JP2006016774A - Method for using diameter-enlarged pipe pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for using a diameter-enlarged pipe pile, which facilitates the selection of the effective sectional area of the leading end of the pile by substituting a different-diameter pipe for a part of a rotary penetration pile for use in the construction of a foundation and the strengthening of ground. <P>SOLUTION: The rotary penetration pile is split into a leading end 12 and a supplementary part 19. At the leading end 12, a spiral vane 18 is attached to the side of an enlarged diameter 14 of the different-diameter pipe 13, and an excavating blade 17 is provided according to need. A pipe 20 with a required length, which is equal in diameter to the side of a reduced diameter 16 of the pipe 13, is connected to the supplementary part 19. After the diameter-enlarged pipe pile 11, wherein both the parts are connected together for integration, penetrates into the required ground, structures on the land are directly or indirectly connected to a pile head part 21 so that the foundation can be constructed of a metal, and the diameter-enlarged pipe pile is made to penetrate into the required ground. After that, the ground corresponding to the pile head part 21 is fixed, and the ground is strengthened by making either or both of a bearing capacity and a tensile force occur on the pile. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of using a diameter-expanded pipe pile in which a part of a rotary penetrating pile used for foundation construction and ground reinforcement is replaced with a different diameter pipe to facilitate selection of an effective cross-sectional area of the tip of the pile.

  Many upper objects are usually supported via a concrete foundation built on the ground surface. When the floor strength is insufficient to support the upper foundation and the concrete foundation, an improved method of inserting a friction pile into the foundation or a supporting pile reaching the ground of the required strength to make up the shortage, or filling the ground with a hardener, Used alone or in combination. Since the bearing capacity of the pile depends on the effective cross-sectional area of the pile tip and the ground strength, the effective cross-sectional area of the tip is increased by using a thick pile depending on the ground strength to be used. When the bottom of the upper object becomes deep from the ground surface and a shaft is formed by excavation, the mountain retaining wall is supported.

  If the bottom surface of the upper object is below the ground surface, if there is a non-permeable layer on the floor, there will be an influence of groundwater pressure, and the floor will be lifted up, which is called a blister. After that, the floor board of the surface on which the upper object is to be installed is reinforced with a hardener, and reinforcement called a ground anchor that suppresses the pressurized water that is connected to the support pile and causes board swelling is applied, and the pile to be used is Doubles as support pile and tension pile. When the reinforcement is completed and excavation progresses and a shaft is created, ground anchors are used as tension piles on the retaining wall, and reinforcement that improves the shearing force of the ground may be applied.

[Non-Patent Document 1] describes a bladed pile (rotary penetrating pile) with an increased effective cross-sectional area at the tip. [Patent Document 1] discloses a ground anchor technique for increasing a shearing force. [Patent Document 2] discloses a technique for preventing board bulging by a rotating penetrating pile. There is also a ground anchor that improves the fixability of the pile and the ground by replacing the blades at the tip of the pile in [Patent Document 2] with a hardened material and inflating into a bulb shape (without attached material).
Catalog published by Japan Architecture Center, 2002 edition Patent Publication No. Hei 6-81334 Patent Publication 2001-182088

  The construction of concrete foundations in places where it is difficult to use heavy machinery raises the problem of excessive manual work and excessive construction days. Also, if thick piles are used for weak ground, the bearing capacity will increase, but it will be difficult to become an effective solution due to the negative effects of reduced handling and increased costs. Therefore, the rotary penetration pile shown in [Non-Patent Document 1], which aims at the same effect by attaching a blade to the tip instead of expanding the pipe diameter, is used, but the supporting force is only related to the tip effective cross-sectional area. In consideration of the fact that most of the parts other than the tip only have to withstand the bearing force transmission and torsion at the time of penetration, in the case of a rotary penetration pile with the same overall length, an excessive specification is included in the considerable length part. Become.

  In the case of a ground anchor as a tension pile used for strengthening the retaining wall and slope of [Patent Document 1], the work of inserting the anchor into the ground, the work of filling the ground material forming the anchor fixing portion, and Since fastening work with the mountain wall is required, it can be said that it is a very time-consuming work. In addition, when the filler to be filled permeates and foams, the ground is consolidated and strengthened. However, there is a concern that the reinforcing state cannot be visually confirmed and the fixing power varies from anchor to anchor.

  Also in the case of the ground anchor used for the prevention of blistering in [Patent Document 2], there is an over-specification problem in the rotary penetration pile. In addition, there is a problem in the technique of inflating the fiber body at the tip of the pile that the degree of swelling cannot be visually observed, and the possibility of variation cannot be denied as in the previous section. In order to solve various problems related to foundation construction and ground strengthening, the present invention makes it easy to increase the cross-sectional area by using a different diameter pipe at the tip of the support pile, and uses a thin pipe after the tip to support Provide foundation construction and ground strengthening method with expanded pipe piles with expanded diameter.

The present invention divides the rotary penetrating pile into a tip part and a supplement part,
At the tip, a spiral blade is attached to the enlarged diameter side of the different diameter pipe, and if necessary, a configuration with a drilling blade is provided,
Connect the pipe of the required length with the same diameter as the reduced diameter side of the different diameter pipe to the supplementary part,
It is a method of using expanded pipe piles that have a foundation constructed of metal by directly or indirectly connecting the upper part to the pile head after penetrating the expanded pipe pile with both parts integrated and integrated to the required depth.
It is a usage method of the expanded pipe pile which penetrated the said pile to required depth, fixed the ground corresponding to a pile head, and generated tension in the pile, and strengthened the ground.

  Expanded pipe piles can combine the expanded diameter of different diameter pipes with the blade diameter, thus expanding the options for the tip effective cross-sectional area. In addition, the reduced diameter side is useful for weight reduction because it selects a thin tube that can withstand the transmission of support force and torsion during penetration. Since the pile was divided into a tip and a supplement and connected at any time and integrated, the structure was less wasteful than a conventional rotary penetrating pile. If both ends of the different diameter tube satisfy the requirements, the intermediate shape may be easily attached to the blade, and may be a commercially available product that is easily available. If the tip is cast, the blade welding and bending can be omitted.

  Expanded pipe piles with large support force can reduce the number of pipes used compared to the conventional type, are light in weight for support force, have a narrow pile head at the time of penetration, and can be used in small size heavy machinery. This feature means that an effect that cannot be obtained with a normal rotary penetration pile can be obtained with an expanded pipe pile. Narrow pile heads are easy to attach flanges and reinforcing plates, and when combined with a frame made of metal shapes or plates, the foundation of the structure can be easily created. If used instead of the foundation, it will help to significantly reduce the number of working days.

  Expanded pipe piles are propelled by spiral blades, but there is no concern about the generation of residual soil because the pipes in the supplementary part are thinner than the tip part. Since the blade and the tip of the different diameter pipe generate support force, the pulling resistance by the back of the blade and the different diameter pipe is large, and thus generates a large tensile force. It can be used as a ground anchor that doubles as a support pile and a tension pile, and a tension anchor ground anchor that strengthens the shearing force of the retaining wall and slope. In the case of retaining walls and slopes, expanded pipe piles do not require filling with a fixing material, so the construction is simplified. Use of expanded pipe piles in this way has a positive effect on materials, production, storage, transportation, assembly and construction, and greatly contributes to a reduction in total construction costs.

  Rotating penetrating piles using different diameter pipes have a spiral blade on the enlarged diameter side of different diameter pipes compared to rotating penetrating piles of the same diameter pipe. There are more options to increase or decrease the support or pull-out force by selecting the area. In addition, on the reduced diameter side, it is only necessary to apply a supporting tube suitable for the penetration depth or a thin tube that considers the transmission of the supporting force and tension and the torsional strength at the time of penetration, and the pile is shaped based on a reasonable strength distribution. be able to.

  Expanded pipe piles are prepared by separately preparing a tip part of a different diameter pipe with a spiral blade and a drilling blade to be attached when necessary, and a supplementary part pipe used on the reduced diameter side. If the shape is integrated by means selected from the above, a favorable effect can be obtained for storage and transportation. The different-diameter pipe may be a standard welded pipe material, a tapered pipe, or an arbitrary shape between both ends. Since the supplemental part occupies most of the length of the pile, it is convenient for weight reduction. The use of a different diameter pipe increases the effective cross-sectional area of the tip, ensuring the necessary support force even on weak ground.

  When the pile penetrates, the soil and sand flowing into the pile from the opening at the tip is compressed and densified by the different diameter pipes whose diameter is reduced, clogging occurs near the tip and the inflow stops. Therefore, the expanded-pipe pile can provide a supporting force equivalent to that of the blockage without closing the tip. The thin head of the expanded pipe pile is easy to attach a connection fitting for connection with the foundation. For ground anchors that use expanded pipe piles as support piles and tension piles or tension piles, after penetration, it is only necessary to apply a connecting means between the earth retaining plate and reinforced flooring, so There is no need.

  The both-ends diameter ratio of the different diameter pipe is selected from the range of 1.2 to 2.5, preferably 1.5 to 2.5, more preferably 1.5 to 2.0. This ratio is small when the depth from the bottom surface of the upper object to the support ground is deeper than the different diameter pipe at the tip, because the supplementary pipe on the reduced diameter side is long, and when it is shallow, the overall length of the pile is short. do it. Use of expanded pipe piles when supporting ground near the ground surface has a positive effect on the total cost.

  1A and 1B are a side view and a bottom view of a steel expanded pipe pile 11 having a length L1. The distal end portion 12 uses a steel different diameter pipe 13 having a length L2 and diameters D1, D2 (D1> D2), and a special steel excavating blade 17 is attached to the enlarged diameter 14 side of D1 to enlarge A steel spiral blade 18 having an outer diameter D3 and a required angle is attached to the outer periphery of the diameter side intermediate 15 and a tube 20 of the supplementary portion 19 is added to the reduced diameter 16 side of D2. The tip and the supplement may be integrated by welding. Alternatively, the tip portion may be cast and the connection with the supplementary tube may be a flange and a bolt. Installation of the drilling blade is determined by the ground condition and is not a requirement.

  The bearing capacity of the normal type rotary penetrating steel pipe pile 1 is determined by the combination of the pipe diameter and the blade diameter, but the effective cross-sectional area of the tip is determined. The options are limited. If the tube diameter is deferred and the blade diameter is increased, the blade strength decreases, and the balance between the two is essential. In the case of the expanded diameter steel pipe pile 11, there are many degrees of freedom of both the expanded diameter D1 and the blade diameter D3 of the different diameter pipe, and there is a feature that the tip effective sectional area can be easily selected. Furthermore, the tube of the supplemental portion that occupies most of the entire length L of the pile is limited to support force transmission and torsional strength, and is convenient for weight reduction regardless of increase or decrease in support force.

  FIG. 2 shows an enlarged steel pipe pile 11 having a length L1 that uses a normal-type rotary-penetrating steel pipe pile 1 having a length L1 and a diameter D1 that supports the load W, and different diameter pipes 13 having a diameter D1 and D2 and a length L2. In comparison, when a pile having the same length as the effective cross-sectional area at the tip is used for the strong support layer N2, the latter can be reduced in weight by using the pipe 20 of D2 (D2 <D1) for the supplementary portion 19. In addition, if the expanded steel pipe pile with the enlarged diameter D4 and the blade diameter D6 increases the effective cross-sectional area at the tip and supplements the pipe with the diameter D5 to make the length L3, it can be used for the support layer N1 (N1 <N2). However, a sufficient support force can be obtained, and at the same time, the weight can be further reduced and the production cost and the construction cost can be reduced. There is no need for pilot holes in expanded steel pipe piles, and there is almost no generation of excavated soil when penetrating.

  Many of the tops are supported by concrete foundations. Concrete foundations that do not use reinforcing bars or piles have processes such as root cutting, chestnut stone, abandoned concrete casting, temporary frame assembly, concrete casting, curing, temporary frame removal, and backfilling. Adds troubles such as head processing and connection with concrete. Furthermore, if a period until the concrete strength is included is included, it takes a considerable number of days to complete, and the foundation is completed and it is possible to shift to a method of raising an upper part. Therefore, it takes a considerable number of days to complete the final construction. However, if the expanded steel pipe pile is used, the concrete foundation can be omitted.

  FIG. 3 is a front view in which a connection fitting 22 is attached to the head portion 21 of the diameter-expanded steel pipe pile 11 and a column (streetlight) 31 is directly supported without a concrete foundation. FIG. 4 is a front view in which a plurality of expanded steel pipe piles 11 are arranged at each vertex of a square, connected to the pile fittings and the metal mount 32, and directly support an upper object (wind generator) without a concrete foundation. It is a top view. FIG. 5 is a front view in which a connection fitting is attached to the head portion of the expanded steel pipe pile 11 and the legs 33 of the upper object (three-dimensional parking lot) are directly supported without a concrete foundation. As shown in each figure, the head of the expanded steel pipe pile and the upper object or mount are directly connected, which helps shorten the construction period. The appearance and safety will be improved if the connection between the expanded steel pipe pile and the upper part is placed below the ground surface.

  If the expanded steel pipe pile can secure the minimum space where heavy machinery can work, it can shift to the main construction of pile driving and how to set up the upper part with minimal leveling of the slope and uneven terrain. Concrete winding, etc., can be done after the completion of pile driving and erection, which has an outstanding effect on shortening the construction period of the main body. 6A and 6B are a front view and a side view in which a reinforcing plate 23 is attached to the head 21 of the expanded steel pipe pile 11 and fixed with chestnut stone 34 and discarded concrete 35, and a fabric foundation 36 is directly constructed on the reinforcing plate. It is. In this way, in the case of a fabric foundation, a reinforcing plate is used for the thin head of the expanded steel pipe pile. The effect which is not described above obtained from an expanded steel pipe pile is the same as [Example 1].

  FIG. 7A is a construction state diagram in which the expanded steel pipe pile 11 is used as a ground anchor for reinforcing the retaining wall 41, and FIG. 7B is a current ground anchor construction state diagram for reference. An expanded steel pipe pile is inserted diagonally into the wall or slope of the excavated shaft. The earth and sand at a distance from the insertion opening to the blade surface becomes the pulling resistance of the pile, and when the pile head and the wall plate 42 of the excavation hole are connected, it works as a ground anchor. The current ground anchors need to be filled with reinforcing material for fixing to the ground, but they are not necessary for expanded steel pipe piles, and can reduce the effort required to bury ground anchors. The effect which is not described above obtained from an expanded steel pipe pile is the same as [Example 1].

  FIG. 8 is a construction state diagram in which the expanded steel pipe pile 11 is used as a ground anchor for preventing a board bulge in which the floor board is lifted by the impermeable layer around the excavated floor board 43 and the pressurized water. The expanded steel pipe pile extending from the ground surface to the planned floor 43 and the supporting ground is penetrated, and the ground is improved by filling the planned floor with a hardener, and the retaining plate 24 of the head of the expanded steel pipe pile is improved. To settle. The expanded steel pipe pile works as a support pile for the upper object, and similarly to [Example 3], the earth and sand reaching the floor and the support layer serve as a pulling resistance of the pile, and works as a ground anchor for preventing overburden. The effect which is not described above obtained from an expanded steel pipe pile is the same as [Example 1].

(A, B) are the side view and bottom view of a diameter-expanded steel pipe pile. (Example 1) It is sectional drawing of the ground which compared the normal type rotation penetration pile and the diameter expansion steel pipe pile. It is a front view in which a connecting bracket is attached to the head of an expanded steel pipe pile and a support is directly supported without a concrete foundation. (Example 2) It is a front view and a plan view in which a plurality of expanded steel pipe piles are arranged at each vertex of a square, the pile fittings and metal mounts are connected, and the upper object is directly supported without a concrete foundation. It is a front view in which a fitting is attached to the head of an expanded steel pipe pile and the upper leg is directly supported without a concrete foundation. (A and B) are a front view and a side view in which a reinforcing plate is attached to the head of the expanded steel pipe pile to support the fabric foundation. (A) is a construction phase diagram using expanded steel pipe piles for ground anchors that reinforce the retaining wall, and (B) is a current ground anchor construction phase diagram for comparison. Example 3 It is a construction diagram in which the expanded steel pipe pile is used for the ground anchor to prevent the blistering phenomenon that the floor is lifted by the non-permeable layer and the pressurized water around the excavated floor. Example 4

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Expanded steel pipe pile 12 Tip part 13 Different diameter steel pipe 14 Expanded diameter 16 Reduced diameter 18 Blade 19 Supplement part 20 Steel pipe 21 Head 22 Connection metal fitting 23 Reinforcement plate 24 Stopping plate 31 Pillar 32 Mounting base 36 Cloth foundation 41 Earth retaining wall 43 Floor

Claims (6)

Dividing the rotary penetrating pile into a tip (12) and a supplement (19)
The tip (12) is provided with a spiral blade (18) on the enlarged diameter (14) side of the different diameter pipe (13) and, if necessary, with a drilling blade (17),
The supplementary part (19) is connected with a pipe (20) having the same diameter as the reduced diameter (16) side of the different diameter pipe (13) and a required length,
Expanded pipe piles (11) with both parts connected and integrated into the required ground, and then expanded pipe piles constructed with metal foundations directly or indirectly connected to the pile head (21). Method.   A method for using an expanded pipe pile in which the pile described in claim 1 is penetrated into a required ground, the ground corresponding to the pile head (21) is fixed, and tension is applied to the pile to strengthen the ground.   After the pile described in claim 1 has penetrated into the required ground, the ground corresponding to the pile head (21) is fixed, tension is applied to the pile by the pressurized water acting on the ground, and the pile acts on the ground. The usage method of the expanded pipe pile of Claim 2 which generated the supporting force to the pile with the thing and strengthened the ground.   The usage method of the expanded pipe pile in any one of Claim 1 to 3 which selected the aperture ratio of the different diameter pipe (13) from the range of 1.2-2.5.   The usage method of the expanded pipe pile in any one of Claim 1 to 4 which made the pile steel. The usage method of the expanded pipe pile of Claim 5 which integrated the front-end | tip part (12) of the pile with the casting.