JP7703482B2 - Removal method and removal tool - Google Patents

Description

The present invention relates to a method for removing hardened material from the head of a hollow pile and a removal tool used for this method.

When constructing hollow piles using the pre-boring pile method, the ground is excavated to a specified depth using an auger (drilling and mixing device), and then a base strengthening liquid is injected into the bottom of the hole. The auger is then pulled up and removed while a fixing liquid is injected around the pile. The hollow pile is then erected into the excavated hole and submerged in the liquid.

The hardening material cement milk is used for the base fixing liquid and pile circumference fixing liquid, and the inside of the hollow pile is filled with soil cement, which is a hardened mixture of cement milk and soil.

In order to firmly connect the head of a hollow pile to the building foundation, it is necessary to remove the soil cement from the head of the pile and fill it with concrete from the building foundation. Patent documents 1 and 2 disclose a method for easily removing the soil cement from the head of a hollow pile, in which a cylinder of a specified length is inserted into the head of the hollow pile, the hollow pile is then erected into a borehole, and the soil cement from the head of the pile is removed together with the cylinder, thereby shortening the construction period, etc.

JP 2000-54373 A Utility model registration No. 3028203

In the case of large-diameter hollow piles, if the soil cement at the pile head is to be removed using the methods described in Patent Documents 1 and 2, the soil cement to be removed becomes very large, and a large lifting machine must be provided to handle its weight. However, providing a large lifting machine exclusively for lifting the soil cement is costly and wasteful, so there was a demand for a removal method that could be handled with a small lifting machine.

The present invention was made in consideration of the above problems, and aims to provide a method for removing hardened material from inside the pile head that can be handled even with a small lifting machine.

The first invention for solving the above-mentioned problems comprises the steps of: inserting a hollow pile into a hardening material with a removal tool used for removing the hardened material with a hardening material, the removal tool being inserted in advance along the inner peripheral surface of the head of the hollow pile; and removing the hardened material within the head of the pile, the removal tool having a plurality of tubular portions which divide the inside of the head of the pile into a plurality of compartments in a planar view, the plurality of tubular portions being arranged concentrically in a planar view, and in the step (b), the tubular portions are removed in order from the inside to the outside, thereby individually removing the hardened material from each compartment divided by the plurality of tubular portions.
The second invention is a removal method comprising the steps of: inserting a hollow pile into a hardening material with a removal tool used for removing the hardened material with a hardening material, the removal tool being pre-inserted along the inner circumferential surface of the head of the hollow pile; and removing the hardened material within the head of the pile, the removal tool having a plurality of tubular portions which divide the inside of the head of the pile into a plurality of compartments in a planar view, the plurality of tubular portions being arranged side by side in a planar view, and in the step (b), the plurality of tubular portions are individually removed, thereby individually removing the hardened material in each compartment divided by the plurality of tubular portions.
A third invention is a removal method comprising the steps of: inserting a hollow pile into a hardening material with a removal tool used for removing the hardened material with a hardening material, the removal tool being inserted in advance along the inner peripheral surface of the head of the hollow pile; and removing the hardened material inside the head of the pile, the removal tool having a plurality of tubular parts that divide the inside of the head of the pile into a plurality of compartments in a planar view, the tubular parts being arranged inside the outer tubular parts, a framework material being attached to the inside of each of the tubular parts, the framework material having bottom members arranged in a cross shape in a planar view at the ends of the tubular parts on the pile bottom side, the bottom members of the outer tubular parts being provided with positioning members that laterally abut against the bottom members of the inner tubular parts to position the inner tubular parts, and in the step (b), the hardened material in each compartment divided by the plurality of tubular parts is individually extracted.

In the present invention, by using the above-mentioned removal tool, it is possible to divide the inside of the pile head of the hollow pile into multiple sections and extract the hardened material from each section individually. This makes it possible to reduce the size and weight of each hardened material to be extracted, and even in the case of a large-diameter hollow pile, it can be handled with a small lifting machine.

In the first invention, the plurality of cylindrical parts are arranged concentrically in a plan view, and the hardened material of each section is individually extracted by extracting the cylindrical parts in the order of the inside and the outside . In the first and third inventions, the diameter of the inner cylindrical part may be narrowed toward the bottom of the pile.
The removal jig can be easily manufactured and the hardened material can be easily extracted by concentrically arranging the cylindrical parts as described above. In addition, the diameter of the inner cylindrical part can be reduced toward the bottom of the pile, which makes it easier to extract the cylindrical part and the hardened material inside it.

In the second invention, the plurality of tubular portions are arranged side by side in a plan view, and the hardened material of each section is extracted individually by extracting the plurality of tubular portions individually.
This also makes it possible to divide the inside of the head portion of the hollow pile into a number of sections using the removal tool, and to extract the hardened material from each section individually.

In the third invention, a framework material is attached to the inside of each tubular portion, and the framework material has a bottom member arranged in a cross shape in a planar view at the end of the tubular portion facing the pile bottom, and a positioning member is provided on the bottom member of the outer tubular portion which abuts laterally against the bottom member of the inner tubular portion to position the inner tubular portion .
This makes it possible to position the bottom of the inner cylindrical part when arranging the cylindrical parts inside and outside, and to prevent the cylindrical part from tilting and ensure verticality, which makes it easier to remove the inner cylindrical part.

The fourth invention is a removal jig that is inserted in advance along the inner surface of the pile head of a hollow pile to be inserted into a hardening material and used to remove the hardened material from the hardening material inside the pile head, characterized in that the removal jig has a plurality of tubular sections that divide the inside of the pile head into a plurality of compartments in a planar view , the plurality of tubular sections are arranged concentrically in a planar view, and the hardened material in each compartment can be individually removed by removing the tubular sections in order from the inside to the outside .
The fifth invention is a removal jig that is inserted in advance along the inner surface of the pile head of a hollow pile to be inserted into a hardening material and used to remove the hardened material from the hardening material inside the pile head, characterized in that the removal jig has a plurality of tubular portions that divide the inside of the pile head into a plurality of compartments in a planar view, the plurality of tubular portions are arranged side by side in a planar view, and the hardened material in each compartment can be individually removed by removing the plurality of tubular portions individually.
The sixth invention is a removal jig that is inserted in advance along the inner surface of the pile head of a hollow pile to be inserted into a hardening material and used to remove the hardened material from inside the pile head, the removal jig having a plurality of tubular sections that divide the inside of the pile head into a plurality of compartments in a planar view, making it possible to individually remove the hardened material from each compartment, the removal jig having a configuration in which the tubular sections are arranged inside the outer tubular section, and a framework material is attached to the inside of each of the tubular sections, the framework material having a bottom member that is arranged in a cross shape in a planar view at the end of the tubular section on the pile bottom side, and the bottom member of the outer tubular section is provided with a positioning member that abuts laterally against the bottom member of the inner tubular section to position the inner tubular section.
The fourth to sixth aspects of the present invention are removal jigs used in the removal methods of the first to third aspects of the present invention. In the fourth and sixth aspects of the present invention, the inner cylindrical portion may have a diameter that is narrowed toward the bottom of the pile.

The present invention provides a method for removing hardened material from inside pile heads that can be handled even with a small lifting machine.

A diagram showing the construction procedure of hollow pile 2. A diagram showing the construction procedure of hollow pile 2. FIG. A diagram showing the cushioning material 115 and the edge cutting material 116. FIG. 2 is a diagram showing a method for removing soil cement 301 using a removal tool 1. A diagram showing removal tools 1', 1a, and 1b.

The following describes in detail a preferred embodiment of the present invention with reference to the drawings.

(1. Construction procedure for hollow pile 2)
1 and 2 are diagrams showing a procedure for constructing a hollow pile 2. The method for removing a hardened material according to the embodiment of the present invention is carried out during the construction of the hollow pile 2.

The hollow pile 2 is a steel pipe concrete pile, and is constructed by the pre-boring pile construction method as described above. That is, as shown in FIG. 1(a), the ground is excavated with an auger 100 while injecting drilling fluid (not shown) into a borehole 200, and after the ground is excavated to a specified depth as shown in FIG. 1(b), a base fixing fluid 300a is injected into the bottom of the borehole 200. Then, as shown in FIG. 1(c), the auger 100 is pulled up while injecting a pile periphery fixing fluid 300b, and the auger 100 is removed as shown in FIG. 1(d). The base fixing fluid 300a and the pile periphery fixing fluid 300b are made of cement milk 300, which is a hardening material.

Then, as shown in FIG. 1(e), the hollow pile 2 is erected in the excavation hole 200 and inserted into the cement milk 300 (root strengthening liquid 300a, pile circumference fixing liquid 300b) and sunk. A removal jig 1 is inserted in advance into the head of the hollow pile 2. Details of the removal jig 1 will be described later.

The cement milk 300 is mixed with soil and hardens, and in this embodiment, the hardened soil cement is removed from the head of the hollow pile 2. At this time, first, as shown in FIG. 2(a), the ground around the head of the pile is excavated with a backhoe 400, and then, as shown in FIG. 2(b) and (c), the soil cement 301 in the head of the pile is removed in multiple steps using a removal tool 1. After that, as shown in FIG. 2(d), concrete 500 for the building foundation is poured into the head of the hollow pile 2, etc.

In this way, in this embodiment, by using the removal tool 1, it is possible to remove the soil cement 301 in the pile head in multiple batches. This makes each soil cement 301 smaller and lighter, and as shown in Figures 2(b) and (c), it is possible to use the backhoe 400 used to excavate the ground around the pile head to pull up the soil cement 301 and remove it from the pile head, eliminating the need to provide a large lifting machine exclusively for lifting the soil cement 301.

(2. Removal jig 1)
Fig. 3 is a diagram showing the removal jig 1. Fig. 3(a) shows a state in which the removal jig 1 is inserted into the head portion of the hollow pile 2, in a cross section in the axial direction of the hollow pile 2. Fig. 3(b) is a top view of the removal jig 1 in Fig. 3(a), and Fig. 3(c) is a horizontal cross section of the removal jig 1. Fig. 3(a) shows a cross section along line A-A in Fig. 3(b), and Fig. 3(c) shows a cross section along line B-B in Fig. 3(a).

The removal jig 1 has a configuration in which multiple tubular sections 11, 12 are arranged inside and outside. The tubular sections 11, 12 are cylindrical and arranged concentrically in a plan view. The removal jig 1 is inserted inside the head of the hollow pile 2 so that the outer tubular section 12 fits along the inner peripheral surface of the head of the hollow pile 2. This divides the inside of the head of the hollow pile 2 into multiple sections in a plan view, namely, a section inside the tubular section 11 and a section between the tubular sections 11, 12. The tubular sections 11, 12 are made of, for example, cardboard tubes, but are not limited to this.

A framework member 110 is attached to the inside of the tubular portion 11. The framework member 110 has a shaft member 111 arranged along the axial direction of the tubular portion 11, and a bottom member 112 arranged at the end of the tubular portion 11 on the pile bottom side. Steel materials such as angle bars are used for the shaft member 111 and bottom member 112.

The shaft members 111 are provided on the inner surface of the cylindrical portion 11, and multiple shaft members 111 are arranged at intervals in the circumferential direction of the cylindrical portion 11. In this embodiment, four shaft members 111 are arranged at approximately equal intervals (approximately 90° intervals). A horizontal plate 113 is attached to the end of the shaft member 111 on the pile bottom side. The outer end of the horizontal plate 113 protrudes slightly outward beyond the shaft member 111, and the cylindrical portion 11 is placed on the protruding part. The horizontal plate 113 is a small piece with a flat rectangular shape, but is not limited to this, and the horizontal plate 113 can also be arranged in a ring shape along the circumferential direction of the cylindrical portion 11.

The bottom member 112 is arranged inside the tubular portion 11 in a cross shape when viewed from above. The four ends of the cross-shaped bottom member 112 are each fixed to the side of the shaft member 111. An edge-cutting material 114 such as a vinyl sheet is wrapped around the bottom member 112.

A framework member 120 is also attached to the inside of the tubular portion 12. The framework member 120 has the same configuration as the framework member 110 described above. That is, the framework member 120 has an axis member 121, a bottom member 122, a horizontal plate 123, and an edge cutting member 124, which are the same as the axis member 111, the bottom member 112, the horizontal plate 113, and the edge cutting member 114 described above.

The lower end of the tubular portion 12 reaches a deeper position than the lower end of the tubular portion 11, and the bottom member 122 is located closer to the bottom of the pile than the bottom member 112 of the tubular portion 11. This bottom member 122 is provided with a positioning member 1221 for positioning the inner tubular portion 11.

The positioning member 1221 is a member for fixing the planar position of the bottom of the tubular portion 11 and for positioning. In this embodiment, the positioning member 1221 is a bar material such as a steel rod, but is not limited to this. It can also be a plate material such as a steel plate. As shown in FIG. 3(c), the positioning members 1221 are attached to both sides of the center of the bottom member 122 on each side of the cross-shaped bottom member 122, and are arranged so as to extend upward from each attachment position.

As shown in FIG. 3(b), these positioning members 1221 are arranged on the counterclockwise sides of both ends of one side (vertical side in FIG. 3(b)) of the cross-shaped bottom member 112 of the tubular portion 11, and on the clockwise sides of both ends of the other side (horizontal side in FIG. 3(b)) of the bottom member 112. By abutting the bottom member 112 from the sides, the planar position of the bottom member 112 of the tubular portion 11 can be fixed, and the planar position of the bottom of the tubular portion 11 can be fixed.

The upper ends of the shaft member 111 of the inner cylindrical portion 11 and the shaft member 121 of the outer cylindrical portion 12 protrude upward from the cylindrical portions 11 and 12, respectively, and holes are provided in the protruding portions. A steel rod 30 such as a reinforcing bar is passed through the holes in the shaft members 111 and 121 on both sides of the hollow pile 2, and the steel rod 30 is fixed by welding or the like to a metal end plate 21 provided at the upper end of the hollow pile 2, thereby attaching the removal jig 1 to the hollow pile 2 and preventing it from floating up due to the pile periphery fixing liquid 300b.

As shown in FIG. 4, a cushioning material 115 is provided on the outer surface of the inner tubular portion 11, and an edge-cutting material 116 is further provided on the outer surface of the cushioning material 115. An air cushion or the like is used for the cushioning material 115, and a vinyl sheet or the like is used for the edge-cutting material 116. This is also the case for the outer surface of the outer tubular portion 12, where the cushioning material and edge-cutting material are provided in this order from one side to the other. As with the above, an air cushion or the like is used for the cushioning material, and a floor film or the like is used for the edge-cutting material. It is also possible to provide an edge-cutting material such as a vinyl sheet to cover the lower edges of the tubular portions 11 and 12.

In the above-mentioned Figures 2(b) and (c), when removing the soil cement 301 from the pile head of the hollow pile 2, first cut the steel rod 30 and remove it from the holes in the shaft members 111 and 121. Then, as shown in Figure 5(a), the wire L hanging down from the tip of the backhoe 400 is attached to the upper end of each shaft member 111 using the holes, and the cylindrical portion 11 is pulled up as shown in Figure 5(b). As a result, the soil cement 301 in the section inside the cylindrical portion 11 is removed from the pile head at the same time as the cylindrical portion 11.

The edges between the cylindrical portion 11 and the soil cement 301 outside it, and between the bottom member 112 and the soil cement 301 below it are almost completely cut by the edge-cutting materials 114 and 116. However, when lifting the cylindrical portion 11, the remaining soil cement 301 can be cut by rocking the cylindrical portion 11 from side to side, allowing the cylindrical portion 11 to be lifted up appropriately. The cushioning material 115 on the outside of the cylindrical portion 11 also serves the purpose of making such work possible.

Then, as shown in FIG. 5(c), the outer cylindrical portion 12 is pulled up in the same manner as the inner cylindrical portion 11. As a result, the soil cement 301 in the section between the cylindrical portions 11 and 12 is simultaneously pulled out from the head portion of the hollow pile 2 together with the cylindrical portion 12, and all of the soil cement 301 in the head portion of the pile is removed.

As described above, according to this embodiment, by using the removal tool 1, it is possible to divide the inside of the head of the hollow pile 2 into multiple sections and extract the soil cement 301 from each section individually. This makes it possible to reduce the size and weight of the individual soil cement 301 to be extracted, and even in the case of a large-diameter hollow pile 2, it can be handled with a small lifting machine. As in this embodiment, it is also possible to utilize the backhoe 400 used to excavate the ground around the pile, achieving a significant streamlining of the work.

In addition, the removal jig 1 of this embodiment is composed of cylindrical sections 11 and 12 arranged concentrically, which simplifies the manufacture of the removal jig 1 and allows the soil cement 301 to be easily extracted using the above-mentioned procedure.

In addition, in this embodiment, the positioning member 1221 positions the bottom of the inner cylindrical portion 11, preventing the cylindrical portion 11 from tilting and ensuring verticality. As a result, it becomes easier to remove the inner cylindrical portion 11.

However, the present invention is not limited to the above embodiment. For example, the hollow pile 2 in this embodiment is a steel pipe concrete pile, but it is not limited to this and may be a concrete pile.

The configuration of the removal jig 1 is not limited to the above. For example, as shown in FIG. 6(a), the inner cylindrical portion 11 of the removal jig 1' may be an inverted truncated cone whose diameter decreases toward the bottom of the pile, making it easier to remove the cylindrical portion 11 and the soil cement 301 inside it.

The removal tool 1 is not limited to having cylindrical parts 11 and 12 on the inside and outside, but may be any tool that divides the inside of the pile head into multiple sections. For example, as shown in FIG. 6(b), the removal tool 1a may be a tool in which cylindrical parts 11a and 12a having semicircular flat surfaces are arranged side by side in a plan view. In this case, the removal tool 1a is inserted along the inner periphery of the pile head and the cylindrical parts 11a and 12a are individually removed, so that the soil cement 301 in the sections inside the cylindrical parts 11a and 12a can be individually removed. The example in FIG. 6(b) divides the inside of the pile head into two sections, but it is also possible to configure the inside of the pile head to be divided into three or more sections.

As shown diagrammatically in FIG. 6(c), the removal jig 1b can also be configured such that the inside of a cylindrical body 13 arranged along the inner circumferential surface of the pile head is divided by partitions 14. In this case, too, the inside of the pile head is divided into multiple compartments by left and right tubular parts 131 separated by the partition 14, and the soil cement 301 from each compartment can be extracted individually.

The above describes preferred embodiments of the present invention with reference to the attached drawings, but the present invention is not limited to these examples. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas disclosed in this application, and it is understood that these also naturally fall within the technical scope of the present invention.

1, 1', 1a, 1b: Removal jig 2: Hollow pile 11, 11a, 12, 12a, 131: Cylindrical part 13: Cylindrical body 14: Partition 110, 120: Frame material 111, 121: Shaft member 112, 122: Bottom member 113, 123: Horizontal plate 114, 116, 124: Edge cutting material 115: Cushioning material 300: Cement milk 301: Soil cement 400: Backhoe 1221: Positioning member

Claims (8)

A step (a) of inserting a hollow pile into a hardening material with a removal jig used for removing the hardened material by the hardening material, the removal jig being inserted in advance along the inner peripheral surface of the head of the hollow pile;
(b) removing the hardened material from within the pile head;
having
The removal tool includes a plurality of cylindrical portions that divide the inside of the pile head into a plurality of sections in a plan view,
The plurality of cylindrical portions are arranged concentrically in a plan view,
A removal method characterized in that in the step (b), the cylindrical portion is removed in the order of the inside and outside, so that the hardened material in each section divided by the multiple cylindrical portions is individually removed. A step (a) of inserting a hollow pile into a hardening material with a removal jig used for removing the hardened material by the hardening material, the removal jig being inserted in advance along the inner peripheral surface of the head of the hollow pile;
(b) removing the hardened material from within the pile head;
having
The removal tool includes a plurality of cylindrical portions that divide the inside of the pile head into a plurality of sections in a plan view,
A plurality of the cylindrical portions are arranged side by side in a plan view,
A removal method characterized in that in the step (b), the multiple tubular portions are individually removed, so that the hardened material in each section divided by the multiple tubular portions is individually removed. A step (a) of inserting a hollow pile into a hardening material with a removal jig used for removing the hardened material by the hardening material, the removal jig being inserted in advance along the inner peripheral surface of the head of the hollow pile;
(b) removing the hardened material from within the pile head;
having
The removal tool has a configuration including a plurality of cylindrical portions that divide the inside of the pile head portion into a plurality of compartments in a plan view, and the cylindrical portions are arranged inside the outer cylindrical portions,
A framework is attached to the inside of each of the cylindrical portions,
The framework material has a bottom member arranged in a cross shape in a plan view at an end portion of the cylindrical portion on the pile bottom side,
a positioning member that laterally contacts the bottom member of the inner cylindrical portion to position the inner cylindrical portion is provided on the bottom member of the outer cylindrical portion;
A removing method, characterized in that in the step (b), the hardened material in each section divided by the multiple cylindrical portions is individually extracted. 4. The removal method according to claim 1 , wherein the inner cylindrical portion has a diameter that decreases toward the bottom of the pile. A removal tool that is inserted in advance along the inner circumferential surface of the pile head of a hollow pile to be inserted into a hardening material and is used to remove a hardened material from the hardening material inside the pile head,
A removal tool comprising a plurality of cylindrical sections which divide the inside of the pile head into a plurality of compartments in a planar view , the plurality of cylindrical sections being arranged concentrically in a planar view, and which is characterized in that the hardened material in each compartment can be individually removed by removing the cylindrical sections in order from the inside to the outside . A removal tool that is inserted in advance along the inner circumferential surface of the pile head of a hollow pile to be inserted into a hardening material and is used to remove a hardened material from the hardening material inside the pile head,
A removal tool comprising a plurality of cylindrical portions which divide the inside of the pile head into a plurality of compartments in a planar view , the plurality of cylindrical portions being arranged side by side in a planar view, and which makes it possible to individually remove the hardened material from each compartment by individually removing the plurality of cylindrical portions. A removal tool that is inserted in advance along the inner circumferential surface of the pile head of a hollow pile to be inserted into a hardening material and is used to remove a hardened material from the hardening material inside the pile head,
By providing a plurality of cylindrical portions that divide the inside of the pile head into a plurality of compartments in a plan view, the hardened material in each compartment can be individually extracted ,
The cylindrical portion is disposed inside the outer cylindrical portion,
A framework is attached to the inside of each of the cylindrical portions,
The framework material has a bottom member arranged in a cross shape in a plan view at an end portion of the cylindrical portion on the pile bottom side,
A removal jig, characterized in that the bottom member of the outer cylindrical portion is provided with a positioning member that abuts against the bottom member of the inner cylindrical portion from a side to position the inner cylindrical portion . The removal jig according to claim 5 or 7, wherein the inner cylindrical portion has a diameter tapered toward the bottom of the pile .

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