JPH0823137B2 - Sand pile building equipment - Google Patents

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 enables the excavated soil to be efficiently discharged when driving the casing, thereby increasing the driving speed of the casing and improving the construction work efficiency, and further raising the casing. An object of the present invention is to provide a sand pile building device that can effectively discharge sand from the lower end of the casing at the time.

[0004]

A sand pile forming apparatus according to the present invention comprises a rotary casing 3 which is rotated by a rotary drive means 2 at a lower portion of a machine frame 1, and the rotary casing which is inserted into the rotary casing 3 to be rotated. 3 and a fixed casing 5 for sand injection that forms a space 4 for introducing the excavated soil are connected in a hanging manner, and the inside of the fixed casing 5 is for jetting air for jetting jet air from the lower end thereof. The pipe 6 is inserted and arranged, the excavated soil discharge hole 18 is formed in the rotary casing 3, and the air jet pipe 19 for jetting jet air from the excavated soil discharge hole 18 is provided on the outer peripheral surface of the fixed casing 5. A fixed casing opening / closing lid 22 is provided at the bottom of the fixed casing 5 and is closed by earth pressure when the casing is driven in and opened when pulled up.

[0005]

EXAMPLES Examples will be described with reference to the drawings.
In FIG. 1, reference numeral 1 denotes a cylindrical machine frame, which is not shown in the drawings, but is suspended from the top of the leader via a lifting wire while being guided by the side surface of the leader. In the lower part of the machine casing 1, a rotary casing 3 rotated by the rotary drive means 2 and a space 4 for introducing excavated soil is formed between the rotary casing 3 and the rotary casing 3 concentrically inserted therein. A fixed casing 5 for sand injection is installed in a hanging manner. Inside the fixed casing 3, an air jetting middle pipe 6 for jetting jet air from the lower end of the fixed casing 3 is concentrically inserted and arranged.

Inside the machine frame 1, there are provided an upper sand storage tank 8 and a lower sand storage tank 9 which are divided into upper and lower stages through an inner wall 10, and a bottom portion of the lower sand storage tank 9 is provided. It is connected to the upper end of the fixed casing 5 for communication. The upper sand storage tank 8 is divided into left and right tank portions 8a and 8b by a partition wall (not shown) that passes through the central axis portion thereof. Then, sand supply hoppers 11 are provided in communication with the upper portions of the left and right tank portions 8a, 8b of the upper sand storage tank 8, and the outlet side end portions of the hoppers 11 are opened and closed by an air cylinder 12, for example. An on-off valve 13 is provided. In addition, an opening / closing valve that is driven to open and close by the same air cylinder 14 as described above is provided at each of the communication ports on the inner wall 10 that communicate from the left and right tank portions 8a, 8b of the upper sand storage tank 8 to the lower sand storage tank 9. 15 are provided. Incidentally, 16 is the upper sand storage tank 8
Air nozzles for supplying air to the left and right tank portions 8a, 8b, and 17 are air nozzles for supplying air to the lower sand storage tank 9.

The rotating casing 3 has a structure shown in FIGS.
As is clear with reference to FIG.
A large number of excavated soil discharge holes 18 for discharging the excavated soil introduced into the casing to the outside of the casing 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). The space for introducing the excavated soil 4
A plurality of (for example, four) air ejection pipes 19 are vertically arranged along the outer peripheral surface of the fixed casing 5, and each air ejection pipe 19 is provided at a position corresponding to each of the excavated soil discharge holes 18. An air nozzle 20 is provided, and each excavated soil discharge hole 18
It is designed to eject more jet air.

A pair of digging blades 21 are fixed to the lower end of the rotary casing 3 at diametrically opposite positions by welding or the like, and each digging blade 21 has a cutting edge 21a at the lower end, as shown in FIG. However, the cutting edge 21a has an outer end projecting outward from the outer peripheral surface position of the rotating casing 3 and an inner end projecting sufficiently inward from the inner peripheral surface position of the fixed casing 5 to have its outer end. To the inner end so as to cross both casings 3, 5. Further, the entire side surface of each excavating blade 21 is, for example, 30 with respect to the vertical plane passing through the central axis of the rotating casing 3.
The arrangement is such that the inclination is about -40 degrees and the inner end side is tilted by 20 to 30 degrees in the rotation direction of the rotary casing 3.

At the lower end of the fixed casing 5, as shown in FIGS. 1 and 3, a fixed casing opening / closing lid 2 in which a pair of half-moon shaped plates 22a, 22a are pivotally attached by a hinge 22b.
2 is attached, and this lid 22 is always in an open position which forms an inverted V shape as shown by the solid line in FIG. 1 by its own weight, and at the time of driving the casing, it is fixed by the earth pressure as shown by the phantom line in FIG. It is configured to close the lower end of 5 to close it.

The air jetting middle pipe 6 penetrates the upper wall portion of the upper sand storage tank 8 through the central portions of both tanks 8 and 9 and is suspended in the fixed casing 5. The upper end of the pipe 6 is attached to a connection block 7 attached to the upper wall of the upper sand storage tank 8, and air is supplied to the air injection middle pipe 6 through the block 7.

The rotation driving means 2 is composed of a pair of electric motors 24 arranged on the machine frame 1 on both sides and a gear transmission mechanism 25. In the upper sand storage tank 8 and the lower sand storage tank 9, a well-known weight type sand surface detector 26,
27 are deployed. In FIG. 1, 28 is a cylindrical cover body for protecting the upper end portion of the air jetting inner tube 6,
It is provided at the center of the upper sand storage tank 8.

Next, a method of constructing a sand pile by using the apparatus having the above-mentioned structure will be explained. First, the wire for raising and lowering operation is fed out to lower the entire apparatus, and the rotary casing 3 is rotated to excavate the ground. Meanwhile, the rotary casing 3 is driven into the ground together with the fixed casing 5. At the same time when the casing is started to be driven, air is supplied to each of the air ejection pipes 19 and each of the air nozzles 2
Jet air is jetted from 0 respectively. The on-off valves 13 and 15 are opened in advance prior to the driving of the casing, and when the fixed casing opening / closing lid 22 is closed by earth pressure at the start of the driving of the casing, the sand for sand pile formation is removed from each hopper. From 11 through the left and right tank portions 8a, 8b of the upper sand storage tank 8 and the lower sand storage tank 9, the solid sand is loaded into the fixed casing 5.

When the ground is excavated by the rotation of the rotary casing 3, the excavated soil is introduced into the excavated soil introducing space 4 from the lower end of the rotary casing 3, and the introduced excavated soil is Each of the excavated soil discharge holes 1 of the rotating casing 3 by the jet air jetted from each air nozzle 20.
8 is forcibly discharged to the outside of the casing and adhered to the wall surface of the hole H. In this case, since a large number of excavated soil discharge holes 18 are arranged from the lower portion to the upper portion of the rotary casing 3, the excavated soil that cannot be discharged through the excavated soil discharge holes 18 on the lower side is sequentially excavated on the upper side. It is discharged from the soil discharge hole 18, and therefore stays in the space 4 for introducing the excavated soil,
It doesn't get stuck.

Further, in the excavation of the ground by the rotation of the rotary casing 3, the excavation is performed by the turning operation of the excavating blade 21 at the lower end of the rotary casing 3, so that the excavation can be performed quickly and efficiently, and a hard ground layer is encountered. Even if it is possible to dig easily. In particular, the digging blade 21 has an outer end projecting outward from the rotary casing 3 and an inner end projecting inward from the fixed casing 5 so as to traverse the casings 3, 5 inward and outward from the outer end to the inner end. Since the extending cutting edge 21a is formed, the ground is not limited to the peripheral portion of the rotating casing 3 but also the rotating casing 3
Most of the cross-sectional area surrounded by is to be excavated, so that the ground resistance applied to the lower ends of the rotating casing 3 and the fixed casing 5 during the excavation is significantly reduced, thereby making the casing driving operation easier and quicker. You will be able to do it.

When the rotary casing 3 has been dug to the required depth in the ground as described above, each air ejection pipe 19
The supply of air to the air nozzles is stopped, the jet of jet air from each air nozzle 20 is stopped, and the rotation of the rotary casing 3 is also stopped. In addition, normally (when the length of the sand pile to be constructed is relatively short), by the time the casing driving is completed,
The sand is supplied to the upper sand storage tank 8 until a predetermined amount is reached. The amount of sand supplied at this time is measured by the weight type sand surface detector 26. That is, when the amount of sand reaches a predetermined amount, the sand surface detector 26 operates and the sand supply hopper 11
Give a signal to stop the sand supply from. Further, the open / close valve 13 is closed by this detection signal, and the air nozzle 16 above the upper sand storage tank 8 is also provided.
The supply of air from the
The upper space inside is pressed and presses the supplied sand.

Then, the raising and lowering wires are operated to raise the rotary casing 3 together with the fixed casing 5. Simultaneously with this casing lifting operation, pressure air is supplied to the air jetting inner pipe 6 so that jet air is jetted from the lower end nozzle portion of the inner pipe 6. Therefore, as the casing is pulled up, the sand in the fixed casing 5 is pressed by the pressurized air in the upper space of the upper sand storage tank 8 and jetted from the lower end nozzle portion of the air jetting middle pipe 6. Due to the jetting action of air, it is strongly pushed out from the lower end of the fixed casing 5 to form a sand pile in the dug hole. In this case, in particular, the jet air jetted from the lower end of the air jetting middle pipe 6 not only pushes the sand in the fixed casing 5 stronger than its lower end, but also pushes the sand pushed out into the pit to strengthen the sand. Form a compact consolidation pile.

The supply of sand into the fixed casing 5 is
When the length of the sand pile to be constructed is short, it may be supplied so that a predetermined amount is accumulated in the upper-stage sand storage tank 8 by the end of driving the casing as described above, but the length of the sand pile is long. In some cases, supplying once until the end of driving the casing is not sufficient. In such a case, the sand is supplied several times during the drawing of the casing.

When supplying the sand during the extraction, it is necessary to seal the upper space of the sand supplied into the fixed casing 5 and pressurize it. Therefore, the upper sand storage tank 8 and the lower sand are first supplied. Inner wall 10 that separates from the storage tank 9
The lower opening / closing valve 15 on the lower side and the upper opening / closing valve 13 on the upper side are opened. In this state, the sand is supplied from the sand supply hopper 11 into the upper sand storage tank 8, and the lower end of the fixed casing 5 is closed. When the amount of sand in the lower-stage sand storage tank 9 decreases as the sand is discharged from the ground, and the sand surface position falls to a predetermined position, this is detected by the lower-surface sand surface detector 27, and the lower-surface sand detector 27 detects it. The open / close valve 15 is opened and the sand supply hopper 1
The supply of sand from 1 is stopped and the open / close valve 13 on the upper stage side is closed. As a result, the sand in the upper sand storage tank 8 flows down into the lower sand storage tank 9 and is supplied into the fixed casing 5. When the sand surface position in the upper sand storage tank 8 drops to a predetermined position, this is detected by the upper sand surface detector 26 or another suitable level detector, and the lower open / close valve 15 is thereby detected. And the upper opening / closing valve 13 is opened, and the sand is again supplied from the sand supply hopper 11 into the upper sand storage tank 8. By repeating such an operation, sand can be continuously supplied into the fixed casing 5 according to the length of the sand pile to be constructed.

The upper sand storage tank 8 is divided into left and right tank portions 8a and 8b, and a sand supply hopper 11 is provided for each of the tank portions 8a and 8b. 8a and 8b may be used alternately.

[0020]

According to the present invention, when the rotary casing is driven into the ground while being rotated, the excavated soil is introduced from the lower end of the casing into the space for introducing the excavated soil. The excavated soil thus obtained is forcibly discharged to the outside of the casing from each of the excavated soil discharge holes of the rotary casing by the jet air jetted by the air jet pipe, and attached to the wall surface of the dug hole. When the hole is dug to the required depth in the ground in this way, the sand casing is formed while the rotary casing is pulled up together with the fixed casing and the sand supplied into the fixed casing is discharged from the lower end thereof.

When the casing is pulled up, pressure air is supplied to the air jetting middle pipe to jet jet air from the lower end of the middle pipe, whereby the sand in the fixed casing 5 is strongly discharged from the lower end. , Forming sand piles in the hole. In this case, the jet air ejected from the lower end of the air ejecting middle pipe strongly pushes out the sand in the fixed casing from its lower end, effectively discharging the sand from the fixed casing, and By pressing the sand discharged to the, it is possible to form a firmly compacted consolidated pile.

As described above, according to the present invention, since the excavated soil is forcibly introduced into the excavated soil introduction space and discharged from the excavated soil discharge hole, the casing driving speed can be increased. Therefore, it is possible to improve the efficiency of construction work. 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. By jetting jet air from the lower end of the air jetting middle pipe when pulling up the casing, sand can be effectively discharged from the fixed casing, and a strong consolidation pile can be formed.

Further, by providing an excavating blade with a cutting edge of the tip portion projecting inward of the fixed casing at the lower end of the rotary casing, the ground excavates most of the cross-sectional area surrounded by the rotary casing during casing driving. Therefore, the ground resistance applied to the lower ends of the rotary casing and the fixed casing during the excavation is significantly reduced, whereby the casing driving operation can be performed more easily and quickly.

Further, between the upper end of the fixed casing and the sand supply hopper, an upper sand storage tank and a lower sand storage tank, which can be pressurized and communicate with each other, are connected in series, and the upper stage of the hopper is connected. 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 sectional view taken along line AA of FIG.

FIG. 3 is an enlarged sectional view taken along line BB of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Machine frame 2 Rotation drive means 3 Rotating casing 4 Excavation soil introduction space 5 Fixed casing 6 Air jetting middle pipe 8 Upper stage sand storage tank 9 Lower stage sand storage tank 11 Sand supply hopper 13 Open / close valve 15 Open / close valve 19 Air Spout pipe 21 Drilling blade 21a Cutting edge 22 Fixed casing opening / closing lid

Claims (3)

[Claims] 1. A rotary casing which is rotated by a rotary drive means at a lower portion of a machine frame, and a sand-filling space which is inserted into the rotary casing to form a space for introducing excavated soil between the rotary casing and the rotary casing. A fixed casing is provided so as to hang down, an air injection middle pipe for ejecting jet air from the lower end thereof is inserted and arranged in the fixed casing, and a drilling soil discharge hole is formed in the rotary casing.
An air jet pipe for jetting jet air from the excavated soil discharge hole is provided along the outer peripheral surface of the fixed casing, and the bottom of the fixed casing is closed by earth pressure when driving the casing and opened by the fixed casing. A sand pile forming device characterized by being provided with an opening / closing lid. 2. A cutting blade having an outer end projecting outside of the rotating casing and an inner end projecting inside of the fixed casing at a lower end of the rotating casing to form a cutting edge from the outer end to the inner end. Claim 1 which is provided with
The sand pile building device described in. 3. An upper-stage sand storage tank and a lower-stage sand storage tank, which are pressurizable and can communicate with each other, are connected between the upper end of the fixed casing and the sand supply hopper, and the upper stage of the hopper is provided. The sand pile forming apparatus according to claim 1 or 2, wherein an opening / closing valve is provided in each of the communication section to the side sand storage tank and the communication section to both sand storage tanks.