JPH0332651B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applied to a soil cement pile cap when forming a soil cement pile in soft ground.

<Conventional technology> When constructing a building on soft ground, a cement-based hardening agent is injected into the soil excavated by an auger machine.
Soil-cement piles with a diameter of several tens of centimeters are formed at appropriate intervals by mixing with soil using an auger machine, and the foundation concrete for the building is poured on top of the soil-cement piles.

The head of the soil-cement pile is fragile due to water surfacing, so it will be removed after about 50 to 100 cm of it has solidified. At that time, the height of each pile head should be made the same. This removal of the head is done manually by removing the soil around the head.

<Problems to be Solved by the Invention> In the formation of the soil cement piles mentioned above, there is a problem in that removing the weak parts of the pile head is time-consuming and increases costs, and the removal of the head requires the removal of the pile head. There is also the problem that the strength decreases due to missing parts or cracks.

<Means for Solving the Problems> This means invention provides a disk having a diameter corresponding to the diameter of a soil cement pile for soil improvement formed in the ground;
a flow section for the unsolidified cement formed in the disk so that it can pass from one surface of the disk to the other surface; It consists of reinforced steel bars.

<Operation> The cement will gel 1 to 2 hours after the solidifying agent is injected, so at that point, with the reinforcing bar side of the fitting facing down, push it into the pile using an appropriate tool and insert the disc. Once positioned at a predetermined level, the tool is removed from the disc and pulled out, allowing the cement to solidify. The flow part for the solidified cement provided in the disc is such that when the disc is pushed into the solidified cement at the top end of the pile, the cement on the lower side of the disc moves through the flow part to the upper side of the disc. , the disc can be pushed downward. After the cement hardens, if the upper part of the pile is removed, leaving the disk behind, the disk will be located at the top of the pile, and the reinforcing bar will extend below it, reinforcing the head of the pile. Improved soil cement piles will be completed. The presence of the disc makes it easier to remove the weakened part above it.

<Example> Fig. 1 and Fig. 2 show a pile cap fitting 10, in which 1 is a disk, 2 is a circulation part, and 3 is a reinforcing bar. The disc 1 is made of reinforcing steel, and its diameter is equal to the diameter of the pile to be formed, and its thickness is about 5 mm (generally 3 to 5 mm). A pushing tool coupling portion 13 is formed by a small circular hole 11 bored in the center of the disk 1 and a nut 12 welded to the lower surface of the small circular hole 11. In this case, the pushing tool 16 is T-shaped with an external thread 14 at its lower end and a handle 15 at its upper end, as can be seen in FIG. 3b. The flow portion 2 is four window-like circular holes that vertically penetrate the plate surface of the disk 1. The reinforcing bars 3 are straight bars with a length approximately corresponding to the diameter of the disc 1, and four reinforcing bars 3 are welded at one end to appropriate positions spaced apart from each other on the lower surface of the disc 1, and extend downward.

This pile cap fitting 10 is used in the following manner in the formation of soil cement piles for soil improvement. A solidifying agent is injected into the soil excavated into a cylindrical shape by an auger machine and mixed, and then the pile cap fitting 10 is pushed to a predetermined depth using a pushing tool 16 at an appropriate time when the solidifying agent becomes gelled. In that case, the pile cap fitting 10 and the pushing tool 16 are attached to the nut 1 as shown in FIG. 3a.
2 and a male screw 14, and an operator grasps the pushing tool 16 and pushes the handle 15 until it reaches a predetermined height position, for example by observing the height position of the handle 15 with a horizontal observer. It's crowded. and handle 1
5 is rotated to remove the pushing tool 16 from the pile head metal fitting 10 and take it out, leaving the pile head metal fitting 10 as it is and solidifying it. Once the pile 20 is effectively formed by solidification, the soil around the upper end of the pile 20 is removed, and then the portion of the pile 20 above the disk 1 ( When the weak part) 20a is removed,
Ground improvement soil cement piles are completed.

In addition, in removing the portion 20a, it is necessary to divide the soil cement in the flow section 2 into upper and lower parts, but this is done by using a wedge-shaped tool between the upper surface of the disk 1 and the portion 20a.
It can be easily separated by tapping lightly between the two.

The upper end of this pile is an iron plate, and the reinforcing bars 3 extend downward from the iron plate, so that the pile head is in a reinforced state. In addition, piles with this configuration can be used as needed.
Since reinforcing bars can be welded to iron plates and planted, it is convenient for underground dyeing and foundation concrete installation. FIG. 3c shows a state in which reinforcing bars 30 are welded to the upper surface of the disc 1 and a formwork 31 is provided.

In the above embodiment, the pushing tool 16 was used to push the pile head fitting 10 into the partially solidified soil cement, but the pushing tool is not limited to this type of pushing tool. It doesn't even have to be what it used to be. For example, it may be a coupling structure of a disk 1a and a pushing tool 16a as schematically shown in FIG. 4. The pushing tool 16a has four elastically bendable members 41 at one end of the rod 40.
A claw 42 is formed at the lower end of each extending outwardly to engage with the inner edge of each circulation part 2a of the disk 1a, and a cylinder 43 is slidably attached to the rod 40.
are fitted, and when the cylindrical body 43 is pressed down, the claws 42
is displaced inward to hold the disc 1a as shown. 44 is a cylindrical body position regulating nut.

<Effects of the Invention> According to the present invention, the removal work of the weak portion of the pile head of formed soil cement piles becomes extremely easy, including aligning the top ends of each pile or forming the piles to a predetermined height. This results in significant cost savings. In addition, the completed pile head is reinforced with a pile head metal fitting, which has the effect of preventing strength loss due to chipping or cracking. Furthermore, when forming reinforced concrete structures (underground stains or foundations) on piles, it is easy to align the top ends of each pile, and since it is a steel plate, the reinforcing bars can be welded, making it extremely easy to work. You can also get

[Brief explanation of drawings]

Fig. 1 is a partial longitudinal sectional front view of an embodiment of the present invention, Fig. 2 is a bottom view of the same embodiment, and Fig. 3 shows the state in which the pile head fitting of the same embodiment is used. A longitudinal front view of the pile being pushed into the cement pile, b is a longitudinal front view showing the state in which the weak part that occurs at the top of the pile is removed, and c is a longitudinal front view showing the state in which reinforcing bars are welded and formwork is installed on the completed soil cement pile. FIG. 4 is a partial cross-sectional schematic perspective view showing another example of a coupling structure between a disk and a pushing tool. 1, 1a... Disc, 2, 2a... Distribution section, 3...
...Reinforcing bar, 10...Pile cap fitting, 20...Soil cement pile.

Claims (1)

[Claims] 1. A disk with a diameter roughly corresponding to the diameter of the ground improvement soil cement pile to be formed in the ground, and unsolidified cement formed on the disk so that it can be passed from one side of the disk to the other. A pile head fitting for a ground improvement soil cement pile, which comprises a circulation part of the disk, and reinforcing bars extending from one surface of the disk to the side of that surface.