JPS5854212B2 - Casing equipped with open head and pile driving method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a casing fitted with a special opening head and a pile driving method using the same.

The conventional method for driving piles into the ground is to drill a pile hole in advance by rotating a steel screw called an auger, and then press the pile into the hole. It is.

Diesel hammers, Monken, and other press-in machines are used for this press-fitting, which generates large vibrations and noise, and to prevent the walls of the pre-drilled holes from collapsing, milk made by mixing cement and bentonite with water must be injected. This made the work cumbersome.

Therefore, methods have been proposed in which a spiral protrusion is provided on the outer circumferential surface of the pile itself, or a locking device at the tip of the pile is used to directly screw in the pile without preliminary excavation.

However, because the torsional strength of the concrete is insufficient, it tends to break during excavation, and this is not a satisfactory solution.

In view of this situation, the present invention is intended to more suitably implement a recently developed pile embedding method, which is neither the above-mentioned driving method nor the pile screwing method, and is intended to more preferably construct the pile embedding method, which has been developed recently. This opening head adopts a so-called auger head mechanism, and converges the head into a conical shape so that it can be opened and closed freely, and allows excavation to a predetermined depth and removal of only the casing for the pile device by opening and closing. The purpose of the present invention is to provide an improved casing equipped with a casing and a pile driving method using the casing, thereby completely solving the above-mentioned problems.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a hexagonal pyramid-shaped head 1 is firmly connected to a steel pipe 3 at a base 2, and six triangular steel plates 4,
4... are provided with spiral protrusions 5, 5'... so as to form a single-thread screw or a multi-thread screw.

The steel plate 4 is pivotally attached to the annular base 2 by a hinge 6, while its lower end 4a is fitted into a cap 7 having a conical cavity and converged thereby.

The surface of the lower end of each steel plate is cut into a conical shape to facilitate engagement and disengagement with the cap. It is adapted to be fitted into and removed from a shaped notch 9.

The open state of the head is shown in FIG. 2 as an inverted perspective view, and reference numeral 4a indicates the lower end portion of the steel plate whose outer peripheral surface has been cut into a conical shape.

As shown in Fig. 3, which shows the cap enlarged, the nose 10 fixed in the vertical direction on the outer periphery is press-fitted from the pipe 11 in the center of the inside and has an opening 1 through which filtrate, air, or cement milk is to be discharged.
It has 2.

Figure 4 shows the process of driving piles using a casing equipped with the head 1 described above.
is inserted into the casing 21.

Next, a drive device, such as a reducer 22 of an earth auger, is connected to the top of the casing (as shown in FIG. Confirm this with an appropriate measuring device and stop the drive.

During the above period, the iron pile is inserted into the casing 21 by the press-fitting mechanism 24 interposed between the top of the pile 20 and the lower part of the reducer 22.
It is always pressed toward the bottom of the head 1, that is, toward the head 1.

Following this, the casing 21 is reversed while pouring cement milk 25 as shown in the same figure.

Accordingly, the protrusion 8 on the outer surface of the lower part of the steel plate 4 reverses inside the notch 9 of the cap 7 and moves from the indented part 9a to the wide part 9b, and at the same time the force of the press-fitting mechanism 24 pushes the cap 7 downward via the stake 20. put out.

The head 1 released from the convergence by the cap 7 opens as shown in FIG. 2, and the pile is press-fitted, while the cap 7 remains underground.

Further, while injecting cement milk 25 and reversing the casing 21, it is pulled up as shown in FIG.

Thus, as shown in Figure F, the pile 20 is buried in the ground with its surroundings, ie, the wall of the hole, solidified with the milk.

You can proceed with the work in the same way for the other piles.

In addition, water or air may be injected to reduce earth pressure during excavation, or after the head is reversed to open the head, it may be left for a while until it is pulled up, and the pressure force of the press-in mechanism and the pile's own weight may be used. It is also free to settle the pile as much as possible using the following method.

As is clear from the above, the casing of the present invention can be opened and closed, and when closed (i.e., in a converged state), it is shaped like a cone or pyramid and forms a head that has the function of a so-called auger head. , When quickly assembling before construction, etc., even if it is turned upside down or hung, it will not open automatically (that is, the multiple steel plates will unconverge and separate from each other). It can promote work efficiency and safety, and in general, during rotary excavation, with this type of open head, strong earth pressure acts on the tip of the cone, which is the center point of head convergence, and the soil is damaged. Even though it converges naturally inside and does not open accidentally, the tip of the head may come into contact with a rock mass or hard sand/gravel layer,
If the steel plates are submerged, the steel plates may be deformed or separated due to peeling or abrasion damage, but the tip of the head can be sufficiently protected.

Moreover, due to the process, if you try to excavate with piles etc. inside the casing, the head, which can open and close in the soil, cannot withstand the weight of the pile placed on the tip of the head and attempts to open it. It is possible to converge and hold the tip of the head with great strength, and has other advantages such as simple structure, easy manufacture, and easy handling.

Further, the present invention method of inserting a pile into the casing and reversing it when a desired depth is reached after excavation, leaving the head convergence cap and iron pile in the ground and pulling up the casing, has the above-mentioned special head configuration. Moreover, since the piles can be inserted into the casing in advance, the formation of the excavation hole using the excavated casing and the erection of the piles can be done at the same time. However, since the cap can only be removed at this time, the head has the same function as an auger head with the pile still inserted in the casing, and a series of work processes and operations are guaranteed. .

The generation of noise, vibration, etc. during this operation is extremely suppressed,
In addition, there is little damage to the pile body, and it is possible to prevent excess milk from escaping onto the ground surface, all of the deficiencies of the conventional method described at the beginning are eliminated at once.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic front view of the casing, Fig. 2 is an inverted perspective view of the head, Fig. 3 is a perspective view of the cap, and Fig. 4 is a pile driving method. FIG. 1...Head, 2...Base, 3...
...Steel pipe, 4...Steel plate, 4a...Lower end, 5...Protrusion, 7...Cap, 8...Protrusion , 9...Earth notch, 20...Pile, 21...Casing.

Claims (1)

[Scope of Claims] 1. A plurality of steel plates 4 having spiral protrusions 5 are pivotally connected to an annular base 2 so as to be openable and closable to form a pyramid-shaped head 1, and a lower end 4a of the steel plates 4 is formed. In a casing equipped with an open head in which each outer peripheral surface is cut into a conical shape at the time of convergence and the lower end 4a is inserted into a cap 7 having a conical cavity, the lower end 4a of the head 1 is A protrusion 8 is formed on the outer surface, and the protrusion 8 is removably fitted into an L-shaped notch 9 provided in the cap 7, and the lower end of the head 1 is converged with the cap 7. Casing with opening head attached. 2. The lower end of the head 1, which can be opened and closed, is removably converged with a conical cap 7, and the pile 20 is inserted into the casing 21 to which the head 1 is connected, and the pile 20 is excavated to the desired depth by normal rotation. , a pile driving method comprising reversing this, disassociating the cap 7, opening the head 1, and pulling up the casing 21 while leaving the cap and the pile in the ground.