JP2015021369A - Pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of steps and the amount of removed soil in pile construction.SOLUTION: A pile 10 includes: a bag body 11 which is attached to an outer periphery of the pile 10 so as to be opened and stretched more outward than an outer peripheral surface 10a of the pile 10; a filling pipe 13 for filling the bag body 11 with a consolidating fluid; and a shoe part 15 which has a larger maximum diameter than an outer diameter of the bag body 11 before being opened and stretched and a pointed end 15a in a direction where the pile 10 is buried. The shoe part 15 has a taper shape, preferably a conical shape.

Description

  The present invention relates to a pile. More specifically, the present invention relates to an improvement in the structure of a pile buried in the ground.

  Conventionally, a ready-made pile with a bag having a bag body in order to develop a high vertical support force and a construction method thereof have been proposed (for example, see Patent Document 1).

  When constructing such a pile with a bag on the ground, first drill a hole to fix the pile, inject high-pressure drilling water near the fixing layer at the tip of the pile, or use a drill bit by a hydraulic mechanism. Then, it is generally performed to drill an enlarged excavation hole. Such excavation holes are filled with cement milk simultaneously with excavation, or filled with soil cement mixed and stirred with the surrounding ground, and precast piles and steel pipe piles are inserted into the excavation holes. After that, a caking fluid such as cement milk is introduced and filled into the bag at the fixing depth to build a diameter expanding body at the tip (lower end) of the pile. It functions as an anchor (root firmer) with high resistance.

Japanese Patent No. 2607281

  However, according to the method as described above, a plurality of processes such as preliminary ground excavation, pile burial, and introduction of a solidified fluid must be performed before the construction of the expanded body.

  In addition, when excavating holes, soil is generated that exceeds the pile volume, so there is room for improvement from the viewpoint of environmental protection.

  Then, an object of this invention is to provide the pile of a structure which can reduce the process at the time of construction, and the amount of soil removal.

  In order to solve this problem, the present inventor has made various studies. If a plurality of processes are required from the drilling of the hole to the construction of the expanded body, the labor and time for the construction of the pile with the bag are spent. In addition, for example, in the case of constructing a pile with a bag on the seabed ground due to the construction of an offshore wind turbine, it is difficult to suppress soil drainage and drilling mud from the ground to the sea after many steps. . At the same time, since an excavation hole for embedding the pile with a bag is provided in advance, it is not preferable from the viewpoint of environmental protection that mud is discharged with the pile insertion when the pile with a bag is inserted later. In addition, in the conventional case, since the pile with the bag is buried after the hole is excavated, there is a possibility that the pile with the bag cannot be buried if the loose sand layer of the ground collapses. Based on these points, the present inventor, who has repeatedly studied about reducing the steps required to build a diameter-enlarged body, has obtained new knowledge that leads to the solution of such problems.

The present invention is based on such knowledge, is a pile buried in the ground,
A bag body attached to the outer periphery of the pile in a state in which it can be expanded outward from the outer peripheral surface of the pile;
An injection tube for injecting a caking fluid into the bag;
A collar having a maximum diameter larger than the outer diameter of the bag body before spreading, and having a pointed portion in the direction in which the pile is buried,
It is characterized by having.

  When the pile with a bag configured as described above is driven by a batting method, it is possible to perform the construction without going through an excavation process. Therefore, the number of processes required for the pile construction is reduced, and it is possible to suppress the time and labor from being spent correspondingly.

  In addition, when such a pile with a bag is driven by a batting method, the amount of soil removal becomes almost zero, unlike when excavating the ground. For this reason, it is suitable from an environmental viewpoint. Moreover, since the piles are driven without excavating the ground, the ground disturbance caused by excavation is not caused.

  Furthermore, since the maximum diameter of the heel part (mainly a steel tip attached or formed at the tip of the pile) is larger than the outer diameter of the bag body before the expansion, the bag-made pile is driven into the ground. In this case, a space can be formed between the bag body before opening and the hole wall. For this reason, it is possible to sufficiently inflate the bag body so that the enlarged diameter portion functions as an anchor that provides a large pulling resistance. Moreover, since the maximum diameter of the collar portion is larger than the outer diameter of the bag body before the expansion, the bag body is not damaged when the pile with the bag is driven.

  Moreover, since a collar part has a pointed part in the direction in which the said pile is embed | buried, it makes it drive | work into the ground of a pile smoothly.

  In such a pile, the flange may close the opening end of the pile. Or a collar part may have an opening in a part.

  Moreover, in a pile, it is preferable that a collar part is a taper shape. In this case, it is also preferable that the collar portion has an inverted conical shape.

  According to the present invention, it is possible to reduce the process and the amount of soil discharged during construction.

It is a figure which shows the process of building a pile in the pile center position at the time of construction of the pile which concerns on this invention. It is a figure which shows the initial stage of the striking process at the time of construction of a pile. It is a figure which shows the stage of the final stage of a striking process. It is a figure which shows the process of inject | pouring a caking fluid into a bag. It is a figure which shows the state of a pile etc. in the stage before inject | pouring a caking fluid. It is a figure which shows the state of a pile etc. in the stage after inject | pouring a caking fluid. It is a perspective view which shows an example of the collar part in which the opening was formed in a part.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  1 to 6 show an embodiment of a pile according to the present invention. The pile 10 is embedded in the ground by a hammering method using the pile construction apparatus 1 and includes a bag body 11, an injection pipe 13, and a flange 15 (see FIG. 1 and the like). The main body 9 of the pile 10 is, for example, a ready-made pile made of a steel pipe or a steel pipe concrete composite pile made of a hollow concrete portion whose inner surface is in close contact with the steel pipe. The configuration of the pile 10 is appropriately selected according to the purpose and the properties of the ground G.

  An annular bag body 11 is attached to the pile 10 in a state in which the bag body 11 can expand outward from the outer peripheral surface 10a of the pile 10 in the main body 9 (see FIGS. 1 and 5). The bag body 11 is formed by inserting a solidified fluid (ground improvement material) containing a hydraulic material such as cement milk through the injection pipe 13 after the pile 10 is buried, so that the expanded body 11 ′ is inserted into the ground G. It forms (refer FIG. 4, FIG. 6). The bag body 11 of this embodiment is fastened to the outer peripheral surface 10a in the lower part of the pile 10 by tightening the upper and lower parts thereof with a bag body restraining tool 12 such as a steel band (see FIG. 5).

  The material of the bag body 11 is preferably a synthetic fiber such as nylon, polyester, polyethylene, or vinylon from the viewpoint of a dehydrating function that allows moisture in the caking fluid to be introduced and strength. When the bag body 11 made of a material capable of permeating moisture of the caking fluid is used in this way, by applying a predetermined pressure at the time of introducing or after the caking fluid is introduced into the bag 11, Water in the caking fluid can be permeated and dehydrated, and a denser and stronger cured body can be obtained after curing.

  The injection tube 13 is a tube that forms an introduction path for introducing the caustic fluid into the bag body 11 (see FIG. 5 and the like). Although not shown in detail in the present embodiment, the injection pipe 13 may be of a known configuration such as a solidified fluid supply pipe installed on the inner periphery of the pile 10.

  The eaves part 15 is, for example, a steel tip that is formed or attached to the tip (lower end) of the main body 9 of the pile 10. It is preferable that the heel portion 15 has a shape in which the pile 10 that has been struck is easily driven into the ground G, for example, the outer shape thereof is a tapered shape. In this embodiment, the collar part 15 is made into the inverted cone shape in which the pointed part 15a is located in the center (refer FIG. 5 etc.). The pointed portion 15a is pointed in the direction (tip side) in which the pile 10 is embedded.

  Moreover, the collar part 15 is formed so that the largest diameter may become larger than the outer diameter of the bag body 11 before expansion (refer FIG. 1 etc.). Therefore, when the pile 10 of the present embodiment is driven into the ground G, a hole 20 larger than the bag body 11 before the expansion is formed, and the bag body 11 is not damaged (FIGS. 2 and 2). (See 3 etc.). Furthermore, according to such a collar part 15, a space can be formed between the bag body before expansion and the hole wall 20a (see FIG. 5 and the like).

  The pile construction apparatus 1 is a pile driving apparatus for directly placing the pile 10 on the ground G, and hitting the pile head of the pile 10 with a weight 2 (for example, a hydraulic hammer, a diesel hammer, a drop hammer, etc.). , Express supportive power. As described above, the hitting method in which the pile 10 is directly hit is generally economical because the construction cost is low. Moreover, it can be said that the hitting method is highly reliable in that the support force of the pile 10 can be objectively confirmed from the penetration amount and the rebound amount per hit measured at the time of driving. On the other hand, during construction, vibration and sound are generated due to driving (striking). Although not particularly illustrated, in the case of offshore construction in which the pile 10 is driven into the ground G on the seabed, the pile construction device 1 is arranged on a trolley.

  Subsequently, an example of a procedure for constructing the pile 10 having the above-described configuration will be described (see FIG. 1 and the like).

  First, after pile 10 is built in a pile center position and a hammer cap is put on a pile head, the perpendicularity of the pile 10 concerned is checked (refer to Drawing 1).

  Thereafter, the pile head is hit with the weight 2 and the pile 10 is driven into the ground G (see FIGS. 2 and 3). The tip of the pile 10 penetrates the soft layer and reaches the support layer, and the driving is finished when a required support force is obtained. A hole wall 20a is formed around the pile 10 along a locus through which the maximum diameter portion of the flange portion 15 penetrates (see FIG. 5 and the like). In addition, a space is formed between the hole wall 20a and the bag body 11 at this point before the caking fluid is injected.

  Next, a caking fluid is injected into the bag 11 through the injection tube 13 (see FIG. 4). When the bag body 11 swells, the enlarged diameter body 11 ′ is built near the tip (lower end) of the pile 10. Thereafter, the fluid body is consolidated in a state where the bag body 11 is pressed against the hole wall 20a by the internal pressure, so that the frictional resistance at the time of pushing and pulling out the enlarged diameter body 11 ′ increases, and the supporting force and the pulling resistance It functions as a strong anchor (root fixing part) (see FIG. 6 etc.). Before or after the step of inflating the bag 11 as described above, the consolidated material is taken out from, for example, the upper portion of the flange 15 toward the gap between the pile 1 and the hole wall 20a. If integrated with the main body 9, it is possible to obtain a larger support force.

  When constructing the pile 10 according to the present embodiment by the batting method, it can be constructed without going through the excavation process as described above, and therefore the number of processes required for the pile construction is small. Therefore, it is possible to suppress the time and effort spent accordingly.

  Moreover, unlike the case where the ground G is excavated, when the pile 10 like the present embodiment is driven by the batting method, the amount of soil removal is almost zero, which is preferable from the viewpoint of the environment. That is, when constructing a pile in multiple steps as in the past, especially when constructing the pile 10 on the seabed G, at the time of excavation, when the excavator is pulled up, and further when the pile is buried in the excavation hole, respectively. Since soil discharge occurs, it is difficult to effectively suppress the amount of soil discharged until the completion of construction. On the other hand, in the case of the present embodiment in which the pile 10 is driven by the striking method, the amount of discharged soil is small in the first place, and the influence on the environment can be suppressed as much as possible.

  Moreover, when constructing the pile 10 like this embodiment by a hammering method, a rotational driving force is unnecessary throughout the entire process. For example, in the case of offshore construction (for example, construction of a foundation for a wind turbine for offshore wind power generation), if a drilling hole is to be provided on the seabed, rotational driving force is required, and a large-scale carrier is required. However, according to the present embodiment, there is no such limitation. Therefore, in this embodiment, construction work on a work boat such as an unstable trolley is possible.

  In addition, when the pile 10 such as this embodiment is constructed by a hammering method, it is possible to compact the surrounding ground by hammering, and therefore, friction and tip support force compared to conventional construction with the same pile diameter and hole diameter. Can be expected to increase. Therefore, it is possible to form the stable hole 20 even in a loose sand ground that may collapse in the conventional construction method.

  In addition, when the pile 10 is driven by the striking method as in the present embodiment instead of excavating the ground G, the bag body 11 may naturally be damaged during the driving. In this regard, as described above, the pile 10 of the present embodiment is configured so that the maximum diameter of the flange portion 15 is larger than the outer diameter of the bag body 11 before the expansion, so that it is in the middle of driving. The bag 11 is not damaged.

  Furthermore, according to such a collar part 15, a space can be formed between the bag body 11 before expansion and the hole wall 20a (see FIG. 5 and the like). Accordingly, the diameter-enlarged body that functions as an anchor capable of obtaining a large pulling resistance force by sufficiently inflating the bag body 11 and solidifying the fluid body in a state where the bag body 11 is pressed against the hole wall 20a by the internal pressure. It is possible to build 11 '.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, although the collar part 15 in the above-mentioned embodiment closed the opening end of the main body 9 of the pile 10, it is also possible to employ | adopt the collar part 15 which has an opening instead (as an example, A plurality of substantially elliptical openings (indicated by reference numeral 15b in FIG. 5) are arranged at equal intervals around the tip 15a formed at the center, etc.). Since such an opening 15b allows soil and earth and sand to flow into the main body 9 of the pile 10 when the pile 10 is driven into the ground G, the resistance received from the ground G at the time of impact is reduced accordingly. there is a possibility. In such a collar portion 15, the pointed portion 15 a may not be arranged at the center. For example, when there is an opening 15b in the center of the flange 15, an annular edge around the opening may be a pointed portion 15a (see FIG. 7). Furthermore, unevenness (high and low) may be provided in the circumferential direction, and a plurality of circumferentially arranged protrusions may be formed and used as the pointed ends (see a two-dot chain line in FIG. 7).

  INDUSTRIAL APPLICABILITY The present invention is suitable when applied to a ground with a pile having a bag body that can be expanded outward from the outer peripheral surface of the pile, particularly when applied to a seabed ground.

DESCRIPTION OF SYMBOLS 10 ... Pile 10a ... Outer peripheral surface 11 ... Bag body 13 ... Injection pipe 15 ... Gutter part 15a ... Point part 20 ... Hole G ... Ground

Claims (5)

A pile buried in the ground,
A bag body attached to the outer periphery of the pile in a state in which it can be expanded outward from the outer peripheral surface of the pile;
An injection tube for injecting a caking fluid into the bag;
A collar portion having a large tip and a pointed portion in the direction in which the pile is embedded,
A pile characterized by comprising.   The pile according to claim 1, wherein the flange portion closes an opening end of the pile.   The pile according to claim 1, wherein the flange portion has an opening in a part thereof.   The pile according to any one of claims 1 to 3, wherein the flange portion has a tapered shape.   The pile according to any one of claims 1 to 4, wherein the flange portion has an inverted conical shape.

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