JP2603414B2 - True pipe large diameter cast-in-place pile method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention
The present invention relates to a true-pipe type large-diameter cast-in-place pile method in which a concrete pile is built underground using the standing hole as a concrete formwork.

[0002]

2. Description of the Related Art Conventionally, when drilling a large-diameter vertical hole, conventionally,
It was based on the deep foundation method and the reverse earth drill method.

[0003]

In the conventional deep foundation method,
Manual excavation at the bottom of the hole, manual assembly of the liner plate to stabilize the hole wall, manual assembling of the rebar and work inside the hole are mainly performed by humans. On the other hand, there are not enough workers.

[0004] In addition, the reverse earth drilling method requires a wide muddy water treatment yard because water is used, pollution caused by muddy water becomes a social problem, and in mountainous areas,
There is a problem that water cannot be secured.

[0005] On the other hand, there is provided a method of solving the above-mentioned problem by pushing a casing having a cutting bit attached to a tip thereof by a rotary pushing device to cut a vertical hole. However, the maximum diameter of a hole that can be drilled by this method is currently about 3 m, but there is a demand for a large diameter pile having a diameter of about 5 m.

An object of the present invention is to provide a straight pipe type large diameter cast-in-place pile method capable of easily and safely constructing a large-diameter cast-in-place pile.

[0007]

According to the present invention, in a true-pipe large-diameter cast-in-place pile method for drilling a shaft in the ground and constructing a concrete pile in the ground using the shaft as a concrete form, Installed in the center of the pile to build the rotary indentation device, provided a cutting bit at the lower end with a smaller diameter than the pile diameter, equipped with a sediment intake at the bottom, and has a bit on the outer circumference approximately equal to the outer diameter of the pile A casing equipped with a ring cutter and a wing cutter that can be reduced in diameter is set in a rotary pushing device, and the casing is rotated, pushed in, and drilled while drilling earth and sand from the earth and sand intake port to discharge the soil and cure the hole wall. After the material is settled and drilled, the ring cutter is reduced in diameter, pulled up together with the wing cutter and the casing and removed, and then a steel cage is built and concrete is poured.

[0008]

According to the present invention, when a hole is drilled in a casing and the ground around the drilled hole is excavated with a ring bit and a wing bit, excavated earth and sand falls down to the bottom of the casing, and the excavated soil enters the casing from the sediment intake port. It is taken inside.
As a result, a hole having a diameter larger than that of the casing is drilled.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an apparatus for carrying out the present invention.

A gantry 1 is installed on the guide wall B, and a rotary pushing device 2 is installed on the gantry 1. A pile A to be constructed (FIG. 1)
The casing 3 having a smaller diameter than the outer diameter of 3) is held,
A cutting bit 4 is provided at the tip of the casing 3. A plurality of sediment inlets 5 are formed near the bottom of the casing 3.
A large diameter drilling device indicated by a reference numeral C is provided in the vicinity of the upper part.

A cutter holding device 10 is provided in the diameter increasing drilling device C. In the cutter holding device 10,
An octagonal cylindrical gripping frame 11 is provided to be engaged with the outer periphery of the casing 3. A tightening band 12 provided in a cutout portion of the gripping frame 11 causes the gripping frame 11 to operate by operating a hydraulic jack 13 for tightening. 3 is fixed.

A plurality of wing cutters 14 protrude from the lower edge of the holding frame 11, and a plurality of ring cutters 1
8 are provided. A link arm 1 for connecting the holding frame 11 and the ring cutter 18 is
6 and an expansion / contraction hydraulic jack 17 interposed between the middle of the link arm 16 and the casing 3.

As shown in FIGS. 4 and 5, the ring cutter 18 is provided with eight bit holders 19a to 19h (hereinafter referred to as "19" when collectively referred to), which are equally circumferentially divided. They are connected by a connecting piece 20 and a connecting bolt 21. The same number of tail seals 22 are provided upright on the bit holder 19, and a bit 23 is provided on the lower end thereof so as to protrude from the outer circumference and the inner circumference of the bit holder 19. The outer periphery of the bit 23 is formed substantially equal to the outer diameter of the pile A. Then, when the connecting bolt 21 and the connecting piece 20 are removed and the expanding / contracting hydraulic jack 17 is extended, the diameter of the ring cutter 18 is reduced as shown in FIG.

The hydraulic jacks 13 and 17 are connected to a hydraulic unit 24 provided above the holding frame 11, respectively. The hydraulic unit 24 is provided with a signal transmission device 25. In addition, the code | symbol 6 in a figure is a ring type cutting beam, 7 is a sheet pile which is a hardening material, and D is an earth removal bucket.

Next, the construction of the cast-in-place pile will be described with reference to FIGS.

First, a guide wall B is installed at the center of a pile A to be constructed, and a diameter expanding and drilling device C is set inside the guide wall B (FIG. 6).

Next, the gantry 1 is placed on the guide wall B.
The rotary pushing device 2 is installed via the
, The casing 3 is set, and the hydraulic jack 13 for tightening is set.
To set the diameter increasing drilling device C in the casing 3 (FIG. 7).

Next, the rotary pushing device 2 is operated to rotate and push the casing 3, drill the hole with the cutting bit 4, the wing cutter 14 and the ring cutter 18, and fall down into the casing 3 from the earth and sand intake port 5. The taken excavated earth and sand is discharged by the discharge bucket D (FIG. 8).

Then, while drilling, the sheet pile 7 is driven to cure the hole wall (FIG. 9). Note that a known liner ring may be used instead of the sheet pile 7.

Next, the sheet pile 7 is drilled while being supported by the ring-type cutting beam 6, and when the drilling is completed, the connecting bolt 21 and the connecting piece 20 are removed, and the bit holders 19a to 19 are removed.
h. Then, the hydraulic cutter 17 for expansion and contraction is extended to reduce the diameter of the ring cutter 18, and the gantry 1, the rotary pushing device 2, the casing 3 and the diameter expansion drilling device C are lifted and removed (FIG. 10).

Next, the reinforcing rod cage 8 is built (FIG. 11). Then, concrete is cast by the well-known tremy tube 9 (FIG. 12).

Finally, when the concrete is solidified and a ground pressure is generated, the sheet pile 7 is pulled out and completed (FIG. 13).

In the above operation, except that the connecting bolt 21 is removed and the bit holder 19 is separated, the hydraulic unit 2 is remotely controlled from the ground via the signal transmission device 25.
4 is performed unattended by controlling.

[0025]

As described above, according to the present invention, a large diameter cast-in-place pile can be easily and safely constructed.

Further, the present invention can be particularly effectively applied to the ground of gravel-mixed earth and sand.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an apparatus for implementing the present invention.

FIG. 2 is a side view showing a main part of FIG. 1;

FIG. 3 is a side view showing a reduced diameter state of the ring cutter of FIG. 2;

FIG. 4 is a sectional view taken along line XX of FIG. 1;

FIG. 5 is an enlarged view showing details of a main part of FIG. 4;

FIG. 6 is a side view for explaining an aspect of installation of a guide wall and a diameter-drilling device.

FIG. 7 is a side view illustrating the installation of the rotary pushing device and the manner of setting the casing.

FIG. 8 is a side view illustrating a drilling mode.

FIG. 9 is a side view for explaining a hole wall curing mode.

FIG. 10 is a side view illustrating a state at the time of reducing the diameter of the ring cutter and starting pulling up the apparatus.

FIG. 11 is a side view for explaining a reinforcing cage construction mode.

FIG. 12 is a side view illustrating a concrete casting mode.

FIG. 13 is a view for explaining a sheet pile drawing mode.

[Explanation of symbols]

 A: Pile B: Guide wall C: Diameter drilling device D: Unloading bucket 1: Stand 2, Rotary pushing device 3: Casing 4: Cutting Bit 5 ・ ・ ・ Sand intake port 6 ・ ・ ・ Ring cut beam 7 ・ ・ ・ Pile 8 ・ ・ ・ Reinforced basket 9 ・ ・ ・ Tremy tube 10 ・ ・ ・ Cutter holding device 11 ・ ・ ・ Grip frame 12 ・ ・・ Tightening band 13 ・ ・ ・ Tightening hydraulic jack 14 ・ ・ ・ Wing cutter 15 ・ ・ ・ Expansion / reduction device 16 ・ ・ ・ Link arm 17 ・ ・ ・ Enlargement / reduction hydraulic jack 18 ・ ・ ・ Ring cutter 19 ・ ・ ・Bit holder 20 Connection piece 21 Connection bolt 22 Tail seal 23 Bit 24 Hydraulic unit 25 Signal transmission device

Claims (1)

(57) [Claims] In a true-pipe large-diameter cast-in-place method of drilling a shaft in the ground and constructing a concrete pile in the ground using the shaft as a concrete formwork, the center of the pile for constructing a rotary pushing device is provided. A ring cutter and a wing cutter that can be reduced by installing a cutting bit at the lower end with a diameter smaller than the pile diameter, providing a sediment intake port at the bottom, and having a bit on the outer circumference substantially equal to the outer diameter of the pile Set the casing provided on the rotary pushing device, rotate the casing, push in and drill holes, take in the excavated earth and sand from the earth and sand intake port, discharge the soil, set the hole wall with curing material, and complete drilling After that, the ring cutter is reduced in diameter, pulled up together with the wing cutter and the casing and removed, and then a concrete pipe is poured into the steel pipe with a steel cage built therein.