JPH03286021A - Pile driving method - Google Patents

Abstract

PURPOSE:To enlarge the outer diameter of a pile by inserting a hollow pile into a hole bored in the ground, injecting pressed hardener into the hole through the hollow, and making the hardener permeate the ground around the hole. CONSTITUTION:A prescribed hole 1 is bored having a diameter almost equal to the outer diameter of a hollow pile 2 to be driven into the ground. To the upper part of the injection hole 21 of the pile 2, a pressure pump P is connected for a hardener 4 through a hose 3. The pile 2, having the outer diameter almost equal to the inner diameter of the hole 1, is once hung up and then driven into the hole 1 by its self-weight. After the pile 2 is driven up to a prescribed depth, the pump P is operated to supply the hardener 4, such as cement milk and mortar, and, to discharge it from the tip open port of the pile 2 into the hole 1. The hardener 4 in addition is injected around the pile 2 and then, before it is hardened, it is further injected with higher pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION <Prior Art> Instead of the method of directly driving piles, a method of inserting ready-made piles into holes drilled in the ground has been developed.

It is characterized by solving noise and vibration problems compared to the previous model.

However, it has the disadvantage that its bearing capacity is lower than that of the driving method.

In other words, this method involves first drilling a poling hole with a diameter that is equal to or slightly smaller than the diameter of the pile.
The phenomenon that the frictional force on the circumferential surface decreases is unavoidable.

For this reason, the designed outer diameter of the pile was limited to the outer diameter of the pile itself.

<Objective of the present invention> The present invention was made in order to improve the above-mentioned problems, and it does not generate vibration or noise due to impact, and it also allows the designed outer diameter of the pile to be changed from the actual outer diameter of the pile. The purpose of this invention is to provide a method for driving piles that allows for a wider range of piles.

<Problems to be solved by the present invention> This advance polling method is a driving method. This method of driving piles involves injecting a hardening material under pressure into the hole through the hollow part of the pile, and allowing the pressurized hardening material to permeate into the ground around the hole.

<Description of the present invention> The present invention will be explained in detail below.

<A> A predetermined hole 1 is drilled in the ground in the area for which the hole is to be drilled, using an earth auger or the like.

The inner diameter of this hole 1 is configured to be approximately equal to the outer diameter of the hollow pile 2 to be erected.

In addition, although the gap between the hollow pile 2 and the hole 1 is drawn large in the figure, this is to make the explanation of the injection situation easier to understand.

<Mouth> Hollow pile A ready-made hollow pile 2 is installed in the hole 1.

The hollow pile 2 can be made of either a steel pipe or a concrete pipe.

The hole at the center of the hollow pile 2 is configured as an injection hole 21.

This injection hole 21 is opened in a vertically penetrating state.

Therefore, the lower end of the injection hole 21 opens at the tip of the hollow pile 2, and the upper end of the injection hole 21 opens above the hollow pile 2.

The hardening material 4 is injected into the injection hole 21 from the outside through this opening at high pressure.

For this purpose, a screw thread or the like for attaching a valve is formed at the upper end of the injection hole 21.

<C> Erecting hollow piles A pressurizing pump P for hardening material 4 is connected via a hose 3 to the upper part of the hollow pile 2 having the above structure.

Then, a hollow pile 2 having an outer diameter substantially the same as the inner diameter of the hole 2 is once lifted and inserted into the hole 1 by its own weight.

Once inserted to a certain depth, the pump P is activated to supply a hardening material 4 such as cement milk or mortar from the injection hole 21 of the hollow pile 2 and discharge it into the hole 1 from the opening at the tip.

Therefore, a small gap around the hollow pile 2 is filled with the hardening material 4. In this case, there is no need to inject at high pressure.

In order to obtain the same effect, it is also possible to first fill the hole 1 with a hardening material 4 such as mortar, and then insert the pile 2.

<2> Pressure on the surrounding area After the hardening material 4 is filled around the hollow pile 2 and before the hardening material 4 hardens, the hardening material 4 is injected at high pressure through the injection hole 21.

Then, due to the pressure, the hardened material 4 penetrates into the surrounding ground from the tip of the hollow pile 2 and expands.

Therefore, it is possible to achieve high adhesion between the pile and the ground.
Effective antibodies can be formed.

Even when the hardening material 4 is injected under high pressure, the hardening material 4 does not normally flow back from the mouth of the hole 1.

This is because the outer diameter of the hollow pile 2 and the inner diameter of the hole 1 are almost the same or only a few percent larger, so the hardening material 4 injected from the tip of the hollow pile 2 will clog by itself in the process of rising. This is because it causes a seal backer effect.

Kuho〉Other Embodiments It is also possible to open a plurality of slits 5 around the hollow pile 2.

Then, the hardening material 4 such as cement milk penetrates through the slit 5 into the surrounding ground not only from the tip of the hollow pile 2 but also from the intermediate and upper portions that are particularly desired to be hardened due to the geology, thereby obtaining even more effective frictional resistance. can.

In the case of such a slit opening type hollow pile 2, the hole 1
It is also assumed that the hardening material 4 may flow backwards from the mouth.

In that case, an inflatable sealing material may be attached in an annular manner around the upper part of the hollow pile 2.

Furthermore, after installing the hollow pile 2 in the ground through a series of operations, it is also possible to construct a high-strength composite pile by inserting structural members such as reinforcing bars and H steel into the hollow pile 2 and filling it with hardening material. It is.

<Effects of the present invention> Since the present invention is a method for driving piles through the steps described above, the following effects can be achieved.

<B> A structure can be obtained in which there is a prefabricated pile in the center and the ground around it is integrated with the prefabricated pile.

Therefore, it is possible to make the designed diameter of the pile larger than the actual diameter of the pile.

Therefore, a very economical pile can be obtained.

A method of forming piles of hardened material 4 in the ground using a special device such as a jet has already been developed and is in use in the field.

However, the method of the present invention does not require such special equipment, and a pile made of hardening material 4 can be constructed underground using a simple equipment.

〈C〉Since the construction method does not involve hammering, it does not generate vibration or noise and can be constructed in urban areas.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory national policies showing the construction order of the present invention. figure Figure 2 Third figure Fourth figure

Claims (1)

[Claims] (1) Drill a hole in the ground, insert a hollow pile into the hole, pressurize and inject hardening material into the hole through the hollow part of the pile, and let the hardening material penetrate into the ground around the hole. Method of driving piles