JP2020133319A - Diameter expansion device and diameter expansion method - Google Patents

Abstract

To provide a diameter expansion device capable of accurately and efficiently expanding a diameter of a drilling hole formed for an underground continuous wall with a simple constitution.SOLUTION: A diameter expansion device 1 for expanding a diameter of a drilling hole for forming an underground continuous wall includes: a reamer 2 which forms an expanded diameter hole larger than a width in a traverse direction of the drilling hole by rotation; a guide 10 which is mounted above the reamer and is formed so as to be slid while being brought into contact with the expanded diameter hole; and a bucket 20 which is mounted below the reamer, is formed so that the width in the longitudinal direction is larger than a diameter of the expanded diameter hole and is formed so that the traverse direction is slid while being brought into contact in the traverse direction of the drilling hole.SELECTED DRAWING: Figure 1

Description

The present invention relates to a diameter-expanding device and a diameter-expanding method for forming an enlarged diameter hole in an excavation hole of an underground continuous wall.

After forming an excavation hole that serves as a space for a wall in the ground, a continuous underground wall (hereinafter referred to as a continuous wall) may be formed from reinforced concrete (see, for example, Patent Document 1). Since the continuous wall is constructed of reinforced concrete, it has high rigidity and it is easy to secure a large side area compared to piles, so high-rise buildings and adjacent structures where a large pulling force acts on the foundation in the event of an earthquake etc. It is used as the foundation for main construction such as wall piles of buildings with strict displacement restrictions. Since the construction cost of the continuous wall is relatively high compared to ordinary piles, it is desirable that the wall thickness be formed within the minimum necessary width.

Japanese Unexamined Patent Publication No. 2004-044083

At a construction site such as a high-rise building, a reverse striking method may be used in which a continuous wall is formed and then the floor surface is sequentially formed for each basement floor by digging from the first basement floor side to form an underground space. In the reverse striking method, a plurality of structural pillars are preliminarily formed in the continuous wall at predetermined intervals in order to support the floor surfaces that are sequentially formed. Since the structural pillar used in the reverse striking method has a large axial force, the radial dimension of the structural pillar is formed larger than the thickness of the continuous wall. Therefore, it is necessary to make the width of the excavation hole thicker at the position where the structural pillar is provided in the excavation hole of the continuous wall.

As shown in FIG. 5, it is very costly to form an excavation hole having a width W2 in which the width W1 of the excavation hole H is widened according to the radial width of the structural pillar T formed of the steel frame. There is a problem of becoming. Further, in order to resist a large axial force due to the load of the building, the bearing capacity is insufficient only by the bottom area of the wall pile, so it is necessary to form a long length in the depth direction of the continuous wall.

In order to avoid the above problem, as shown in FIGS. 6 and 7, a method of increasing the bottom area by using the method of expanding the bottom pile in combination has also been proposed. However, since the diameter of the bottom-expanding excavator D is also large in order to form the bottom-expanded bottom surface Z having a large diameter, an excavation hole having a width W2 is formed by expanding the width W1 of the excavation hole H in order to insert the bottom-expanding excavator D. There is a need to.

As shown in FIGS. 8 and 9, as a method of installing a structural pillar T or inserting a large-diameter bottom-expanding excavator without increasing the width W1 of the excavation hole H of the continuous wall, the structural pillar T is used. A method of constructing a T-shaped excavation hole by using an excavator for a continuous wall only at the entrance has been proposed. However, since the required width W2 of the T-shaped excavation hole into which the structural pillar T is inserted is often smaller than the 1 gut width W3 (for example, 3.2 m) of a general excavator for a continuous wall, the continuous wall When excavating with a special excavator, it is necessary to excavate a larger area than the required area, and there is a problem that the labor for excavation increases. Further, if the thickness of the continuous wall is formed according to the structural pillar T by using such a construction method, there is a problem that the amount of excavation increases and the cost increases.

As shown in FIGS. 10 to 12, it is also proposed to expand the diameter of the circular hole C in the excavation hole H by using the bucket B for the earth drill with a reamer used in the cast-in-place expansion pile. ing. However, even in this case, there is a problem that most of the excavated soil M by the reamer falls into the excavation hole H outside the bucket B in the bucket B which fits in the width W1 of the excavation hole H. When the excavated soil falls into the hole, it becomes mud and floats in the stabilizer, which takes time to settle and is difficult to recover.

Therefore, according to the above method, it is necessary to install the suction pump P for reverse circulation and the like on both sides of the bucket B for the earth drill, which is troublesome. Further, since the bucket in the wall center direction cannot be restrained, the bucket B moves during excavation, and there is a problem that the accuracy of widening the hole in the vertical direction cannot be ensured.

The present invention has been made in view of the above-mentioned problems, and provides a diameter-expanding device capable of accurately and efficiently expanding the diameter of an excavation hole formed for an underground continuous wall by a simple configuration. The purpose is.

In order to achieve the above object, the present invention is a diameter-expanding device for expanding the diameter of an excavated hole for forming a continuous underground wall, and has a diameter larger than the width of the excavated hole in the lateral direction. A reamer formed by rotating the enlarged diameter hole, a guide attached above the reamer and formed to slide while abutting against the enlarged diameter hole, and a guide attached below the reamer and having a width in the longitudinal direction. Is formed to be larger than the diameter of the diameter-expanding hole, and is provided with a bucket formed so that the side of the hole slides while being in contact with the side of the excavation hole. Is.

According to the present invention, when the excavation hole for forming the underground continuous wall is enlarged by a reamer and the enlarged hole is excavated, the guide formed so as to abut the enlarged hole is in the lateral direction of the reamer. It is possible to regulate the movement to the reamer and stabilize the vertical movement of the reamer. Then, since the bucket provided below the reamer catches the excavated soil excavated and discharged by the reamer, the excavated soil can be easily collected.

Further, the present invention may be configured such that the bucket is provided with a lid portion that is openably and closably provided on the bottom portion.

According to the present invention, by opening the lid when the inside of the bucket is filled with the excavated soil, the excavated soil falls out of the bucket by its own weight, so that the excavated soil recovery work can be facilitated.

Further, the present invention may be configured to include a main body portion formed in a cylindrical shape so that the guide abuts on the enlarged diameter hole.

According to the present invention, the guide formed in a cylindrical shape abuts on the enlarged diameter hole formed by the reamer to prevent the reamer from shifting in the lateral direction, stabilize the vertical operation of the reamer, and accurately expand the reamer. A diameter hole can be formed.

Further, the present invention is a diameter-expanding method for expanding the diameter of an excavated hole for forming a continuous underground wall, and the reamer is rotated to expand the diameter larger than the width of the excavated hole in the lateral direction. A step of forming a diameter hole, a step of sliding a guide attached above the reamer with the reamer while contacting the enlarged hole, and a step of sliding the guide attached below the reamer with a width in the longitudinal direction. The expansion is characterized by comprising a step of sliding a bucket formed larger than the diameter of the enlarged hole with the reamer so that the lateral direction of the bucket abuts in the lateral direction of the excavation hole. It is a diameter method.

According to the present invention, when the drilling hole for forming a continuous underground wall is enlarged by a reamer to excavate the enlarged hole, the guide abuts on the enlarged hole to move the reamer laterally. Since it slides together with the reamer while being regulated, the vertical movement of the reamer can be stabilized. Then, the bucket provided below the reamer receives the excavated soil excavated and discharged by the reamer, so that the excavated soil can be easily collected.

According to the present invention, it is possible to accurately and efficiently expand the diameter of the excavation hole formed for the continuous underground wall by a simple configuration.

It is a perspective view which shows the structure of the diameter expansion apparatus of this invention. It is a top view which shows the state which the diameter of the excavation hole for a continuous wall is expanded by the diameter expansion device. It is sectional drawing in the front direction which shows the state which the diameter of the excavation hole for a continuous wall is expanded by the diameter expansion device. It is sectional drawing in the side direction which shows the state which expands the diameter of the excavation hole for a continuous wall by the diameter expansion device. It is a top view which shows the construction method which widens the width of the excavation hole for a continuous wall in order to insert a structural pillar in a comparative example. It is a top view which shows the construction method which widens the width of the excavation hole for a continuous wall by using the construction method of the bottom expansion pile in the comparative example. It is sectional drawing in the side direction which shows the construction method which widens the width of the excavation hole for a continuous wall by using the construction method of the bottom expansion pile in the comparative example. It is a top view which shows the construction method which expands the diameter of the excavation hole for a continuous wall into a T-shaped cross section by using the excavator for a continuous wall in the comparative example. It is sectional drawing in the front direction which shows the construction method which expands the diameter of the excavation hole for a continuation wall into a T-shaped cross section by using the excavator for a continuous wall in a comparative example. It is a top view which shows the construction method which expands the diameter of the excavation hole by using the bucket for the earth drill with a reamer in the comparative example. It is sectional drawing in the front direction which shows the construction method which expands the diameter of the excavation hole by using the bucket for the earth drill with a reamer in the comparative example. It is sectional drawing in the side direction which shows the construction method which expands the diameter of the excavation hole by using the bucket for the earth drill with a reamer in the comparative example.

Hereinafter, embodiments of the diameter-expanding device and the diameter-expanding method embodiment of the present invention will be described with reference to the drawings. The diameter-expanding device is a device for expanding the diameter of a drilling hole formed for a continuous wall formed in the ground. The diameter expanding device is used by being attached to a device such as a general earth drill machine.

As shown in FIG. 1, the diameter expanding device 1 provides a reamer 2 for expanding the diameter of the excavation hole H (see FIG. 2), a guide 10 for guiding the excavation direction of the reamer 2, and excavated soil of the reamer 2. A bucket 20 for collecting is provided.

The reamer 2 includes a hub 3 attached to a rotating shaft S (see FIG. 3). The rotary shaft S is rotationally driven by an earth drill machine or the like. The hub 3 is formed in a columnar shape along the vertical axis L. The hub 3 has a rectangular through hole 3A formed along the axis L at the center in a plan view. The tip of the rotating shaft S fits into the through hole 3A. A pair of rotary blades 4 projecting in the horizontal direction orthogonal to the axis L are provided on the side surface portion of the hub 3. The rotary blade 4 rotates in a predetermined rotation direction to expand the diameter of the existing hole. The rotary blade 4 is formed in a blade shape. A plurality of diamond-coated chips 4A are formed in the excavated portion of the rotary blade 4.

The pair of rotary blades 4 are formed so that the diameter at the time of rotation is larger than the width of the excavation hole H in the lateral direction in a plan view. This diameter is set to the size in which the structural pillar used in the reverse striking method is inserted. Not only two rotary blades 4 are provided on the hub 3, but two or more rotary blades 4 may be provided. With the above configuration, when the reamer 2 rotates around the axis L in a predetermined direction, the ground is excavated with a diameter larger than the width of the excavation hole H in the lateral direction to form an enlarged diameter hole.

A guide 10 formed in a cylindrical shape is provided above the reamer 2. The guide 10 is arranged coaxially with the reamer 2 and the axis L in a plan view. The guide 10 comes into contact with the enlarged diameter hole formed by the reamer 2 and prevents the rotation axis S (axis line L) of the reamer 2 from being displaced from the vertical direction. The guide 10 allows the reamer 2 to dig a diameter-expanded hole in the vertical direction along the axis L direction. The guide 10 includes a main body portion 11 formed in a cylindrical shape and a support portion 14 that supports the main body portion 11.

The main body portion 11 is formed, for example, by rolling a metal plate into a cylindrical shape and welding a seam. The main body 11 does not necessarily have to be formed in a cylindrical shape as long as it stabilizes the excavation direction of the reamer 2. A support portion 14 is provided in the internal space of the main body portion 11. The support portion 14 includes, for example, a hub 15 that supports the rotation shaft S, and a plurality of spokes 16 that project radially horizontally from the hub 15 and support the inner wall surface 11A of the main body portion 11.

The hub 15 is formed in a columnar shape. The hub 15 has a rectangular through hole 15A formed at the center of the hub 15 along the axis L in a plan view. A rotation shaft S for rotating the above-mentioned reamer 2 is inserted through the through hole 15A. The rotation shaft S fits into the through hole 15A and rotates the guide 10 together with the reamer 2. The guide 10 does not necessarily have to be rotated by the rotation shaft S, and the rotation shaft S may idle in the through hole 15A.

Further, the guide 10 does not necessarily have to be formed in a cylindrical shape if it functions as a guide for the hole formed by the reamer 2. With the above configuration, the guide 10 fits into the hole drilled by the reamer 2 and becomes a guide along the vertical direction, prevents the reamer 2 from shifting in the lateral direction, and forms a linear hole in the vertical direction. it can. A bucket 20 is provided below the reamer 2.

The bucket 20 is a rectangular container having an opening on the upper surface. The bucket 20 receives and collects the excavated soil generated when the reamer 2 excavates the ground.

The bucket 20 includes a main body 21 having a rectangular opening in a plan view, and a lid 25 covering the opening at the bottom of the main body 21. The main body 21 is formed in a rectangular tubular body in a plan view. The main body 21 includes a pair of sliding walls 22 arranged so as to face each other in the longitudinal direction, and a pair of side plates 23 arranged so as to be orthogonal to the pair of sliding walls 22. The sliding wall 22 is formed in a rectangular plate-like body when viewed from the front. The horizontal width of the sliding wall 22 is formed to be larger than the diameter of the reamer 2 when it is rotated. The side plate 23 is formed in a rectangular plate-like body when viewed from the side. The horizontal width of the side plate 23 is formed to be slightly smaller than the distance between the facing wall surfaces of the excavation holes H when viewed from the side.

The pair of sliding walls 22 slide while abutting against the facing wall surface of the excavation hole H for the continuous wall as the reamer 2 excavates the enlarged diameter hole and moves downward. A support member 26 for connecting the pair of sliding walls 22 to each other is provided at the center of the upper ends of the pair of sliding walls 22.

The support member 26 is formed in a rectangular plate-like body in a plan view. A bearing 26B is fitted in the central portion of the support member 26. The tip of the rotary shaft S described above is rotatably connected to the bearing 26B. As a result, the bucket 20 is rotatably suspended on the rotation axis S.

A lid 25 that can be opened and closed is provided on the bottom of the main body 21. The lid portion 25 is formed in a rectangular plate-like body. One side of the lid 25 is rotatably attached to the lower side of the sliding wall 22 by using a hinge mechanism (not shown) or the like. The lid portion 25 is opened from the closed state by the weight of the excavated soil or the weight of the excavated soil loaded by releasing the lock mechanism (not shown) provided in the bucket 20.

With the above configuration, the bucket 20 receives and collects the excavated soil that falls when the reamer 2 excavates the ground below the reamer 2. By opening the lid 25 at the bottom of the bucket 20, the excavated soil inside the bucket can be discharged in the state of soil without becoming mud.

As shown in FIGS. 2 to 4, the diameter expanding device 1 is used for expanding the diameter of the existing excavation hole H. The excavation hole H is a continuous hole provided in the ground to form a continuous wall. The drilling hole H is filled with a stabilizer produced by a bentonite-based solution for preventing the collapse of the hole wall and preventing the sedimentation of slime-like substances in the solution. The excavation hole H is formed with a space in which a pair of wall surfaces H1 and H2 face each other with a predetermined width F1 so that a continuous wall can be inserted. The reamer 2 forms the enlarged diameter hole Q with a width F2 wider than a predetermined width F1. The width F2 is sized so that the structural pillar and the bottom expansion excavator are inserted. The enlarged diameter hole Q is formed by two spaces Q1 and Q2 in which the excavation hole H is expanded in a half-moon shape.

When expanding the diameter of the excavation hole H, the diameter expanding device 1 is installed from above with respect to the target position. At this time, the bucket 20 is inserted into the excavation hole H first. After the reamer 2 comes into contact with the ground surface, the rotation shaft S is rotationally driven, and the rotation shaft S is pushed downward while rotating the reamer 2 in a predetermined direction. Then, the ground is excavated by the reamer 2. Most of the excavated soil excavated by the reamer 2 falls into the bucket 20. The rotating shaft S is pushed further to dig deeper into the enlarged diameter hole Q. At this time, the bucket 20 slides in conjunction with the reamer while the short side contacts the short side of the excavation hole H. Every time the excavated soil is full in the bucket 20, the diameter expanding device 1 is pulled up, the lock mechanism is released, the lid 25 is opened, and the excavated soil is discharged from the bucket 20. As a result, the excavated soil is prevented from falling into the excavation hole H, becoming mud in the stabilizing liquid, and floating.

When digging the excavation hole H, the guide 10 formed in a cylindrical shape abuts on the enlarged diameter hole Q, slides the excavation hole H in conjunction with the reamer 2, and restricts the lateral movement of the reamer 2. To do. That is, the guide 10 prevents the reamer 2 from shifting in the lateral direction. When the excavation hole H is further dug, the bucket 20 reaches the bottom of the excavation hole H. The height of the bucket 20 from the bottom of the excavation hole H cannot be excavated by the reamer 2. Therefore, the diameter-expanding device 1 is pulled out from the diameter-expanding hole Q, and an earth drill bucket having the same diameter as the reamer 2 is inserted into the diameter-expanding hole Q to excavate to the bottom of the drilling hole H.

When excavating the bottom of the expansion hole Q, the earth drill bucket is pulled out from the expansion hole Q, and instead, a bottom expansion excavator is inserted to perform the bottom expansion excavation to form the bottom expansion hole. After each of the above steps, a continuous wall is formed of reinforced concrete in the excavation hole H. Then, concrete is poured into the bottom-expanding hole, the structural pillar is inserted and positioned, and the structural pillar supported by the expanded pile is formed.

As described above, according to the diameter expanding device 1, the diameter of the excavation hole H formed for the continuous underground wall can be expanded accurately and efficiently by a simple configuration. Further, according to the diameter-expanding device 1, the guide provided above the reamer 2 abuts on the diameter-expanded hole Q to restrict the lateral movement of the reamer 2, so that the expanded hole is accurately formed. can do. Further, according to the diameter expanding device 1, since the width of the bucket 20 in the longitudinal direction is formed to be larger than the diameter of the reamer 2 during rotation, most of the excavated soil excavated by the reamer 2 can be recovered. , Construction cost can be reduced.

Further, according to the diameter expanding device 1, since the width of the bucket 20 in the lateral direction is formed according to the width of the excavation hole H, the size of the diameter expansion is set regardless of the width of the excavation hole H. be able to. Further, according to the diameter expanding device 1, by using an earth drill machine for excavating the enlarged diameter portion, it is possible to reduce the cost and the construction period as compared with expanding the diameter so as to widen the width of the excavation hole H for the continuous wall. it can.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above one embodiment and can be appropriately modified without departing from the spirit of the present invention.

1 Diameter expansion device 2 Reamer 3 Hub 3A Through hole 4 Rotating blade 4A Tip 10 Guide 11 Main body 11A Wall surface 14 Support 15 Hub 15A Through hole 16 Spoke 20 Bucket 21 Main body 22 Sliding wall 23 Side plate 25 Lid 26 Support member 26B bearing

Claims (4)

A diameter-expanding device for expanding the diameter of an excavation hole for forming a continuous underground wall.
A reamer formed by rotating an enlarged hole having a diameter larger than the width in the lateral direction of the excavated hole.
A guide mounted above the reamer and formed to slide while abutting against the enlarged diameter hole.
A bucket mounted below the reamer and formed so that the width in the longitudinal direction is larger than the diameter of the enlarged diameter hole and the lateral direction slides while contacting the lateral direction of the excavation hole. It is characterized by having
Diameter expansion device. The bucket is characterized by having a lid portion that is openable and closable at the bottom.
The diameter expanding device according to claim 1. The guide includes a main body portion formed in a cylindrical shape so as to abut the enlarged diameter hole.
The diameter expanding device according to claim 1 or 2. It is a diameter expansion method for expanding the diameter of the excavation hole for forming a continuous underground wall.
A step of rotating a reamer to form an enlarged hole having a diameter larger than the width of the drilled hole in the lateral direction, and
A step of sliding a guide attached above the reamer in conjunction with the reamer while abutting the enlarged diameter hole.
A bucket attached below the reamer and having a width in the longitudinal direction larger than the diameter of the enlarged hole is attached to the reamer so that the lateral direction of the bucket abuts on the lateral direction of the excavation hole. It is characterized by having a process of sliding in conjunction with each other.
Diameter expansion method.

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