JPH0747846B2 - Pile construction method and its members on soft ground - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing piles on soft ground and members thereof.

Conventional technology So-called pile foundations are often used for basic ground work on soft ground.

As a pile foundation of this type, it is general that the load of the upper structure is supported by a support pile driven into the support layer.
However, in the case of pile foundations with such support piles, there is a phenomenon of so-called slip-out, especially in wide-area ground subsidence areas, so recently, the friction force acting on existing concrete piles such as RC friction piles installed in the ground is used. The friction piles are often used.

Problems to be Solved by the Invention However, the construction cost of the existing concrete pile body requires a large work machine, and a large truck is required to bring the pile body to the construction site. Not only becomes high, but it may not be possible depending on the construction site, and there is a drawback that it is not versatile. Furthermore, since the weight of the pile itself is large, there is a problem in that the supporting force is reduced.

In view of such a problem, the present invention has been made for the purpose of obtaining a pile that can be constructed at low cost and has a strong supporting force even by on-site construction.

Means for Solving the Problems That is, in the present invention, in order to achieve the above object,
After forming a pile hole in the ground in advance, insert and install a mesh cylinder having a plurality of laterally protruding nodular protrusions in the intermediate portion in the vertical direction, and then install the earth material inside the mesh cylinder. I try to throw it in and tamper with it.

Embodiments Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a mesh cylinder (1) used in this embodiment.
Shows an example. This reticulated tubular body (1) is arranged in a substantially horizontal plane at a vertical interval and is connected to each other by a plurality of vertical streaks (2) (2). 3) ..., and a large number of hoop muscles (5) (5), which are also arranged in a substantially horizontal plane at vertical intervals and are connected to each other by a plurality of vertical stripes (4) (4). ...... is composed of and. The pair of left and right hoop muscles (3) and (5), which are annularly arranged in substantially the same plane, are connected to each other via a hinge portion (6) on one end side. The other end sides of both hoop muscles (3) and (5) overlap each other with one hoop muscle (3) inside and the other hoop muscle (5) outside. An engaging portion (5a) that bends inward is provided at the tip of the outer hoop muscle (5). That is, the reticulated tubular body (1) has hoop muscles (3) arranged substantially in the same plane.
(5) By horizontally rotating the hinges (6) between them as a fulcrum, the length of the overlapping portion on the other end side is changed, and both hoop muscles (3) (5) The annular portion formed is adapted to expand radially.

In addition, in this reticulated cylindrical body (1), a pair of suitable hoop muscles (3) and (5) in the middle part in the vertical direction are provided one by one larger than the other ones so as to form concentric circles. A nodular protrusion (7) is provided to protrude to the. Such nodal protrusions (7) (7) ... Are provided at appropriate intervals in the vertical direction. The reticulated tubular body (1) may be made of resin, or may be a reticulated iron wire.

Next, a construction procedure of the present invention will be described with reference to FIGS. 2 (A) to (D).

First, excavate the ground (9) using an auger (8),
Form a pile hole (10) of appropriate depth at a predetermined position (first
See FIG.

Then, the reticulated cylindrical body (1) is inserted into the inside of the pile hole (10) thus preliminarily drilled and installed (first).
See FIG. At that time, as shown in FIG. 3, the mesh tube body (1) is rolled inward with each hinge part (6) (6) ... as a fulcrum, and the pile hole ( Insert into 10). In this way, by connecting the pair of hoop muscles (3) and (5) constituting the reticulated tubular body (1) via the hinge portion (6), the delivery of the reticulated tubular body (1) can be easily changed. Therefore, the insertion into the pile hole (10) can be easily performed.

After that, an appropriate amount of earth material (11) is put in through the opening at the upper end of the mesh cylinder (1). As the soil material (11), soil to which a solidifying agent is added, cut gravel, crusher run, or the like is used. Then, the surface of the soil material (11) is struck sufficiently with the projecting rod (12) and the like to be sufficiently struck (see FIG. 2 (C)). Then, the soil material (11) is compacted by the striking force, and at the same time, a lateral expansive force acts on the reticulated tubular body (1) near the striking portion via the soil material (11). Therefore, in the net-like tubular body (1) of the relevant portion, as shown in FIG. 4, the hoop streaks (3) and (5) expand outward in the radial direction due to the reduced overlapping portion, and thereby the hand-over is performed. It grows and sticks to the wall of the pile hole (10). At that time, although depending on the ground conditions, the nodular protrusions (7) having a slightly larger outer diameter bite into the wall surface of the pile hole (10). In addition,
As for the hoop muscles (3) and (5), the one engaging portion (5a) provided on one hoop muscle (5) is integrated with the other hoop muscle (3) to form a single longitudinal muscle (2). ) By engaging
Never separate from each other.

Then, by repeating the above work, that is, the work of charging the soil material (11) and solidifying it, the soil pile having the projections (13) (13) ... Which project laterally in the depth direction. (14) is built (see Fig. 2 (D)).

Then, as shown in FIG. 5, for example, a plurality of earth piles (14) (14) constructed by the above-mentioned procedure are installed on the upper part of the footings (15) (15). )
(15) …… The upper structure (16) will be built on top. In that case, the protrusions (13) (13) by the nodular protrusions (7) (7) of the reticulated tubular body (1) are vertically arranged on the peripheral wall of each earth pile (14). Since a plurality of nodules are formed in the direction, the protrusions (13) (13) ...
The load of the upper structure (16) acting via 5) can be reliably supported.

Effects of the Invention As described above, in the present invention, the mesh cylinder is inserted into the preliminarily drilled pile hole, and then the earth material is put inside the mesh cylinder to build the pile, so that the pile hole wall surface Is prevented from collapsing,
It is possible to obtain a clay pile having a shape according to the purpose. In addition, the nodular protrusions provided on the net-like tubular body reliably form the protrusions projecting laterally, and these protrusions act as a resistance to generate a large frictional force between the pile hole wall surface and the earth pile. This has the effect of increasing the bearing capacity. Moreover, since the supporting force increases due to the resistance of the protrusions,
It is not necessary to lengthen the entire length, and it is possible to perform drilling work with a small-to-medium-sized working device such as a hand auger or a truck auger, and it becomes possible to carry out a general-purpose work. Further, in the present invention, since the pile body is formed by the soil material, unlike the conventional concrete concrete friction pile, not only the construction cost is reduced, but also the self-weight of the pile body itself is small, so that the super soft ground Can also be implemented.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an example of a mesh cylinder used in the present invention, FIGS. 2 (A) to (D) are schematic cross-sectional views showing a construction procedure of the present invention, and FIG. Figure 2 (B)
In Fig. 4, a cross-sectional view showing a state in which the net-like tubular body is inserted into the pile hole, Fig. 4 is a cross-sectional view showing a state in which the net-like tubular body is enlarged in Fig. 2 (C), and Fig. 5 is It is the schematic which shows the state which built the upper structure on the ground which implemented this invention. (1) ... Mesh tube, (2) (4) ... Vertical streaks, (3)
(5) …… Hoop streak, (7) …… Nodular protrusion, (9)…
… Ground, (10) …… Pile hole, (11) …… Soil material.

Claims (2)

[Claims] 1. After preliminarily forming a pile hole in the ground, a net-like tubular body having a plurality of laterally projecting nodular protrusions at an intermediate portion in the up-down direction is inserted into the pile hole and installed, after which A method of constructing a pile in soft ground, which comprises pouring earth material into the mesh tubular body and solidifying it. 2. A device for inserting and installing in a pile hole,
A plurality of hoops arranged in a substantially horizontal plane with a vertical spacing and connected to each other by vertical streaks, and a plurality of hoops also arranged in a substantially horizontal plane with a vertical spacing, and with each other by vertical vertical streaks The plurality of connected hoop muscles are connected to each other in a substantially hollow cylindrical shape in a state in which they can be expanded in the radial direction, and a plurality of laterally projecting nodal projections are provided at appropriate intervals in the vertical middle portion. A reticulated tubular body characterized by being provided in advance.