JPS60238523A - Remover for slime on bottom of pit for in-place pile - Google Patents

Abstract

PURPOSE:To simply remove deposited slime on the bottom a pit by a method in which plural openings are provided in the bottom plate of a hollow cylinder, the basal portion of an elastic plate is fixed to the upside of the bottom plate on the rear edge side of each opening, and a cover through which slime is discharged is provided to the body of the hollow cylinder. CONSTITUTION:When a kelly bar 22 is rotationally driven, a bit 4 provided to a bottom plate 2 is moved, and slime 17 below the bottom plate 2 is relatively moved. A rubber elastic plate 5 covered on the upper side of an opening 3 is displaced upwards, and the slime 7 is taken into a hollow cylinder 1. When the kelly bar 22 is stopped, the opening 3 of the plate 5 is closed, the device is lifted up to the ground's surface, and slime housed in the cylinder 1 is discharged to the outside. The reslime remover has a simple structure and is free of disorder because of its high strength and can also be easily manufactured at low cost.

Description

[Detailed Description of the Invention] (Technical Field) The present invention removes slime that collects at the bottom of a hole when a hole is excavated for a cast-in-place concrete pile (prior art and its problems) What is a cast-in-place concrete pile? There is a foundation pile C obtained by drilling a vertical hole in the ground at a construction site by hand or various machines, inserting reinforcing bars into the hole, and then filling it with ready-mixed concrete.

There are two methods for constructing cast-in-place piles: deep foundation construction using manual excavation, and methods using various machines.
Earth drill method, reparse serculation method,
There is also the B-HT method, which uses a large-diameter boring machine.

However, since the deep foundation construction method is a manual excavation method that uses visual inspection, the bottom of the hole can be thoroughly dredged, so there is no residual slime at the bottom of the hole. Because slime remains in the pile, if concrete is poured as is, the residual slime reduces the supporting force of the tip of the pile, resulting in a problem in that the reliability of the supporting force of the pile is lost.

During excavation, the earth and sand inside the casing tube are picked up with a hammer grab bucket and discharged to the outside. Although it is not necessary to perform water filling, etc., it is rare that underground excavation does not reach groundwater, so it is unavoidable that slime accumulates at the bottom of the hole even in the Benotoe method. For this reason, the current slime removal method using the bed method is used.

That is, after the final excavation work with the vent machine is completed, the hammer grab bucket is gently lowered to the bottom of the hole, and the process of gently grabbing the bottom of the hole is repeated two to three times. In addition, if particularly severe work is required, after the above work, a simple packet of about 1.5 m in height can be sunk to the bottom of the hole and left to stand still for about 20 minutes. After the slime floating in the packet is allowed to settle inside the packet, the packet is pulled up and discharged to the outside.

In addition, the earth drill method involves rotating the earth drill to avoid sinking and scraping away the earth and sand.In this method, a bottom dredging packet is finally placed in the bottom of the hole to dredge the bottom. However, even if this is done, the slime will accumulate at the bottom of the hole again due to collapse of the hole wall that occurs when reinforcing steel is installed.

Also, reverse circulation method and B.

In the H method, excavated soil is mixed with water or bentonite liquid, transported to the ground by sucking it up or pushing it up, and the earth and sand mixed water or liquid is stored in a tank installed above ground to settle the earth and sand. Mechanical excavation is then carried out by repeatedly injecting water or bentonite liquid from the upper layer into the excavation hole and circulating it.

The method for removing slime in the reverse circulation method described above is to insert reinforcing steel into the hole after digging.
When a tremie pipe for pouring fresh concrete is installed after the concrete is filled, a pump is installed to suck up the slime at the bottom of the hole through the tremie pipe, and this sucks up the slime at the tip of the tremie pipe. However, although it is possible to suck up some of the slime at the bottom of the hole with this method, it is difficult to suck up most of the slime, making it unreliable.

B uses a larger diameter boring machine.

In the H method, there are no measures to remove slime at all, and concrete is poured with the knowledge that slime is present.

(Objective of the Invention) The present invention has been made to solve the above-mentioned problems. The purpose is to increase the bearing capacity of this type of cast-in-place pile and improve its reliability as a foundation pile by making it possible to effectively remove it by operation.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, a plurality of openings are provided in the bottom plate of the hollow cylindrical body in a radial direction from the center, and the front edge of the bottom plate in the rotational direction due to these openings is inclined downward. The base of an elastic plate is fixed to the bottom plate on the rear edge side of each opening, and the elastic plate covers the F side of the opening, and an opening/closing lid for slime discharge is attached to the chest of the hollow cylindrical body. This hollow cylindrical body is connected to the lower end of the Kelly bar and suspended in the hole so as to be able to rise and fall freely, and can be rotated to constitute a device for removing slime from the bottom of a hole for cast-in-place piles.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, a bottom plate 2 is provided at the bottom of the hollow cylindrical body 1, and a plurality of (two in this embodiment) openings 3 (see Figs. 5 and 6) are formed in the bottom plate 2 in the radial direction from the center. The bit 4 is formed so that the front edge thereof is inclined downward (in the direction of rotation of the bottom plate 2 by each of these openings 3 (in the direction of the arrow in FIG. 5) and has a continuous mountain shape. Also, the bottom plate 2 on the rear edge side of each opening 3
The base of an elastic plate 5 such as a rubber plate is fixed and covered by a set screw 6, and the upper surface of the opening 3 is covered by the elastic plate 5. That is, in this embodiment, as shown in FIG. 4, there are two elastic plates 5 on the left and right sides, each having a shape larger than the frontage 3 and provided overlappingly on the bottom plate 2.

In addition, a cross-shaped beam 7 is spanned over the upper part of the hollow cylindrical body 1 as shown in FIG. By connecting with the hollow cylinder, the entire hollow cylinder can be rotated.

Furthermore, in the present invention, the slime discharge opening/closing lid 9 (No. 1.4.
(See Figure 6).

In addition, numeral 10 in the figure is a hinge of the slime discharge opening/closing M9, and numeral 11 is a stopper thereof. Also, if necessary, the first step.
As shown in Figure 3.6, an opening 12 is provided above the chest of the hollow cylindrical body 1, and water or bentonite liquid is allowed to pass through this opening, but the slime suspended in the liquid is prevented from passing through as much as possible. It is advisable to install a filter 13 such as a thin wire mesh that can block the light.

(Function) Next, the method of use and the function of the device of the present invention configured as described above will be explained. 14 in Figures 7 and 8 is the ground where a hole for the pile will be excavated, 15 is a hole excavated by mechanical excavation,
16 is water or bentonite liquid in the hole, and 17 is slime remaining at the bottom of the hole.

Further, in FIG. 7, 18 is a Taller plane, 19 is its crawler, 20 is a swivel base provided on the crawler 19 so as to be freely swiveling, 21 is a crane boom attached to the swivel base 20 so that it can be raised and lowered, and 22 is a crane boom 21. The Kelly bar 123 suspended from the tip of the Kelly bar 123 is a rotation drive device (hydraulic type) for the Kelly bar 22, 24 is a connecting arm that connects this rotation drive device 23 with the swivel table 20, etc. It is a device.

To remove the slime 11 at the bottom of the hole using the device of the present invention, suspend the device E of the present invention from the lower end of the Kelly bar 22 via the connecting fitting 8 and the connecting pin 25 (see Fig. 8).
This is suspended into the hole 15 by operating the crane 18. In this state, when the Kelly bar 22 is rotated in the direction of arrow F in FIG. 8, the bit 4 installed on the bottom plate 2 moves in the direction of arrow G in FIG. is tilted downward as shown in FIG. Due to this action, the elastic plate 5 made of a rubber plate superimposed on the upper surface of the opening 3 is displaced upward as shown in FIG. Therefore, if the hollow cylindrical body 1 does not continue to rotate and sinks to the bottom of the hole, the slime 1 at the bottom of the hole
7 is sucked up onto the bottom plate 2 inside the hollow cylinder 1.

When the slime 17 has been accommodated in the hollow cylindrical body 1 in this way, if the rotation of the hollow cylindrical body 1 is stopped by stopping the rotation of the Kelly bar 22, the elasticity that has been displaced above the bottom plate 2 is The plate 5 returns to the state shown in FIG. 6 due to its elasticity and closes each opening 3.

Therefore, in this state, after moving the main body through the Kelly bar 22 to the hot water outlet of the 179th tsum 111 of the main body, the opening/closing lid 9 is operated. When it is opened as shown by the chain line 9' in FIG. 6, the slime contained inside the hollow cylindrical body 1 is discharged to the outside.

If the rotation of the hollow cylindrical body 1 is too fast or the slime is particularly light, the rotation of the hollow cylindrical body 1 will cause the slime to be rolled up and the water in the hole will increase. Alternatively, there is a possibility that the slime 17 may float in the penmilnite liquid 16 and not settle over the long distance, so it is desirable that the rotational speed of the hollow cylindrical body 1 can be changed to an extremely low speed. .

In addition, if particularly light slime remains suspended in the liquid for a long time and is difficult to settle, an opening 12 may be provided at the top of the hollow cylindrical body 1 as described above, and a filter 13 may be placed over this opening. The effect of this filter 13 is that the slime 17 can be captured quickly.

(Effects of the Invention) As described above, the device of the present invention has no rotating parts and has a simple structure, so it is strong and has little risk of failure due to manual labor, is easy to manufacture, and can be provided at low cost. It has the advantage of being able to

Furthermore, according to the device of the present invention, slime that remains at the bottom of a hole for cast-in-place piles by mechanical excavation, which has been extremely difficult to remove in the past, can be removed extremely effectively with a simple operation. The excellent effect of increasing the bearing capacity of cast-in-place piles and improving their reliability as foundation piles is obtained.

[Brief explanation of the drawing]

Fig. 1 is an elevational view of the device of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a sectional view taken along line A-Δ in Fig. 1, Fig. 4 is a view taken along B-BWI of Fig. 1, and Fig. 5 is a main view. FIG. 6 is a bottom view of the device of the invention, FIG. 6 is a sectional view taken along the line CC in FIG. 1, FIG. 7 is an elevational view showing the device of the invention in use, and FIG. 8 is a partial sectional view thereof. 1...Hollow cylindrical body 2...Bottom plate 3...Opening 4...Flat 1-5...Elasticity number 6...Set screw 7...Beam 8...Connection fittings 9...・Close collar 12 for slime discharge
13...Filter 22...Kerry bar 0 Patent applicant Katsumi Kitanaka Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A plurality of openings are provided in the bottom plate of the hollow cylindrical body in a radial direction from the center, and the front edge of the bottom plate in the rotational direction due to these openings is formed into a downwardly inclined pit shape, and the acid root on the trailing edge side of each opening is A base of an elastic plate is fixed on top, and the elastic plate covers the upper surface of the opening, an opening/closing lid for slime discharge is provided on the body of the hollow cylindrical body, and this hollow cylindrical body is connected to the lower end of the Kelly bar. A device for removing slime from the bottom of a hole for a cast-in-place pile, characterized in that it is suspended in the hole so that it can be raised and lowered, and is also rotatably driven.