JP2017106280A - Excavator and diameter expansion method of pipe hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excavator and a diameter expansion method of a pile hole of using the excavator, capable of forming a diameter expansion part being high in finished shape accuracy in the pile hole, even when constructing the pile hole in the large depth, for constructing a cast-in-place concrete-made knotted pile having the huge pile length.SOLUTION: An excavator for forming a diameter expansion part on a hole wall of a pile hole drilled in the ground for constructing a cast-in-place concrete-made knotted pile, comprises a kelly bar erected in a vertical shape in the pile hole and rotating around the axis, a diameter expansion part excavator fixed to the kelly bar and having a diameter expansion blade for freely protruding-retreating toward the hole wall and a stabilizer rotatably installed around the axis to a lower end part of the diameter expansion part excavator, allowing an outer peripheral surface to abut on the hole wall and composed of a cylindrical member of forming an earth removal hole by penetrating the inside in the vertical direction.SELECTED DRAWING: Figure 1

Description

  The present invention is for forming a diameter-expanded portion in a pile hole such as a columnar hole for a round pile or a pile excavation groove for a rectangular pile, which has been drilled in the ground to construct a pile with a cast-in-place concrete structure. The present invention relates to a drilling device and a method for expanding a pile hole using the drilling device.

  Conventionally, in order to resist the pushing force and pulling force of the structure, a cast-in-place concrete structure with an expanded bottom part at the bottom of the foundation pile supporting the structure and a node part at the middle part of the pile shaft part is also provided. A knotted pile is known.

  For example, Patent Document 1 discloses a method for forming a diameter-expanded portion in a drilling groove constructed by excavating the ground with a horizontal multi-axis excavator so as to provide a node in a cast-in-place concrete wall pile. ing. Specifically, in the excavation groove, excavation provided with a kelly bar that rotates about an axis, a bucket attached to the tip of the kelly bar, and a stabilizer that is disposed above the bucket and is pivotally supported by the kelly bar. The apparatus is arranged and the groove wall is excavated by rotating the bucket via the kelly bar to form an enlarged diameter portion in the excavation groove.

  The excavator described above is designed to suppress bucket misalignment and swinging during rotary excavation by performing rotary excavation of the bucket with the stabilizer pivotally supported by the kelly bar fixed to the groove wall. In the case where is short and small, it is possible to construct the enlarged diameter portion with high accuracy in the excavation groove.

Japanese Patent No. 45525228

  However, when a wall pile having a long pile length corresponding to a large depth is constructed, the length of the kelly bar is also long. For this reason, if the vibration generated during the rotary excavation of the bucket directly acts on the kelly bar, excessive deflection occurs in the kelly bar, and the stabilizer supported on the kelly bar cannot sufficiently suppress this deflection. As a result, the shaft centers of the kelly bar and the bucket are likely to be eccentric from the axial center position of the enlarged diameter portion to be constructed, and the accuracy of the finished shape of the enlarged diameter portion is likely to be reduced.

  The present invention has been made in view of such problems, and its main purpose is to construct column-shaped holes for round piles and rectangular piles in order to construct a cast-in-place concrete pile with a long pile length. Even when a pile hole such as a pile excavation groove is constructed at a deep depth, it is possible to form a diameter-expanded part with high shape accuracy in the pile hole and to expand the pile hole using the excavator and the excavator. It is to provide a diameter method.

  In order to achieve such an object, the excavating apparatus of the present invention is an excavating apparatus for forming a diameter-expanded portion in a hole wall of a pile hole drilled in the ground in order to construct a cast-in-place concrete pile with a joint. A diameter expanding portion excavating apparatus comprising a kelly bar that stands vertically in the pile hole and rotates about an axis, and a diameter expanding blade that is fixed to the kelly bar and can protrude and retract toward the hole wall. And an outer peripheral surface abutting on the hole wall and penetrating in the vertical direction to form a soil removal hole. And a stabilizer made of a cylindrical member.

  According to the excavator of the present invention described above, since the stabilizer is installed at the lower end portion of the enlarged-diameter excavator, it is possible to directly suppress the shaking that occurs during the rotary excavation of the enlarged-diameter excavator. As a result, the vibration acting on the kelly bar is reduced, so that even when a long kelly bar is used in the excavator to form an enlarged portion in a pile hole constructed at a deep depth, excessive deflection is applied to the kelly bar. It does not occur. Therefore, at the time of excavation work by the excavator, the kelly bar and the axis of the enlarged-diameter excavator are not greatly decentered from the axial position of the enlarged-diameter portion to be constructed, and the hole wall can be excavated with high accuracy. It becomes.

  In addition, since the excavated earth and sand generated when excavating the hole wall with the expanded-diameter excavator can pass through the drain hole smoothly, the excavation work is not hindered by the excavated earth and sand, and the hole wall is efficiently excavated. Thus, it becomes possible to form an enlarged diameter portion.

  The method for expanding the diameter of a pile hole according to the present invention is to project the expanded diameter blade after disposing the expanded diameter portion excavator at a position where the expanded diameter portion is to be formed in the pile hole drilled in the ground. In this state, the enlarged-diameter portion excavator is rotated to excavate the hole wall to form an enlarged-diameter portion.

  According to the method for expanding the diameter of a pile hole of the present invention, by using an excavator having a stabilizer installed at the lower end of the above-mentioned expanded-diameter portion excavator, a diameter-expanded portion that ensures high shape accuracy is formed on the hole wall. This makes it possible for the cast-in-place pile made of cast-in-place concrete built in the pile hole to exhibit high bearing capacity performance.

  According to the present invention, even when a cast-in-place concrete pile with a long pile length is constructed, the swing of the enlarged-diameter excavator generated during the excavation work of the hole wall is reduced by the lower end of the enlarged-diameter excavator. It is possible to efficiently control with a stabilizer installed in the section and to build a node with high shape accuracy in the pile hole.

It is a figure which shows the state which excavates an enlarged diameter part to a pile hole with the excavation apparatus in this invention. It is a figure which shows the state which moves the excavation apparatus in this invention within a pile hole. It is a figure which shows the planar view of the pile hole in this invention. It is a figure which shows the state which formed the enlarged diameter part in the pile hole with the excavation apparatus in this invention. It is a figure which shows the state which excavates a bottom expansion part with the excavation apparatus in this invention. It is a figure which shows the other example of the stabilizer in this invention.

  The excavation apparatus and pile hole diameter expanding method of the present invention are an apparatus and method used for forming an enlarged diameter portion in a pile hole drilled in the ground to construct a cast-in-place concrete pile with a joint. Yes, the pile hole may have any cross section such as a columnar hole for a round pile or a pile excavation groove for a rectangular pile. In the present embodiment, in order to provide a node with a node in a rectangular pile and to make a pile with a node, taking as an example the case of forming a diameter-enlarged portion by excavating a groove wall forming a hole wall of a pile hole made of a pile excavation groove, This will be described in detail below.

  As shown in FIG. 1, the excavator 1 inserted into a pile excavation groove 10 drilled in the ground includes a vertically extending kerry bar 2 and a diameter-enlarged portion installed at the tip of the kelly bar 2. The excavator 3 and the stabilizer 4 installed in the lower end part of the enlarged diameter part excavator 3 are provided.

  The kelly bar 2 is made of a rod-like member, and as shown in FIG. 1, the base end portion is installed on the arm of the traveling body (not shown) in a state of being rotatable about the axis C1, and the rotational force applied from the traveling body is applied. This is transmitted to the expanded-diameter excavator 3.

  As shown in FIG. 1, the enlarged-diameter excavator 3 includes a bucket 31 made of a cylindrical body coaxial with the axis C <b> 1 of the kelly bar 2, and a plurality provided at equal intervals on the outer peripheral surface of the bucket 31. A plurality of diameter-expanded blades 32 arranged so as to cover the opening 36, and the diameter-expanded blade 32 is made of a plate-like member formed in a curved shape so as to follow the outer peripheral surface of the bucket 31. A diameter expansion blade 321 for excavating a groove wall is provided at one side edge and a lower edge of the diameter expansion blade 32, and the other side edge is an edge of the opening 36 of the bucket 31 via the hinge 33. It is connected to the part.

  In addition, one end of a hydraulic jack 34 housed inside the bucket 31 is joined to the back surface of the diameter expansion blade 32, and each of the plurality of diameter expansion blades 32 rotates the hinge 33 by expansion and contraction of the hydraulic jack 34. It is configured to rotate as a moving shaft. That is, when the hydraulic jack 34 is contracted, the diameter-expanded blade 32 is stored in the bucket 31 so as to cover the opening 36 of the bucket 31 as shown in FIG.

  On the other hand, when the hydraulic jack 34 is extended, as shown in FIG. 1, the diameter expanding blade 32 is in a state where the excavation blade 321 protrudes toward the groove wall and projects outward from the bucket 31. The enlarged-diameter excavator 3 excavates the groove wall of the pile excavation groove 10 while rotating around the axis of the bucket 31 in a state in which the enlarged wings 32 project outward from the bucket 31 to obtain a desired depth. The enlarged diameter portion 11 is formed at the position. Therefore, the shape of the side end portion of the enlarged diameter blade 32 on the side where the excavating blade 321 is provided is formed in a shape that matches the outer shape of the enlarged diameter portion 11 to be formed.

  Further, at the lower end portion of the bucket 31, a projection 35 is installed coaxially with the axial center of the bucket 31, that is, the axial center C1 of the kelly bar 2, and as shown in FIG. When excavating the bottom expanded portion 12 in the vicinity, it penetrates into the groove bottom ground. Thus, the protrusion 35 functions as a spike so that the axial center position of the bucket 31 does not deviate from the axial center of the expanded bottom portion 12 to be constructed. It also has a function as a connecting portion for connecting the stabilizer 4.

  As shown in the plan view of FIG. 3A, the stabilizer 4 is formed of a cylindrical member having a rectangular shape in a plan view in which the outer peripheral surface abuts against the groove wall of the pile excavation groove 10, and a plurality of reinforcing ribs 42 are provided radially. The inner space portion is a drain hole 41 penetrating in the vertical direction. Further, as shown in FIG. 1, a swivel joint 43 is installed on the upper portion of the reinforcing rib 42, and the stabilizer 4 is connected to the protruding portion 35 of the bucket 31 via the swivel joint 43. In addition, the connection means of the protrusion part 35 of the bucket 31 and the stabilizer 4 is not necessarily limited to the swivel joint 43, and any means such as a bearing mechanism may be used as long as it can be connected in a relatively rotatable manner. You may connect via.

  As described above, the stabilizer 4 has the outer peripheral surface in contact with the groove wall of the pile excavation groove 10 in a state of being directly installed at the lower end portion of the enlarged-diameter excavation device 3, so that the enlarged diameter portion generated at the time of rotary excavation of the groove wall The shaking of the excavator 3 can be efficiently suppressed, and the shake that acts on the kelly bar 2 from the enlarged-diameter excavator 3 can be reduced.

  Thereby, even when the long kelly bar 2 is adopted in the excavator 1, the kelly bar 2 is not excessively bent due to the pile excavation groove 10 being constructed at a great depth. Therefore, at the time of excavation work, the kelly bar 2 and the axis C1 of the enlarged-diameter excavator 3 are not greatly deviated from the axial center position of the enlarged-diameter part 11 to be constructed, and the groove wall can be excavated with high accuracy. It becomes possible.

  By the way, in this Embodiment, as shown in FIG. 1, the expansion-contraction type stabilizer 6 is arrange | positioned at the kelly bar 2 of the excavator 1. As shown in FIG. As shown in the plan view of FIG. 3B, the telescopic stabilizer 6 opposes the rectangular main body portion 61 formed smaller than the groove width of the pile excavation groove 10 and the groove wall of the main body portion 61. Abutting members 63 arranged on both side surfaces are provided, and the Kelly bar 2 is passed through the main body 61 in a rotatable state.

  One end of a hydraulic jack 62 housed in the main body 61 is connected to the back surface of the contact member 63, and when the hydraulic jack 62 is contracted, the contact member 63 is housed near the side surface of the main body 61. On the other hand, when the hydraulic jack 62 is extended, the contact member 63 is in contact with the groove wall of the pile excavation groove 10, while maintaining the axis C <b> 1 of the kelly bar 2 on the center line C <b> 2 of the pile excavation groove 10. Suppresses the shaking generated in the kelly bar 2.

  Therefore, even when the vibration generated in the enlarged-diameter excavator 3 cannot be suppressed by the stabilizer 4, in order to suppress the vibration applied to the kelly bar 2 by the telescopic stabilizer 6, the kelly bar 2 is bent or constructed. The eccentricity of the kelly bar 2 and the enlarged-diameter excavator 3 with respect to the axial center position of the enlarged-diameter part 11 can be efficiently suppressed.

Next, a method for expanding the diameter of the pile excavation groove 10 using the excavator 1 described above will be described below.
In the present embodiment, when a cast-in-place concrete rectangular pile is constructed, a case where the excavator 1 includes the telescopic stabilizer 6 will be described as an example and will be described in detail below.

  First, as shown in FIG. 2, in the state where the diameter-expanded blade 32 of the diameter-expanded section excavator 3 is stored in the bucket 31 and the contact member 63 of the telescopic stabilizer 6 is stored in the main body 61 side, 1 is inserted into the pile excavation groove 10. Note that the stabilizer 4 is always in contact with the groove wall while the excavator 1 is moving.

  Next, when the enlarged-diameter excavator 3 reaches the position where the enlarged-diameter portion 11 is to be formed, the insertion operation is stopped, the contact member 63 of the telescopic stabilizer 6 is brought into contact with the groove wall, and the enlarged-diameter portion The diameter-expanded blade 32 of the excavator 3 is extended toward the groove wall.

  Then, the enlarged-diameter excavator 3 is rotated through the kelly bar 2, and the excavation blade 321 of the enlarged-expansion blade 32 rotates and excavates the groove wall of the pile excavation groove 10 as shown in FIG. 1. At this time, the excavated earth and sand 5 generated by excavation passes through the drain hole 41 of the stabilizer 4 and settles to the groove bottom.

  In addition, when it is desired to form the enlarged diameter portion 11 in a groove shape extending in the longitudinal direction of the pile excavation groove 10, the excavator 1 as shown in FIG. 1 is horizontally moved in the vicinity of the groove opening of the pile excavation groove 10. It is good to equip the movement apparatus 7 for this. Although any device may be employed as the moving device 7, in the present embodiment, the moving device 7 travels on the rail 71 and a pair of rails 71 arranged on the ground surface along the groove opening of the pile excavation groove 10. A kelly bar support member 72 provided with a grip 722 that supports the wheel 721 and the kelly bar 2 in a rotatable state.

  When the groove wall of the pile excavation groove 10 is excavated by the enlarged-diameter excavator 3 while horizontally moving the excavator 1 with these moving devices 7, as shown in FIG. An extending groove-shaped enlarged diameter portion 11 can be formed. Even during such horizontal movement of the excavator 1, the contact member 63 of the telescopic stabilizer 6 and the outer peripheral surface of the stabilizer 4 are in contact with the groove wall.

  After forming the enlarged diameter portion 11 in the pile excavation groove 10 according to the procedure described above, the rotation of the enlarged diameter portion excavating device 3 by the kelly bar 2 is stopped, and the enlarged diameter blade 32 of the enlarged diameter portion excavating device 3 is stored. The contact member 63 of the telescopic stabilizer 6 is accommodated. And when forming the enlarged diameter part 11 further in the pile excavation groove 10, the enlarged diameter part excavator 3 of the excavator 1 moves so that it may reach the formation planned position of the enlarged diameter part 11 to be constructed next. Then, the above procedure may be repeated.

  Further, as shown in FIG. 5, when the bottom expanded portion 12 is constructed at the bottom of the pile excavation groove 10, the excavator 1 is once extracted from the pile excavation groove 10, the stabilizer 4 is removed, and the protruding portion 35 is exposed. In this state, it is inserted into the pile excavation groove 10 again. Then, when the enlarged-diameter excavator 3 reaches the bottom of the hole, the projecting portion 35 penetrates into the pile bottom ground and the enlarged-diameter excavator 3 is stabilized, and the enlarged-diameter excavator 3 via the kelly bar 2. Is rotated to excavate the groove wall near the bottom of the pile to form the widened portion 12.

  In the pile excavation groove 10 in which the enlarged diameter portion 11 and the expanded bottom portion 12 are formed in the groove wall by the above-described method, concrete is placed after inserting a reinforcing bar as necessary, and a node portion is provided. A cast-in-place concrete rectangular pile is constructed.

  According to the method of expanding the diameter of the pile excavation groove 10 described above, the diameter of the pile excavation groove 10 constructed at a large depth is increased by using the excavation apparatus 1 in which the stabilizer 2 is installed at the lower end of the diameter expansion section excavation apparatus 3. Even when the portion 11 is formed, the diameter-enlarged portion 11 that secures high accuracy in forming can be formed, and thus high support performance can be expected for the rectangular pile after construction. Further, it is possible to avoid a situation in which re-excavation is performed without obtaining the specified volume accuracy, and the excavation process is not delayed.

  In addition, it is needless to say that the excavation apparatus 1 and the method for expanding the diameter of the pile hole of the present invention are not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Absent.

  For example, in this embodiment, since the case where the enlarged diameter portion 11 is formed in the pile excavation groove 10 for constructing the rectangular pile is taken as an example, the stabilizer 4 is formed on the rectangular in plan view, but is not necessarily limited thereto. It is not something.

  When constructing a pile with a node by providing a node with a circular pile, as shown in FIG. 6, the planar view shape of the stabilizer 4 is formed in a circular shape, and the columnar hole 13 having a circular shape in a planar view is formed on the outer peripheral surface. It is good to make it contact | abut to a hole wall.

DESCRIPTION OF SYMBOLS 1 Excavator 2 Kelly bar 3 Expanded part excavator 31 Bucket 32 Expanded blade 321 Excavation blade 33 Hinge 34 Hydraulic jack 35 Protruding part 4 Stabilizer 41 Excavation hole 42 Reinforcement rib 43 Swivel joint 5 Excavation earth and sand 6 Telescopic stabilizer 61 Main part 62 Contact member 63 Hydraulic jack 7 Moving device 71 Rail 72 Kelly bar support member 721 Wheel 722 Grip portion 10 Pile excavation groove (pile hole)
11 Expanded portion 12 Expanded bottom portion 13 Columnar hole

Claims (2)

A drilling device for forming a diameter-expanded portion in a hole wall of a pile hole drilled in the ground to construct a cast-in-place concrete pile with a knot,
A kerry bar that is vertically installed in the pile hole and rotates around an axis;
An enlarged-diameter excavating device provided with an enlarged blade fixed to the kelly bar and freely projecting and retracting toward the hole wall;
A cylindrical shape that is installed to be rotatable about the shaft center with respect to the lower end portion of the expanded-diameter excavator, the outer peripheral surface abuts on the hole wall, and the inner side penetrates in the vertical direction to form a drain hole. An excavator comprising a stabilizer made of a member. A method for expanding a pile hole using the excavator according to claim 1,
After disposing the enlarged-diameter excavator at the planned location of the enlarged-diameter portion in the pile hole drilled in the ground,
A method for expanding the diameter of a pile hole, wherein the diameter-extended portion excavating device is rotated in a state where the diameter-expanding blade is extended, and the hole wall is excavated to form an enlarged-diameter portion.

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