JPH04221118A - Drawing method for core material of concrete pole and cutting casing used for the method - Google Patents

Abstract

PURPOSE:To dismount a core material without the need of digging the periphery of a pole by cutting the peripery of the core material of the concrete pole extending over the full length of the pole by a cutting casing with cutting claws to pull out the pole portion. CONSTITUTION:A cutting casig 3 is constructed so that a thick steel pipe 11 is concentrically connected to the lower end of a thin steel pipe 10 to form a cylindrical casing body 12. Subsequently, spiral blades 13 are disposed on the inner and outer peripheral surfaces, cutting claws 14 are fitted to the lower end of the body 12, further an air or water supply passage 15 is passed through the inner peripheral surface side, and simultaneously a jet nozzle (a). Thus, a core material can be removed safely and easily without digging the periphery of the concrete pole and breaking the concrete.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to, for example, a core material such as H-shaped steel embedded in a concrete column forming a column retaining wall, or a core material such as H-shaped steel or PC pile. The present invention relates to a method for pulling out the core material of a concrete column itself, and a cutting casing used in the method.

0002

[Prior Art] For example, around an existing building with a basement floor, there are pillar-type retaining walls that are required when constructing the basement floor.
There are concrete columns with core materials such as C piles. Column-type mountain retaining walls are generally made by forming concrete columns (so-called soil piles) in which excavated soil is partially mixed, and when forming every other concrete column, for example, an H-shaped steel is placed in the center of the column. It is constructed by embedding a core material such as P
Concrete columns with core materials such as C piles are constructed by inserting core materials such as PC piles into underground holes formed with an earth auger, driving the lower ends into the ground, and pouring concrete. There is.

When the above-mentioned existing building is removed and a new building is built or expanded over the area where the pillar-row type retaining wall or concrete column exists, the pillar-row type retaining wall or concrete pillar is removed. It is necessary to remove these as they obstruct the construction.

[0004] Removal of this mountain retaining wall and concrete columns is
If there is no core material in the column, it can be easily removed using an earth auger or the like without the need for large-scale heavy equipment, but due to the presence of the core material, conventional methods Either the site is excavated and the concrete around the core material is crushed, or the area around the concrete column is excavated, the concrete around the core is crushed and the core is pulled out.

[0005]

[Problem to be solved by the invention] However, the above work requires a great deal of time and effort, and there is a great danger that the walls of the excavated ground will collapse or the concrete walls from which the core material has been pulled will collapse. Therefore, it was necessary to take measures such as separately providing a retaining wall using sheet piles or the like around the excavated area.

The present invention was devised in view of the above circumstances, and provides a method for safely removing the core material without requiring excavation around the column, and a cutting tool suitable for use in the method. The purpose is to provide casing.

[0007]

[Means for Solving the Problems] A method for pulling out the core material of a concrete column according to the first invention that has achieved the above object is to remove the core material of a concrete column by using a cutting casing equipped with a cutting claw at the lower end. The method is characterized in that the area around the material is cut over the entire length of the column, and after the column portion including the core material formed by this cutting is pulled out, earth and sand is backfilled into the cutting casing, and then the cutting casing is pulled out and recovered. It is said that

In the cutting casing according to the second invention, a plurality of cutting claws are provided at a predetermined interval at the lower end of the steel cylindrical casing main body, and as the casing main body is rotated in the cutting direction by the cutting claws, A spiral wing body is provided on the inner and outer circumferential surfaces of the casing body to lift up the cutting material, and a nozzle for jetting air or water toward the cutting part and a flow path for supplying air or water to the nozzle are provided. It is distinctive in that it has been established.

Further, the cutting casing according to the third invention is provided with a plurality of cutting claws at a predetermined interval at the lower end of the cylindrical lower casing made of steel, and a metal pipe is spirally wound. A possible helical casing is connected across the cylindrical upper casing made of steel and the lower casing, and a nozzle is provided to inject air or water into the cutting section through the pipe channel of the helical casing, and the helical casing is expanded. It is characterized by the provision of an expansion/contraction prevention means for preventing diameter and diameter contraction.

0010

[Operation] According to the method for pulling out the core material of a concrete column according to the first invention, the column part including the core material can be easily removed without the hassle of excavating around the retaining wall or concrete column and crushing the concrete part. It gets pulled out.

[0011] Here, when the cutting claws of the cutting casing cut the concrete part around the core material and the surrounding ground, in the case of a columnar retaining wall, the cutting claws of the cutting casing cut the concrete part around the core material and the surrounding ground. By pulling out the part, only the concrete column without the core material inserted remains in an intermittent state, resulting in P
In the case of concrete columns with core materials such as C piles, the concrete columns themselves will be removed.

[0012] When the cutting claw of the cutting casing cuts within the thickness of the concrete part around the core material,
A column type mountain retaining wall is a coreless mountain retaining wall, and a concrete column with a core material such as a PC pile is a coreless hollow concrete column.

[0013] Since the cutting casing is backfilled with earth and sand before the cutting casing is pulled out, wall collapse around the pull-out hole is prevented even if the cutting casing is pulled out.

After that, if the cutting casing is pulled out and recovered, the remaining concrete structure can be easily removed using an earth auger or the like, if necessary.

According to the cutting casing according to the second and third aspects of the invention, the concrete portion around the core material can be easily cut while being cooled by air or water. Furthermore, since the concrete portion around the core material is cut, the diameter of the cutting casing can be reduced, which is preferable in terms of cost and driving force.

In the cutting casing according to the second invention, the cutting material is lifted and discharged to the ground by the supply pressure of air or water and the spiral wing body inside and outside the casing body,
In the cutting casing according to the third aspect of the invention, the cutting material is lifted and discharged to the ground by the supply pressure of air or water and the spiral portions inside and outside the spiral casing.

By the way, depending on the verticality of the core material inserted into the concrete column, there is a concern that the cutting claws may come into contact with the core material as the concrete portion is cut. Then,
In the cutting casing according to the second invention, since the concrete part is cut in a straight line, the core material is cut after the cutting claw comes into contact with the core material, and the concrete part including the core material is cut out. Not only does it take a lot of time to do this, but part of the core material ends up remaining in the retaining wall or concrete column, which has no core.

In this respect, according to the cutting casing of the third aspect of the present invention, since it has a helical casing that can be flexibly deformed, when the cutting claw at the lower end of the casing comes into contact with the core material as the concrete part is being cut and excavated, This becomes a cutting resistance, and the cutting progress of the cutting claws in that part becomes slow and slow, and in the opposite part, the cutting progresses by the cutting claws, so that the helical center of the spiral casing is This causes the lower casing with the cutting claws to be tilted into a position along the core material.

[0019] After that, the spiral casing is bent and the cutting continues without receiving almost any cutting resistance from the core material, thereby cutting the concrete part without leaving any part of the core material. Cut as specified.

[0020]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 2 shows a cutting casing 3 used to pull out the core material 2 inserted into, for example, every other concrete column 1 of a columnar retaining wall, and a heavy machine 4 to which the cutting casing 3 is connected. , this heavy equipment 4 is located in the operator's room 5
The crawler-type traveling device 7 is provided with a swivel base 6 equipped with a swivel base 6, and a casing driving means 9 for rotating the cutting casing 3 is mounted on a post 8 erected on the swivel base 6.
It is installed so that it can be raised and lowered freely.

FIG. 1 shows an embodiment of the cutting casing 3.
And this cutting casing 3 shown in FIGS. 3 to 5,
The thick-walled steel pipe 1 is attached to the lower end of the thin-walled steel pipe 10 with the inner peripheral surfaces connected.
A spiral wing body 13 is provided on the inner and outer circumferential surfaces of a cylindrical casing body 12 concentrically connected with each other, with the helical direction facing the same direction, and a spiral wing body 13 is provided on the lower end of the cylindrical casing body 12 at a predetermined interval in the circumferential direction. A cutting claw 14 is attached to the air or water supply channel 15 (metal pipe) extending through the spiral blade body 13 on the inner peripheral surface side of the casing. A nozzle a is provided for spouting air or water to the cutting portion made by the cutting claws 14.

More specifically, the cylindrical casing body 12 is formed by connecting a plurality of casing structures 12a, as shown in FIG. Each pipe portion 15a is connected by a simple coupling 16, and the spiral blade portion is configured to be smoothly continuous.

[0023]The uppermost casing structure 12a, which is successively connected as cutting is performed, is connected each time to the drive rotation member 17 of the casing drive means 9, and the drive rotation member 17 is connected to the top casing structure 12a. is a branch pipe 2 connected via a rotary joint 19 to a main pipe 18 located at the center of rotation of the casing drive means 9;
0 is provided, and pipe portions 1 of the uppermost casing structure 12a are sequentially connected to this branch pipe 20.
5a are connected via a coupling 16.

[0024] The cutting claw 14 has an outer edge of the blade body made of the thick-walled steel pipe 1.
1, an intermediate cutting claw 14 whose inner edge of the blade protrudes slightly more inward than the inner surface of the thick-walled steel pipe 11; There are three types of inward cutting claws 14 that protrude inward to a greater extent than the inner surface of the steel pipe 11. The cutting claw 1 is provided at the lower end of the thick-walled steel pipe 11, and
The helical direction of the helical blade body 13 is set so that the helical blade body 13 lifts the cut object as the cylindrical casing body 12 rotates in the cutting direction.

The outer circumferential diameter d1 of the spiral wing body 13 attached to the outer circumferential surface of the casing 12 is the same as that of the thick-walled steel pipe 1.
1, and the outward cutting claw 1
The helical wing body 1 is set to be slightly smaller than the circumscribed circle diameter d2 in contact with the outer edge of the blade body 4, and is attached to the inner circumferential surface of the casing 12.
3 is set to be slightly larger than the inscribed circle diameter d4 that is in contact with the inner edge of the blade of the inward cutting claw 14, and the inscribed circle diameter d4 of the inward cutting claw 14 is set as shown in FIG. As shown in 6,
The diameter d5 of the circumscribed circle is set to be slightly larger than the diameter d5 of the circumscribed circle that contacts the outer end of the core material 2 from which the retaining wall 1 is to be pulled out.

On the other hand, the nozzle a is provided so as to correspond to the arrangement of the outward cutting claws 14, with the air or water jetting port being slightly offset toward the rear in the cutting direction.

Next, referring to FIGS. 1 and 3 to 6 and based on FIGS. The extraction procedure will be explained.

First, as shown in FIG. 7A, the casing structure 12a provided with the cutting claws 14 at the lower end is connected to the drive rotating member 17 of the casing drive means 9, and the pipe portion 15a is connected to the branch pipe 20. The center of the casing structure 12a is aligned with the center of the core material 2 to be pulled out.

Next, the cutting casing 3 is rotated downward while cooling the cutting claw 14 by blowing out air or water from the nozzle a, thereby cutting the concrete portion 21 around the core material 2 of the concrete column 1. The surrounding ground is cut, and the cut material is lifted by the air or water supply pressure and the spiral wing body 13.

As cutting progresses, the casing structure 12a and the pipe portion 15a are successively connected between the casing structure 12a and the drive rotating member 17, as shown in FIG.
As shown in (B), the core material 2 of the concrete column 1
The entire length of the column is cut around it.

[0031] Once cutting has been completed over the entire length of the column around the core material 2, the driving rotating member 17 of the casing driving means 9 is removed, leaving the cutting casing 3 as shown in FIG. 7(C). Until, for example, crane 23
The column portion 1a including the core material 2 is pulled out by means of methods such as the above, and is moved out of the working range as necessary.

Next, as shown in FIG. 7(D), earth and sand are poured into the cutting casing 3, and as shown in FIG. 7(E), the driving rotating member 1 is inserted into the casing driving means 9.
7 and connect it to the top casing structure 1.
2a, the cutting casing 3 is recovered by the casing driving means 9, and the hole 22 formed by pulling out the column part 1a is backfilled with earth and sand to prevent wall collapse of the ground around the hole 22. Let it happen.

[0033] According to the above method, the core material 2 can be safely and easily pulled out without the trouble of digging around the periphery of the retaining wall and crushing the concrete portion 21, and can be turned into a so-called coreless mountain retaining wall, which is made up of intermittent concrete columns with no core material inserted through them. Therefore, the retaining wall can later be removed using simple heavy equipment such as an earth auger, if necessary.

Moreover, since the cutting part of the cutting claw 14 is cooled by supplying air or water, the concrete portion 21 around the core material 2 can be cut well, and the supply pressure of the air or water is applied to the helical wing body. By synergistically with the lifting of the cut object by the rotation of 13, the cut object is also lifted up satisfactorily.

Furthermore, the extraction hole 22 of the columnar portion 1a
Since the inside is backfilled with earth and sand, the ground around the hole 22 may be subject to earth pressure or vibrations caused by heavy machinery.
A dangerous situation in which the wall surface around the hole 22 collapses is avoided.

[0036] If the above method is used to pull out the core material 2 of the concrete column 1 whose core material is a PC pile or the like, the concrete column will be removed by pulling out the column part 1a including the core material 2. Body 1 itself is removed. Alternatively, when cutting within the thickness of the concrete portion 21 around the core material 2 with the cutting claws 14, the columnar type retaining wall becomes a coreless retaining wall, and PC piles etc. are used as the core material 2. The concrete column will be a coreless hollow concrete column.

FIG. 8 shows another embodiment of the cutting casing 3. This cutting casing 3 includes a cylindrical upper casing 31 made of steel connected to a driving rotation member 17, a cylindrical lower casing 32 in which a plurality of cutting claws 14 are provided at a lower end at a predetermined interval, and an upper and lower cylindrical lower casing 32. It is mainly composed of a helical casing 33 extending over the casings 31 and 32 of the part, and an expansion/contraction preventing means 34 for preventing diameter expansion and diameter reduction of the helical casing 33. A nozzle a is provided for spouting air or water.

More specifically, as shown in FIG. 9, the upper casing 31 is made by cutting two substantially rectangular materials 31a with slightly inclined lower edges from a steel plate with a wall thickness of 45 mm, for example. The edges of the two materials 31a are formed by forming semicircular flow path portions b along the vertical direction on both left and right edges, bending the material 31a into a semicylindrical shape, and making the upper edges flush. They are welded together, and two air or water supply channels B are formed by the semicircular channel portion b.

The cylindrical lower casing 32 has the same shape as the upper casing 31 but is turned upside down, and is made of two pieces of material 32 whose upper edges are slightly inclined.
Forming semicircular flow path portions c along the vertical direction on both left and right edges of a, bending this material 32a into a semicylindrical shape, and
It is made by welding the edges of two pieces of material 32a with their lower edges flush with each other, and two air or water supply channels C are formed by the semicircular channel portion c.

A plurality of cutting claws 14 are provided at a predetermined interval in the circumferential direction at the lower end of the lower casing 32, which is flush with the lower end of the lower casing 32. Nozzle a is screwed onto C.

The cutting claws 14 include an outward cutting claw 14 in which the outer edge of the blade protrudes a little further outward than the outer surface of the lower casing 32, and an intermediate cutting claw 14 in which the outer edge of the blade body protrudes slightly more inward than the inner surface of the casing. There are three types of cutting claws 14 and inward cutting claws 14 in which the inner edge of the blade protrudes more inward than the inner surface of the casing, and parts of the claws that are adjacent in the rotational direction of the cutting casing 3 are lapped with each other, Three sets of them are provided at the lower end of the casing. Although not shown, the inward cutting claw 1
The diameter of the inscribed circle of No. 4 is set to be slightly larger than the diameter of the circumscribed circle that contacts the outer end of the core material 2 from which the concrete column 1 is to be pulled.

As shown in FIGS. 10 and 11, the spiral casing 33 is made of metal pipes, for example, two boiler steel pipes with an outer diameter of 40 mm and a wall thickness of 11 mm, which are connected to each other in a spiral portion. It has a double helical structure in which the spirals 33a are right-handed so that they intertwine, and the center of the helix can be bent and deformed.

Then, the upper end of the spiral casing 33 is welded to the upper casing 31 so that the upper end of the pipe passage A of the spiral casing 33 communicates with the supply passage B of the upper casing 31, and the pipe passage A is connected to the supply passage B of the upper casing 31. The lower end of the spiral casing 33 is connected to the lower casing 3 so that the lower end of the spiral casing 33 is connected to the supply channel C of the lower casing 32.
It is welded to 2.

Furthermore, U-shaped metal bands 35 are secured to the first to third spiral portions 33a on the upper and lower sides of the spiral casing 33 at appropriate predetermined intervals. In addition to welding to the spiral portion 33a, the metal band 35 is attached to the upper and lower casings 31, respectively.
, 32, the upper and lower casings 31, 32 are welded to the upper and lower casings 31, 32.
The connection strength of the helical casing 33 to the helical casing 33 is increased.

The expansion/contraction prevention means 34 consists of a set of three U-shaped metal bands 36, and the plurality of sets are appropriately locked to two vertically adjacent spiral portions 33a, and each set is In this case, a lower spiral portion 33a is attached to both ends of one central metal band 36 that is locked to the upper spiral portion 33a.
The two metal bands 36 latched to the metal bands 36 are brought into contact with each other, and both lower ends of the metal bands 36 are welded to the lower helical portion 33a, respectively, so that the helical casing 33 is excavated in the clockwise direction. Diameter expansion due to rotation and spiral casing 33
The diameter reduction caused by the rotation of the metal bands 36 in the counterclockwise direction is prevented by the side ends of the adjacent metal bands 36, 36 coming into contact with each other.

[0046] Between the spiral portion 33a and the metal band 36 locked thereto, and between the metal band 3
6 and the upper spiral portion 33a of this, 2 to 3 mm.
The spiral portions 33a, which are adjacent to each other on the upper and lower sides, with a gap of
33a are made close to each other so that the helical center of the helical casing 33 can be bent.

Reference numeral 37 in the figure denotes a metal band for connecting the upper and lower helical portions 33a of the helical casing 33, which is provided in the same form as the metal band 36 of the expansion/contraction prevention means 34, and these metal bands 36 , 37 have a function of preventing the spiral portions 33a of the spiral casing 33 from expanding.

It should be noted that the arrangement of the metal bands 36 is not limited to the above-mentioned arrangement of three metal bands, for example, as shown in FIG.
As shown in FIG. 2, multiple sets of four metal bands 36 are appropriately locked to two vertically adjacent spiral parts 33a, and in each set, the upper spiral part 33
Two metal bands 36 are locked at intervals on a, and the lower ends of these are welded to the lower spiral portion 33a, and these two
Two metal bands 3 are fixed to the lower spiral portion 33a at one end and the other end of the metal bands 36, respectively.
6 are brought into contact with each other, and the lower end thereof is welded to the lower helical portion 33a, thereby expanding the diameter of the helical casing 33 as it rotates in the clockwise direction and pulling out and rotating the helical casing 33 in the counterclockwise direction. It is possible to make a modification such that the diameter reduction caused by this is prevented by abutment of the side ends of the adjacent metal bands 36, 36.

According to the above configuration, as shown in FIG. 13, when the core material 2 inserted into the concrete column 1 is slightly inclined, as the concrete portion 21 is cut by the cutting casing 3, the core material 2 is slightly tilted. Eventually, the cutting claws 14 will come into contact with the inclined core material 2, but when the cutting claws 14 come into contact with the core material 2, this becomes cutting resistance and the cutting claws 14 at that part become abutted. Cutting progress becomes delayed, and
On the opposite side, the cutting by the cutting claws 14 progresses in a more advanced manner, so that the upper and lower helical portions 33a of the helical casing 33 on the side where the cutting progress is delayed come closer to each other.

[0050] As a result, the helical center of the helical casing 33 is bent, the lower casing 32 is tilted to a position along the core material 2, and the cutting claws 14 are able to cut the concrete portion 21. After that, the cutting continues in the bent position in which the spiral casing 33 is bent, without receiving almost any cutting resistance from the core material 2, and the concrete column 1 is cut without leaving any part of the core material 2. Core material 2
The surrounding concrete portion 21 can be cut over the entire length of the column.

[0051]

[Effects of the Invention] As explained above, according to the method for extracting the core material of a concrete column according to the present invention, it is possible to safely and efficiently remove the core material of a concrete column without the hassle of excavating around the retaining wall or concrete column or crushing the concrete part. It is possible to easily pull out the column part including the core material, thereby making it possible to create a columnar retaining wall or concrete column into a so-called coreless concrete structure, or to remove the concrete column itself. be able to.

Moreover, since earth and sand are backfilled into the cutting casing before the cutting casing is pulled out, a dangerous situation such as collapse of the wall around the extraction hole even if the cutting casing is pulled out can be reliably avoided. Ru.

On the other hand, according to the cutting casing of the present invention, the concrete part around the core material can be easily cut while being cooled by air or water, and the cut material can be easily cut by the supply pressure of air or water, inside and outside the casing body. The helical airfoil or the helical part of the helical casing itself effectively lifts and discharges it to the ground.

[0054] Furthermore, by configuring the cutting casing to cut the concrete portion around the core material, the diameter of the cutting casing can be reduced to suitably reduce costs and driving force.

In particular, according to the cutting casing of claim 3, since it has a helical casing that can be flexibly deformed, when the cutting claw at the lower end of the casing comes into contact with the core material as the concrete part is being cut, The abutting part acts as a cutting resistance, causing the helical center of the helical casing to bend, and the lower casing is tilted to a position along the core material, so that the helical casing is deflected without receiving almost any cutting resistance from the core material. Cutting of the concrete part continues in the bent position, and regardless of the verticality of the core material, the concrete part can be cut over the entire length of the column without leaving any part of the core material.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a cutting casing and a driving rotating member.

FIG. 2 is a side view of a heavy machine to which a cutting casing is connected.

FIG. 3 is a sectional view of the lower part of the cutting casing.

FIG. 4 is a cross-sectional plan view of the cutting casing.

FIG. 5 is a partial cross-sectional view of the casing structure.

FIG. 6 is a bottom view of the cutting casing.

FIG. 7A to FIG. 7E are explanatory diagrams showing a procedure for pulling out a core material.

FIG. 8 and subsequent figures show another embodiment of the cutting casing, and FIG. 8 is a perspective view of the cutting casing.

FIG. 9 is an exploded perspective view showing details of the upper casing.

FIG. 10 is a detailed view of the expansion/contraction prevention means.

FIG. 11 is a sectional view of the expansion/contraction prevention means.

FIG. 12 is a detailed view of another embodiment of the expansion/contraction prevention means.

FIG. 13 is a sectional view showing the spiral casing in a bent state.

[Explanation of symbols]

1... Concrete column, 1a... Column part, 2... Core material, 3
... Casing for cutting, 12 ... Cylindrical casing body, 13
... Helical wing body, 14 ... Cutting claw, 15 ... Supply channel, 31 ... Upper casing, 32 ... Lower casing, 33 ... Spiral casing, 34 ... Expansion/contraction prevention means, a... Nozzle, A... Pipe flow path.

Claims (3)

[Claims] Claim 1: After cutting around the core material of a concrete column over the entire length of the column using a cutting casing equipped with cutting claws at the lower end, and pulling out the column portion including the core material formed by this cutting, A method for extracting a core material from a concrete column, comprising backfilling the cutting casing with earth and sand, and then pulling out and recovering the cutting casing. 2. A spiral blade that has a plurality of cutting claws provided at a predetermined interval on the lower end of a steel cylindrical casing body, and lifts a cut object as the casing body is rotated in the cutting direction by the cutting claws. A cutting device characterized in that a body is provided on the inner and outer circumferential surfaces of a casing main body, a nozzle for ejecting air or water toward the cutting part, and a flow path for supplying air or water to the nozzle. casing. 3. A flexibly deformable helical casing made of a steel cylindrical lower casing provided with a plurality of cutting claws at predetermined intervals at the lower end thereof and a metal pipe spirally wound. A nozzle is connected across the cylindrical upper casing and the lower casing, and is provided with a nozzle for jetting air or water to the cut portion through the pipe channel of the helical casing, and further includes an expansion/contraction prevention device that prevents the spiral casing from expanding or contracting in diameter. A cutting casing characterized by being provided with a means.