JP2005299206A - Method of supporting erection of foundation steel pipe pile, and prefabricated foundation steel pipe pile for use in the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of supporting erection of a foundation steel pipe pile, according to which even a small-diameter foundation steel pipe pile can be positively penetrated into a foundation without a burden applied thereto and stably erected. <P>SOLUTION: According to the method, a shaft portion of a pile main body 1 is inserted into a pipe of an auxiliary casing 2, and a hooking projection 13 projected from an outer peripheral surface of the pile main body 1 is inserted into and engaged with a hook socket 22 formed at an aperture edge at a lower end of the auxiliary casing 2, to thereby assemble a unitedly combined pile body. Then the combined pile body is erected and rotated, and therefore excavation blades 11 arranged at a tip head of the pile main body 1 and an auger screw 21 formed on an outer peripheral surface of the auxiliary casing 2 function to excavate the ground and to screw the combined pile body into the ground down to a predetermined depth. Thereafter the hooking projections 13 of the pile main body inserted into and engaged with the hook socket is disengaged to separate the auxiliary casing 2 from the pile main body, and the auxiliary casing 2 is reversely rotated to pull the same upward by depressing the earth on the periphery thereof by means of the auger screw 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement of a construction method and material, more specifically, a foundation steel pipe pile that can be erected and stably erected without burden even if it is a small diameter foundation steel pipe pile. The present invention relates to a standing support method and an assembly-type foundation steel pipe pile used in the method.

  In the foundation steel pipe pile driven in the construction foundation construction of the structure, a screw is usually formed on the outer peripheral surface, and is erected by rotating and penetrating with a torque type pile driving machine (for example, see Patent Document 1). .

  By the way, in recent years, there are many opportunities to construct relatively small structures such as single-family houses, or to construct narrow spaces, etc., and it may not be possible to drive a steel pipe pile with a large diameter. May be unavoidably small.

However, in order to stabilize the foundation pile, it is necessary to penetrate to a certain depth, but there is a soft-hard imbalance in the geology of the target ground or there are cases where obstacles are buried, it penetrates In some cases, the pile may be bent with respect to a large torque, and the pile head may be deformed or damaged, making it difficult to penetrate the pile to the design depth.
JP 2004-11204 (page 3-5, Fig. 1-2)

  The present invention was made in view of the above-mentioned problems in the construction of conventional foundation steel pipe piles, and even in the case of small diameter foundation steel pipe piles, it is surely inserted without incurring a burden. It is a technical problem to provide a support method for erection of a foundation steel pipe pile that can be installed and stably erected.

  Moreover, this invention makes it a technical subject to provide the assembly-type foundation steel pipe pile which is easy to assemble and is suitable for using for this invention construction method.

  Means employed by the present inventor for solving the above-described problems will be described with reference to the accompanying drawings.

That is, the present invention, when penetrating the pile body 1 as the foundation of the construction structure into the ground,
The shaft portion of the pile body 1 in which the excavating blade 11 is disposed at the distal end and at least the bottom expansion plate 12 is disposed on the outer peripheral surface is inserted into the pipe of the auxiliary casing 2, and the outer peripheral surface of the pile body 1 On the other hand, the latching projection 13 formed on the auxiliary casing 2 is inserted into the latching socket 22 formed on the lower end opening edge of the auxiliary casing 2 to be engaged with each other, thereby assembling an integrated coupling pile body,
The coupled pile body is excavated by the auger screw 21 formed on the outer peripheral surface of the auxiliary casing 2 and the excavating blade 11 provided at the tip of the pile body 1 by standing up and rotating the coupled pile body. After screwing into the ground and penetrating to the required position,
The auxiliary casing 2 is separated by releasing the engagement of the engagement protrusion 13 of the pile body 1 that has been inserted and engaged,
The auxiliary casing 2 is rotated in the reverse direction and pulled up while pushing down the surrounding earth and sand with the auger screw 21, so that the ground around the pile is compacted and the pile body 1 can be stably erected. As a result, the foundation support method for the foundation steel pipe pile was completed.

In addition, the present invention, when penetrating the pile body 1 as the foundation of the construction structure into the ground,
The pile main body 1 having the excavation blade 11 disposed at the tip head and at least the bottom expansion plate 12 disposed on the outer peripheral surface is driven alone to a required position, and then the shaft portion of the pile main body 1 is mounted on the ground. The auxiliary casing 2 is inserted into the pipe from the lower end opening edge, and the engaging protrusion 13 formed on the outer peripheral surface of the pile body 1 is inserted into the engaging socket 22 formed at the lower end opening edge of the auxiliary casing 2. While assembling a united pile body by hooking,
By rotating this coupled pile body, the coupled pile body is brought into the ground while excavating the ground soil with the auger screw 21 formed on the outer peripheral surface of the auxiliary casing 2 and the excavating blade 11 disposed at the tip head of the pile body 1. After screwing and penetrating to the required position,
The auxiliary casing 2 is separated by releasing the engagement of the engagement protrusion 13 of the pile body 1 that has been inserted and engaged,
The technical means of allowing only the auxiliary casing 2 to reversely rotate and pulling it up while pushing down the surrounding earth and sand with the auger screw 21 to compact the ground around the pile and enable the pile body 1 to stand stably. Adopted.

Moreover, in order to solve the said subject, in addition to the said means as needed, this invention pushed up only the auxiliary casing 2 by normal rotation after driving in a coupling pile body, and took out the surrounding earth and sand on the ground surface. Then, while mixing the earth and sand and cement-based solidifying agent, while rotating the auxiliary casing 2 in reverse, the mixed earth and sand are poured,
After intruding to the prescribed depth while compacting the circumference of the pile while stirring in the ground by rotating forward and reverse,
By rotating only the auxiliary casing 2 in reverse and pulling up the surrounding earth and sand with the auger screw 21, the ground around the pile is consolidated, and the cement-based solidifying agent is hardened, whereby the pile body 1 is Adopted technical means to enable stable installation.

  Furthermore, in order to solve the above-mentioned problems, the present invention employs technical means of using a hydraulic hardening agent mainly composed of light-burning magnesia as a cement-based solidifying agent in addition to the above-described means as necessary. did.

  Furthermore, in order to solve the above-described problems, the present invention provides technical means for inserting the shaft portion of the pile body 1 into the pipe from the lower end opening edge of the auxiliary casing 2 in addition to the above-described means as necessary. Adopted.

Further, the present invention is a steel pipe pile that penetrates into the ground as a foundation of a construction structure,
A pile body 1 having an excavating blade 11 disposed at the distal end thereof and at least an enlarged bottom plate 12 disposed on the outer peripheral surface; and an auxiliary casing 2 comprising a hollow steel pipe having an auger screw 21 formed on the outer peripheral surface. And consists of
The shaft portion of the pile main body 1 was inserted into the pipe of the auxiliary casing 2, and the latching protrusion 13 formed on the outer peripheral surface of the pile main body 1 was formed at the lower end opening edge of the auxiliary casing 2. While it is possible to assemble the united pile body by inserting it into the latching socket 22 and engaging it,
The pile body 1 can be erected by releasing the engagement protrusion 13 of the bayonet-type pile body 1 and pulling out only the auxiliary casing 2 at a required position in the ground after the penetration is completed. By adopting the technical means to do, the assembly-type foundation steel pipe pile used for the standing support method of the foundation steel pipe pile was completed.

  Moreover, in order to solve the said subject, in addition to the said means, this invention forms the flange-like earth and sand inflow stop board 14 in the lower part of the pile main body 1, and plugs the lower end opening part of the auxiliary casing 2 as needed. Adopted technical means to be able to.

  Furthermore, in order to solve the above problems, the present invention provides a base member 3 for rotating the steel pipe pile by forming a base mounting portion 23 at the upper end portion of the auxiliary casing 2 in addition to the above means as necessary. The technical means of making it detachable was adopted.

  In the present invention, since the foundation steel pipe pile is constructed in an assembly type that can be built in the pipe of the auxiliary casing, even if the diameter of the foundation pile to be installed is small, the torsional moment due to the torque is Therefore, there is little burden on the pile body, and it can be penetrated reliably.

  Moreover, since the auxiliary casing protects the pile main body, even if the pile main body is a thin wall type, it can be easily constructed. Furthermore, for liquefied ground and soft ground, it is possible to prevent corrosion of the pile body by mixing and stirring the cement solidifying agent in the earth and sand as necessary, so that the pile main body pile can be prevented. The practical value is very high.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

  An embodiment of the present invention will be described with reference to FIGS. In the figure, what is indicated by reference numeral 1 is a pile body, this pile body 1 is a straight steel pipe, a drilling blade 11 is disposed at the tip of the head, and at least an expanded base plate 12 is provided on the outer peripheral surface. Is arranged (see FIG. 1).

  The bottom expansion plate 12 of the pile body 1 in the present embodiment is, for example, a flange member welded or integrally formed on the outer periphery of the pile body 1 and cut at least partially, and is horizontal to the suspended pile body 1. And the horizontal plate portion 12a occupies at least half of the total area of the expanded base plate 12. The diameter of the expanded base plate 12 is preferably in the range of about 1.5 to 3 times the circumference of the pile body 1.

  Also, what is indicated by reference numeral 2 is an auxiliary casing made of a hollow steel pipe, and an auger screw 21 is formed on the outer peripheral surface of the auxiliary casing 2 (see FIG. 2).

  Therefore, a specific procedure for penetrating the pile body 1 into the ground as a foundation of a construction structure will be described below. First, the shaft portion of the pile body 1 is inserted into the pipe from the lower end opening edge of the auxiliary casing 2, and the latching protrusion 13 formed on the outer peripheral surface of the pile body 1 is formed on the lower end opening edge of the auxiliary casing 2. It inserts in the formed latching socket 22 (it is what is called a bayonet type), and it assembles | assembles an integral joint pile body (refer FIG. 3).

  At this time, if necessary, a flange-like earth and sand inflow stop plate 14 can be formed in the lower part of the pile body 1 and the lower end opening of the auxiliary casing 2 is closed to prevent the earth and sand from flowing in through the gap. be able to.

  Next, this coupled pile body is erected and rotated so that the ground soil is coupled while excavating the ground soil with the excavating blade 11 provided at the front end of the pile body 1 and the auger screw 21 formed on the outer peripheral surface of the auxiliary casing 2. The pile body is screwed into the ground and penetrated to the required position.

  In this embodiment, the base attachment part 23 can be formed in the upper end part of the auxiliary casing 2, and the base member 3 for rotating a steel pipe pile can also be attached or detached, and even if it is a big torque force, a pile head Damage or the like can be prevented.

  Then, at the required position, the auxiliary casing 2 is separated by releasing the engagement of the engagement protrusion 13 of the pile main body 1 engaged with the insertion.

  Thereafter, by rotating the auxiliary casing 2 in the reverse direction and pulling up the surrounding earth and sand with the auger screw 21, the ground around the pile can be compacted and the pile main body 1 can be erected stably.

In addition, after driving in the combined pile body, only the auxiliary casing 2 is pulled up in the forward direction to bring out the surrounding earth and sand, and then the earth and sand and cement-based solidifying agent are mixed, and the auxiliary casing 2 is rotated in the reverse direction. While putting this mixed earth and sand,
By rotating in forward and reverse directions, it is possible to penetrate to a predetermined depth while compacting the periphery of the pile while stirring in the ground.

  As the cement-based solidifying agent, a hydraulic hardening agent mainly composed of light-burning magnesia can be used. This light-burning magnesia (trade name: Mag White, manufactured by National Agricultural Research Institute) is a combination of seawater magnesia and A natural magnesium carbonate that has been fired and fired at a firing temperature of 700 ° C. to 900 ° C. and ground to 70 to 120 mesh is used.

  And, as described above, by rotating only the auxiliary casing 2 backward and pulling up the surrounding earth and sand with the auger screw 21, the ground around the pile is consolidated, and the cement-based solidifying agent is hardened. The pile body 1 can be erected stably.

  In this embodiment, when the pile main body 1 is rotated forward by forming the earth and sand scooping protrusion 12b on the upper surface of the bottom plate, the bottom plate 12 usually pushes the earth and sand outward when penetrating. It is possible to scrape the earth and sand in the vicinity of the upper surface of the bottom expansion plate 12 toward the pile body 1 by the earth and sand scraping protrusion 12b, and to prevent the earth and sand density from being lowered at the excavation site.

  The mixed earth and sand and the hydraulic hardener are scraped in the direction of the pile main body 1 by the earth and sand scraping protrusions 12b formed on the upper surface of the bottom expansion plate 12 of the pile main body 1, and then the hydraulic hardener is By hardening, it is possible to prevent a decrease in density in the excavation hole and increase the frictional resistance on the peripheral surface of the pile body 1 to provide a stable support force.

  At this time, the hydraulic hardener can be injected while solving the soil at the excavation site by repeatedly rotating the pile body 1 alternately and forward and backward, and can be more appropriately injected into the soil. Moreover, it is possible to stabilize the pile body 1 by preventing the decrease in sediment density and the liquefaction phenomenon by adding the soil (eg, gravel of 2 mm or more) to the excavation site and stirring it appropriately. is there.

  Therefore, the frictional resistance with the earth and sand in the surrounding surface of the pile main body 1 can be strengthened, and the supporting force of the vertical direction of a steel pipe pile can be ensured. Furthermore, the horizontal plate portion 12a can prevent the generation of the rotational force of the pile body 1 with respect to the loaded load and is very stable.

  At this time, by observing the mounting load applied to the screw head of the auxiliary casing 2, it is possible to manage the ground strength (N value) compacted by the reverse rotation of the screw from the correlation. it can.

  In the present embodiment, the ground can be compacted to an N value of 4 or more when a standard penetration test is performed with a loading load of about 1 ton, and the pile body 1 has a depth dominant to horizontal resistance. It can be fully compacted up to about 5m.

  Moreover, since the method of compacting with the screw of the auxiliary casing 2 in this embodiment is used, it is suitable for construction of a short foundation pile, and a piled raft method is also possible. Furthermore, when a steel pipe pile with a bottom expansion plate is constructed when the layer thickness is thin (about 1.0 m) on the ground surface layer part and is a hard ground, it can be effectively used without loosening the ground with a bent corner. .

  The present invention is generally configured as described above. However, the present invention is not limited to the illustrated embodiment, and various modifications can be made within the scope of the claims. For example, The position where the pile body 1 and the auxiliary screw 2 are engaged can be redesigned according to the geological condition of the target ground, and the length of the auger screw 21 of the auxiliary screw 2 can be changed. It can be changed or formed from the upper edge of the outer peripheral surface, and belongs to the technical scope of the present invention.

  Moreover, in this embodiment, in penetrating the pile main body 1 into the ground, after driving the pile main body 1 alone to a required position according to the ground situation, as described above, the shaft portion of the pile main body 1 on the ground Is inserted into the pipe from the lower end opening edge of the auxiliary casing 2, and the latching protrusion 13 formed on the outer peripheral surface of the pile body 1 is inserted into the latching socket 22 formed on the lower end opening edge of the auxiliary casing 2. As a matter of course, it is possible to assemble the united pile body by engaging them.

It is a perspective view showing the pile main body of the embodiment of the present invention. It is a perspective view showing the auxiliary casing of the embodiment of the present invention. It is a front view showing the assembled pile body of the embodiment of the present invention.

Explanation of symbols

1 Pile body
11 Drilling blade
12 Expanded bottom plate
12a Horizontal plate
12b Sediment protrusion
13 Engagement protrusion
14 Sediment flow stop plate 2 Auxiliary casing
21 Auger screw
22 Hook socket
23 Base mounting part 3 Base part

Claims (8)

In penetrating the pile body 1 as the foundation of the construction structure into the ground,
The shaft portion of the pile body 1 in which the excavating blade 11 is disposed at the distal end and at least the bottom expansion plate 12 is disposed on the outer peripheral surface is inserted into the pipe of the auxiliary casing 2, and the outer peripheral surface of the pile body 1 On the other hand, the latching projection 13 formed on the auxiliary casing 2 is inserted into the latching socket 22 formed on the lower end opening edge of the auxiliary casing 2 to be engaged with each other, thereby assembling an integrated coupling pile body,
The coupled pile body is excavated by the auger screw 21 formed on the outer peripheral surface of the auxiliary casing 2 and the excavating blade 11 provided at the tip of the pile body 1 by standing up and rotating the coupled pile body. After screwing into the ground and penetrating to the required position,
The auxiliary casing 2 is separated by releasing the engagement of the engagement protrusion 13 of the pile body 1 that has been inserted and engaged,
A foundation characterized in that the pile body 1 can be stably erected by reversing the auxiliary casing 2 and pulling it up while pushing down the surrounding earth and sand with the auger screw 21. Steel pipe pile standing support method. In penetrating the pile body 1 as the foundation of the construction structure into the ground,
The pile main body 1 having the excavation blade 11 disposed at the tip head and at least the bottom expansion plate 12 disposed on the outer peripheral surface is driven alone to a required position, and then the shaft portion of the pile main body 1 is mounted on the ground. The auxiliary casing 2 is inserted into the pipe from the lower end opening edge, and the engaging protrusion 13 formed on the outer peripheral surface of the pile body 1 is inserted into the engaging socket 22 formed at the lower end opening edge of the auxiliary casing 2. While assembling a united pile body by hooking,
By rotating this coupled pile body, the coupled pile body is brought into the ground while excavating the ground soil with the auger screw 21 formed on the outer peripheral surface of the auxiliary casing 2 and the excavating blade 11 disposed at the tip head of the pile body 1. After screwing and penetrating to the required position,
The auxiliary casing 2 is separated by releasing the engagement of the engagement protrusion 13 of the pile body 1 that has been inserted and engaged,
By rotating only the auxiliary casing 2 in reverse and pulling up the surrounding earth and sand with the auger screw 21, the ground around the pile can be compacted and the pile body 1 can be stably erected. Support method for standing steel pipe piles. After driving the combined pile body, after pulling up only the auxiliary casing 2 in the forward direction and taking out the surrounding earth and sand on the ground surface, the earth and sand and the cement-based solidifying agent are mixed, and while rotating the auxiliary casing 2 in the reverse direction, I put this mixed earth and sand,
After intruding to the prescribed depth while compacting the circumference of the pile while stirring in the ground by rotating forward and reverse,
By rotating only the auxiliary casing 2 in reverse and pulling up the surrounding earth and sand with the auger screw 21, the ground around the pile is consolidated, and the cement-based solidifying agent is hardened, whereby the pile body 1 is The method for supporting the standing up of a foundation steel pipe pile according to claim 1 or 2, wherein the standing up can be stably established.   4. A method for supporting the standing up of a foundation steel pipe pile according to claim 3, wherein a hydraulic hardening agent mainly composed of light-burning magnesia is used as the cement-based solidifying agent.   The shaft steel pile pile supporting method according to any one of claims 1 to 4, wherein the shaft portion of the pile body 1 is inserted into the pipe from the lower end opening edge of the auxiliary casing 2. A steel pipe pile that penetrates into the ground as the foundation of a construction structure,
A pile body 1 having an excavating blade 11 disposed at the distal end thereof and at least an enlarged bottom plate 12 disposed on the outer peripheral surface; and an auxiliary casing 2 comprising a hollow steel pipe having an auger screw 21 formed on the outer peripheral surface. And consists of
The shaft portion of the pile main body 1 was inserted into the pipe of the auxiliary casing 2, and the latching protrusion 13 formed on the outer peripheral surface of the pile main body 1 was formed at the lower end opening edge of the auxiliary casing 2. While it is possible to assemble the united pile body by inserting it into the latching socket 22 and engaging it,
The pile main body 1 can be erected by releasing the engagement protrusion 13 of the bayonet-type pile main body 1 and pulling out only the auxiliary casing 2 at a required position in the ground after the penetration is completed. Assembled foundation steel pipe pile.   The assembly-type foundation steel pipe pile according to claim 6, wherein a flange-like earth and sand inflow stop plate (14) is formed at a lower part of the pile body (1), and the lower end opening of the auxiliary casing (2) can be closed.   8. The assembly-type foundation steel pipe pile according to claim 6 or 7, wherein a base mounting portion 23 is formed at an upper end portion of the auxiliary casing 2, and a base member 3 for rotating the steel pipe pile can be attached and detached. .

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