JP2006214169A - Cast-in-place concrete pile hole construction method and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cast-in-place concrete pile hole construction method capable of controlling the movement of excavated earth and sand in a casing to the minimum amount by a spiral induction blade consolidating the excavated earth and sand to a hole wall between the lower end of the casing and a drill projected downward thereof and aiming at the decrease of the removal of the approaching earth and sand to the ground surface in a large caliber reinforced concrete pile excavation construction by downward excavation engagements of the lower end of the cast-in-place large caliber casing. <P>SOLUTION: When the large caliber casing 1 planting a plurality of downward excavation engagements in the lower end is pivoted around the center line c and is driven to the base 3, the cast-in-place concrete pile hole construction method is so characterized that earth and sand excavated by a ground excavating drill 5 provided to the lower end of an inner tube 4 engaged with the casing 1 in the rotational direction are consolidated to the hole wall 7 by the spiral earth and sand induction drill 6 provided between the drill 5 and the lower end plate 4' of the inner tube 4 and that surplus soil is removed to the ground surface 8 from the inner tube 4 and the casing 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for constructing a low-drainage concrete pile using a cast-in-place large-diameter casing and an apparatus therefor.

  Conventionally, in a construction method in which a cast-in-place pile is constructed by grasping and swinging or rotating a casing tube (hereinafter referred to as a casing) provided with a drill bit at the tip, it takes time to discharge earth and sand in the casing ( For example, Patent Document 1).

  Further, a pile hole excavating apparatus without a residual soil treatment has been developed in which excavated soil (residual soil) is compacted to a pile hole wall without being discharged to the ground (for example, Patent Document 2).

  In the former cast-in-place pile, most of the earth and sand in the large-diameter casing is discharged to the ground, so it takes excavation time, and it takes labor and time to dispose of a large amount of soil, and pollutes the global environment.

  The latter does not use a steel casing, and all the excavated sediment is consolidated to the pile wall and is not discharged to the ground. There is no disposal of the discharged soil and no pollution of the global environment, but excavation with a cast-in-place large-diameter casing. Not suitable for law.

JP 2003-206687 JP 2004-293267 A

  The present invention relates to a large-diameter reinforced concrete pile excavation work by lower-end downward excavation biting of a cast-in-place large-diameter casing, and a spiral-shaped induction for consolidating excavated earth and sand between the lower end of the casing and a cone protruding below the casing. The purpose is to suppress the excavation sediment in the casing to a small amount by the blades and to reduce the discharge of the entrance sediment to the ground as much as possible.

In order to achieve the above object, the present invention firstly rotates a large-diameter casing having a plurality of downward excavation bites at the lower end around the center line and propels it to the ground. The earth and sand excavated by a ground excavation cone provided at the lower end of the inner cylinder engaged with the inner cylinder is consolidated into a hole wall by a spiral earth and sand guide vane provided between the cone and the lower end plate of the inner cylinder, Cast-in-place concrete pile hole construction method, wherein residual soil is discharged from the inner cylinder and the casing to the ground,
Secondly, the inner cylinder that engages in the rotational direction is detachably fitted to the inner surface of the casing provided with a downward excavation bite at the lower end, and the lower end plate lower surface of the inner cylinder extends from the center portion to the outer periphery of the lower end plate. A spiral-shaped earth and sand guiding blade is provided, a disk sharing the center line with the lower edge plate is provided on the lower surface of the earth and sand guiding blade, a fan-shaped opening for excavating earth and sand is provided on the disk, and the remaining soil is raised on the lower edge plate Forming a fan-shaped opening for the disk, bending the edge of the disk in the direction of rotation of the disk toward the direction of rotation, and providing a ground excavation cone at the center of the lower surface of the disk; A cast-in-place concrete pile hole construction device in which the inner cylinder is supported by the casing in a protruding state below the lower end of the casing;
Consists of.

Therefore, when constructing large-diameter concrete piles at the construction site (location), the large-diameter casing is projected downward on the lower end plate of the inner cylinder that rotates around the center line through the inner cylinder and propels it to the ground. Ground excavation drills advanced ground excavation,
The advanced excavated earth and sand are scooped up on the disk by a downward bent edge in which the advanced excavated earth and sand faces the rotation direction of the fan-shaped opening of the disk.

  The excavated soil that has been scooped up on the disk is guided to the side surface of the spiral earth and sand guide vane that rotates about the center line, and the pile hole side wall is consolidated to strengthen the pile hole side wall.

  The remaining soil rises into the inner cylinder through a rising fan-shaped opening formed in the lower end plate of the inner cylinder.

  The inner cylinder rotates around the center line together with the casing, and the casing excavates and promotes the outer peripheral ground of the excavation part by the excavation cone by the downward excavation bite planted at the lower end of the casing. Also rises on the disc and is compacted to the pile hole side wall by the guide vanes.

  After reaching a predetermined depth, the rotation of the casing and the cylinder is stopped, the residual soil that has risen in the inner cylinder is poured into the cylindrical bucket, this is raised to the ground, the bucket is opened, and the operation of dropping and discharging to the ground is repeated.

  After that, the empty inner cylinder and the bucket are disengaged, and only the cylinder is lifted to the ground by a lifting / lowering rotary rod (kelly bar), and then a steel bar is inserted into the casing, and the concrete passes through the casing into the pile hole. Pull the casing up to the ground while pouring into the ground.

  Since the present invention is configured as described above, it is sufficient that the large-diameter pile hole sidewalls are consolidated and strengthened by excavated soil, and only a small amount of the consolidated residual soil is discharged to the ground, and the discharge of the excavated soil to the ground is reduced. In addition to obtaining, the consolidation force of the consolidation side wall is released toward the side surface of the buried large-diameter reinforced concrete pile, and the frictional force between the hole wall and the side surface of the concrete pile is improved.

  A casing lifting / lowering device 9 including a hydraulic side opening / closing grip, a hydraulic rotation motor, and a lifting / lowering cylinder of the steel large-diameter casing 1 is disposed on the ground 8.

  A plurality of downward excavation bites 2 are planted at the lower end of the casing 1, and are rotated around the center line c by the lifting device 9, and the casing 1 is propelled and raised to the ground 3 by the device 9. (Patent Document 1).

  As shown in FIGS. 9 (a), (b) and (c), the excavation bite 2 has a portal frame 2 'welded to the lower end of the casing 1, and can be attached to and detached from the portal frame 2'. Can be stopped by.

  The lower wall plate of the casing 1 is formed thick, an L-shaped concave portion 10 is formed at the upper end of the thick portion, and the L-shaped convex portion 11 protruding from the side surface of the inner cylinder 4 inserted into the casing 1 is formed as described above. 3, 4, 5, and 9, the lower end plate 4 ′ of the inner cylinder 4 is shown in FIGS. 3, 4, 5, and 9. Thus, the lower end of the casing 1 is supported.

  A disc 4 ″ sharing a center line c is provided on the lower surface of the lower end plate 4 ′ via a spiral earth and sand guide vane 6, and a center axis sharing the center line c at the center of the lower surface of the disc 4 ″. A ground excavation cone 5 provided with spirals 5 ", 5" around 5 'is projected downward.

  The guide blade 6 is spirally bent from the center of the lower end plate 4 ′ and the disc 4 ″ toward the outer periphery of the both plates 4 ′, 4 ″, and the tip portion is the outer periphery of the both plates 4 ′, 4 ″. The curvature matches the direction.

  Therefore, the disk 4 ″ and the cone 5 below the spiral earth and sand guiding blade 6 are arranged below the lower end level of the casing 1.

  The lower end plate 4 ′ and the disc 4 ″ are formed with fan-shaped openings 12 and 13 from the terminal end to the start end in the clockwise direction (clockwise direction) of the guide vane 6, and one end portion 4a of the disc 4 ″. Is bent downward in the right-turning direction, the excavation bites 14 and 14 are implanted at the bent tip, and the downward excavation bite 14 'is arranged on the outer periphery of the disk 4 ".

  Then, the upper end of one spiral 5 ″ of the cone 5 is made to oppose the bent tip (one end 4a) of the disc 4 ″, and the excavated soil by the cone 5 is spiral-shaped earth and sand from the bent tip (one end 4a). The guide blade 6 can be guided up to the starting end of the guide blade 6, that is, the disk 4 ″.

  The center shaft 5 'of the cone 5 is detachably fitted to and attached to a downward hollow shaft 4b provided at the center of the lower surface of the disk 4 ", and is fixed by a pin 4c.

  The upper end of the inner cylinder 4 is maintained at a level in the middle of the inner circumference of the casing 1, engaging notches 15, 15 are formed at the upper end of the inner cylinder 4, and provided at the lower end of a drive pivot 16 (kelly bar) that can be raised and lowered. The driven drum 17 is lowered into the inner cylinder 4, and the engaging protrusions 15 ′ and 15 ′ projecting from the side surface of the drum 17 are engaged with the engaging notches 15 and 15, and the driving rotary rod 16 is engaged. The inner cylinder 4 and the casing 1 can be rotated clockwise by rotating the (Keriba) clockwise, and the casing 1 is rotated clockwise by the casing lifting / lowering device 9 at the same rotation speed (γpm). The inner cylinder 4 and the casing 1 can be simultaneously rotated and propelled into the ground 3 with the same γpm.

  The spiral earth and sand guide vane 6 is interposed between the lower end plate 4 ′ and the disc 4 ″, and is a block extending from the center of the lower end plate 4 ′ and the disc 4 ″ to the outer periphery of both plates 4 ′ and 4 ″. The guide plate 6 'is formed in a spiral shape, and the excavated earth and sand rising from the fan-shaped opening 13 of the disk 4 "is rotated to the right of the guide plate 6' (in the direction of arrow a in FIG. 4, FIGS. 6 and 7). Then, it is guided to the pile hole wall 7 from the center by the arrow a ′ direction) and is consolidated to the hole wall 7.

  The unconsolidated residual soil rises into the inner cylinder 4 from the fan-shaped opening 12 of the lower end plate 4 ′ as the cylinder 4 and the casing 1 are propelled.

  After the completion of the propulsion, the above-mentioned remaining soil in the inner cylinder 4 is moved down by rotating the short cylindrical bucket 18 shown in FIGS. The residual soil is accommodated in the bucket 18 by 'and raised to the ground, and the bottom plate 18 "is opened as shown by phantom lines in FIG. 8 (b), and the residual soil is discharged to the ground 8.

  A spiral guide flange 6 "parallel to the two plates 4 'and 4" is provided in the middle of the spiral guide plate 6 "of the spiral soil guide vane 6 to stabilize the sand guide direction.

  Further, one guide vane 6 is used as shown in FIGS. 6 (a) and 6 (b), but two guide vanes 6 are provided at symmetrical positions as shown in FIGS. A pair of fan-shaped openings 12 and 13 of the lower end plate 4 ′ and the disc 4 ″ are also provided at a symmetrical position.

  The kelly bar 16 is suspended from a crawler crane disposed on the ground 8 by a wire rope so as to be movable up and down, and is provided by a hydraulic motor (not shown) provided on an elevating adjustment frame pivotally supported by a horizontal axis at the tip of the front arm of the crawler. It is designed to rotate horizontally.

  In FIG. 1 (b), 17 ′ is a funnel-shaped guide plate of the drive drum 17, and FIG. 6 (b) and FIG. 7 (b) are 19 of the fan-shaped opening 12 of the lower end plate 4 ′ of the inner cylinder 4. Fan-shaped plate for adjusting the opening area, fan-shaped long holes 19 ', 19' are drilled and supported by the lower end plate 4 'with bolts 19 ". Adjustment of the above-mentioned pressure density and the amount of residual soil by adjusting the opening area Can do.

(A) The figure is an exploded side view of the casing, the inner cylinder and the drive drum, and (B) is a side view of the other side of the drive drum. (A) The figure is a cross-sectional view taken along line AA in FIG. 1 and (b) is a side view taken along line BB. FIG. 2 is an assembled side view of FIG. 1. FIG. 3 is a partially cutaway front view taken along line C-C. It is a partial longitudinal front view of a disassembled casing and inner cylinder of a drive drum and a short cylindrical bucket. FIG. 5B is a bottom view taken along the line D-D in FIG. 5 and FIG. 5B is a transverse bottom view taken along the line E-E. FIG. 5B is a bottom view of another embodiment taken along line D-D in FIG. 5 and FIG. 5B is a transverse bottom view of another embodiment taken along line E-E. (A) (B) is a front view of a short cylindrical bucket, and (C) is a front view of a partially cut casing. (A) is a front view of a detachable downward excavation bite, (b) is a bottom view of (b), and (c) is a partially enlarged front view of (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Large diameter casing 2 Downward excavation bite 3 Ground 4 Inner cylinder 4 'Bottom plate 5 Ground excavation cone 6 Spiral earth and sand guide vane 7 Hole wall 8 Ground

Claims (2)

When rotating a large-diameter casing with a plurality of downward excavation bites at the lower end around the center line and propelling it to the ground,
The earth and sand excavated by the ground excavation cone provided at the lower end of the inner cylinder engaged with the casing in the rotation direction,
By the spiral earth and sand guide vane provided between the cone and the lower end plate of the inner cylinder, the hole wall is consolidated,
A cast-in-place concrete pile hole construction method, wherein residual soil is discharged from the inner cylinder and the casing to the ground. An inner cylinder that engages in the rotational direction is detachably fitted to the inner surface of the casing provided with a downward excavation bite at the lower end,
A spiral earth and sand guiding blade is provided on the lower surface of the lower end plate of the inner cylinder from the center to the outer periphery of the lower end plate
A disc sharing the center line with the lower end plate is provided on the lower surface of the earth and sand guiding blade,
The disc is provided with a fan-shaped opening for excavating earth and sand, and a fan-shaped opening for raising the residual soil is formed on the lower end plate,
Bending the edge of the disc in the direction of rotation of the opening in a downward direction, providing a ground excavation cone at the center of the lower surface of the disc,
A cast-in-place concrete pile hole construction apparatus in which the spiral-shaped earth-and-sand guide vane protrudes below the lower end of the casing and the inner cylinder is supported by the casing.

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