JPH0366823A - Method of forming sand pile and device therefor - Google Patents

Abstract

PURPOSE:To facilitate the formation of a sand pile by providing digging blades in the lower end part of a rotary casing so that the outer end part of the blade is projected out from the rotary casing while the inner end part thereof is projected into a stationary casing, thereby digging is made during intrusion of the casing. CONSTITUTION:A stationary casing 4 is inserted into a rotary casing 2 suspended from and rotatably connected with the lower section of a frame 1, and is connected thereto with a sand tank 5 and the like. Each of digging blades 10 fixed to the lower end of the stationary casing 2 is projected at its outer end from the casing 2, and is projected at its inner end into the casing 4. Then the casing 2 is rotated and intruded into the ground together with the outer casing 4. The blades 10 are rotated so as to dig not only an area around the casing 2 but also a substantial part of the cross-sectional area thereof. Accordingly, it is possible to easily and rapidly intrude the casing.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method and apparatus for constructing piles made of sand, gravel, crushed stone, etc. (hereinafter simply referred to as sand) in soft ground, and in particular, Using two casings, a rotating casing and a fixed casing inserted into the rotating casing, the rotating casing is rotated and penetrates into the ground together with the fixed casing to a predetermined depth, and then sand is introduced into the fixed casing from a hopper. The present invention also relates to a method and apparatus for constructing a sand pile by discharging sand from the lower end of a fixed casing and leaving it in the ground while pulling out both casings.

(Prior art and its problems) The rotating casing conventionally used in this type of sand pile construction method does not have any excavation means at its lower end, and when the casing penetrates, it rotates only by the simple rotational downward action of the rotating casing. Since the casing is made to penetrate into the ground, the penetration speed is inevitably slow and work efficiency is poor.Also, since a shoe (bottom cover) is usually attached to the lower end of the rotating casing, this The shoe was subjected to considerable resistance from the ground, making the casing work even more difficult.

The present invention aims to solve these conventional problems.

(Means for Solving the Problems) The present invention penetrates into the ground while rotating a rotating casing in which a fixed casing is inserted, and after reaching a predetermined depth, both casings are pulled out and the fixed casing is inserted into the ground. In a sand pile construction method in which a sand pile is constructed by discharging sand thrown into the fixed casing from the lower end of the fixed casing, the outer end protrudes outward from the rotating casing and the inner end protrudes from the fixed casing at the lower end of the rotating casing. The excavator blade is integrally provided with an excavator blade that protrudes inward and forms a cutting edge from the outer end to the inner end, and when penetrating the casing, the excavator blade is rotated by the rotation of the rotating casing to excavate the ground. It is something to do.

Further, the present invention comprises a rotating casing which is connected to the lower part of the machine frame so as to be rotatably driven, and a fixed casing which is inserted into the rotating casing in a hanging manner and is provided with a sand supply pump at its upper end. In the sand pile construction device, a cutting edge is formed at the lower end of the rotating casing, with an outer end projecting outward from the rotating casing and an inner end projecting inward from the fixed casing, from the outer end to the inner end. It is characterized by being integrally equipped with a digging blade.

In the device of the present invention, an inner rod that can be moved vertically by a vertical drive means is inserted into the fixed casing, and a vibrator is attached to the lower end of the inner rod that protrudes from the lower end of the fixed casing. The lower end of the fixed casing may be closed by the vibrator at the upper limit position of the inner rod.

(Example) To explain the example with reference to the drawings, Fig. 1 shows a sand pile construction device, and in this figure, 1 is a device that can be freely raised and lowered from a league (not shown) installed on a crawler crane or the like. A cylindrical rotating casing 2 is rotatably suspended from the lower part of the machine frame 1, and this rotating casing 2 is connected to a pair of electric motors 3 and 3 on both sides provided on the machine frame 1.
and a gear transmission Ia (not shown).

A cylindrical fixed casing 4 is inserted concentrically into the rotating casing 2, and its lower end extends to near the lower end of the rotating casing 2, and its upper end extends to the upper part of the machine frame l. 5 is a large-diameter cylindrical sand tank installed concentrically with the fixed casing 2 on the upper part of the machine frame 1, and is formed in a size that can sufficiently accommodate the capacity of four fixed casings. A sand supply pumper 6 is connected to the upper end of the sand tank 5. Reference numeral 7 denotes a hollow inner rod inserted concentrically into the fixed casing 4, the upper end of which is interlocked and connected to a hydraulic cylinder 8 serving as a vertical drive means, and the lower end thereof protruding from the lower end of the fixed casing 4. , a vibrofront 9 as a vibrator is attached to its protruding end.

Reference numeral 10 denotes an excavating blade disposed at the lower end of the rotary casing 2 so as to protrude downward and inward.

A protection pipe 11 for protecting the fluid pressure cylinder 8 is provided in the sand tank 5, the upper end of which is fixed to the earthen wall of the sand tank 5, and the lower end of which is fixed to the mortar-shaped bottom wall of the sand tank 5. It passes through the portion 5a and is communicatively connected to the upper end portion of the fixed casing 4. A sand discharge opening 12 is provided in the bottom wall 15a of the sand tank 5, and the opening 12 is connected to the upper end of the fixed casing 4 through an inclined communication path 13 formed below the bottom wall 5a. The outer opening of this communication path 13 is closed by a blind flange 14.

The sand discharge opening 12 is provided with an on-off valve 15, which is pivotally attached to the lower surface of the bottom wall 5a of the sand tank 5 and opens and closes the sand discharge opening 12 from the lower surface side. F
i16, and a fluid pressure cylinder 17 (for example, an air cylinder) for driving a valve plate installed on the outer surface of the side wall 5b of the sand tank 5.
and a wire 18 that interlocks and connects the valve plate 16 and the fluid pressure cylinder 17, and a slider 19 connected to the tip of the piston rod 17a of the fluid pressure cylinder 17 is fixed to the sand tank side wall 5b. One end of the wire 18, whose intermediate portion is supported by a sheep 22, is fixed to the slider 19, and the other end is fixed to the valve plate 16. As shown in FIG. 1, when the piston rod 17a contracts, the valve plate 16 is in the open position, and the piston rod 17
When a extends downward, the valve plate 1 is connected via the wire 18.
6 rotates upward to close the sand discharge opening 12. An air supply pipe 21 as an air supply means is protruded into the communication path 13, and this pipe 2
1 allows pressurized air to flow from the communication path 13 to the fixed casing 4.
supplied within.

The fluid pressure cylinder 8 for vertically driving the inner rod is, for example, a hydraulic cylinder, and the upper end of the cylinder body is attached to the earthen wall of the sand tank 5, and the tip of the piston rod 8a is attached to the inner rod 7. Connected to the top end. When the piston rod 8a of the fluid pressure cylinder 8 contracts upward and the inner rod 7 reaches its upper limit position, the vibrofront 9 attached to the lower end of the inner rod 7 is moved along the dashed-dotted line in FIG. As shown in the figure, the upper end portion is located at the lower end portion of the fixed casing 4 and closes the lower end opening, and the piston rod 8a
When the inner rod 7 extends downward and moves downward, it separates downward from the lower end portion of the fixed casing 4 and opens its lower end opening. At the lower limit position of the inner rod 7, the vibrofront 9 is in the position shown by the solid line in FIG.

The excavating blade 10 is fixed to the respective lower ends of a pair of mounting frames 23, 23 on both sides that are fixed to diametrically opposed positions on the outer peripheral surface of the lower end of the rotary casing 2 and protrude downward. As is clear from FIGS. 1 and 2, each excavation blade 10 has a cutting edge loa at its lower end, and this cutting edge 10a has an outer end located outside the outer peripheral surface position of the rotating casing 2. It protrudes so that its inner end protrudes sufficiently inward from the position of the inner circumferential surface of the fixed casing 4, and crosses both casings 2 and 4 in the inner and outer directions from its outer end to its inner end. It is extending. Further, each excavation blade lO has its entire side surface at an angle of, for example, 30° to a vertical plane passing through the center axis of the rotating casing 2.
It has an inclination of 40'', and the inner end side is the rotating casing 2.
It is arranged so as to be tilted, for example, by 20° to 30° in the direction of rotation.

A reinforcing frame piece 24 is interposed between the lower end of each mounting frame 23 and the excavating blade 10. Further, both excavating blades 10 are provided at the lower end of the rotating casing 2. A reinforcing excavation piece 25 is attached to the intermediate position in the circumferential direction of IO, and this reinforcing excavation piece 25 has the function of further crushing the earth and sand etc. excavated by each excavation blade 10, and has a balance that balances with the excavation blade 10. It has the role of a weight.

The rotary casing 2 has a large number of holes 20 for soil removal, and inside the fixed casing 4 is installed an air jet supply pipe 27 for blowing out an air jet from the lower end of the fixed casing 4.

Although not shown, the vibrofront 9 has a built-in electric motor and an eccentric shaft connected to its output shaft, and generates lateral vibration by eccentric rotation of the eccentric shaft due to rotation of the electric motor. It looks like this. The cassock tire for the electric motor is inserted into the inside of the inner rod 7 and extends to the outside from a suitable location on the upper part of the inner rod 7. When the vibrofront 9 penetrates the casing, it is in the position shown by the dashed line in FIG. 1 due to the rise of the inner rod 7, and is in an inactive state. When the casing is pulled out, the inner rod 7 is lowered to the position shown by the solid line in the same figure, and the fixed casing 4 is
The lower end surface is open, and the vibration effect is performed at this position.

Next, a method for constructing sand piles in soft ground using the apparatus configured as described above will be explained.

To start sand pile construction work, first open the on-off valve 15 and fill the fixed casing 4 with sand supplied from the hopper 6 into the sand tank 5 through the communication path 13 from the sand discharge opening 12. .

Of course, at this time, the inner rod 7 is at the upper limit position, and the lower end of the fixed casing 4 is closed by the vibrofront 9. Once the required amount of sand has been filled into the fixed casing 4 (the amount of sand filled is determined using a well-known weight-type sand surface detection device installed inside the fixed casing 4), the on-off valve 15 is closed, and the ho... 7 Supply sand from the bar 6 and fill the sand tank 5 with sand equivalent to the size of the fixed casing 4 (wood level detection device installed in the sand tank 5).
.

In this way, from the state in which the fixed casing 4 and the sand tank 5 are each filled with the required amount of sand, the rotary casing 2 is driven to rotate and penetrates into the ground together with the fixed casing 4. In this casing penetrating operation, the excavating blade lO at the lower end of the rotating casing 2 and the auxiliary excavating piece 25
Since the ground can be excavated by the turning motion of the machine, even if a hard ground layer is encountered, it can be easily dug and penetration operations can be performed. In particular, the excavating blade 10 has an outer end protruding outward from the rotating casing 2, an inner end protruding inward from the fixed casing 4, and the casings 2 and 4 are moved inward and outward directions from the outer end to the inner end. Since the cutting edge 10a is formed to extend across the rotating casing 2, the ground covers not only the surrounding area of the rotating casing 2 but also the surrounding area of the rotating casing 3.
Almost a large part of the cross-sectional area surrounded by is excavated, and therefore, the ground resistance applied to the lower end of the rotating casing 2 and the lower end of the fixed casing 4 during excavation is significantly reduced, thereby making it easier and faster to penetrate the casing. be exposed. Incidentally, the excavated earth and sand that entered between the rotating casing 2 and the fixed casing 4 during the casing penetration is air jetted.

The air jet injected from the tip of the jet supply pipe 27 is ejected from the gap between the lower end of the fixed casing 4 and the vibrofront 9 to the outer circumferential side of the fixed casing 2, thereby closing the gap between the outer circumferential surface of the fixed casing 2 and the inner circumferential surface of the rotating casing 2. The frictional resistance between the two casings 2 and 3 is alleviated, and the water passes between the two casings 2 and 3, and is appropriately discharged from the opening 26 for earth and sand discharge.

When the rotating casing 2 is penetrated to a predetermined depth, its rotation is stopped and air supply from the air supply pipe 21 is started, and the fixed casing 4 filled with sand is
increase the air pressure in the head space of the The sand in the fixed casing 4 is pressurized by the pressurized air, and while the rotating casing 2 is driven to rotate in the opposite direction to the direction of penetration, the fluid pressure cylinder 8 is extended. Then, the inner rod 7 is lowered to the lower limit position, the lower end surface of the fixed casing 4 is opened, the vibrofront 9 is vibrated at the same time, and an air jet is ejected from the air jet supply pipe 27. As the rotary casing 2 is pulled out, pressurized sand is pushed out from the lower end of the fixed casing 4 to create sand piles in the ground. In this case, the sand pushed out from the lower end of the fixed casing 4 is subjected to the vibration action of the vibrofront 9, so that a sufficiently consolidated and strong sand pile can be formed. By raising the rotating casing 2 to the ground, 1
Finish building the second sand pile.

When all the sand in the fixed casing 4 is pushed out into the ground as described above and the construction of the first sand pile is completed, the inner rod 7 is raised to the upper limit position to close the lower end of the fixed casing 4,
Then, by opening the on-off valve 15 of the sand tank 5 and filling the fixed casing 4 with sand from the opening 12 through the communication path 13, the device is moved to another new sand pile construction location. Move, and by the time you finish moving, you will have 5 sand tanks.
After filling the fixed casing 4 with sand, a series of operations similar to those described above are continued at the new location to create a second sand pile.

In this way, at the start of the second sand pile, Ho-Tsuba-
Since there is no need to supply sand from the outside according to step 6, step 1
Immediately after the construction of the first sand pile is completed, the construction work of the second sand pile can be started. Therefore, it is sufficient to supply sand from outside as appropriate before starting the construction work of the third pile.

(Effects of the Invention) According to the present invention, at the lower end of the rotating casing, the outer end protrudes outward from the rotating casing and the inner end protrudes inward from the fixed casing, extending from the outer end to the inner end. A digging blade that forms a canting edge is provided integrally, and when penetrating the casing, the cutting blade is rotated by the rotation of the rotating casing to excavate the ground. First, the excavation is carried out sufficiently to the inside of the cross-sectional area surrounded by the rotating casing, and therefore, the ground resistance applied to the lower ends of both casings during excavation is significantly reduced, making it easier and faster to penetrate the casing. I can do it.

Further, in the present invention, an inner rod that can be moved up and down by a fixed stroke is inserted into the fixed casing, a vibrator is attached to the lower end of the inner rod that protrudes from the lower end of the fixed casing, and the vibrator is activated at the upper limit position of the inner rod to cause the lower end of the fixed casing to move upwardly and downwardly. By blocking the casing, it is possible to prevent earth and sand from entering the fixed casing when the casing penetrates without providing a special bottom cover, and
When the casing is pulled out, vibration can be applied to the sand pile construction stepped from the lower end of the fixed casing, and a more consolidated sand pile can be created.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a sand pile building device showing an embodiment of the present invention, and FIG. 2 is a bottom view of the same device. 1... Machine frame, 2... Rotating casing, 3... Electric motor, 4... Fixed casing, 5... Sand tank, 6...
...Sand supply hopper, 7.Inner rod, 8.Fluid pressure cylinder (vertical drive means), 9.Piper flot (vibrator), 10.Drilling blade, 10a..Can Ting edge, 12... Sand discharge opening, 13.
...Communication path, 15...Opening/closing valve, 21...Air supply pipe.

Claims (3)

[Claims] (1) Penetrate into the ground while rotating the rotating casing into which a fixed casing is inserted, and after reaching a predetermined depth, both casings are pulled out and the sand thrown into the fixed casing is transferred to the fixed casing. In a sand pile construction method in which a sand pile is constructed by discharging sand from the lower end, the outer end of the rotating casing has an outer end protruding outward from the rotating casing and an inner end projecting inward from the fixed casing. A method for constructing a sand pile, characterized in that a digging blade is integrally provided to form a cutting edge from the sand pile to the inner end, and when penetrating the casing, the digging blade is rotated by the rotation of a rotating casing to excavate the ground. (2) Sand consisting of a rotating casing that hangs down from the lower part of the machine frame so that it can be rotated, and a fixed casing that is inserted in a hanging manner into the rotating casing and has a sand supply hopper at its upper end. In the pile building device, a cutting edge is formed at the lower end of the rotating casing, the outer end protruding outward from the rotating casing and the inner end protruding inward from the fixed casing, from the outer end to the inner end. A sand pile creation device characterized by being integrally equipped with a digging blade. (3) An inner rod that can be moved vertically by a vertical drive means is inserted into the fixed casing, and a vibrator is attached to the lower end of the inner rod that protrudes from the lower end of the fixed casing. 3. The sand pile construction apparatus according to claim 2, wherein the lower end of the fixed casing can be closed by the vibrator at the upper limit position.