを形成した鋼管１を示した図である。スポット状の凹部２Ｊ，２Ｋは、形成し易さなどから楕円や多角形などから自由に選択できる。また、凹部２Ｄ～２Ｇを同一円周上に配置するかあるいは交互に千鳥状に配置するかなども自由に選択できる。
　ここで、凹部２Ｄ～２Ｇの形状の制約は高さのみで、鋼管１の内面を掘削ビッドが通過できるだけのスペースを確保すればよい。 2D to 2G are views showing the steel pipe 1 in which concave portions 2D to 2G having long sides in an oblique direction with respect to the axis of the steel pipe 1 are formed. 2H and 2I are views showing the steel pipe 1 in which concave portions 2H and 2I having long sides in a direction parallel to the axis of the steel pipe 1 are formed. 2J and 2K are views showing the steel pipe 1 in which round spot-like (circular) recesses 2J and 2K are formed. The spot- like recesses 2J and 2K can be freely selected from ellipses and polygons because of their ease of formation. It is also possible to freely select whether the recesses 2D to 2G are arranged on the same circumference or alternately arranged in a staggered manner.
Here, the shape is limited only by the height of the recesses 2D to 2G, and it is only necessary to secure a space that allows the excavation bid to pass through the inner surface of the steel pipe 1.
　本発明の地盤強化用鋼管５は、後述するように熱間あるいは温間で凹部２を形成する。そのため、例えば鋼管１の肉厚が２ｍｍ以上でも容易に製造できる。ゆえに、厚肉な地盤強化用鋼管５を製造し、この地盤強化用鋼管５を例えば地盤に回転させながら打ち込む際に、この地盤強化用鋼管５にねじれ力が作用し、屈曲したり、先端が潰れたりすることがない。また、地盤強化用鋼管５として実用可能な外径５０ｍｍ以上のものも、容易に製造できる。
　本発明に係る地盤強化用鋼管５を、特に耐食性が要求される用途に使用する場合には、前記の如く凹部２を構成した鋼管１の表面に、めっき、あるいは樹脂被覆を施して、良好な耐食性を発揮させることが望ましい。 As will be described later, the steel pipe 5 for ground reinforcement of the present invention forms the recess 2 hot or warm. Therefore, for example, the steel pipe 1 can be easily manufactured even if the thickness is 2 mm or more. Therefore, when the steel pipe 5 for ground reinforcement 5 is manufactured and this steel pipe 5 for ground reinforcement is driven into the ground while being rotated, for example, the torsional force acts on the steel pipe 5 for ground reinforcement, and the tip is bent. It won't be crushed. Moreover, the outer diameter 50mm or more which can be practically used as the steel pipe 5 for ground reinforcement | strengthening can be manufactured easily.
When the steel pipe 5 for ground reinforcement according to the present invention is used for an application requiring particularly corrosion resistance, the surface of the steel pipe 1 constituting the recess 2 as described above is plated or coated with a resin, so that it is good. It is desirable to exhibit corrosion resistance.
　鋼管１の凹部２については、図３Ａ～３Ｄに示す如く、基本的には断面形状が三角形状の場合と、断面四角形状の場合が考えられる。半円状、及び台形状の場合は、ほぼ三角形と等しいと考えてもよい。いずれの場合も、凹部２の深さ（最も深い部分の深さを指す）Ｈは、鋼管１の周面と地盤あるいはコンクリート等との摩擦力を得るために、０．００５×Ｄ（但し、Ｄ：鋼管外径）以上は必要である。しかし、０．２×Ｄ超で摩擦力向上の効果も飽和してしまうので、凹部２の深さＨは、０．００５×Ｄ～０．２×Ｄとする。さらに凹部２の幅Ｂは、上記摩擦力を得るためには０．０１５×Ｄ以上必要である。しかしながら、２×Ｄ超では、摩擦力向上効果が小さいため２×Ｄ以下とする必要がある。 As for the concave portion 2 of the steel pipe 1, as shown in FIGS. 3A to 3D, there are basically a case where the cross-sectional shape is a triangular shape and a case where the cross-sectional shape is a square shape. In the case of a semicircular shape and a trapezoidal shape, it may be considered substantially equal to a triangle. In any case, the depth H of the concave portion 2 (which indicates the depth of the deepest portion) is 0.005 × D (however, in order to obtain the frictional force between the peripheral surface of the steel pipe 1 and the ground or concrete) D: Steel pipe outer diameter) or more is necessary. However, since the effect of improving the frictional force is saturated when it exceeds 0.2 × D, the depth H of the recess 2 is set to 0.005 × D to 0.2 × D. Further, the width B of the recess 2 needs to be 0.015 × D or more in order to obtain the above frictional force. However, if it exceeds 2 × D, the effect of improving the frictional force is small, so it is necessary to set it to 2 × D or less.
　更に、上記の前提のもとで、凹部２の形状の最適化を図る上で、下記の事項を規定することが重要である。すなわち、凹部２の断面形状が三角形状の時、Ｂ／Ｈ＝３～２０である。凹部２の断面形状が四角形状の時、Ｂ／Ｈ＝４～２０である。凹部２の断面形状が半円状、あるいは台形状の時、Ｂ／Ｈ＝３～２０である。
　以下、上記のＢ／Ｈの関係が導き出された経緯を、図４を用いて説明する。前提として、凹部２での破壊モードは、凹部２の外側、すなわち、図４中の三角形の底辺（凹部２の幅Ｂ）でのソイルセメントのせん断強度と、凹部２の内部でのソイルセメントの支圧強度とのいずれかで決定されるものとする。このとき、いずれかの破壊モードが他方に対して、明らかに先行すると、その破壊モードで強度が決定するため、強度は低下すると考えられる。ゆえに、凹部２の最適形状を考える上では、上記の二つの破壊モードが同時に発生するような形状を見出すことが必要となる。 Furthermore, in order to optimize the shape of the recess 2 under the above assumption, it is important to define the following matters. That is, when the cross-sectional shape of the recess 2 is triangular, B / H = 3-20. When the cross-sectional shape of the recess 2 is square, B / H = 4-20. When the cross-sectional shape of the recess 2 is semicircular or trapezoidal, B / H = 3 to 20.
Hereinafter, the process of deriving the above B / H relationship will be described with reference to FIG. As a premise, the fracture mode in the recess 2 is determined by the shear strength of the soil cement outside the recess 2, that is, at the bottom of the triangle in FIG. 4 (width B of the recess 2) and the soil cement inside the recess 2. It shall be determined by either bearing pressure strength. At this time, if any one of the destruction modes clearly precedes the other, the strength is determined by the destruction mode, and thus the strength is considered to decrease. Therefore, in considering the optimum shape of the concave portion 2, it is necessary to find a shape in which the above two destruction modes occur simultaneously.
　その結果、凹部２の最適形状においては、支圧強度を与える支圧力Ｐと、せん断強度を与えるせん断力Ｓとは、以下の式（１）のつりあい条件式を満たすことが求められる。
　Ｓ＝Ｐｃｏｓθ　　　　　　　　（１）
　ただし、θ：鋼管１の表面と凹部２の入側面とのなす角度である。
　ここで、せん断力Ｓは、せん断力が作用する面積×せん断力で定義される。そのため、せん断力Ｓは、以下の式（２）で定式化される。ここでは、凹部２は鋼管１の周囲全周に配置されるものと仮定する。せん断面積は、鋼管１の周長πＤと、凹部２の幅Ｂ（三角形の底辺部分）の積で表される。
　Ｓ＝τ・Ｂ・π・Ｄ　　　　　　　（２）
　一方、支圧力Ｐは、支圧応力に作用する面積を乗じたものとして、以下の式（３）で定式化される。
　Ｐ＝Ｈ・σｂ・ｃｏｓθ・π・Ｄ　　　　　　　　　（３）
　　τ：せん断応力、Ｄ：鋼管外径、σｂ：支圧力（支圧応力、力／面積の次元）
式（１）に式（２）、（３）を代入して整理すると、以下の式（４）、（４′）が導かれる。
　τ・Ｂ＝（Ｈ・σｂ・ｃｏｓθ）ｃｏｓθ　　　　　（４）
　∴Ｂ／Ｈ＝σｂ・ｃｏｓ２θ／τ　　　　　　　　　　（４′）
　式（４′）は、最適形状を与える際の力のつりあい条件式（１）を変形したものである。ここでは、凹部２の側面、即ち図４の三角形の斜面と、鋼管１の表面とのなす角度（θ）が４５度の場合（これを以下、三角形状とする）と、９０度の場合（これを以下、四角形状とする）に関して、解くこととする。
　θ＝９０°（凹部２が四角形状）とすると、
　Ｂ／Ｈ＝σｂ／τ　　　　　　　　　（５）
　となる。例えば、ソイルセメントの支圧強度σｂ＝１Ｎ／ｍｍ２と、せん断強度τ＝０．１Ｎ／ｍｍ２とを（５）式に代入すると、Ｂ／Ｈ＝１０（凹部２の幅が高さの１０倍）となり、凹部２の形状は、長辺１０Ｈ、高さＨの長方形となる。 As a result, in the optimum shape of the recess 2, the support pressure P that provides the support strength and the shear force S that provides the shear strength are required to satisfy the following balance condition formula (1).
S = P cos θ (1)
However, θ is an angle formed by the surface of the steel pipe 1 and the entrance surface of the recess 2.
Here, the shear force S is defined by the area where the shear force acts × shear force. Therefore, the shearing force S is formulated by the following formula (2). Here, it is assumed that the recess 2 is arranged around the entire circumference of the steel pipe 1. The shear area is represented by the product of the circumferential length πD of the steel pipe 1 and the width B (the bottom portion of the triangle) of the recess 2.
S = τ ・ B ・ π ・ D (2)
On the other hand, the support pressure P is formulated by the following formula (3) assuming that the area acting on the support stress is multiplied.
P = H · σb · cosθ · π · D (3)
τ: shear stress, D: steel pipe outer diameter, σb: bearing pressure (bearing stress, force / area dimension)
Substituting the formulas (2) and (3) into the formula (1) and rearranging leads to the following formulas (4) and (4 ′).
τ · B = (H · σb · cosθ) cosθ (4)
∴B / H = σb · cos 2 θ / τ (4 ′)
Expression (4 ′) is a modification of the force balance conditional expression (1) for giving the optimum shape. Here, the angle (θ) formed between the side surface of the recess 2, that is, the triangular slope of FIG. 4 and the surface of the steel pipe 1 is 45 degrees (hereinafter referred to as a triangular shape), and 90 degrees ( This is hereinafter referred to as a square shape).
When θ = 90 ° (the concave portion 2 is a square shape),
B / H = σb / τ (5)
It becomes. For example, when substituting strength σb = 1 N / mm 2 of soil cement and shear strength τ = 0.1 N / mm 2 are substituted into equation (5), B / H = 10 (the width of the recess 2 is high) 10 times), and the shape of the recess 2 is a rectangle having a long side 10H and a height H.
　一方、最終的な凹部２の形状が三角形状で、更にその三角形が二等辺三角形とすると、Ｂ、Ｈ、θには下記の関係式（６）が成立する。
　ｔａｎθ＝２・Ｈ／Ｂ　　　　　　　（６）
これを式（４′）に代入すると、
　２／（ｓｉｎθ・ｃｏｓθ）＝σｂ／τ　　　　（７）
となる。この式（７）に、ソイルセメントの支圧強度σｂ＝１Ｎ／ｍｍ２、せん断強度τ＝０．１Ｎ／ｍｍ２を代入すると、
　ｓｉｎθ・ｃｏｓθ＝１／５　　　　　　　　　（８）
　ｓｉｎ２θ＝２／５＝０．４　　　　　　　　　（８′）
　∴θ＝１１．８
となる。
　ソイルセメント（コンクリート）の支圧強度σｂとせん断強度τの関係を
　１／２０≦τ／σｂ≦２／９とすると（通常はτ／σｂ＝１／１０程度）、
（ａ）凹部２の形状が四角形の場合、凹部２の幅Ｂと深さＨの関係は式（５）により、
　４．５≦Ｂ／Ｈ≦２０．０
（ｂ）凹部２の形状が三角形の場合、適正なθの範囲は式（７）により
　５．８≦θ≦３１．４
このとき、凹部２の幅Ｂと深さＨの関係は、式（６）により
　３．３≦Ｂ／Ｈ≦１９．８
となる。
　ここで、図２Ｄ～２Ｋに示したような鋼管１の軸方向に斜め、平行、あるいはスポット状の凹部２の場合についても、図２ＤのＡ－Ａ断面、図２ｈのＨ－Ｈ断面、図２ｊのＣ－Ｃ断面について前記式を適用すればよい。
　以上のことから、本発明においては、Ｂ／Ｈを下記の如く規定した。
　（１）凹部２の断面形状が三角形状の時、Ｂ／Ｈ＝３～２０
　（２）凹部２の断面形状が四角形状の時、Ｂ／Ｈ＝４～２０
　（３）凹部２の断面形状が半円状、あるいは台形状の時、Ｂ／Ｈ＝３～２０ On the other hand, if the final shape of the recess 2 is a triangle, and the triangle is an isosceles triangle, the following relational expression (6) is established for B, H, and θ.
tan θ = 2 · H / B (6)
Substituting this into equation (4 ')
2 / (sin θ · cos θ) = σb / τ (7)
It becomes. Substituting the bearing strength σb = 1 N / mm 2 and the shear strength τ = 0.1 N / mm 2 of the soil cement into this formula (7),
sinθ · cosθ = 1/5 (8)
sin2θ = 2/5 = 0.4 (8 ′)
∴θ = 11.8
It becomes.
When the relationship between bearing strength σb and shear strength τ of soil cement (concrete) is 1/20 ≦ τ / σb ≦ 2/9 (usually about τ / σb = 1/10),
(A) When the shape of the concave portion 2 is a quadrangle, the relationship between the width B and the depth H of the concave portion 2 is expressed by the equation (5):
4.5 ≦ B / H ≦ 20.0
(B) When the shape of the concave portion 2 is a triangle, an appropriate range of θ is 5.8 ≦ θ ≦ 31.4 according to the equation (7).
At this time, the relationship between the width B and the depth H of the recess 2 is 3.3 ≦ B / H ≦ 19.8 according to the equation (6).
It becomes.
Here, also in the case of the concave portion 2 that is oblique, parallel, or spot-like in the axial direction of the steel pipe 1 as shown in FIGS. 2D to 2K, the AA cross section of FIG. 2D, the HH cross section of FIG. The above formula may be applied to the CC section of 2j.
From the above, in the present invention, B / H is defined as follows.
(1) When the cross-sectional shape of the recess 2 is triangular, B / H = 3 to 20
(2) When the cross-sectional shape of the recess 2 is a square, B / H = 4 to 20
(3) When the cross-sectional shape of the recess 2 is semicircular or trapezoidal, B / H = 3 to 20
　次に、本発明に係る地盤強化用鋼管５の製造方法について説明する。
　本発明においては、以下のａ）、ｂ）、ｃ）、ｄ）のいずれかの工程でも適用可能であるが、鍛接鋼管の製造ラインを代表例として本発明を説明する。
　ａ）電縫鋼管製造ラインにて、電縫溶接後、この鋼管を加熱し、押圧手段によりその表面を押圧する。
　ｂ）熱間あるいは温間溶接鋼管製造ラインにて、溶接後、押圧手段によりその表面を押圧する。
　ｃ）鍛接鋼管製造ラインにて、衝合後、押圧手段によりその表面を押圧する。
　ｄ）シームレス鋼管製造ラインにて、造管後、押圧手段によりその表面を押圧する。 Next, the manufacturing method of the steel pipe 5 for ground reinforcement | strengthening which concerns on this invention is demonstrated.
Although the present invention can be applied to any of the following steps a), b), c), and d), the present invention will be described using a forged steel pipe production line as a representative example.
a) In an electric resistance steel pipe production line, after electric resistance welding, this steel pipe is heated and the surface is pressed by a pressing means.
b) The surface is pressed by pressing means after welding in a hot or warm welded steel pipe production line.
c) After the abutment in the forged steel pipe production line, the surface is pressed by pressing means.
d) In the seamless steel pipe production line, the surface is pressed by pressing means after pipe forming.
　図５は通常の鍛接管の製造ラインを示す図である。
　所望の幅にスリットされた鋼帯１０をロール２１で断面円形状に成形する。その後、ロール２２でその両端部を高熱に加熱し、圧接し、衝合する。衝合された管をそれ以降のロール２３～３４により所定の寸法に縮径するために絞り込む。そして切断機３８により所定の長さに切断し、以降のロール３５～３７で形状を整えて鍛接管１１（鋼管１）が製造される。 FIG. 5 is a view showing a production line of a normal forged pipe.
A steel strip 10 slit to a desired width is formed into a circular cross section with a roll 21. Thereafter, both ends of the roll 22 are heated to high heat, pressed, and abutted. The collided tube is narrowed to reduce the diameter to a predetermined size by the subsequent rolls 23-34. Then, the forged pipe 11 (steel pipe 1) is manufactured by cutting into a predetermined length by the cutting machine 38 and adjusting the shape with the subsequent rolls 35-37.
　図６は、鍛接管製造ラインの一実施例である。
　従来の製造ラインに対して、切断機３８前の絞りロールの最終ロール３４のみを変更している。このロール３４は、図７Ａ，７Ｂのように、ロール３４の周面に、ロール軸方向に１箇所あるいは複数箇所に凸部αを設けている。この凸部αを押圧手段としている。この凸部αを設けたロール３４を上下両方あるいは片側に使用する。図６、７Ａ～７Ｂでは、上下２基のロール３４ａ，３４ｂで示しているが、１組が３基以上のロールでも構わない。このような凸部αを有したロール３４で、高温の（およそ１２００～１３００℃程度）鍛接管１１に圧力を加える。そのため、その凸部αの当たる鍛接管１１の部分は容易に凹部２が形成される。しかも冷間での加工に比較して凹部２の形状は、ロール３４の凸部αの形状に則した形状で形成される。ゆえに、より鋭角の凹部２が得られる。その後、所定の長さに切断され、定形され、凹部１１ａ付きの本発明の地盤強化用鋼管５が完成される。
　ここで、鍛接管１１上の凹部２の高さ、幅、ピッチを変更したい場合は、ロール３４の凸部αの形状やピッチを変更すれば良い。また、上下のロール３４ａ，３４ｂ両方に凸部αを設け、鍛接管１１上の凹部２の位置を同じ位置で形成したい場合は、上下のロール３４ａ，３４ｂの凸部αの位置を初期に合せておき、例えば上下のロール３４ａ，３４ｂを一つの駆動源およびユニバーサルジョイントなどを介して連結し、同期させて上下のロール３４ａ，３４ｂを駆動すれば良い。 FIG. 6 is an example of a forged pipe manufacturing line.
Only the final roll 34 of the squeeze roll before the cutting machine 38 is changed with respect to the conventional production line. As shown in FIGS. 7A and 7B, the roll 34 is provided with convex portions α on the circumferential surface of the roll 34 at one or a plurality of locations in the roll axis direction. This convex part α is used as a pressing means. The roll 34 provided with the convex portion α is used both vertically and on one side. In FIGS. 6 and 7A to 7B, two upper and lower rolls 34a and 34b are shown, but one set may be three or more rolls. Pressure is applied to the high-temperature (approximately 1200 to 1300 ° C.) forged weld tube 11 with the roll 34 having such a convex portion α. Therefore, the concave portion 2 is easily formed in the portion of the forged welded tube 11 where the convex portion α hits. Moreover, the shape of the concave portion 2 is formed in a shape conforming to the shape of the convex portion α of the roll 34 as compared with the cold processing. Therefore, a more acute recess 2 is obtained. Thereafter, the steel pipe 5 for ground reinforcement according to the present invention is completed by being cut into a predetermined length, shaped, and provided with a recess 11a.
Here, when it is desired to change the height, width, and pitch of the concave portion 2 on the forged pipe 11, the shape and pitch of the convex portion α of the roll 34 may be changed. If the upper and lower rolls 34a and 34b are both provided with a convex portion α and the concave portion 2 on the forged pipe 11 is to be formed at the same position, the convex portions α of the upper and lower rolls 34a and 34b are initially aligned. For example, the upper and lower rolls 34a and 34b may be connected via one drive source and a universal joint, and the upper and lower rolls 34a and 34b may be driven in synchronization.
　ロール３４に形成する凸部αの形状は、図７Ｂに示すように、ロール３４の中心部を高くし、ロール３４の端部に向うに従い低くすることが望ましい。ロール３４の中心部と端部とでは、周速が異なる。そのため、径が大きい端部の方が、周速が大きくなる。従って、通過する管よりも早くロール３４の回転が進行するために、鍛接管１１に対し無用な力が加わる。その結果、必要以上の変形や歪を鍛接管１１に与えてしまう。 As shown in FIG. 7B, the shape of the convex portion α formed on the roll 34 is desirably made higher at the center of the roll 34 and lower toward the end of the roll 34. The peripheral speed is different between the center portion and the end portion of the roll 34. For this reason, the end portion having a larger diameter has a higher peripheral speed. Accordingly, since the rotation of the roll 34 progresses faster than the passing pipe, an unnecessary force is applied to the forged pipe 11. As a result, the deformation and distortion more than necessary are given to the forged pipe 11.
　図８は、別の鍛接管製造ラインの例である。
　本例では、絞りロール３４と切断機３８との間に、専用の鍛接管１１（鋼管１）への加圧装置（押圧手段）３９を設けた例である。加圧装置３９としては、前述の凸部αを有したロール３４でも良く、また、上下から挟み込む形で鍛接管１１に加圧するタイプのものでも良い。そしてこの加圧装置３９は、鍛接管１１に対して進退、あるいは鍛接管１１の進行方向に進退可能な機構を有することが望ましい。
　加圧装置３９が、鍛接管１１に対して近接、退避可能なことにより、鍛接管１１の任意の位置に凹部２を形成できる。また、凹部２のピッチを変更したいときでも、ロール３４の交換などしなくても良い。更に、この機能により、予め鍛接管１１の切断位置を制御部が認識しておき、この切断位置に凹部２が位置しないように制御することも可能となる。鍛接管１１の端部に凹部２がくると、鍛接管１１毎に端面の径や形状が異なってしまう。この場合、例えば鍛接管１１同士の接続が困難となる。
　また、加圧装置３９が鍛接管１１の進行方向に移動可能とすることにより、鍛接管１１の進行と同調して縮径部の形成装置を移動できる。そのことにより、前述したようなロール３４の中心部と端部の周速の差による鍛接管１１への無用な歪などが発生せずに、凹部２の形状も自由に形成できる。
　以上、専用装置において説明したが、これらの機能を既存の最終絞りロールに凸部αを設けたロール３４にもたせても良い。 FIG. 8 is an example of another forged pipe manufacturing line.
In this example, a pressurizing device (pressing means) 39 for the dedicated forged welding pipe 11 (steel pipe 1) is provided between the drawing roll 34 and the cutting machine 38. The pressurizing device 39 may be the roll 34 having the above-described convex portion α, or may be a type that pressurizes the forging pipe 11 while being sandwiched from above and below. The pressurizing device 39 preferably has a mechanism capable of moving back and forth with respect to the forged weld tube 11 or moving forward and backward in the direction of travel of the forged weld tube 11.
Since the pressurizing device 39 can be moved close to and retracted from the forged weld tube 11, the concave portion 2 can be formed at an arbitrary position of the forged weld tube 11. Even when it is desired to change the pitch of the recesses 2, the roll 34 need not be replaced. Furthermore, this function makes it possible for the control unit to recognize the cutting position of the forged tube 11 in advance, and to control so that the concave portion 2 is not positioned at this cutting position. If the recess 2 comes to the end of the forged pipe 11, the diameter and shape of the end face will be different for each forged pipe 11. In this case, for example, connection between the forged pipes 11 becomes difficult.
Further, by allowing the pressurizing device 39 to move in the traveling direction of the forged weld tube 11, the reduced diameter portion forming device can be moved in synchronization with the progress of the forged weld tube 11. As a result, the shape of the recess 2 can be freely formed without causing unnecessary distortion to the forged welded tube 11 due to the difference in the peripheral speed between the center portion and the end portion of the roll 34 as described above.
As described above, in the dedicated apparatus, these functions may be applied to the roll 34 in which the existing final squeeze roll is provided with the convex portion α.
　前述のように、造管方法は、電縫による造管方法、熱間あるいは温間で溶接する造管方法、鍛接による造管方法、シームレス造管方法のいずれでもよい。造管中、あるいは造管後に加熱などし、温間あるいは熱間の状態で押圧手段によりその造管された表面を押圧すれば良く、オンラインでの凹部２付き鋼管１の製造が可能である。
　そして、これらの製造方法で製造された鋼管１は、熱間で凹部２が形成されるので、鋼管１の肉厚が２ｍｍ以上でも容易に製造可能である。例えば、鋼管杭として地盤に回転させながら打ち込む際に、鋼管１は肉厚なため、鋼管１にねじれ力が作用し、この鋼管１が屈曲したり、先端が潰れたりすることがない。また、地盤強化用鋼管５として実用可能な外径５０ｍｍ以上のものも容易に製造できる。しかも生産能率は、通常の鍛接鋼管を製造する際と同じである。 As described above, the pipe making method may be any one of a pipe making method by electric sewing, a pipe making method for hot or warm welding, a pipe making method by forging, and a seamless pipe making method. It is only necessary to heat the piped surface by a pressing means during or after pipe making and press the piped surface by a pressing means in a warm or hot state, and it is possible to manufacture the steel pipe 1 with the recess 2 online.
And since the recessed part 2 is formed in the steel pipe 1 manufactured with these manufacturing methods, it can be easily manufactured even if the thickness of the steel pipe 1 is 2 mm or more. For example, when the steel pipe 1 is driven into the ground while being rotated as a steel pipe pile, the steel pipe 1 is thick, so that a torsional force acts on the steel pipe 1 and the steel pipe 1 is not bent or the tip is not crushed. In addition, a steel pipe having an outer diameter of 50 mm or more that can be practically used as the ground reinforcing steel pipe 5 can be easily manufactured. Moreover, the production efficiency is the same as when producing a normal forged steel pipe.
　以上のような鋼管の製造方法により通常の鋼管の製造ラインにて、突起を付与した専用ロールで製管することで、鋼管製造と同時に凹部２を連続的に付与できる。さらに、専用ロール３４の突起部αの形状の変更により、任意に自在な形状、間隔、配置の凹部２を付与できる。また、別工程での加工の必要がなく、非常に安価に凹部２付の鋼管１を提供できる。 By manufacturing a steel pipe with a dedicated roll provided with protrusions in a normal steel pipe manufacturing line by the steel pipe manufacturing method as described above, the concave portion 2 can be continuously provided simultaneously with the steel pipe manufacturing. Furthermore, by changing the shape of the protrusion α of the dedicated roll 34, the concave portions 2 having any shape, spacing, and arrangement can be given. Further, there is no need for processing in a separate process, and the steel pipe 1 with the recesses 2 can be provided at a very low cost.
　本発明の地盤強化用鋼管５では、このように鋼管１の外表面側でなく、内表面側へ凸形状（すなわち凹部２）を付与することで、鋼管１の打設時に、この凹部２が邪魔になることがない。また、十分な密着性を確保できる大きな凹部２を有する地盤強化用鋼管５を、生産性を落とすことなく低コストで製造できる。
　そして凹部２を設けた鋼管１に、複数の通孔３を穿孔する。通孔３は、鋼管１の周上の凹部２でも良いし、凹部２以外の平滑部に設けても良い。或いはどちらにも設けても良い。通孔３の径や配置は、注入材が全長にわたって万遍なく行き渡るようなものであればよく、注入する強化剤の性状や注入する地盤の状態によって任意に決定すれば良い。 In the steel pipe 5 for ground reinforcement of the present invention, the concave portion 2 is formed when the steel pipe 1 is placed by providing a convex shape (that is, the concave portion 2) on the inner surface side instead of the outer surface side of the steel pipe 1 in this way. It will not get in the way. Moreover, the steel pipe 5 for ground reinforcement | strengthening which has the big recessed part 2 which can ensure sufficient adhesiveness can be manufactured at low cost, without reducing productivity.
And the several through-hole 3 is drilled in the steel pipe 1 which provided the recessed part 2. As shown in FIG. The through hole 3 may be the concave portion 2 on the periphery of the steel pipe 1 or may be provided in a smooth portion other than the concave portion 2. Or you may provide in either. The diameter and arrangement of the through-holes 3 are not particularly limited as long as the injection material spreads over the entire length and may be arbitrarily determined depending on the properties of the reinforcing agent to be injected and the state of the ground to be injected.
　図９は掘削用のビット４，７と地盤強化用鋼管５の位置を示した図である。外側ビット４は、ロッド６及び内側ビット７から伝達された動力によって回転しながら、前方の地盤などを掘削する。外側ビット４の後方には、本発明の地盤強化用鋼管５が配置されている。従って、地盤強化用鋼管５の外径は、外側ビット４の外径よりも小さければ良い。
　また、地盤強化用鋼管５の内側は、ロッド６と内側ビット７が通過する。そのため、鋼管１の最小内径は、内側ビット７の最大外径よりも大きくする必要がある。以上の条件を満足する限り、鋼管１周上の凹部２の深さを大きくとることができる。 FIG. 9 is a view showing the positions of the excavating bits 4 and 7 and the ground reinforcing steel pipe 5. The outer bit 4 excavates the ground or the like ahead while rotating by the power transmitted from the rod 6 and the inner bit 7. The ground reinforcement steel pipe 5 of the present invention is disposed behind the outer bit 4. Therefore, the outer diameter of the steel pipe 5 for ground reinforcement should just be smaller than the outer diameter of the outer side bit 4.
The rod 6 and the inner bit 7 pass through the inside of the steel pipe 5 for ground reinforcement. Therefore, the minimum inner diameter of the steel pipe 1 needs to be larger than the maximum outer diameter of the inner bit 7. As long as the above conditions are satisfied, the depth of the recess 2 on the circumference of the steel pipe can be increased.
　この地盤強化用鋼管５の使用に際しては、図９に示すように、先端部に内側ビット７を装着したさく孔ロッド６を、この鋼管１内に挿通し、先端部の内側ビット７が鋼管１の外側ビット４よりも突出するようにして、このさく孔ロッド６と鋼管１の後端部をさく岩機（図示を省略）に接続する。そして、さく孔ロッド６と鋼管１にさく岩機から打撃と回転と推力を与えつつ穿孔を行う。穿孔中は、さく岩機から水又は圧縮空気が供給され、外側ビット４の先端部から吐出される。穿孔によって生じる繰り粉は、大部分が鋼管１の内側を通って排出されるが、一部は鋼管１の外側を通って後方へ排出される。
　所定深さの穿孔が終了し、鋼管１が地山中に埋設されたら、さく孔ロッド６を内側ビット７とともに鋼管１から後方へ引き抜く。その後、鋼管１の後端部に注入装置（図示を省略）を取り付けて、注入材を鋼管１内に圧入する。この注入材は、鋼管１内に充満し、この鋼管１に設けられている多数の通孔３を通って外部へ流出する。そして、鋼管１の外面に沿って流動しつつ、地山内に浸透して固化する。これにより、地山が強化される。 When using the steel pipe 5 for ground reinforcement, as shown in FIG. 9, a drill rod 6 having an inner bit 7 attached to the tip is inserted into the steel pipe 1, and the inner bit 7 at the tip is inserted into the steel pipe 1. The drill rod 6 and the rear end of the steel pipe 1 are connected to a drilling machine (not shown) so as to protrude from the outer bit 4 of the drill. Then, the drilling rod 6 and the steel pipe 1 are drilled while being hit, rotated and thrusted from the rock drill. During drilling, water or compressed air is supplied from the rock drill and discharged from the tip of the outer bit 4. Most of the flour produced by the drilling is discharged through the inside of the steel pipe 1, but a part is discharged backward through the outside of the steel pipe 1.
When the drilling of a predetermined depth is completed and the steel pipe 1 is buried in the natural ground, the drill rod 6 is pulled out from the steel pipe 1 together with the inner bit 7 backward. Thereafter, an injection device (not shown) is attached to the rear end of the steel pipe 1, and the injected material is press-fitted into the steel pipe 1. The injected material fills the steel pipe 1 and flows out through a large number of through holes 3 provided in the steel pipe 1. Then, while flowing along the outer surface of the steel pipe 1, it penetrates into the ground and solidifies. Thereby, the natural ground is strengthened.
　この鋼管１は、その外周部に凹部２が形成されているので、この凹部２が固化した注入材の層に埋め込まれた状態となり、両者が強固に一体化する。このため、鋼管１に軸方向の力が作用しても、この凹部２と注入材層との係合によって引っ掛かり抵抗が生じ、鋼管１の移動が防止される。このようにして、鋼管１が強固に地山中に固定される。凹部２は、所定の断面形状を持つので、注入材や繰り粉の流動性と逸脱防止のための引っ掛かり抵抗とを共に向上できる。 Since this steel pipe 1 has a concave portion 2 formed on the outer peripheral portion thereof, the concave portion 2 is embedded in a solidified injection material layer, and both are firmly integrated. For this reason, even if an axial force is applied to the steel pipe 1, the engagement between the recess 2 and the injection material layer causes a catching resistance and prevents the steel pipe 1 from moving. In this way, the steel pipe 1 is firmly fixed in the natural ground. Since the recess 2 has a predetermined cross-sectional shape, it is possible to improve both the fluidity of the pouring material and flour and the catching resistance for preventing deviation.
　上記凹部２は、通常圧延ロールで形成される。そのため、その断面形状は、エッジ部やコーナー部のないなだらかな形状となっている。ゆえに、繰り粉や注入材がスムーズに流動し、部分的に詰まりや空隙が生じない。このため、繰り粉の排出状態が良好であるのみならず、注入材と鋼管１との密着性が向上し、すぐれた地盤強化を達成できる。以上の説明では、ビットとして、鋼管１の先端部に固着したリング状の外側ビット４と、さく孔ロッド６の先端部に装着された内側ビット７との組み合わせを採用したが、口径が拡縮可能な拡縮ビットを使用し、穿孔時は口径を鋼管１の外径よりも大きくなるように拡張して穿孔を行い、穿孔終了時には、鋼管１の内径よりも小さくなるように口径を収縮して後方へ引き抜くようにしてもよい。この場合は、鋼管１の先端部にリングビット（外側ビット）４を固着しておく必要がない。 The concave portion 2 is usually formed by a rolling roll. Therefore, the cross-sectional shape is a gentle shape with no edge or corner. Therefore, the flour and the injected material flow smoothly and do not partially clog or void. For this reason, not only the discharge state of the flour is good, but the adhesion between the injection material and the steel pipe 1 is improved, and excellent ground reinforcement can be achieved. In the above description, the combination of the ring-shaped outer bit 4 fixed to the distal end portion of the steel pipe 1 and the inner bit 7 attached to the distal end portion of the drilled rod 6 is adopted as the bit. When the drilling is performed, the diameter is expanded so as to be larger than the outer diameter of the steel pipe 1, and at the end of the drilling, the diameter is contracted so as to be smaller than the inner diameter of the steel pipe 1, and the rear You may make it pull out. In this case, it is not necessary to fix the ring bit (outer bit) 4 to the tip of the steel pipe 1.
次に、以下の水準で密着力を比較したのでそれを説明する。水準は表１の３水準とした。サイズ：７６．３ｍｍφ×３．２ｍｍｔ×６ｍＬ、規格ＳＴＫ
Figure JPOXMLDOC01-appb-T000001
 Next, since the adhesion strength was compared at the following levels, it will be described. The levels are the three levels shown in Table 1. Size: 76.3mmφ × 3.2mmt × 6mL, standard STK
Figure JPOXMLDOC01-appb-T000001
　密着力の評価方法は、図１０Ａ，１０Ｂに示すように、ソイルセメント１００中に地盤強化用鋼管５を埋設し、上部１０１より荷重をかけ最大荷重を計測した（最大荷重にて密着度を評価した）。図１０Ａは、本発明の地盤強化用鋼管５を埋設した際の、評価方法を模式的に示した図である。図１０Ｂは、比較例２として凸部１０３が配された鋼管１０２を埋設した際の、評価方法を模式的に示した図である。
　ソイルセメント１００は、土と固化剤を混ぜ合わせたものを用いた。この際、土は、粘性土と砂質土のものの２例で実施した。粘性土の粒径は、０．００１～０．００５ｍｍ、砂質土の粒径は、０．０７４～２．０００ｍｍである。　その結果、図１１のように本発明は他の比較例に比べて押しぬき荷重が大きい、即ち、密着力が大きいことが認められた。 As shown in FIGS. 10A and 10B, the adhesion strength is evaluated by embedding a ground reinforcing steel pipe 5 in the soil cement 100 and applying a load from the upper portion 101 to measure the maximum load (the degree of adhesion is evaluated at the maximum load). did). FIG. 10A is a diagram schematically showing an evaluation method when the ground reinforcing steel pipe 5 of the present invention is embedded. FIG. 10B is a diagram schematically illustrating an evaluation method when a steel pipe 102 provided with a convex portion 103 is embedded as Comparative Example 2.
As the soil cement 100, a mixture of soil and a solidifying agent was used. At this time, the soil was carried out in two cases of clay and sandy soil. The particle size of the cohesive soil is 0.001 to 0.005 mm, and the particle size of the sandy soil is 0.074 to 2.000 mm. As a result, as shown in FIG. 11, it was confirmed that the present invention has a larger push-through load, that is, a higher adhesion force than the other comparative examples.
　本発明の凹部が形成された地盤強化用鋼管は、製造コストは比較例１の直管の製造コストとほぼ同レベルである。一方、比較例２の凸付鋼管は、造管コストに、凸部を形成するための肉盛り溶接コストが上乗せされる。そのため、高コストとなる。このようにコスト面でも本発明は優れていることがわかる。 The manufacturing cost of the ground reinforcing steel pipe in which the concave portion of the present invention is formed is almost the same level as the manufacturing cost of the straight pipe of Comparative Example 1. On the other hand, the convex steel pipe of the comparative example 2 adds the build-up welding cost for forming a convex part to the pipe making cost. Therefore, the cost is high. Thus, it can be seen that the present invention is superior in terms of cost.
　以上の説明から明らかなように、本発明に係る地盤強化用鋼管は、従来の鋼管の外周面に凹部を形成したもので、トンネル工事等における地盤強化あるいはコンクリート基礎などの構造体の強化を低コストで効果的に行える。 As is apparent from the above description, the steel pipe for ground reinforcement according to the present invention has a concave portion formed on the outer peripheral surface of a conventional steel pipe, which reduces ground reinforcement in tunnel construction or the strengthening of structures such as concrete foundations. Effective at cost.

Claims (14)

  1. 　地盤に打設され、この地盤の中に注入材を注入するための地盤強化用鋼管であって、
    　その外周面に配された凹部及び平滑部と、
    　前記凹部あるいは前記平滑部にあって、この地盤強化用鋼管の内外に通ずる複数の通孔と、
    　を有することを特徴とする地盤強化用鋼管。     It is a steel pipe for ground reinforcement for being poured into the ground and injecting an injection material into the ground,
    A concave portion and a smooth portion arranged on the outer peripheral surface;
    A plurality of through-holes in the recess or the smooth portion, which communicate with the inside and outside of the ground reinforcing steel pipe;
    The steel pipe for ground reinforcement characterized by having.
  2. 　前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；
    　前記凹部の断面形状が三角形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、
    Ｂ／Ｈ＝３～２０である；
    　ことを特徴とする請求項１記載の地盤強化用鋼管。     The cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D;
    When the cross-sectional shape of the recess is triangular, the width of the recess is (B), and the depth of the recess is (H),
    B / H = 3-20;
    The steel pipe for ground reinforcement according to claim 1, wherein:
  3. 　前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；
    　前記凹部の断面形状が四角形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、Ｂ／Ｈ＝４～２０である；
    　ことを特徴とする請求項１記載の地盤強化用鋼管。     The cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D;
    B / H = 4 to 20 when the cross-sectional shape of the concave portion is a square shape, the width of the concave portion is (B), and the depth of the concave portion is (H);
    The steel pipe for ground reinforcement according to claim 1, wherein:
  4. 　前記凹部の断面形状は、前記鋼管の外径を（Ｄ）としたときに、前記凹部の深さが０．００５Ｄ～０．２Ｄでかつ前記凹部の幅が０．０１５Ｄ～２Ｄであり；
    　前記凹部の断面形状が半円状、あるいは台形状であり、前記凹部の幅を（Ｂ）、前記凹部の深さを（Ｈ）としたときに、Ｂ／Ｈ＝３～２０である；
    　ことを特徴とする請求項１記載の地盤強化用鋼管。     The cross-sectional shape of the recess is such that when the outer diameter of the steel pipe is (D), the depth of the recess is 0.005D to 0.2D and the width of the recess is 0.015D to 2D;
    B / H = 3 to 20 when the cross-sectional shape of the concave portion is semicircular or trapezoidal, the width of the concave portion is (B), and the depth of the concave portion is (H);
    The steel pipe for ground reinforcement according to claim 1, wherein:
  5. 　前記凹部が、前記鋼管の同一円周上に複数設けられている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     2. The ground reinforcing steel pipe according to claim 1, wherein a plurality of the recesses are provided on the same circumference of the steel pipe.
  6. 　前記凹部が、前記鋼管の円周方向に複数設けられ、
    　少なくとも向かい合う前記凹部が、前記鋼管の同一円周上をさけて設けられている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     A plurality of the recesses are provided in the circumferential direction of the steel pipe,
    The steel pipe for ground reinforcement according to claim 1, wherein at least the concave portions facing each other are provided on the same circumference of the steel pipe.
  7. 　前記凹部が、前記鋼管の軸に対し、斜め方向に複数設けられている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     2. The ground reinforcing steel pipe according to claim 1, wherein a plurality of the concave portions are provided in an oblique direction with respect to the axis of the steel pipe.
  8. 　前記凹部が、前記鋼管の軸に対し、平行に複数設けられている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     The ground-reinforcing steel pipe according to claim 1, wherein a plurality of the recesses are provided in parallel to the axis of the steel pipe.
  9. 　前記凹部が、前記凹部を正面視した際に、円形状に複数設けられている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     The ground reinforcement steel pipe according to claim 1, wherein a plurality of the recesses are provided in a circular shape when the recess is viewed from the front.
  10. 　前記鋼管の表面にめっき、あるいは、樹脂被覆が配されている
    　ことを特徴とする請求項１に記載の地盤強化用鋼管。     The steel pipe for ground reinforcement according to claim 1, wherein a surface of the steel pipe is plated or resin-coated.
  11. 　地盤強化に際して、地盤を掘削しながら請求項１に記載の地盤強化用鋼管を打設し、
    　この地盤強化用鋼管を打設後、この地盤強化用鋼管の内部から前記複数の通孔を通して前記地盤強化用鋼管の外部に注入材を注入する
    　ことを特徴とする地盤強化方法。     When the ground is strengthened, the ground reinforcing steel pipe according to claim 1 is placed while excavating the ground,
    A ground strengthening method comprising injecting an injection material from the inside of the ground reinforcing steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes after the ground reinforcing steel pipe is placed.
  12. 　前記地盤強化用鋼管の最小内径が、前記地盤を掘削する際に用いる内側ビットの外径よりも大きい
    　ことを特徴とする請求項１１記載の地盤強化方法。     The ground strengthening method according to claim 11, wherein a minimum inner diameter of the ground reinforcing steel pipe is larger than an outer diameter of an inner bit used when excavating the ground.
  13. 　前記地盤強化用鋼管の最大外径が、前記地盤の掘削に用いる外側ビットの外径よりも小さい
    　ことを特徴とする請求項１１記載の地盤強化方法。     The ground reinforcement method according to claim 11, wherein a maximum outer diameter of the steel pipe for ground reinforcement is smaller than an outer diameter of an outer bit used for excavation of the ground.
  14. 　コンクリートを含む構造体の強化に際して、この構造体を掘削しながら請求項１に記載の地盤強化用鋼管を打設し、
    　この地盤強化用鋼管を打設後、この地盤強化用鋼管の内部から前記複数の通孔を通して前記地盤強化用鋼管の外部に注入材を注入する
    　ことを特徴とする構造体の強化方法。     When reinforcing a structure including concrete, the ground reinforcing steel pipe according to claim 1 is placed while excavating the structure.
    A structure strengthening method, comprising: injecting an injection material from the inside of the ground reinforcing steel pipe to the outside of the ground reinforcing steel pipe through the plurality of through holes after the ground reinforcing steel pipe is placed.
PCT/JP2009/050568 2008-01-18 2009-01-16 Steel pipe for reinforcing foundation, method of reinforcing foundation using the same, and method of reinforcing structure WO2009091041A1 (en)

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Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102071679B (en) * 2010-12-29 2012-07-04 西安建筑科技大学 Method for consolidating existing building foundation
CN102226338A (en) * 2011-04-12 2011-10-26 中国十九冶集团有限公司 Method for reinforcing bearing platform foundation with soil bearing capacity less than 0.1Mpa
JP5965778B2 (en) * 2012-08-16 2016-08-10 エスティーエンジニアリング株式会社 Long mirror bolt method
JP6221512B2 (en) * 2013-08-27 2017-11-01 新日鐵住金株式会社 Roll stand for forming recess in stepped steel pipe, roll drawing mill equipped with the same, and method for manufacturing stepped steel pipe
JP6515325B2 (en) * 2015-02-26 2019-05-22 日本製鉄株式会社 Reinforcement structure of reinforced steel pipe and concrete structure
JP6460835B2 (en) * 2015-02-26 2019-01-30 新日鐵住金株式会社 Reinforcing structure of concrete structure and method of reinforcing the same
JP6307136B2 (en) * 2016-09-27 2018-04-04 植村　誠 Open shield method
JP6307135B2 (en) * 2016-09-27 2018-04-04 植村　誠 Open shield method

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6221200U (en) * 1985-07-23 1987-02-07
JPH03247899A (en) * 1990-02-26 1991-11-06 Taisei Corp Driving method for rock bolt or the like
JP2007085157A (en) * 2005-08-24 2007-04-05 Nippon Steel Corp Steel pipe pile with recess, its manufacturing method, and composite steel pipe pile using the steel pipe pile

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0540935Y2 (en) * 1988-06-06 1993-10-18
JPH025500U (en) * 1988-06-17 1990-01-16
JPH11280394A (en) * 1998-03-27 1999-10-12 Tokai Rubber Ind Ltd Resin-made lock-bolt and its manufacture
JP2997237B2 (en) * 1998-05-19 2000-01-11 株式会社ケー・エフ・シー Rock bolt
JP2002081300A (en) * 2000-09-07 2002-03-22 Masato Yamada Lock bolt fixing method of mountain tunnel and water stop packing therefor
JP2005061002A (en) * 2003-08-11 2005-03-10 Nisshin Steel Co Ltd Spill-proof method for steel pipe expansion type lock bolt
JP4502730B2 (en) * 2004-07-06 2010-07-14 株式会社奥村組 Steel pipe for ground reinforcement
JP2006106085A (en) * 2004-09-30 2006-04-20 Brother Ind Ltd Karaoke system and program

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6221200U (en) * 1985-07-23 1987-02-07
JPH03247899A (en) * 1990-02-26 1991-11-06 Taisei Corp Driving method for rock bolt or the like
JP2007085157A (en) * 2005-08-24 2007-04-05 Nippon Steel Corp Steel pipe pile with recess, its manufacturing method, and composite steel pipe pile using the steel pipe pile

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