JPH0612033Y2 - Pile building equipment - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a pile forming device which prevents water from entering a casing penetrated into the ground for pile formation.

(Prior art and its problems) As one of the construction methods for improving soft ground, a casing whose bottom surface is closed by an openable / closable bottom lid is penetrated into the ground,
Then, quick lime (calcium oxide) is put into the casing from a hopper provided at the upper part of the casing, then the casing is pulled up, whereby the bottom lid is opened and the quick lime in the casing is left in the ground. There is a method in which the remaining quick lime is reacted with water in the ground to form slaked lime (calcium hydroxide), and a so-called chemical pile is created.

In the construction of the above construction method, the lower end of the casing is closed by the bottom lid as described above, but it is not completely closed and water enters the casing through the gap around the bottom lid. It's easy to do. Then, when water infiltrates into the casing, the infiltrated water reacts with the quick lime charged in the casing before the casing is pulled up, and the solidifying slaked lime generated by the reaction takes root in the ground, and Even if you try to raise the price, there may be cases where it cannot be raised. Therefore, it is necessary to provide means for preventing water from entering the casing when the casing penetrates into the ground.

As described above, Japanese Patent Publication No. 56-53048 discloses a pile forming device equipped with a means for preventing water from entering the casing. In this pile forming device, a partition member consisting of a butterfly valve is pivotally mounted in the lower end portion of the casing so as to be openable and closable, and the partition member is driven to open and close by a fluid pressure cylinder. When it penetrates, the partition member is closed to prevent water from entering the inside of the casing, the casing reaches a predetermined depth, and after the soil improvement agent is put into the casing, the partition member is opened by a fluid pressure cylinder. However, as the casing is pulled up, the soil conditioner in the casing is discharged into the ground from its lower end.

However, in this conventional pile forming device, since the partition member is mechanically driven by the cylinder, the manufacturing cost is high, and the driving cylinder is immersed in the mud or muddy water in the lower end of the casing, and the soil Therefore, there is a problem in that it is easy to fail due to the influence of the above, and frequently requires repair.

In view of the above problems, the present invention is a disposable type, but the cost is extremely low, the installation in the lower end of the casing is easy and easy, and it is possible to reliably prevent the intrusion of water into the casing. An object is to provide a pile forming device provided with a watertight plate.

(Means for Solving Problems) In order to achieve the above-mentioned object, the present invention provides a lower end of a casing 2,41 which is disposed below a machine frame 1 suspended by a leader and penetrates into the ground. A bottom lid 32 is arranged to be openable and closable in the section, and a pile forming device in which the hoppers 10 and 46 for feeding a soil improvement agent such as quick lime are placed on the upper portions of the casings 2 and 41 thereof, of the casings 2 and 41. A flexible watertight plate 34 whose outer peripheral edge elastically adheres to the inner peripheral surface of the casing and closes the lower end of the casing is inserted into the lower end portion so that the flexible watertight plate 34 can be dropped by its weight when the soil improvement agent is put into the casing. It adopts the structure of wearing.

(Operation) According to the above configuration, the casing 2, 41 is formed before the pile is constructed.
By inserting the flexible watertight plate 34 into the lower end of the
The lower ends of the casings 2,41 are closed. Next, in a state where the lower ends of the casings 2,41 are closed by the bottom lid 32, the casings 2,41 are allowed to penetrate into the ground, and then the hoppers 10,46.
After pouring a soil improvement agent such as quick lime into the casings 2,41 from, when the casings 2,41 are pulled up, the bottom lid 32 is opened because the earth pressure of the ground does not act, and the watertight plate 34 is the casings 2,41. Due to the weight of the soil improvement agent put inside, it automatically comes off from the lower end of the casing 2,41 and falls into the ground,
Then, the soil conditioner is left in the ground, and the water in the ground reacts with the soil conditioner to form the pile.

(Embodiment) Next, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 shows a pile forming device. In this figure, 1 is a machine frame suspended up and down by a leader (not shown) installed upright on a crawler crane, and 2 is a machine frame 1 below. A screw 3 is screwed over the entire length of the outer peripheral surface of the hanging rotating casing. Reference numeral 4 denotes a hollow shaft-shaped inner rod that is inserted from inside the machine frame 1 along the central axis of the rotary casing 2. The upper end of the inner rod 4 is a vertical drive means 5 for vertically moving the inner rod 4 for a predetermined stroke. And a vibrator 6 at the lower end. Between the machine casing 1 and the rotary casing 2, there are provided a cylindrical fixed casing 7 having substantially the same diameter as the rotary casing 2 and a diameter sufficiently smaller than the fixed casing 7 and substantially the same length. Between the fixed casing 7 and the intermediate pipe 8, a cylindrical fixed intermediate pipe 8 concentrically arranged in a state of being fitted to the inner rod 4 is interposed in the fixed casing 7. The upper end portion of the fixed pipeline 9 formed in 1 is communicated with the hopper 10 for feeding the soil improvement agent such as quick lime provided in the machine frame 1, and the lower end portion is open in the rotary casing 2. . Reference numeral 11 denotes a connecting sleeve that is rotatably fitted between the fixed middle tube 8 and the inner rod 4. The upper end of the connecting sleeve is rotatably held and rotated by a bearing device 12 provided in the machine frame 1. As shown in FIG. 4, the lower end portion of the rotary casing 2 is connected to the drive unit 13 in an interlocking manner, and the lower end portion is integrally formed with the upper end portion of the rotary casing 2 via a plurality of connecting pieces 14 arranged radially below the fixed middle pipe 8. The rotation driving force of the rotation driving device 13 is transmitted to the rotation casing 2 through the connection sleeve 11 and the connection piece 14 to rotate the rotation casing 2.

The vertical drive means 5 has hydraulic or pneumatic cylinders 15, 15 installed on both sides of the inner rod 4 in the machine frame 1,
The piston rods 15a, 15a of the cylinders 15, 15 are fixed at their upper ends to the movable rod 16 which is fixed to the upper end of the inner rod 4 and is vertically slidable with respect to the machine frame 1. The inner rod 4 is moved up and down by a vertical expansion and contraction operation of a fixed stroke of 15a.
Instead of such a cylinder device, a so-called air spring device may be used as the vertical drive means. Rotation drive means 13
Is a gear 19 fixed to the output shaft 18 of the electric motor 17 installed in the machine frame 1, for example, meshed with a gear 20 fixed to the upper end of the connecting sleeve 11, and the gears 19 and 20 are rotated by the rotation of the electric motor 17. The connecting sleeve 11 is rotated via the connection sleeve 11. The upper end of the fixed casing 7 is the lower mount 1a of the machine frame 1.
The upper end of the fixed middle tube 8 is fixed to the hopper 10 or the machine frame 1, and the upper end of the rotary casing 2 is connected to the connecting sleeve 11 via the connecting piece 14 as described above. It is rotatably supported by the lower end of the fixed casing 7 via a bearing 21.

As shown in FIG. 5, the vibrator 6 includes an electric motor 23 arranged in a cylindrical flot body 22 and the electric motor 23.
The eccentric shaft body 24 integrally connected to the output shaft of the shaft 23 is mounted on the shaft 23. Vibration is generated. The flot body 22 is connected to the lower end of the inner rod 4 via a coupling 25. Further, the cap tire (power cord) 26 for the electric motor 23 is provided from the upper end required portion of the inner rod 4 to the hollow portion 27 of the inner rod 4.
It is inserted inside. There is a possibility that the inner rod 4 may be damaged by the soil-improving agent such as quick lime that is compacted at the lower end of the rotary casing 2 and the inner rod 4 may be damaged. The upper inner rod 4a is divided into an upper inner rod 4a and a lower inner rod 4b rotatably connected to the upper inner rod 4a. As shown in FIG. 6, the upper inner rod 4a has a large connecting diameter at the lower end thereof. The pipe portion 28 is integrally connected, and the upper end portion of the lower inner rod 4b is rotatably connected to the large diameter pipe portion 28 via a bearing 29 so as to support the lower inner rod 4b in a suspended state. . A so-called slip ring 30 slidable between each other is provided between the outer peripheral surface of the upper end portion of the lower inner rod 4b and the inner peripheral surface of the large diameter pipe portion 28 for connection, and the cap tire 26 is mounted via the slip ring 30. It is inserted in the lower inner rod 4b. Therefore, even if the lower inner rod 4b rotates, the cap tire
There is no inconvenience that 26 is twisted.

As shown in FIG. 1, a bottom cover 32 is openably and closably arranged at the lower end of the rotary casing 2, and, as shown in FIGS. 1 and 2, on the inner peripheral surface of the lower end of the rotary casing 2, A plurality of (four in this embodiment) stoppers 33 made of round bars are welded at predetermined intervals in the circumferential direction. A disc-shaped flexible watertight plate 34 made of rubber or synthetic resin as shown in FIG.
The outer peripheral edge of the watertight plate 34 is elastically brought into close contact with the inner peripheral surface of the rotary casing 2 until it hits the bottom of the rotary casing 2. In this embodiment, in order to improve the adhesion of the outer peripheral edge of the watertight plate 34 to the rotating casing 2, the outer peripheral edge of the watertight plate 34 is provided with cuts 35 at predetermined intervals and the watertight plate 34 is rotated. When it is inserted into the casing 2, its outer peripheral edge is bent, and the bent outer peripheral edge is elastically brought into close contact with the inner peripheral surface of the rotary casing 2. In FIG. 1, reference numeral 36 denotes a dead weight type detection device, which has a dead weight W placed on the surface of the soil improvement agent charged in the rotary casing 2 and one end of the dead weight W.
A cord 37 connected to the cord 37 and a measuring machine 38 that uses an encoder or the like to wind the other end of the cord 37 so as to always maintain a constant tension, and the cord wound by the measuring machine 38. body
Measure the height of the surface S and its change from the length of 37,
This is to detect whether or not the pile is properly constructed.

The bottom lid 32 is formed by screwing two half-split bodies 32a, 32a, which are formed by vertically dividing a hollow inverted conical body into two, to the lower end of the rotary casing 2. When the rotating casing 2 is suspended above the ground, it is open as shown by the solid line in FIG. 1, and when the rotary casing 2 penetrates into the ground, it is an inverted cone as shown by the phantom line in FIG. When the rotary casing 2 is pulled up in the ground, it takes an open position shown by a solid line in the figure.

In the operation of the pile forming apparatus having the above-described structure, first, the machine frame 1 is suspended and supported at a proper height from the top of a leader (not shown), and the cylinders 15 serving as the up-and-down drive means 5 are provided.
The piston rod 15a is held in the extended position (raised position), thereby fixing the inner rod 4 in the fixed position. Further, the watertight plate 34 is inserted into the lower end portion of the rotary casing 2 until it hits the stopper piece 33, and the outer peripheral edge of the watertight plate 34 is elastically brought into close contact with the inner peripheral surface of the rotary casing 2.
As a result, the lower end of the rotary casing 2 is closed by the watertight plate 34.

Next, the rotary drive device 13 is operated to rotate the rotary casing 2 through the connecting sleeve 11, and the lifting operation wire is fed out. When the bottom cover 32 at the lower end of the rotary casing 2 hits the ground, the bottom cover 32 closes as shown by the phantom line in FIG. 1, and the rotary casing 2 penetrates into the ground while rotating like a screw. Go. At this time, even if water enters the bottom lid 32 through the gap around the bottom lid 32, the watertight plate 34 prevents the intruded water from entering the rotary casing 2.

As described above, when the rotary casing 2 is penetrated into the ground to a predetermined depth, the wire feeding is stopped and the casing 2 is rotated as it is. A soil conditioner such as quick lime is charged through a fixed conduit 9 between the upper and lower parts, while the vertical drive device 5 and the vibrator 6 are operated, and the rotating casing 2 is pulled out while winding the lifting operation wire. enter. Then, the bottom lid 32 is opened by the weight of the soil conditioner and the watertight plate 34 is disengaged from the rotary casing 2 and falls, as shown by the solid line in FIG. Therefore, the soil improvement agent charged into the rotary casing 2 is crushed and finely compacted by the vertical movement of the inner rod 4 and the lateral vibration of the vibrator 6, and the casing 2 is pulled out with the extraction operation of the casing 2. It is extruded from the lower end of the in a compacted state and reacts with the water in the ground to form a strong pile (so-called chemical pile) in the ground. At the time of this withdrawal, a weight detecting device is used to check whether the soil conditioner is being smoothly lowered to the lower part of the rotating casing 2 and is being surely extruded from the lower end of the casing 2. Since the soil improvement agent is stored up to the fixed pipeline 9,
Since it does not move in the circumferential direction inside, the surface of the soil improvement agent can be properly detected even if the casing 2 is pulled up while being rotated.

A second embodiment of the present invention will be described with reference to FIGS. 7 and 8. The pile forming device of this embodiment has a rotary casing 40.
An upper end of a fixed casing 41 loosely fitted in the fixed casing 41 is fixed to the machine frame 1, and a vibrator 43 is concentrically arranged with the fixed casing 41 via a mounting frame 42 in the lower end of the fixed casing 41. Power cord 44 of vibrator 43 fixed casing
Insert it in the protection tube 45 that extends upward along the inner peripheral surface of 41,
Fixed tube between the upper end of fixed casing 41 and hopper 46
An on-off valve 48 is rotatably mounted on the valve 47, an air supply nozzle 49 is provided in the fixed tube 47, and the motor casing 52 rotates the rotating casing 40 via gears 50 and 51. Is provided. Then, similarly to the first embodiment, the stopper piece 33 is welded to the inner peripheral surface of the lower end portion of the fixed casing 41, and the lower end portion of the fixed casing 41 is
The watertight plate 34 is inserted until it hits the stopper piece 33, and the lower end of the fixed casing 41 is closed. Since the configuration other than the above is the same as that of the first embodiment, the same reference numerals are given and the description thereof is omitted.

In the above structure, when constructing the pile, as in the case of the first embodiment, the watertight plate 34 is inserted into the lower end portion of the fixed casing 41 to close the lower end portion thereof, and then the electric motor 52
Thus, the rotary casing 40 is rotated and the machine casing 1 is lowered to penetrate the rotary casing 40 into the ground.
Then, when the predetermined depth is reached, a soil improving agent such as quick lime is charged into the fixed casing 41 from the hopper 46, and after the charging is completed, air is pressed into the fixed pipe 47 from the air supply nozzle 49. Then, the opening / closing valve 48 is rotated upward by the air pressure, and the upper end of the fixed tube 47 is closed. The air pressure also applies pressure to the soil conditioner. At the same time, the vibrator 43 is activated to give vibration to the soil improvement agent. When the casings 40 and 41 are pulled up by raising the machine casing 1, the bottom lid 32 is opened, and the watertight plate 34 is disengaged from the lower end portion of the fixed casing 41 by the air pressure and the weight of the soil conditioner and falls. Therefore, the soil improvement agent put into the fixed casing 41 is pushed out from the fixed casing 41 while being crushed and densely compacted by the air pressure and the lateral vibration of the vibrator 43, and reacts with the water in the ground. A strong, so-called chemical pile is formed.

Although the vibrators 6 and 43 are used in the first and second embodiments, they may be omitted. In particular, according to the second embodiment,
Since air pressure is applied, the air pressure and vibrator 43
Of these, either one can be omitted.

(Effect of the Invention) According to the pile forming device of the present invention, the flexible watertight plate is inserted into the lower end portion of the casing, and the outer peripheral edge of the watertight plate is elastically adhered to the inner peripheral surface of the casing. Since the lower end of the casing is closed, when the casing is penetrated to a predetermined depth in the ground when constructing a pile, the water that enters from the gap of the closed bottom lid is Intrusion of the watertight plate into the casing is prevented. Thus, the flexible watertight plate can be automatically disengaged from the casing and dropped into the ground due to the weight of the soil improvement agent introduced into the casing after the casing is penetrated to a predetermined depth.

Thus, although the flexible watertight plate is a disposable type, it can be formed by using an appropriate flexible plate material so as to have an outer peripheral shape corresponding to the inner peripheral shape of the casing. Compared with the conventional partition member consisting of a butterfly valve of the type described above, it is significantly simpler and easier to manufacture and can be provided at a very low cost. Moreover, this watertight board
Since it is flexible and only needs to be inserted so that its outer peripheral edge is in close contact with the inner peripheral surface of the lower end portion of the casing, it is easy and easy to attach it to the casing, and the water inside the casing is also easily attached. Can be reliably prevented from entering.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention, FIG. 1 is a vertical sectional view of a pile forming device, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG. A perspective view of a watertight plate used in a pile forming device,
FIG. 4 is a view taken along the line IV-IV in FIG. 1, FIG. 5 is a vertical cross-sectional view of a vibrator used in a pile forming device, and FIG. 6 is an enlarged vertical cross-sectional view of a main part of an inner rod used in the pile forming device. Is. 7 and 8 show a second embodiment of the present invention, FIG. 7 is a vertical cross-sectional view of a pile forming device, and FIG. 8 is a view on arrow VIII-VIII of FIG. 1 ... Machine frame, 2 ... Rotating casing, 10,46 ... Hopper, 32 ... Bottom lid, 34 ... Watertight plate, 41 ... Fixed casing.

Claims (1)

[Scope of utility model registration request] 1. A bottom cover is provided at the lower end of a casing that is placed below a machine frame suspended from a leader and penetrates into the ground, and a bottom lid is openably attached to the casing. In the pile forming device in which a hopper for feeding the improving agent is arranged, in the lower end portion of the casing, a flexible watertight plate that closes the lower end portion of the casing by elastically adhering the outer peripheral edge to the inner peripheral surface of the casing is provided. A pile forming device, which is inserted and attached so that the soil improving agent can be removed by its weight when the soil improving agent is put into the pile.