JPH0633442A - Sand piling device - Google Patents

Abstract

PURPOSE:To efficiently remove excavated soil produced through pilling of a casing, to improve effective remove of sand from the bottom of the easing at the time of raising the casing and to compact the sand discharged. CONSTITUTION:A easing 2 consisting of an outer easing 3 and an inner easing 4 are vertically connected to the bottom of a housing 1, and a space 5 for introducing excavated soil is formed between the easing 3 and the casing 4. A center rod 6 which vertically penetrates the housing 1 is installed in the casing 4 and a vibration exciter 7 is connected with the top of the rod 6 which protrudes upwards from the housing 1 and an air spring 8 is mounted in bet the exciter 7 and the housing 1, and an excavated soil-discharge holes 19 are provided in the easing 3. An air-jetting pipe 20 is installed along the periphery of the easing 4 to emit jet air from the holes 19 and a set of easing covers 27 for opening and closing is installed in the bottom of the casing 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand pile forming apparatus for forming a sand pile made of sand, gravel, gravel or the like (hereinafter, simply referred to as sand) in the ground in order to improve soft ground.

[0002]

2. Description of the Related Art Conventionally, in this type of construction method, a casing having an opening / closing lid at its lower end is driven into the ground while vertically vibrating or rotating to make a hole, and after a required depth is dug, the casing is pulled up. At the same time, the sand, etc. supplied into this casing is discharged from the lower end to create sand piles in the ground.However, when the casing is driven into the digging, the lower end opening of the casing is closed, so The soil is discharged from the outer periphery of the lower end of the casing through a narrow gap between the casing and the dug hole. For this reason, it is difficult to smoothly remove the soil, and therefore, the driving speed of the casing becomes slow, and the construction work efficiency is very poor.

In view of the above problems, the present invention makes it possible to efficiently discharge the excavated soil when driving the casing, thereby increasing the driving speed of the casing and improving the efficiency of construction work. It is an object of the present invention to provide a sand pile forming device capable of promoting effective discharge of sand from the lower end of the casing in (1) and compacting the discharged sand to form a consolidated and strong sand pile.

[0004]

The sand pile forming apparatus according to the present invention comprises an outer casing 3 and an inner casing 4 for concentrating sand, which is concentrically inserted in the outer casing 3 at the lower portion of the machine casing 1. The casing 2 is vertically connected, and a space 5 for introducing the excavated soil is formed between the inner and outer casings 3 and 4 from the lower end thereof, and the intermediate rod vertically penetrates the machine frame 1. 6 is inserted into the inner casing 4, and a vibration exciter 7 is connected to the upper end of the intermediate rod 6 projecting above the machine frame 1, and the vibrating machine 7 and the machine frame 1 are connected to each other. The outer casing 3 is provided with an air spring 8, and the outer casing 3 is provided with an excavated soil discharge hole 19, and an air ejection pipe 20 for ejecting jet air from the excavated soil discharge hole 19 is provided on the outer peripheral surface of the inner casing 4. Along the bottom of the inner casing 4, Pacing characterized by comprising providing a casing opening and closing lid 27 inner open when pulling closed by earth pressure at the time of driving.

[0005]

EXAMPLES Examples will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a cylindrical machine frame, and a casing 2 is provided so as to extend downward from the lower part of the machine frame 1. The casing 2 includes an outer casing 3 for a hole and the outer casing 3
And an inner casing 4 that is concentrically inserted in the inner casing 3. A space 5 for introducing the excavated soil is formed between the inner and outer casings 3 and 4 from the lower end thereof. A center rod 6 for sand compaction is concentrically inserted in the inside. The middle rod 6 penetrates the machine frame 1 vertically, and an upper end thereof projects above the machine frame 1. A vibrating machine 7 is connected to the upper end of the projecting middle rod 6 and the vibrating machine An air spring 8 is interposed between 7 and the machine casing 1.

Inside the machine frame 1, upper and lower parts 2 are provided with a middle wall 9 interposed therebetween.
An upper-stage sand storage tank 10 and a lower-stage sand storage tank 11 that are divided into stages are provided, and a bottom portion of the lower-stage sand storage tank 11 is integrally connected to the upper end of the inner casing 4 so as to communicate therewith. Further, the upper sand storage tank 10 has a partition wall (not shown) that passes through the central axis portion thereof, and the left and right tank portions 10 are
It is divided into a and 10b. Then, sand supply hoppers 12 are provided in communication with the upper portions of the left and right tank portions 10a, 10b of the upper sand storage tank 10, respectively, and the outlet side end portions of the hoppers 12 are opened and closed by an air cylinder 13, for example. An on-off valve 14 is provided. Also,
On the inner wall 9, an opening / closing valve 16 that is opened and closed by an air cylinder 15 similar to the above is provided at each communication port that communicates from the left and right tank portions 10a and 10b of the upper sand storage tank 10 to the lower sand storage tank 11. It is provided. 1
7 is each of left and right tank parts 10 of the upper sand storage tank 10.
Reference numeral 18 denotes an air nozzle for supplying air to a and 10b, and 18 denotes an air nozzle for supplying air to the lower sand storage tank 11.

As is apparent from FIGS. 1 and 2, the outer casing 3 has an excavated soil discharge hole for discharging the excavated soil introduced into the excavated soil introducing space 5 to the outside of the casing. A large number of holes 19 are provided over the substantially entire length of the casing 3 at regular intervals in the circumferential direction (for example, at intervals of 45 degrees), and the excavated soil introducing space 5 is provided.
A plurality of (for example, four) air ejection pipes 20 are vertically piped inside along the outer peripheral surface of the inner casing 4, and each air ejection pipe 20 has an air nozzle at a position corresponding to each excavated soil discharge hole 19. 21 is provided so that jet air is ejected from each excavated soil discharge hole 19.

A fixed plate 23 is mounted and fixed on the upper surface of the machine frame 1 via a pedestal 22, and columns 24 are erected at the four corners of the fixed plate 23. A movable plate 25 is moved up and down on these columns 24. The exciter 7 is mounted and fixed at the center of the movable plate 25, and the pedestal 22 and the fixed plate 23 are supported.
The upper end of the intermediate rod 6 extending upwards through the respective central portions thereof is integrally connected to the exciter 7 via the movable plate 25, and between the movable plate 25 and the fixed plate 23. Well-known bellows type air springs 8 are provided at four positions in front, rear, left and right thereof. In FIG. 1, 26 is the movable plate 2
It is a bellows-like cover that protects the center rod 6 between the fixing plate 5 and the fixing plate 23.

The air spring 8 is appropriately controlled by the air pressure control means. When the internal pressure of the air spring 8 is set to the maximum fully extended condition as shown in FIG. 8 acts as a vibration transmitting means, and therefore the vibration generated by the exciter 7 is transmitted from the movable plate 25 through the air spring 8, the fixed plate 23, the pedestal 23 and the machine frame 1 to the casing 1 (the outer casing 3 and the inner casing 3). It will be transmitted to the casing 4). Also this air spring 8
The internal pressure of the stroke of the maximum extension (eg 600c
stroke shorter than m) (eg 450 cm)
When it is set to be able to expand and contract, the air spring 8 acts as a damper, so that the vibration from the exciter 7 is not transmitted to the casing 1. The exciter 7
Is always transmitted to the center rod 6. Further, if the air spring 8 is expanded and contracted with the short stroke as the maximum stroke, the center rod 6 can be moved up and down.

As shown in FIG. 1, an inner casing opening / closing lid 27 consisting of a pair of half-moon shaped plates is attached to the lower end of the inner casing 4, and the lid 27 is normally attached by its own weight. In the open position forming an inverted V-shape as shown by the solid line in FIG. 2, when the casing 2 is driven in, it is configured to be closed by earth pressure so as to close the lower end of the inner casing 4 as shown by the phantom line in the figure. There is.

In the upper sand storage tank 10 and the lower sand storage tank 11, well-known weight type sand surface detectors 28,
29 are deployed. In FIG. 1, 30 is an upper plate attached to the upper ends of columns 24 standing on the four corners of the fixed plate 23, and 31 is a cylindrical cover body for protecting the upper end side of the intermediate rod 6. It is provided at the center of the upper sand storage tank 10.

Next, a method of constructing a sand pile by using the apparatus having the above-described structure will be described. First, a casing 2 is raised while a lifting operation wire (not shown) is fed from the top of the leader to lower the entire apparatus. When driving the casing 2, the vibrator 8 is operated and the air spring 8 is set to the maximum tension as shown in FIG. The vibration is transmitted to the casing 2, that is, the outer casing 3 and the inner casing 4, and while vibrating these casings 3 and 4 up and down, the ground is excavated at the lower end of the outer casing 3 and driven. The opening / closing valves 14 and 16 are opened in advance before the driving of the casing 2, and the inner casing opening / closing lid 2 is opened when the driving of the casing is started.
When 7 is closed by earth pressure, sand for sand pile construction is supplied from each hopper 12 to each of the left and right tank parts 10 of the upper sand storage tank 10.
It is thrown into the inner casing 4 through a, 10b and the lower sand storage tank 11.

When the ground is excavated at the lower end of the outer casing 3 as described above, the excavated soil is introduced from the lower end of the casing 2 into the excavated soil introducing space 5, The introduced excavated soil is forcibly discharged from the excavated soil discharge holes 19 of the outer casing 3 to the outside of the outer casing 3 by jet air ejected from the air nozzles 21,
It is attached to the wall surface of the hole H. In this case, since a large number of excavated soil discharge holes 19 are arranged from the lower portion to the upper portion of the outer casing 3, the excavated soil that cannot be discharged through the excavated soil discharge holes 19 on the lower side is sequentially excavated on the upper side. Soil discharge hole 19
Discharged from the ground and stay in the excavated soil introduction space 5,
It won't get stuck.

When the casing 2 reaches the required depth in the ground as described above, the supply of air to each air ejection pipe 20 is stopped and the ejection of jet air from each air nozzle 21 is stopped. The exciter 7 continues to operate, and the air spring 8 sets the internal pressure of the air spring 8 so that it can expand and contract with a stroke that is appropriately shorter than the stroke at the time of maximum expansion when driving the casing. As a result, the air spring 8 acts as a damper, so that the vibration from the exciter 7 is not transmitted to the casing 1 and the middle rod 6
Only the chisel vibrates vertically due to the vibration of the exciter 7. In this case, the air spring 8 may be vertically expanded and contracted by continuously supplying and discharging air to and from the air spring 8 to move the intermediate rod 6 up and down as shown by the phantom line in FIG.

The sand for forming the sand piles is usually (when the length of the sand piles to be formed is relatively short), and the sand is usually placed in the upper sand storage tank 10 by the time the driving of the casing 2 is completed. Supply until a fixed amount is reached. The amount of sand supplied at this time is measured by the weight type sand surface detector 28. That is, when the sand reaches a predetermined amount, the sand surface detector 28 operates,
A signal is given to instruct to stop the sand supply from the sand supply hopper 12. The open / close valve 14 is closed by the detection signal, and the upper sand storage tank 1
The supply of air from the upper air nozzle 17 is started,
As a result, the upper space in the tank 10 is pressurized and presses the supplied sand.

When the lifting wire is raised and the casing 2 is pulled up, the inner casing 4
The sand inside is pressed by the pressure air in the upper space in the upper sand storage tank 10 from above and the vibration of the center rod 6 transmitted from the vibration exciter 7 causes the inner casing 4 to move. It is quickly extruded from the bottom edge of the sand and forms sand piles in the hole. In this case, in particular, the middle rod 6 not only promotes effective discharge of sand from the lower end of the inner casing 4 by its vertical vibration action, but also compacts the sand extruded into the pit, thereby consolidating and strengthening it. Form a sand pile.

When the length of the sand pile to be constructed is short, a predetermined amount of sand is supplied into the inner casing 4 by the end of the driving of the casing 2, as described above, in the upper sand storage tank 10. However, there is a case where the sand pile becomes long and one time supply until the end of driving the casing is not enough. In such a case, the sand is supplied several times during the drawing of the casing.

At the time of supplying the sand during the extraction, it is necessary to seal the upper space of the sand supplied into the inner casing 4 and pressurize the sand. Therefore, first, the upper sand storage tank 10 and the lower sand are stored. Inner wall 9 that separates from the storage tank 11
The lower opening / closing valve 16 on the lower side is closed and the upper opening / closing valve 14 is opened. In this state, the sand is supplied from the sand supply hopper 12 into the upper sand storage tank 10 to lower the lower end of the inner casing 4. When the amount of sand in the lower sand storage tank 11 decreases and the sand surface position drops to a predetermined position due to the discharge of sand from the sand, the lower sand surface detector 29 detects this and the lower sand The open / close valve 16 is opened, the sand supply from the sand supply hopper 12 is stopped, and the open / close valve 14 on the upper stage side is opened.
Close. As a result, the sand in the upper sand storage tank 10 flows down into the lower sand storage tank 11 and is supplied into the inner casing 4. Then, when the sand surface position in the upper sand storage tank 10 is lowered to a predetermined position, this is detected by the sand surface detector 28 on the upper shelf or another suitable level detector,
Thereby, the lower opening / closing valve 16 is closed, the upper opening / closing valve 14 is opened, and the sand is again supplied from the sand supply hopper 12 into the upper sand storage tank 10. By repeating such an operation, sand can be continuously supplied into the inner casing 4 according to the length of the sand pile to be constructed.

The upper sand storage tank 10 is divided into left and right tank portions 10a and 10b, and a sand supply hopper 12 is provided for each of the tank portions 10a and 10b. 10a and 10b may be used alternately.

[0020]

According to the present invention, when driving the casing, the exciter is actuated and the air spring is fully stretched to the maximum extent so that the vibration of the exciter is transmitted through the casing to the casing. Then, while vibrating this casing, the ground is excavated and driven into. Then, the excavated soil is introduced from the lower end of the casing into the space for introducing the excavated soil, and the introduced excavated soil is ejected from each excavated soil discharge hole of the outer casing to the outside of the casing by the jet air jetted by the air jet pipe. Forced out
It is attached to the wall of the pit.

When the hole is drilled to the required depth in the ground as described above, the air spring is made to have a stroke appropriately shorter than the stroke at the maximum extension when the casing is driven, while the operation of the exciter is continued. Set. As a result, the air spring acts as a damper, and the vibration from the vibration exciter is not transmitted to the casing, and only the middle rod vibrates. Then, pulling up the casing,
The sand in the inner casing is rapidly pushed out from the lower end of the inner casing due to the vibration action of the intermediate rod, and sand piles are formed in the drill hole. In this case, the intermediate rod not only promotes effective discharge of sand from the lower end of the inner casing by its vibration action, but also compacts the sand pushed out into the pit,
As a result, a consolidated and strong sand pile is formed.

As described above, according to the present invention, since the excavated soil is forcibly introduced into the excavated soil introduction space during the driving of the casing and discharged from the excavated soil discharge hole, the driving speed of the casing can be increased, As a result, the efficiency of creation work can be improved. In this case, since the excavated soil discharged from the excavated soil discharging hole is attached to the wall surface of the hole, collapse of the wall surface of the hole can be prevented. Then, when the casing is pulled up, by vibrating the middle rod, the effective discharge of sand from the lower end of the inner casing is promoted, and the sand pushed out into the digging hole is compacted, thereby forming a consolidated and solid sand pile. You can

Further, between the upper end of the fixed casing and the sand supply hopper, an upper-stage sand storage tank and a lower-stage sand storage tank, which are pressurizable and communicable with each other, are connected in series, and the upper stage of the hopper is provided. When an opening / closing valve is provided in each of the communication part to the side sand storage tank and the communication part to both sand storage tanks, the lower opening / closing valve is closed to supply sand from the lower sand storage tank to the fixed casing. Between,
Sand is temporarily stocked by supplying sand from the hopper to the upper sand storage tank.When the sand in the lower sand storage tank decreases, the lower open / close valve is opened and the upper open / close valve is closed to close the upper sand. By supplying the sand in the storage tank to the lower sand storage tank, it is possible to continuously supply the sand while constantly pressurizing the sand to be supplied into the fixed casing from above.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a sand pile building device showing an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

 1 Machine Frame 2 Casing 3 Outer Casing 4 Inner Casing 5 Space for Introducing Excavated Soil 6 Middle Pipe 7 Vibrator 8 Air Spring 10 Upper-stage Sand Storage Tank 11 Lower-stage Sand Storage Tank 12 Sand Supply Hopper 14 Open / close valve 16 Open / close valve 19 Excavated soil discharge hole 20 Air jet pipe 27 Inner casing opening / closing lid

Claims (2)

[Claims] 1. A casing consisting of an outer casing and a sand-filling inner casing concentrically inserted in the outer casing is hung and continuously connected to the lower part of the machine frame, and the lower end is provided between the inner and outer casings. A space for introducing excavated soil is formed to introduce more excavated soil, and a sand compaction center rod vertically penetrating the machine frame is inserted downward into the inner casing, and above the machine frame. An exciter is connected to the upper end of the projecting middle rod, an air spring is interposed between the exciter and the machine frame, and an excavated soil discharge hole is provided in the outer casing, and the excavated soil is excavated. An air ejection pipe for ejecting jet air from the discharge hole is laid along the outer peripheral surface of the inner casing, and at the bottom of the inner casing, an inner casing opening / closing lid that is closed by earth pressure when driving the casing and opened when pulling up is opened. Provided Sand pile building equipment. 2. An upper-stage sand storage tank and a lower-stage sand storage tank, which can be pressurized and communicate with each other, are connected between the upper end of the inner casing and the sand supply hopper, and the upper stage of the hopper. The sand pile forming device according to claim 1, wherein an opening / closing valve is provided in each of the communication portion to the side sand storage tank and the communication portion to both sand storage tanks.