JP2014118807A - New pile establishment method and cutter bucket therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of newly providing an underground pile by excavating a pile hole in a required size while crushing an obstacle such as an existing pile or an existing underground structure regardless of the presence/absence or the position of the obstacle, and a special cutter bucket for pile hole excavation therefor.SOLUTION: A special cutter bucket comprises: a cutter drum 2 including a plurality of cutter bits 8 tilted at 45° with respect to a rotation direction on a lower circumferential end face 9; and a blade plate 5 including a plurality of drill bits 7 and having a sweep-back angle of about 60° between an inner circumferential surface of the drum 2 and a surface of a drill pipe 3 which is a rotation center axis. The special cutter bucket is characterized in that the cutter bit 8 of the cutter drum 2 has an inclination of about 45° with respect to the rotation direction of the drum, the cutter bit 7 provided in the blade plate 5 has an inclination of about 30° with respect to an axial line of the drill pipe 3, and a finish tail 6 in a distal end of the drill pipe does not protrude from the lower circumferential end face 9 of the cutter drum 2. The special cutter bucket is used to newly provide an underground pile by excavating a pile hole in a required size while crushing existing underground obstacles.

Description

  The present invention uses a cutter bucket having a special configuration regardless of the presence of obstacles such as existing piles and underground structures, and excavates the pile holes while crushing the obstacles, and underground piles of the necessary diameter Is related to the construction method.

  Conventionally, in urban redevelopment and rebuilding of buildings, dismantling existing buildings, removing piles and underground structures that supported the buildings, and renewing them on existing underground structures When building a building, the existing piles were pulled out and backfilled, or piles were piled up avoiding existing obstacles. Many incomplete pile removals occurred due to poor welds, etc., and this was a cause of trouble during the new pile driving. In addition, there are cases where it is difficult to set the pile length due to lack of data on existing pile driving.

  In addition, in the case of pile removal by the casing method, since a large amount of water is used for several days, unexpected problems due to ground subsidence or collapse have occurred. In addition, in the case of pile removal by the normal casing method, the hole from which the pile has been removed is backfilled with pile sand after removing the pile, but when excavating to the position of the existing pile that was backfilled at the time of new pile driving Since most of the backfill soil is discarded together with the excavated sediment, the amount of excavated sediment is increased, and the amount of ready-mixed concrete is also increased. In some cases, it can be a deformed pile.

  There is already known a method of simply crushing and refilling an existing pile remaining in the ground without removing an existing pile (see Patent Document 1). It is intended only for crushing and discharging concrete piles. Various earth auger heads for excavation work with high excavation efficiency for removing piles and underground structures are also known (see Patent Document 2 and Patent Document 3), but they are newly installed ignoring existing obstacles as they are. A pile hole in a pile cannot be formed.

JP, 2008-144561, A Drawing) (Japanese Patent Publication No. 47-2401)

  As described above, the present invention does not remove or refill obstacles such as existing piles or existing underground structures, regardless of the presence or position of obstacles such as piles or underground structures. A special cutter bucket for excavating a pile hole for excavating a pile hole of the required diameter by excavating a pile hole of the required size while crushing an obstacle using a cutter bucket having a different configuration It is intended to provide.

  The invention described in claim 1 of the present invention conforms to a newly installed pile diameter by crushing and removing an existing underground pile or an obstacle including a part thereof with an earth drill device suitable for the newly installed pile diameter. After excavating the hole with the diameter to be reinforced, a reinforcing member with a reinforcing bar is constructed in the excavated pile hole, a so-called reinforcing bar is built, and ready-mixed concrete is injected, so that there is no need for existing piles at the site. It is a new pile construction method for directly creating an underground pile, and the invention described in claim 2 is a method for mounting an existing ground which should be removed by attaching a cutter bucket to a tip of a kelly bar of an earth drill device attached to a heavy machine. Set the cutter bucket on an obstacle such as a pile or concrete structure, rotate the cutter bucket to fix the excavation position, and then excavate to the depth of the surface casing, After the excavation to a predetermined depth by alternately repeating the cutting operation by the cutter bucket of the present invention and the discharging operation of the pulverized slag by the well-known drilling bucket while injecting the bentonite solution, the cutter bucket is lifted up by the drilling bucket. It is a new pile construction method characterized by removing the obstacles that became crushed dredging as the final process of excavation of pile holes. Therefore, it is possible to build a new pile by laying reinforcing material (rebar rod) directly into the excavation hole and pouring ready-mixed concrete into it, so that the existing pile and existing obstacles can be removed without removing the existing obstacle. It can be created.

  The invention described in claim 3 relates to the structure of the cutter bucket, wherein the upper portion of the cutter bucket is a cutter drum fixed to a kelly bar socket via an upper reinforcing plate of the cutter drum and a drill pipe reinforcing plate. The blade plate fixed between the inner peripheral surface of the cutter drum and the outer peripheral surface of the drill pipe, and a triangular plate pipe tail at the lower end of the drill pipe, and the lower peripheral end surface of the cutter drum and the The blade plate is provided with a plurality of cutter bits each inclined in the rotation direction, and the invention according to claim 4 is a triangular plate-like finish at the lower end of the drill pipe. The tail is characterized in that it is located inside the drum from the lower circumferential end surface of the cutter drum. In this way, the lower circumferential end surface of the cutter drum protrudes beyond the triangular plate-like finish tail at the lower end of the drill pipe, so that it is stable regardless of the presence or absence of obstacles when positioning for drilling holes. Thus, the cutter bucket position can be set.

The invention described in claim 5 specifies the attachment structure of the blade plate described in claims 3 and 4, and the inclination angle of the blade plate is in the rear and rotational directions with respect to the longitudinal axis of the drill pipe. It has a tilt angle of about 60 ° and 30 °, respectively. In this way, the blades are inclined backward and in the direction of rotation, so that the bite of the cutter bit is improved, and it is easy to make a pile hole that adapts to the required pile diameter regardless of the presence or absence of obstacles such as piles and underground structures. Can be excavated.

  By using a special cutter bucket having the above-described configuration, the present invention excavates a pile hole adapted to the size of the newly installed pile without removing the existing pile or existing structure in advance. In addition, it is possible to construct a new pile by inserting concrete reinforcements as it is and pouring concrete, so that the construction time and labor can be drastically reduced compared to conventional methods. In addition, by providing a blade plate with a cutter bit inside the cutter drum, positioning of the pile hole to be excavated can be easily stabilized, and the cutter bite during excavation is good. Since it is possible to easily excavate a pile hole adapted to the required pile diameter regardless of the presence or absence of obstacles, a new underground pile can be created directly on site without performing the work of pulling out the existing pile.

  In addition, according to the present invention, since obstacles such as existing piles and underground structures can be crushed and removed in the ground, industrial waste disposal can be performed without removing existing piles and existing structures in advance. There is no need to bring it to the final disposal site. The crushed pulverized slag can be used as excavated sediment as backfill sediment or recycled sediment. Furthermore, there is no fear of land subsidence due to the supply of a huge amount of water that occurs during the pile removal work of the conventional casing method. And by preparing multiple cutter buckets adapted to the required new pile standards, you can immediately create underground piles according to the new pile standards without pulling out the existing piles, which is also economical in time This also has a remarkable effect.

    Moreover, by using the cutter bucket of the present invention, even if there is an existing pile or an existing underground structure, the cutter bucket has an effect that can stably excavate a pile hole for a new pile without tilting. It is.

It is an outline explanatory view of the new pile construction method of the present invention. It is structure explanatory drawing of the cutter bucket of this invention. It is cutter bit arrangement | positioning explanatory drawing which looked at the cutter bucket from the bottom face.

  Hereinafter, although the Example of the new pile construction method of this invention and the bucket for it are demonstrated, embodiment of this invention is not limited to the following Example. In the following description, steps, materials, configurations, parts, and the like having the same function may be assigned the same reference numerals and description thereof may be omitted.

FIG. 1 is a schematic explanatory diagram of the new pile construction method of the present invention, in which a pile hole is excavated using the cutter bucket of the present invention.
A is a well-known heavy machine equipped with a drilling device. B is an earth drill device which is an ordinary excavator, and the kelly bar C is loaded with a cutter bucket 1 or a well-known drilling bucket for soil removal (not shown).

  At the time of excavation, first, the center of the kelly bar of the earth drill device is set at the pile core position to be newly created, the cutter bucket 1 is loaded into the kelly bar C of the earth drill device, and the cutter bucket 1 is rotated and removed at the excavation position. Start cutting work for obstacles such as existing piles or existing structures. At first, rotate slowly, gradually turn up while injecting water, proceed with excavation while cutting obstacles, and excavate to the built-in depth of the surface casing E. After discharging and installing the surface casing E, the cutting operation by the cutter bucket 1 while injecting the bentonite solution and the discharging operation of the pulverized soot by a known drilling bucket are alternately repeated. When the cutting operation proceeds to a predetermined depth, the cutter bucket 1 is pulled up and the crushed slag is completely discharged and removed by the drilling bucket to complete the excavation of the pile hole. A new pile is built by building and building ready-mixed concrete.

2 and 3 are explanatory views of the structure of the cutter bucket 1 of the present invention. FIG. 2 (a) is a partial sectional view of the cutter bucket, and FIG. 2 (b) is a state in which the cutter bit is attached to the blade plate. It is explanatory drawing shown.
2 is a cutter drum, 2a is an upper reinforcing plate of the drum, 3 is a drill pipe, and 3a is a drill pipe reinforcing plate. Reference numeral 4 denotes a Kelly bar socket, which is provided with a pin hole 4a for retaining. The Kelly bar socket 4, the upper reinforcing plate 2a of the cutter drum 2, and the reinforcing plate 3a of the drill pipe 3 are integrally fixed together by welding, for example.

5 is a wing plate, 6 is a finish tail, 7 is a cutter bit provided on the wing plate 5, and 8 is a cutter bit provided on the lower circumferential end surface of the cutter drum 2, both of which are cemented carbide at the tip. Is a well-known cutter bit embedded.
The blade 5 is fixed between the surface of the drill pipe 3 and the inner peripheral surface of the cutter drum 2 by welding or the like as shown in FIG. 2 (a), and rearward from the finish tail provided at the tip of the drill pipe 3. 55 ° to 65 °, preferably 60 °, and the blade tip is retracted, and as shown in FIG. 2 (b), the blade tip is inclined backward from the rotational direction of 25 ° to 35 °, preferably 30 °. .

  The finish tail 6 is formed of a triangular plate-shaped steel plate, and is provided so as to be located inside the drum from the lower circumferential end surface of the cutter drum 2. The depth of this position becomes deeper as the length of the drum is longer, but when the drum length is 1000 to 1300, 50 mm to 200 mm is preferable. Since the finish tail is positioned on the inner side of the lower circumferential end surface of the cutter drum 2 as described above, the pile hole excavation work after setting the excavation start position of the cutter bucket 1 is stably performed. is there.

FIG. 3A is an explanatory diagram of the arrangement of the cutter bits as seen from the bottom of the cutter bucket. A plurality of cutter bits are provided on the lower circumferential end surface of the cutter drum as shown in the figure. As shown in FIG. 3 (b), it is attached with an inclination of 40 ° to 50 °, preferably 45 °, in the direction of drum rotation.
Three blades are provided between the drill pipe 3 and the cutter drum 2 at an opening angle of 120 °, and the arrangement intervals of the cutter bits 7 provided on these blades are adjacent to each other. It does not overlap with the trajectory of the cutter bit of the blade.

A ... Heavy machine B ... Earth drill device C ... Kelly bar E ... Casing 1 ... Cutter bucket 2 ... Cutter drum 2a ... Cutter drum upper reinforcement plate 3 ... Drill pipe 4. ··· Kelly bar socket 4a ··· Pin hole 5 ··· Blade plate 6 ··· Finish tail 7 · · · Blade blade cutter bit 8 · · · drum cutter bit 9 · · · lower end edge of the cutter drum

Claims (5)

  After crushing and removing existing underground piles or obstacles including a part of them with an earth drill device suitable for the new pile diameter, excavating a hole with the new pile diameter, the excavated pile hole with a reinforcing bar A new pile construction method that directly builds underground piles on site regardless of the presence or absence of existing piles by constructing and building reinforcement members and driving ready-mixed concrete.   Attach the cutter bucket to the tip of the kelly bar of the earth drill device attached to the heavy machinery, set the cutter bucket on the obstacle such as the existing underground pile or concrete structure to be removed, rotate the cutter bucket and remove it The position is fixed, and then the surface casing is built by excavating to the depth of the surface casing, and the cutting operation and the discharging operation of the pulverized slag using a known drilling bucket are alternately repeated while injecting the bentonite solution. The new pile construction method according to claim 1, wherein after the excavation to a depth, lifting the cutter bucket and removing obstacles that have become crushing troughs by the drilling bucket is a final process of excavating the pile hole.   The cutter bucket includes a cutter drum upper reinforcing plate, a drill pipe, a drill pipe reinforcing plate fixed to the drill pipe, a kelly bar socket fixed integrally with the reinforcing plate and the cutter drum upper reinforcing plate, a drill A finish tail provided at the tip of the pipe, and a plurality of blades provided with the blade tip retracted about 60 ° rearward from the finish tail and inclined rearward from the rotation direction about 30 ° relative to the axis of the drill pipe. 3. A new pile construction according to claim 2, comprising a blade plate provided with a blade plate cutter bit, and a blade drum fixed between the surface of the drill pipe and the inner peripheral surface of the cutter drum. Cutter bucket for construction method.   The cutter bucket for a new pile construction method according to claim 3, wherein a plurality of drum cutter bits inclined by about 45 ° with respect to the rotation direction of the drum are provided on a lower circumferential end surface of the cutter bucket.   5. The cutter pile for a new pile construction method according to claim 3, wherein a finish tail provided at a tip of the drill pipe is located inside the drum from a lower circumferential end surface of the cutter drum.

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