JPH0621449B2 - Coated sand pile driving method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for driving a coated sand pile (sand pile covered with a water-permeable and tough coating) in the ground.

(Problems of the invention and its characteristic points) As a conventional example of a coated sand pile driving method, at the outlet of the sand hopper located above the casing of the driving machine, a long bag-shaped bag for many piles is provided outside the tubular portion. With the cover in a contracted state and with the cassette inserted so that it can be pulled out downwards, the casing is penetrated into the ground with the cover attached detachably, and sand is supplied to the cylindrical part of the cassette during this penetration process. It is known that the coated sand piles are sequentially formed and filled in the casing (see Japanese Patent Publication No. 58-39972).

This conventional example is superior to the other conventional example using a cover wound on a roll (see Japanese Patent Publication No. 52-608) in that the work to be performed with the casing stopped is small and the construction efficiency is good. However, there are the following problems. That is, in this conventional example, since a cassette equipped with a covering for a large number of piles is used, a long cassette is inevitably required, and the height of the driving machine is correspondingly large, and in this conventional example. In order to drive a covered sand pile of a predetermined length, the movement of the covering body that is pulled out from the cassette and descends is stopped, so that the lower end of the covering body reaches the bottom of the casing and the covering body of a predetermined length is formed. Assuming that the sand has entered the inside, confirm that the sand has been filled to the specified depth (position below the damper) from the viewing window provided at the top of the casing, and stop supplying sand at this point. However, the lowering of the cover does not always stop only when the lower end of the cover reaches the bottom of the casing. The descent of the covering may stop To obtain Ri, since in this prior art it is not possible to determine this point, accompanied by anxiety punching 設砂 pile length is whether a predetermined expected.

The present invention uses a cassette to which a covering for one pile is attached and replaces it with a new cassette after each driving, and solves the problem while taking advantage of the above-mentioned conventional example. The constructional features are as described in the claims.

The length of one pile of the covering body according to the present invention is the predetermined length of the driving pile + α (α ≧ 0) in terms of length, and the covering body of the cassette is covered at a predetermined place where the length α remains in the extended state. If the body is cut, the covering body of a predetermined length enters the casing by itself, and if the movement of the covering body stops while part of the covering body is in a contracted state, the covering sand pile of a predetermined length cannot be laid. Since it is immediately understood that this is not done, it is possible to reliably control the length of the driven sand pile.

(Detailed Description of the Invention According to the Drawings) First, the coated sand pile driving machine for carrying out the invention illustrated in FIGS. 1 to 3 will be described. 1 is a penetrating machine, 2 is a sand hopper, and 3 is a cassette. The frame of the mounting portion, 4 is a box with a built-in air valve, 5 is a casing, and the whole of these is suspended by a wire 6 so that it can be lifted and lowered by a main body of a construction machine (not shown).

At the outlet of the sand hopper 2, a slide valve having a valve plate 8 operated by a cylinder device 7 and a groove 9 for mounting a cassette.
There is a cassette 10, and the cassette 11 is attached by fitting the flange at the upper end of the cylindrical portion 12 into the groove 9.

On the outside of the cylindrical portion 12 of the unused cassette 11, a cylindrical covering body 13 for one pile is fitted in a contracted state.
The upper end of the cover 13 is fixed to the tube portion 12 by an appropriate means, and the cover 13
The lower end of is closed by means of binding or the like and can be pulled out downward.

The length of the cover 13 is approximately equal to the length of the driving pile, which is longer than the length l _{1 of the} casing 5 by α (α ≧ 0), and the cover 13 mounted on the cassette 11 is extended from the fixing point. When cut at the length α, the covering body 13 having the length l ₁ is adapted to enter the casing 5.

A cover retainer 16 including a fixed portion 14 and a rotating portion 15 is mounted on the box 4, and the rotating portion 15 is a support portion.
An arm piece 19 that is supported by 17 (both sides but only one side is shown) via a rotary shaft and that rotates integrally with the fixing pin 18 and the rotary portion 15 located above the rotary shaft. It is urged by a spring 21 stretched between the tip pin 20 and the cover body retainer 16 and the tubular portion 12.
It is designed so that it can be switched between a closed state in which resistance is applied to the covering body 13 passing through the gap between and, and an open state in which the cassette 11 is replaced.

The air valve 22 in the box 4 has a balance weight 23,
The box 4 is always biased in the closing direction, and a pressure air supply / discharge port 24 is provided in the box 4.

The lower end portion 25 of the casing 5 is thinly formed over a considerable length so that the covered sand pile body filled in the casing 5 can be smoothly removed. A prevention valve 26 is provided.

Next, an embodiment of the present invention made by using the above-mentioned coated sand pile driving machine will be described with reference to FIG. 4. The penetration of the casing 5 of the driving machine into the ground is started (state a), and the penetration is started. At an appropriate stage of the process, the slide valve 10 is opened to feed the sand of the sand hopper 2 through the cylindrical portion 12 of the cassette 11 toward the tip of the covering body 13,
The inside of the casing 5 is lowered while forming the covered sand pile body P by sequentially expanding the contracted cover body 13 (state of B).

At this time, in consideration of the penetration of the casing 5 and the tamping of the growth of the coated sand pile body P, at the stage where the penetration of the casing 5 is completed, the coating body 13 is substantially extended and the planned cutting position (the length α is left). It is preferable that the coated sand pile body P grows up to the position), in which the slide valve 10 is closed and the coating body 13 is cut to coat the casing 5 with a predetermined length (≈l ₁ ). The sand pile P'is filled, and the used cassette 11 and the new cassette 11 'used in the next placing work are replaced, and in parallel with this, the supply / discharge port
The supply of compressed air to the inside of the box 4 and the casing 5 is started from 24 (state of C).

Next, while continuing to supply the compressed air, the casing 5 is started to be withdrawn (d state), and the casing 5 is completely withdrawn to the ground (e state) with the coated sand pile body P ′ left in the ground, once. Finish the placement work of.

(Effects of the Invention) The present invention is as described above, in which the casing is hardly stopped during the casting work, and the work performed by the worker with the casing stopped is relatively short-lived. Since it is only cutting the covering and replacing the cassette, it can be expected to significantly improve the construction efficiency and ensure the safety of the operator,
Moreover, since the cassette equipped with the cover for one pile is used, the length of use of the cover can be surely set to the predetermined pile length. Not only can the placement be carried out, but a secondary effect that the length of the cassette and thus the length of the entire placement machine can be saved can be expected.

[Brief description of drawings]

FIG. 1 is an overall view of a coated sand pile driving machine for carrying out the present invention, and FIG.
The figure is also an enlarged perspective view of the slide valve, FIG. 3 is an enlarged plan view of the same with part of the covering body suppressed, and FIG. 4 is a process diagram for explaining the present invention. In the figure, 2 ... Sand hopper, 5 ... Casing, 11 ... Cassette, 13 ... Cover, ....

Claims (1)

[Claims] 1. A cassette in which a bag-shaped covering for one pile is contracted outside the tubular portion and is fitted in the outlet of a sand hopper located above the casing of the driving machine in a contracted state and can be pulled out downward. In a state where the casing is detachably attached, the casing is pierced into the ground, and during this piercing process, sand is supplied to the cylindrical portion of the cassette, and the coated sand pile body is gradually lowered to form the inside of the casing. A method for placing a coated sand pile, characterized in that a cassette sand to be used in the next placing is installed before the casing that has penetrated to a prescribed depth is withdrawn and the casing is inserted to a predetermined depth.