JPS6319325A - Pile construction in soft ground and parts therefor - Google Patents

Abstract

PURPOSE:To obtains a pile having strong bearing capacity at low cost even in in-situ construction work by a method in which a netted cylinder having plural projected knots on its middle portion is penetrated into an excavated pit, and soil is charged into the cylinder and compacted. CONSTITUTION:Many hoops 3 and 5 vertically connected by plural vertical reinforcements 2 and 4 are set in an annular form in such a way as to form a pair of them in the same plane. A netted cylinder 1 having plural projected knots 7 with the hoops set expandably through a hinge provided between them together with paired intermediate hoops larger than the others is formed. The cylinder 1 is penetrated into an excavated pit 10 in the ground and soil 11 is charged into the cylinder 1 and compacted by a rammer 12. The operations are repeated upwards to construct a strong soil pile whose projected knots 7 are penetrated into the wall of the pile pit 10 by the expansion of the hoops 3 and 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a method for building piles in soft ground and members thereof.

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

In this type of pile foundation, the load of the upper structure is generally supported by support piles driven into the support layer.

However, with pile foundations using such support piles, there is a so-called uplift phenomenon, especially in areas with widespread ground subsidence, so recently, methods have been developed that utilize the frictional force acting on pre-formed concrete bodies such as RC friction piles installed in the ground. Many of the problems are due to friction caused by friction.

Problems to be Solved by the Invention However, construction costs are high, as large working machines are required for the construction of the above-mentioned prefabricated concrete antibodies, and large trucks are also required to transport the above-mentioned antibodies to the construction site. Not only that, but it may not be possible to implement it depending on the construction location, and it has the disadvantage of lacking in versatility. Furthermore, since the antibody itself has a large weight, there is a problem in that the supporting force is reduced.

In view of these problems, the present invention was made with the aim of providing a pile that can be constructed at low cost even on-site and has a strong supporting capacity.

Means for solving the problems, that is, in this invention, in order to achieve the above object,
After forming pile holes in the ground in advance, a net-like cylinder having a plurality of laterally protruding knot-like protrusions is raked and installed in the middle part in the vertical direction, and then the soil material is placed on top 2! It is placed inside the rope body and tamped down.

Embodiments Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Figure 1 shows the mesh cylinder (1) used in this example.
- An example is shown. This reticular cylinder (1) is made up of a large number of hoop bars arranged in a substantially horizontal plane with vertical intervals and connected to each other by a plurality of vertical bars (2) (2)... (3) (3)...... are also arranged in a substantially horizontal plane with vertical intervals, and are connected to each other by a plurality of vertical bars (4) (4)... A large number of hoop muscles (5) (5)...
It is composed of... A pair of left and right hoop muscles arranged in a ring in approximately the same plane (3) (5)
The two hoop muscles (3) and (5) are connected to each other via the hinge part (6) on one end side.The other end side of both hoop muscles (3) and (5) are connected with one hoop muscle (3) inside and the other hoop muscle ( 5) are on the outside and overlap each other. Lateral hoop muscle (
5) At the tip &a 91<, there is an engaging part (
5a) is provided. That is, this reticulated cylinder (1
) are hoop muscles (3) (5
) are horizontally rotated about the hinge part (6) between them, the length of the over-ramp part on the other end side changes, and the length of the over-ramp part formed by both hoop muscles (3) and (5) changes. The annular portion extends t in the radial direction.

In addition, in this reticulated cylinder (1), a suitable pair of hoop muscles (3) and (5) in the vertically intermediate portion are made concentrically larger than the others, so that the lateral side A knot-shaped protrusion (7) is provided that protrudes from the top.

Such nodular protrusions (7), (7), etc. are provided at appropriate intervals in the vertical direction. Note that this reticulated cylinder (1) may be made of resin or may be made of iron wire formed into a reticulated shape.

Next, the construction method of this invention will be explained with reference to FIGS. 2(A) to 2(D).

First, excavate the ground (9) using an auger (8) etc.
A pile hole (10) of an appropriate depth is formed at a predetermined position (see FIG. 1(A)).

Next, the mesh cylinder (1) is inserted and installed inside the pile hole (10) drilled in advance in this way (see FIG. 1(B)). ) is inserted into the above-mentioned pile hole (10) with each hinge part (6) (6) ...... rolled up inward using the fulcrum as shown in Fig. 3, and with the overall width reduced. do. in this way,
A pair of hoop muscles (3) (5) constituting the reticular cylinder (1)
By connecting each through the hinge part (6), the span of the mesh cylinder (1) can be easily changed,
This allows for easy insertion into the pile hole (10).

After that, 31 soil materials (11) are poured into the opening at the upper end of the net-like cylinder (1). As this top material (11),
Use soil with added solidifying agent, cut gravel, crusher run, etc. Then, the surface of the soil material (11) is
) or the like (see Figure 2 (C)). Then, soil material (11
) is compacted by the striking force, and at the same time, a lateral expansion force acts on the mesh cylinder (1) near the striking part via the soil material (11). Therefore, as shown in FIG. 4, in the reticular cylinder (1) in this part, the hoop muscles (3) and (5) expand in the radial direction as the overlapping portion decreases, and the width becomes larger. The pile hole (10) is in close contact with the wall surface. At that time, although it depends on the ground conditions, the nodal protrusion (7) with a large outer diameter will bite into the wall surface of the pile hole (10).

In addition, the hoop muscles (3) and (5) are arranged so that the above-mentioned engaging part (5a) provided on one hoop muscle (5) is connected to one edge that is integrated with the hoop muscle (3) on the other side. By engaging with the striations (2), they do not separate from each other.

Then, by repeating the above-mentioned work, that is, adding soil material (11) and tamping it,
Projections (13) that protrude laterally in the depth direction (1
3) The upper pile (14) having... is constructed (
(See Figure 2 (D)).

Then, for example, as shown in Fig. 5, a plurality of upper piles (14) (14)...... footings (15) (15)... has been installed, and its footing (15) (15)...
...A superstructure (16) will be built on top. In that case, in the peripheral wall portion of each of the above-mentioned upper piles (14),
Nodular protrusions (7) (7) of the mesh cylinder (1)
The protrusions (13) (13)... are formed in a plurality of knots in the vertical direction, so the protrusions (13)...
3) (13) . . . acts as a resistance and the frictional force becomes large, so that the load of the upper structure (16) acting through the footing (15) can be reliably supported.

Effects of the Invention As described above, in this invention, a mesh cylinder is inserted into a pre-drilled pile hole, and then soil is poured into the mesh cylinder to construct a pile, so that the wall surface of the pile hole is Collapse is prevented,
It is possible to obtain an upper pile of a shape according to the purpose. In addition, since the nodal protrusions provided on the net-like cylinder reliably form protrusions that protrude laterally, these protrusions act as resistance and create a large frictional force between the pile hole wall and the upper pile. This has the effect of increasing the supporting capacity. Moreover, the supporting force increases due to the resistance caused by the protrusions, so
There is no need to increase the overall length, and the hole drilling work can be performed with small and medium-sized work equipment such as a hand auger or a truck auger, making it possible to carry out the drilling work in general. Furthermore, since the antibody is formed using soil materials in this invention, construction costs are not only reduced, unlike conventional prefabricated concrete friction piles, but the antibody itself has less weight, making it suitable for use even on ultra-soft ground. It can be implemented.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is an overall perspective view showing an example of a mesh cylinder used in the present invention, and Figs. 2 (A) to (D) are schematic sectional views showing the construction procedure of the present invention. , Figure 3 is Figure 2 (B)
In FIG. 4, a cross-sectional view showing a state in which the reticulated cylinder is inserted into the pile hole, and FIG. 5, a cross-sectional view showing the expanded state of the reticulated cylinder in FIG. FIG. 2 is a schematic diagram showing a state in which an upper structure is constructed on the ground in which the present invention is implemented. (1)...Reticular cylinder, (2)<4)...Pupillary muscles, (3
) (5)... Hoop muscle, (7)... Nodular protrusion, (
9)...Ground, (10)...Pile hole, (11)...
Soil material.

Claims (1)

[Claims] 1. After forming a pile hole in the ground in advance, a net-like cylinder having a plurality of laterally projecting joint-like protrusions in the vertically intermediate portion is inserted into the pile hole and installed. A method for constructing piles in soft ground, characterized in that after that, soil material is thrown into the inside of the mesh cylinder and tamped. 2. It is installed by inserting into a pile hole, and is arranged in a substantially horizontal plane with vertical intervals, and is connected to each other by vertical vertical bars, and A plurality of hoop muscles arranged in a horizontal plane and connected to each other by vertical vertical muscles are connected in a roughly hollow cylindrical shape in a radially expandable state. 1. A net-like cylinder, characterized in that a plurality of nodular protrusions protruding in one direction are provided at appropriate intervals.