JP4490710B2 - Pile foundation construction equipment and construction method - Google Patents

Description

  The present invention relates to a construction apparatus and a construction method for a pile foundation used for a foundation of a building such as a house, and in particular, constructs a solidified material column below a pile hole dug vertically from the ground, and the solidified material column. It is related with the construction method of the pile foundation which embeds the lower part of an existing support pillar member so that it may be positioned in the upper part, and integrates and constructs | assembles two types of pillar members.

Conventionally, when constructing a structure such as a house or other small-scale building, the condition of the ground at the construction site is investigated, and the strength of the ground supports the structure to be built. If it is determined that it cannot be done, construction is being carried out to increase the support capacity. In order to increase the bearing capacity of the ground, an existing pile such as concrete or a steel pipe pile or the like is placed, a columnar ground improvement is performed, or an existing pile member is attached to a hole subjected to the ground improvement. Various construction methods such as casting and integration are used. The construction method generally used as the support column is known to use, for example, technical means as disclosed in the following document 1, and mixes the soil in the excavation hole and the solidified material. As an example, it is possible to easily construct a foundation with a support pillar integrated with a pillar of improved soil by placing an existing pile in a pillar-shaped improved soil structure. It is known (see Patent Document 1).
Japanese Patent Publication No.1-40173

  In the conventional method as disclosed in the above-mentioned conventional example, the soil that is considered to be excessive when the ground is excavated, that is, the soil whose volume is increased by being loosened by an auger or the like is eliminated in advance. Thus, it is possible to easily dispose of excess soil after the ground improvement work. However, in the case of using the conventional construction method, in order to mix while solidifying material (cement milk or the like) is pressed into the soil excavated by the excavating blade, the solidified material and the soil are mixed on the ground surface during mixing. There is a drawback that the solidified material overflows or the solidified material flows out through gaps in the ground, and the injected solidified material is consumed wastefully. Therefore, even if the amount of solidification material set according to the design value is pumped, it will not be mixed with the soil, and an improved pillar with improved ground will not be built. There were many questions about the strength of the.

  In addition, since the method of injecting the solidified material at a high pressure is used, the soil near the ground surface may rise, and in addition to requiring disposal of the soil, the solidified material is mixed. If some of the soil is discharged to the ground, it may be necessary to remove the discharged soil. However, since the soil discharged from the excavation hole is mixed with a solidifying material, it cannot be dumped as it is or used for landfill. And, since it is necessary to treat it as industrial waste according to a special disposal method, there are still problems such as extra costs for disposal of residual soil and many disadvantages that need to be resolved later. .

  The present invention constructs a solidified pillar of a predetermined height in the lower part of the pile hole, and embeds and integrates the base of an existing underground pile member in the solidified pillar without discharging residual soil. The object of the present invention is to provide a pile foundation construction device that can reduce the construction cost of the pile foundation and increase the strength of the pile, and a construction method for constructing such a support pile.

The present invention relates to a pile foundation construction device for excavating a pile hole perpendicular to the ground, placing a solidified material to a predetermined depth below the excavated pile hole, and constructing a column of the solidified material.
According to a first aspect of the present invention, in the excavator of the construction apparatus, a double rod member configured to be slidable by combining hollow inner and outer rod members concentrically and arranged so as to be slidable is used. Are provided in combination with each other for the drive member that provides
Of the double rod members, the excavation means for digging the ground is provided on the excavation blades held at the lower end portion of the middle rod member, and the screw-like flight member is provided on the lower end portion of the outer rod member, respectively. Provided,
The excavation blade held at the lower end portion of the middle rod member is positioned below the screw-like flight member at the lower end portion of the outer rod member, and the flight member provided at the lower end portion of the outer rod member has an upper portion. It is configured as a screw-shaped conical shape with a small diameter and a large lower diameter, and the excavation blade and the flight member can act as one screw-shaped excavation / stirring mechanism, and individually based on each configuration Configure as a mechanism that can move up and down,
The outer rod is supported via a cylinder device between a middle head member provided at the upper end of the outer rod member and a rotary head of the upper device provided with a suspension support means and a drive means, and the concentric circles are supported. Of the double rod members combined in a shape, the middle rod member is fixed and held at the lowered position, and only the outer rod member is raised, and formed between the upper and lower flight members and the excavating blades. Corresponding to the operation of filling the space with the solidifying material,
By performing the operation of raising the outer rod member, the action of pressing the soil excavated by the excavating blade toward the hole wall is performed at the upper portion of the flight member.

In the invention of claim 2, following the step of excavating the pile hole using the excavator provided by combining the lower excavation blade and the upper flight member with respect to the double rod member, While holding the excavating blade fixed to the bottom of the hole and gradually raising the flight member, letting the step of ejecting the solidified material,
When raising the upper flight member with respect to the lower excavation blade,
Drive means for individually operating the two mechanisms is provided so as to push up the upper flight member with reference to the excavating blade fixed to the lower part.

The invention of claim 3 relates to a construction method of a pile foundation,
A pile hole is excavated perpendicularly to the ground using the pile foundation construction device, and a solidified material is injected up to a predetermined height above the bottom surface of the dug pile hole to form a solidified columnar structure. At the time, the lower excavation blade and the upper flight member of the excavator are driven as an integral unit,
While digging the pile hole with the excavator to a predetermined depth, following the step of operating to excavate without removing the soil on the ground surface,
While the lower excavation blade is stopped and held at the bottom of the hole, the solidified material is ejected from the ejection holes provided in the middle rod at the upper portion of the excavation blade while gradually lifting the flight member, and the upper and lower flight members and While filling the solidified material in the space formed between the excavating blades, constructing the solidified material column to a predetermined height in sequence, constructing the solidified material column of a predetermined length,
Before the solidified material pillar solidifies, it is erected by embedding underground pile members to a predetermined depth,
A foundation of a structure is constructed on the upper part of the underground pile member.

According to a fourth aspect of the present invention, an underground pile member is erected in the pile hole before the solidified pillar is solidified, and a base portion of the underground pile member is placed in the solidified structure. Integrated so as to be buried at a predetermined depth,
For the underground pile member constructed as an integrated pile in the state of standing above the solidified material pillar, an auxiliary means for promoting integration with the solidified material constructed in a column shape is provided. Provided in combination,
The auxiliary means has a function of aligning the core of the underground pile inserted and erected with the excavated pile hole.

  When constructing a column with only solidified material in the lower part of the excavated pile hole using the device configured as described above, the planned amount of all solidified material is placed in the lower part of the pile hole as a column without soil mixing. Since it is constructed and an existing pile is erected and integrated on it, the reliability and strength of the column of solidified material are sufficiently ensured. In the pillar constructed by the construction device, the wall is reinforced by pressing the soil against the wall of the excavated hole, so even if there is a gap in the soil at the site, the gap etc. Therefore, a pillar made of only the injected solidified material can be easily built without waste, and its supporting column is a solidified material (concrete) column that is stronger than a soil-improved soil column mixed with soil. The strength of can be increased. In addition, the underground pile member standing upright in a state where the base is embedded in the column of the solidified material can be fixedly held in a state of being centered in the center of the excavated hole by a guide action by an auxiliary member attached to the lower part thereof, It is possible to easily perform the work of standing the existing underground pile member. And since construction can be performed without discharging soil when constructing underground piles, cleanup is easy and additional costs associated with the construction can be reduced.

  When the pile foundation construction method described below is carried out, it is fixed to a vehicle such as a crane equipped with a self-propelled suspension arm, or to the site, in the same manner as a conventionally known cast-in-place pile construction device. It can be used as being supported by a bowl-shaped support device. Concentrated cement milk or mortar-like solidified material is manufactured for the pile foundation construction equipment, and the solidified material pillar is built in the excavation hole by ejecting it from the ejection hole through the hollow part of the middle rod. For this purpose, it is equipped with a combination of solidifying material supply mechanisms. Further, in the operation of supplying the solidified material, the amount of the solidified material supplied can be automatically adjusted according to the control information of the supply amount designed in advance according to the speed at which the upper excavation blade is raised. A combination of various adjusting means such as

  In addition to the above configuration, the screw-like wing member provided at the lower part of the outer pipe is movable in the upward direction so as to be separated from the excavating wing with respect to the drilling wing attached to the lower part of the inner pipe of the excavator. Thus, it is possible to obtain a columnar underground structure by performing ground improvement with high reliability without removing excess soil from the upper part of the excavated hole. Therefore, if it is possible to cope with the requirements described above, it is possible to cope with the soil conditions at the site by improving some mechanisms in the apparatus described below, or a part of limited equipment It is possible to improve and use.

  According to the illustrated example, the configuration of the apparatus of the present invention will be described first. The illustrated working device 1 can be configured as a construction device provided with a mechanism similar to a conventional cast-in-place pile construction device. For example, a device having a mechanism as shown in FIG. 1 can be used. it can. The work device 1 uses a support arm 3, 3 a that protrudes from a crane device or other self-propelled work vehicle 2 to fix and support a column member 5 that is erected at a predetermined height. The upper device 10 is supported by the winch 4a so as to be movable up and down. The upper device 10 that is moved up and down along the column member 5 is provided with a drive mechanism that drives the rods 15 and 18 of the excavator, and drives the double concentric rods 15 and 18. Drill a vertical hole.

  Further, in the double hollow pipe member that is supported by the support device 10 via the rotary head 11 and is used for excavation of a pile hole, the intermediate rod 15 is supported by the rotary head 11 as shown in FIG. The excavator blade 16 provided at the lower end is responsible for excavating the hole. The outer rod 18 arranged as a double pipe with the middle rod 15 inserted therein is provided with a flight member 19 at its lower end, but the upper portion of the outer rod 18 is connected to the middle head member 12. It is fixed. A cylinder device 13... Is arranged between the rotary head 11 and the middle head member 12 so that the distance between the two heads 11 and 12 can be changed. It is comprised so that 18 can be slid. The flight member 19 is composed of a spiral flight having a small diameter at the top and a large diameter at the bottom, and the outer diameter of the spiral is the diameter of the excavation blade 16 of the middle rod located at the bottom. And are formed with substantially the same outer diameter, and are formed as a screw conical shape as a whole.

  Of the two head members, when the middle head member 12 is separated from the rotary head 11, the excavating blade 16 of the middle rod 15 and the flight member 19 of the outer rod 18 are brought close to each other. And the operation | movement which excavates the excavation hole 20 can be performed by rotating the two wing members 16 and 19 simultaneously. On the other hand, the operation of shrinking the cylinder device 13 between the rotary head 11 and the middle head member 12 is performed, and the middle rod 15 is moved upward by moving the outer rod 18 relative to the middle rod 15. Since the flight member 19 of the outer rod 18 is gradually separated from the excavation blade 16, a space portion where no soil enters can be formed between the two blade members 16, 19. It can be used as a space to be filled with a solidifying material.

  In the excavator 14, an excavation blade 16 is provided at the lower end portion of the middle rod 15, and the excavation blade 16 corresponds to conditions such as soil properties of the formation and the shape of the excavation blade and the blade member (for excavation). The conditions such as the bit provided at the tip of the flight) are arbitrarily selected from the examples of conventionally known excavators. In the construction device 1, the upper device 10 moved up and down along the column member 5 is provided with a mechanism for supplying a mortar-like solidified material through the middle rod 15 of the excavator 14. . As the solidification material supply mechanism, an arbitrary pipe member 8 is supplied to the upper device 10 from a supply device 7 combining a mixer and a pressure pump, and a solidified material having fluidity such as mortar is applied to the middle rod 15. It is configured to supply toward.

  An operation process for excavating the excavation hole 20 using the excavation apparatus 14 of the construction apparatus 1 configured as described above will be described below with reference to FIG. As in the example shown in FIG. 3A, first, the rotary head 11 is driven in a state in which the excavation blade and the flight member are integrally combined, and the excavator 14 is perpendicular to the ground at a predetermined depth. A drilling hole 20 is drilled. The soil 22 in the excavation hole 20 excavated by the excavator 14 is excavated soil 22 even if a part of the soil above the hole is discharged to the ground in the state where the soil of the natural ground is loosened. Most of the remaining remains in the borehole 20 in a state of being stirred.

  Next, as shown in FIG. 3 (b), the outer rod 18 is gradually lifted upward while keeping the middle rod 15 fixed to the bottom portion of the excavation hole 20. When pulling up the outer rod 18, the head portion 11 supporting the upper portion of the cylinder device 14 is raised so that the middle head 12 approaches, so that the excavating blade 15 is stretched to the bottom of the hole, The flight member 19 is operated to be pulled up. At that time, the solidified material is ejected from the ejection holes 17 of the middle rod 15, and the gap formed between the upper and lower wing members 16, 19 is filled with the solidified material 23.

  The operation of raising the flight member 19 together with the outer rod 18 is performed by moving the middle head 12 closer to the rotary head 11 of FIG. 2, that is, by operating the cylinder device 14 in a contracting direction. Further, by performing the operation of raising the flight member 19 without rotating the outer rod 18, the loosened soil 22 positioned above the excavation hole 20 is formed by the conical slope of the flight member 19. The conical flight member 19 is pressed against the wall of the borehole 20 by a guide action. And while raising the said flight member 19 at low speed, the effect | action which strengthens the wall of a hole is performed by performing the effect | action which strongly presses the excavated soil toward the wall of a hole.

  As described above, the excavation blade 16 is fixed to the bottom of the excavation hole 20, and the flight member 19 is lifted, and the mortar or the like is injected into the gap between the upper and lower blade members 16, 19 from the ejection hole 17. The solidified material 23 is supplied to construct the columnar solidified layer 24. As shown in FIG. 3C, the column solidified layer 24 is constructed by injecting a solidified material until a predetermined height is reached, and the solidified material supplied from the upper part of the middle rod 15 is used. The material 23 is pushed from the ejection hole 17 at a predetermined pressure, and the flight member 19 is pushed up by the solidified material 23 in a pressurized state at the same time.

  After the work of supplying the solidified material 23, as shown in FIG. 4D, the excavating blade 16 of the middle rod 15 is raised and pulled up to the upper part of the columnar solidified layer 24, thereby The columnar solidified layer 24 (solidified material column 23) that is not solidified and has a height of H is left in the lower portion. In the upper part of the columnar solidified layer 24, the loosened soil 22 remaining in the excavation hole 20 is raised while the excavation blade 16 and the flight member 19 are rotated in the reverse direction, so that the soil above the hole is formed. It remains in the excavation hole 20 without being discharged to the ground surface. When the intermediate rod 15 and the outer rod 18 are pulled up, the rod member is not rotated in the reverse direction but pulled up at a low speed without rotating, so that the soil is pressed toward the hole wall by the slope shape of the flight member 19. Then, the hole for inserting the pipe pillar as the next underground pile member is left. In addition, although it demonstrates by using the said pipe pillar member as an underground pile member demonstrated in a present Example, as this pillar, conventionally well-known arbitrary pile members, for example, H-section steel, a concrete pillar, Etc. can be arbitrarily used.

  After the steps shown in FIGS. 3A to 3D, the excavation hole 20 in which the columnar solidified layer 24 (solidified material column 23) is formed in the lower portion is created, and then the solidified material column 23 is solidified. Before, the pipe pillar 30 is inserted as shown in FIG. A lower rebar member 31 having a predetermined shape is integrally provided at the lower portion of the pipe column 30 as auxiliary means for promoting integration of the column with the solidified material. It fixes to the lower part of the pillar 30, and is provided so that it may stretch around it. The pipe column 30 is positioned so as to coincide with the center of the columnar solidified layer 24 and the core of the pile hole, and is fixedly held in the column 23 of the solidified material. As described above, the pipe pillar 30 standing in the excavation hole 20 is provided so as to protrude from the ground surface to a predetermined height. Alternatively, the upper portion of the pipe pillar 30 is protruded to a predetermined height in a foundation construction groove constructed by excavating the ground. And, by projecting the upper part of the pipe pillar in the groove for the foundation that has been dug, by placing the concrete for the foundation, a part of the protruding pillar is integrated with the base, Build and use the foundation of the building firmly.

  Further, the lower reinforcing bar member 31 for holding the pipe column 30 with respect to the columnar solidified layer 24 positioned below the pipe column 30 is formed of a pipe column and a solidifying material as shown in FIG. It attaches so that the effect | action which integrates both members with a pillar may be exhibited. As shown in FIG. 2B, the lower reinforcing bar member 31 includes an insertion part 32 to be inserted into the pipe column 30 and an outer member 33 that protrudes outward from the bottom part of the lower reinforcing bar member 30 with a predetermined diameter. The outer diameter of the outer member 33 is preferably substantially the same as the inner diameter of the excavation hole 20. Further, as shown in FIG. 5C, the lower rebar member 31 is not used with only one member, and the rebar is crossed at the lower part of the pipe column 30 so that two or more lower rebar members 31 are used. By arranging them in combination, it is possible to easily position the existing pile to be driven later, in accordance with the center portion (axial core) of the excavated pile hole. In addition to the above configuration, the reinforcing material insertion portion 32 is fixedly held inside the pipe at the lower part of the pipe column so that the solidified material can enter the pipe column from the opening at the lower part of the pipe column 30 driven later. Thus, the columnar solidified layer 24 is also strongly integrated through the outer member 33 of the reinforcing bar 31.

  As described above, after drilling the pile hole with the auger device, the bottom of the hole is filled with solidification material such as concrete, and the pipe column is erected on the top of the concrete column to create a highly reliable pile foundation. It is possible to build. By the way, the apparatus shown in FIG. 6 will be described as a modification of the excavator described in FIG. In the excavating apparatus illustrated in FIG. 6, the rods 15 and 18 arranged in a double concentric shape are moved by the upper apparatus 10 which is moved up and down along the support member 5 and has a rotation mechanism for the rod. Although it drives, it is the same as that of the said Example also that the said double rod, the excavation blade 16 provided in the lower part of the rod, and the flight member 19 are provided.

  In this embodiment, a casing member 35 is provided on the upper portion of the outer rod 18, and the casing member 35 is pushed in from the upper portion of the excavation hole 20 so that the hole wall is protected in a portion close to the ground. . The casing member 35 can be configured as a cylindrical member having an arbitrary length, and the diameter of the cylinder is slightly larger than the diameter of the pile hole to be excavated. Further, the lower portion of the casing member 35 is formed in a taper shape so that it can be easily inserted into the pile hole. And, in the middle of the work of digging the pile hole by the excavating blade, the hole is protected by inserting the casing from the upper part of the hole, the working device moves on the ground, the vibration generated from the working part, etc. Thus, the hole wall at the top of the pile hole can be prevented from collapsing.

  An elevating device 40 is provided for sliding the double rods 15 and 18 with each other, that is, for the operation of sliding the outer rod 18 with respect to the middle rod 15. The lifting device 40 is configured such that the lower device 42 is integrated with a reaction force plate 41 provided on the upper portion of the casing member 35, and the lower portion of the cylinder device 45 is fixed to the lower device 42. Provided. The telescopic rod 46 provided in the cylinder device 45 is provided with a chuck member 47 at an upper end portion thereof, and when the chuck member 47 is slid with respect to the intermediate rod 15 and thereafter a force in the opposite direction is applied. Further, the chuck member 47 is locked in a state in which the middle rod 15 is engaged, and acts to move the outer rod 18 up and down by the force of the cylinder device 45.

  In the example illustrated in FIG. 6, the lifting device 40 is provided with two cylinder devices 45, 45 a. By alternately operating the two cylinder devices 45, 45 a, An action of sliding the outer rod 18 in the shape of a scale insect is performed. That is, in this embodiment, the same operation as the excavation of the pile hole described in FIG. 3 is performed, but in the operation of raising the outer rod 18 little by little from the hole, the lifting device 40 is used, The operation of excavating the pile hole and the action of protecting the upper portion of the hole wall are performed by inserting the casing member 35 into the hole.

  7A to 7C will be described with reference to FIGS. 7A to 7C, with reference to FIG. 3, an operation process of supporting the excavation device 14 using the lifting device 40 and excavating the excavation hole 20. In the example shown in FIG. 7A, as in the example shown in FIG. 3A, first, excavation is performed by driving the rotary head in a state where the excavating blade 16 and the flight member 19 are integrally combined. . Next, after drilling the hole 20 to a predetermined depth, as shown in FIG. 5B, the solidified material is supplied from the jet port 17 toward the bottom portion of the hole, and the cylinder device 45 of the lifting device 40, The operation | movement which raises the outer rod 18 and the flight member 19 one by one is performed using 45a. When the hole 20 is dug down, when the casing member 35 is gradually inserted from the upper part of the hole 20 and the hole 20 reaches a predetermined depth, the wall at the upper part of the hole as shown in FIG. To protect.

  As shown in FIG. 7 (b), the solidifying material is filled from the lower part of the hole, and when the solidifying material 23 reaches a predetermined height (shown in FIG. 7 (c)), Finish the injection process. Thereafter, as shown in FIG. 3 (d), the excavator is pulled out from the hole and, as shown in FIG. 4, the rebar 31 is inserted into the solidified material, and then the pipe member 30 as a support column. To support the work of building the support foundation for buildings, etc.

  In the embodiment of the present invention, in order to improve the supporting strength, a column of a solidifying material capable of exhibiting a predetermined strength is provided at the lower end portion of the pile hole and used as a pile foundation used for a foundation of a building such as a house. Is possible. In particular, in a pile hole dug vertically (or vertically) from the ground, a solidified column is constructed at the lower end of the pile hole, and the lower part of the support column member is embedded in the solidified column, and integrated with the column By doing so, the reliability of the foundation can be improved. And when constructing a structure such as a house or other small-scale building, according to the result of investigating conditions such as the strength of the ground in the construction site in advance, the structure against the insufficient strength in the ground It is possible to easily construct a construction that sufficiently exhibits the strength to support an object.

  When constructing a column with only solidified material in the lower part of the excavated pile hole using the device configured as described above, the planned amount of all solidified material is placed in the lower part of the pile hole as a column without soil mixing. Since it is constructed, it is erected by driving a pre-made pile onto it and integrated so as to act as one pile, so that the reliability and strength of the column of solidified material can be sufficiently secured. And, in the pillar constructed by the construction apparatus as described above, the process of strengthening the hole wall by adding the action of pressing the soil to the wall of the excavated hole by the operation of pulling up the flight member. Since it has given, the intensity | strength of the support pillar standing in the excavation hole can be set more largely. Moreover, the underground pile member by the existing pile member standing upright in the state which embeds the base (lower part) in the column of the solidification material is guided to the center of the drilled hole by the auxiliary member provided in the lower part. It is positioned in the centered state, and the underground work of the underground pile member can be easily performed. Furthermore, since construction can be performed without discharging excess soil to the ground when constructing underground piles, it is easy to clean up after the construction, and additional costs associated with construction can be reduced.

  In the embodiment of the present invention, when a concrete support pillar is constructed at a predetermined height in the excavated pile hole, the height of the concrete pillar is the strength of the ground for constructing the foundation, etc. Depending on the, it can be constructed as of any height. In addition, when constructing the foundation pillar using the solidified material, it is possible to provide pillar supporting means having an arbitrary thickness depending on the weight, structure, etc. of the building constructed on the upper part. It is also possible to appropriately set the strength and other conditions. Furthermore, when constructing the foundation pillar at the lower part of the pile hole, it is possible to select and use any of the conventionally known materials having arbitrary properties. Corresponding to the weight and the like, it is possible to use a material that can exhibit any support strength.

It is explanatory drawing which shows the structure of a construction apparatus. It is explanatory drawing of a structure of a working device. (A) thru | or (d) are explanatory drawings of the process of constructing | assembling the pillar of a solidification material in the lower part of a digging hole. It is explanatory drawing of the state which inserted the pipe pillar member in the pillar of solidification material. It is explanatory drawing of a pipe pillar member and an auxiliary means, (a) is explanatory drawing of the pillar of a solidification material, The figure (b) is explanatory drawing which shows the structure of an auxiliary means, The figure (c) is from the lower surface of a pipe pillar. FIG. It is explanatory drawing which shows the structure of another Example of a working device. (A) thru | or (c) is explanatory drawing explaining the process of excavating a hole with the apparatus of FIG. 6 corresponding to FIG.

Explanation of symbols

1 construction equipment, 2 working equipment, 3 arm members, 4 wires,
5 strut members, 6 head sheaves, 7 mixer devices,
8 Supply pipe, 10 Upper device, 11 Rotating head,
12 Medium head, 13 Cylinder device, 14 Drilling device,
15 middle rod, 16 excavating blade, 17 ejection hole, 18 outer rod,
19 flight members, 20 drilling holes, 22 holes of soil,
23 solidified material-filled columns, 24 columns, 30 pipe columns, 31 lower rebar,
32 insertion part, 33 outer member, 35 casing member,
40 Lifting device, 41 Reaction force plate, 42 Lower device,
45 cylinder device, 46 rod, 47 chuck member.

Claims (4)

A pile foundation construction device for excavating a pile hole perpendicular to the ground, placing a solidified material to a predetermined depth below the excavated pile hole, and constructing a column of the solidified material,
In the excavator of the construction device, a double rod member configured to be slidable by arranging hollow inner and outer rod members concentrically in combination, with respect to a drive member for imparting rotation and vertical movement Provided in combination,
Of the double rod members, the excavation means for digging the ground is provided on the excavation blades held at the lower end portion of the middle rod member, and the screw-like flight member is provided on the lower end portion of the outer rod member. Provided,
The excavation blade held at the lower end portion of the middle rod member is positioned below the screw-like flight member at the lower end portion of the outer rod member, and the flight member provided at the lower end portion of the outer rod member has an upper portion. It is configured as a screw-shaped conical shape with a small diameter and a large lower diameter, and the excavation blade and the flight member can act as one screw-shaped excavation / stirring mechanism, and individually based on each configuration Configure as a mechanism that can be moved up and down,
The outer rod is supported via a cylinder device between a middle head member provided at the upper end of the outer rod member and a rotary head of the upper device provided with a suspension support means and a drive means, and the concentric circles are supported. Of the double rod members combined in a shape, the middle rod member is fixed and held at the lowered position, and only the outer rod member is raised, and formed between the upper and lower flight members and the excavating blades. Corresponding to the operation of filling the space with the solidifying material,
The pile foundation characterized in that the action of pushing the soil excavated by the excavating blade toward the hole wall is performed at the upper part of the flight member by performing the operation of raising the outer rod member. Construction device. Following the step of excavating the pile hole using the excavator provided by combining the lower excavating blade and the upper flight member with respect to the double rod member, the lower excavating blade is placed at the bottom of the hole. While fixing and holding, while gradually raising the flight member, let the step of ejecting the solidified material,
When raising the upper flight member with respect to the lower excavation blade,
The pile foundation construction apparatus according to claim 1, further comprising a driving unit that individually operates the two mechanisms so as to push up an upper flight member with reference to the excavating blade fixed to the lower part. . A pile hole is excavated perpendicularly to the ground using the pile foundation construction device, and a solidified material is injected up to a predetermined height above the bottom surface of the dug pile hole to form a solidified columnar structure. At the time, the lower excavation blade and the upper flight member of the excavator are driven as an integral unit,
While digging the pile hole with the excavator to a predetermined depth, following the step of operating to excavate without removing the soil on the ground surface,
While the lower excavation blade is stopped and held at the bottom of the hole, the solidified material is ejected from the ejection holes provided in the middle rod at the upper portion of the excavation blade while gradually lifting the flight member, and the upper and lower flight members and While filling the solidified material in the space formed between the excavating blades, constructing the solidified material column to a predetermined height in sequence, constructing the solidified material column of a predetermined length,
Before the solidified material pillar solidifies, it is erected by embedding underground pile members to a predetermined depth,
The construction method of a pile foundation using the construction device according to claim 1 or 2, wherein a foundation of a structure is constructed on an upper portion of the underground pile member. Before the solidified pillar is solidified, an underground pile member is erected in the pile hole, and a base portion of the underground pile member is embedded in the solidified structure to a predetermined depth. Integrated as
For the underground pile member constructed as an integrated pile in the state of standing above the solidified material pillar, an auxiliary means for promoting integration with the solidified material constructed in a column shape is provided. Provided in combination,
The said auxiliary | assistant means has the effect | action which aligns the core of the underground pile inserted and erected by the excavated pile hole, The construction method of the pile foundation of Claim 3 characterized by the above-mentioned.

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