JP2021085218A - Pile foundation, base member, and construction method of pile foundation - Google Patents

Abstract

To provide a pile foundation, a base member and a construction method of a pile foundation capable of installing a structure in a short construction period while suppressing cost for a construction.SOLUTION: A pile foundation 1 comprises: a base member 2 in which a central cylinder portion 21 and a plurality of guide cylinder portions 22 that is in a twist positional relation with respect to the central cylinder portion 21 are integrated; a post 3 capable of being inserted into the central cylinder portion 21; and a plurality of piles 4 capable of being respectively inserted into the plurality of guide cylinder portions 22. The central cylinder portion 21 includes a plurality of through holes 211 penetrating the central cylinder portion 21 in a radial direction and the post 3 includes a metal pipe 31 having a wall thickness in which it can be bored by a drill inserted into the through hole 211.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pile foundation, a base member, and a method for constructing a pile foundation.

One of the foundations for erection of structures on the ground is a pile foundation. A pile foundation is a foundation that supports a structure by driving piles into the ground. One of the foundation methods using pile foundations is the pin foundation method. In the pin foundation method, a steel pipe (pin) is driven diagonally into the ground to support the structure by its bearing capacity.

Patent Document 1 discloses a support for construction work in which three steel pipes and a central vertical pipe are fixed by welding. Anchor pipes as piles are inserted into the three steel pipes. Patent Document 2 discloses a base member for a pile foundation, which is a molded product through which a plurality of piles are inserted. The base member is installed on the ground surface, and after the pile and the support are inserted, the support is fixed to the base member.

Special Table 2003-526747 JP-A-2017-206816

In recent years, disasters such as typhoons, heavy rains, and earthquakes have frequently occurred in Japan. In the event of these disasters, a large number of temporary housing, which may exceed hundreds to thousands, may be needed promptly. Currently, the mainstream of temporary housing is an assembly house that is assembled from the foundation using concrete, wooden piles, etc., and requires a lot of manpower and heavy machinery. In addition, since the temporary housing is a temporary housing, it is dismantled after several years of use, but the current foundation structure is discarded without being reused after the dismantling.

In addition, a trailer house may be provided as a temporary housing in the event of a disaster. Since the trailer house can transport the finished product to the site by a towing vehicle, it has the advantages of less labor and cost at the time of installation and a shorter construction period than the above-mentioned assembly house type temporary housing. However, in order to install a mobile home as it is, it is necessary to have solid ground such as concrete foundation ground, and it is difficult to quickly secure land with such ground after a disaster. is there. In addition, due to legal issues, mobile homes do not have a foundation, so there are many areas where they are not recognized as temporary housing due to safety issues.

Therefore, an object of the present invention is to provide a method for constructing a pile foundation, a base member, and a pile foundation, which can install a structure in a short construction period while suppressing the construction cost.

The pile foundation of the present invention can be inserted into the central cylinder portion and a base member in which the central cylinder portion and a plurality of guide cylinder portions having a twisted positional relationship with respect to the central cylinder portion are integrated. The support is provided with a support and a plurality of piles that can be inserted into the plurality of guide cylinders, respectively, and the central cylinder has a plurality of through holes that penetrate the central cylinder in the radial direction. A pile foundation including a metal pipe having a wall thickness that can be drilled by a drill inserted through the through hole.

According to such a pile foundation, the column can be drilled by a drill inserted into the through hole of the base member after being inserted into the base member, so that it is not necessary to drill the column in advance. For this reason, the height of the pillars can be easily adjusted by cutting the pillars on site or adjusting the amount of embedding of the pillars according to the shape of the ground surface on which the pile foundation is installed, and then any length. The stakes can be fixed to the base member. Therefore, the structure can be installed in a short construction period while suppressing the construction cost.

Preferably, the base member is a single member. According to such a configuration, the strength of the base member can be improved as compared with the case where the central cylinder portion and the plurality of guide cylinder portions are joined as separate independent members by welding or the like.

Preferably, the base member is two dividing members in which the central tubular portion is divided into one side and the other side in the radial direction, and the two dividing members each have the through hole and the above 2 A connecting tool for connecting the divided members is further provided. According to such a configuration, the weight of one member is lighter than that in the case where the base member is a single member, and the worker can easily carry the member manually. Therefore, the construction period of the pile foundation can be shortened.

Preferably, the two partitioning members have the same shape as each other. According to such a configuration, the number of points of the mold, the mold, and the like for manufacturing the divided member can be reduced, and the size of the mold, the mold, and the like can be reduced. Therefore, the manufacturing cost can be reduced.

The base member of the present invention is a base member used as one member of a pile foundation, and is a central cylinder portion through which a support is inserted and a guide cylinder portion integrated with the central cylinder portion through which a plurality of piles are inserted. The plurality of guide cylinders have a twisted positional relationship with respect to the central cylinder, and the central cylinder has a through hole that penetrates the central cylinder in the radial direction. The central tubular portion is a base member through which the support column including a metal tube having a wall thickness that can be drilled by a drill inserted through the through hole is inserted.

According to such a configuration, since the support column that can be drilled by the drill inserted into the through hole of the base member is inserted into the base member, it is not necessary to drill the column in advance. For this reason, the height of the pillars can be easily adjusted by cutting the pillars on site or adjusting the amount of embedding of the pillars according to the shape of the ground surface on which the pile foundation using the base member is installed. , A support of any length can be fixed to the base member. Therefore, the structure can be installed in a short construction period while suppressing the construction cost.

In the method of constructing a pile foundation of the present invention, a central cylinder portion through which a support is inserted and a guide cylinder portion into which a plurality of piles are inserted, which are in a twisted positional relationship with respect to the central cylinder portion, are integrated. It is a method of constructing a pile foundation using the base member, which is a preparatory step for preparing the base member in a state where the support column and the plurality of piles are inserted, and a penetration through the central cylinder portion in the radial direction. A drilling step of drilling a pillar inserted into the central cylinder portion by a drill through a hole, and a bolt being inserted into a hole of the pillar drilled by the drilling step through the through hole, and the center. This is a pile foundation construction method including a fixing step of fixing the support column to the cylinder portion.

According to such a configuration, after inserting the support column into the base member at the construction site, the support column can be drilled by a drill. Therefore, even after adjusting the height of the support column in the vertical direction according to the shape of the ground surface, the support column can be easily fixed to the central cylinder portion. As a result, the structure can be installed in a short construction period while suppressing the construction cost.

Preferably, the base member is a single member, and the preparatory steps include a base member installation step of installing the base member on the ground with the axial direction of the central cylinder portion in the vertical direction, and the base member. After the installation step, the pile penetration step of penetrating the plurality of piles into the ground via the plurality of guide cylinders and the length of the columns in the axial direction by cutting the columns in the radial direction. It has a support column preparation step for adjusting the above, and a support column insertion step for inserting the support column into the central cylinder portion after the pile penetration step and the support column preparation step. According to such a configuration, the height of the support column in the vertical direction can be easily adjusted by cutting the support column to an appropriate length according to the shape of the ground surface.

Preferably, the base member is two divided members in which the central tubular portion is divided into one side and the other side in the radial direction, and the preparatory step is performed on the support column with the axial direction of the support column as the vertical direction. After the strut intrusion step of partially penetrating into the ground and the strut intrusion step, the portion of the strut that protrudes to the ground is separated from one side and the other side in the radial direction of the strut by the two dividing members, respectively. After the base member installation step of connecting the two divided members and the base member installation step in the covered state, the plurality of piles are penetrated into the ground via the plurality of guide cylinders. It has a pile penetration process.

According to such a configuration, the length (height) of the strut can be easily adjusted by the amount of the strut penetrating into the ground. Further, since the base member is installed by covering the two divided members from one side and the other side in the radial direction of the support, a support having an outer diameter larger than the inner diameter of the central cylinder part or already The base member can also be installed on the support column that supports the structure. Therefore, flexible construction can be performed according to the situation at the construction site.

According to the present invention, it is possible to provide a pile foundation, a base member, and a pile foundation construction method capable of installing a structure in a short construction period while suppressing the construction cost.

It is a schematic diagram which shows the structure supported by the pile foundation which concerns on 1st Embodiment of this invention. It is a perspective view which looked down on the base member which concerns on 1st Embodiment of this invention from diagonally above. It is a side view which shows the base member seen from the direction of arrow III of FIG. It is a side view which shows the pile foundation in the state which the support and a plurality of piles are inserted into the base member shown in FIG. It is sectional drawing on the cutting line shown by the arrow V of FIG. It is a top view which shows the base member seen from the arrow VI direction of FIG. It is a flowchart which shows each process about the construction method of the pile foundation which concerns on 1st Embodiment of this invention. It is a flowchart which shows the detail of the preparation process of FIG. It is explanatory drawing which shows the state of each process about the construction method of the pile foundation which concerns on 1st Embodiment of this invention. It is explanatory drawing which shows the operation of the pile foundation which concerns on 1st Embodiment of this invention. It is a perspective view which looked down on the pile foundation which concerns on 2nd Embodiment of this invention from diagonally above. It is a perspective view which shows only a part base member of the pile foundation shown in FIG. It is a side view which shows the pile foundation seen from the direction of arrow XIII of FIG. It is a top view which shows only a part base member of the pile foundation seen from the arrow XIV direction of FIG. It is a flowchart which shows the detail of the preparation process which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the state of each process about the construction method of the pile foundation which concerns on 2nd Embodiment of this invention. It is a schematic diagram which shows the modification of the structure supported by the pile foundation which concerns on 1st Embodiment of this invention. It is a perspective view which shows the state which the support | support which concerns on the modification of this invention is inserted through a pile foundation.

[1. First Embodiment]
Hereinafter, the pile foundation and the construction method of the pile foundation according to the first embodiment of the present invention will be described with reference to the drawings, taking the pile foundation supporting the trailer house as an example. In the present invention, the structure supported by the pile foundation is not limited to the trailer house, but can be applied to various structures such as a container house, a unit house, stairs, a passage, or a stand for a solar panel.

[1.1 Overview of pile foundations and structures]
FIG. 1 is a schematic view showing a pile foundation 1 according to the first embodiment and a trailer house 9 supported by the pile foundation 1. The trailer house 9 has a house 91, wheels 92, and a traction tool 93, and is supported by a plurality of pile foundations 1 (for example, 30 pile foundations 1). A bolt mounting portion (not shown) is formed at the bottom of the house 91, and by fastening the bottom of the house 91 and the upper part of the pile foundation 1 with bolts, the trailer house 9 is connected via the pile foundation 1. It is fixed to the ground G1. Since the trailer house 9 is supported by the pile foundation 1, it has higher stability than the conventional case where the trailer house 9 is left on the ground G1 as it is. The trailer house 9 before being fixed to the ground G1 can be moved by being towed by the towing vehicle with the towing tool 93 connected to the towing vehicle.

The ground G1 is a surface having an inclination (inclination angle An) with respect to the horizontal direction, such as a slope. The pile foundation 1 according to the first embodiment can easily adjust the height described later with respect to the height direction (vertical direction). Therefore, on the sloped ground G1, the height of the pile foundation 1 located on the upper side of the slope (left side in FIG. 1) is adjusted to be low, and the height of the pile foundation 1 located on the lower side of the slope (right side in FIG. 1) is adjusted. The trailer house 9 can be installed horizontally by adjusting the height.

[1.2 Pile foundation configuration]
The pile foundation 1 will be described with reference to FIGS. 2 to 6 as appropriate. FIG. 2 is a perspective view of the base member 2 viewed from diagonally above. FIG. 3 is a side view showing the base member 2 as viewed from the direction of arrow III in FIG. FIG. 4 is a side view showing a pile foundation 1 in a state where a support column 3 and a plurality of piles 4 are inserted into the base member 2 shown in FIG. FIG. 5 is a cross-sectional view taken along the cutting line indicated by the arrow V in FIG. FIG. 6 is a plan view showing the base member 2 as viewed from the direction of the arrow VI in FIG.

See FIG. The pile foundation 1 includes a base member 2, a support column 3, and a plurality of piles 4. The pile foundation 1 supports a structure on the upper part of the support column 3 with the support column 3 and the plurality of piles 4 inserted through the base member 2.

See FIGS. 2 and 3. The base member 2 is a member in which the central cylinder portion 21 and a plurality of guide cylinder portions 22a, 22b, 22c, and 22d having a twisted positional relationship with respect to the central cylinder portion 21 are integrated. Unless otherwise specified, the respective guide cylinder portions 22a, 22b, 22c, and 22d are simply referred to as "guide cylinder portion 22". In the present embodiment, the guide cylinder portion 22 and the pile 4 are each four, but in the embodiment of the present invention, the number is not limited to this, and may be, for example, two or three, or five or more. May be good.

The central cylinder portion 21 and the guide cylinder portion 22 are cylinders each having a hollow inside. In the present embodiment, the cross-sectional shapes of the cylinders of the central cylinder portion 21 and the guide cylinder portion 22 are circular (see FIG. 6), but may be polygonal or elliptical. The cross-sectional shapes of the cylinders of the central cylinder portion 21 and the guide cylinder portion 22 are shaped according to the cross-sectional shapes of the columns 3 and the pile 4, which will be described later. The central cylinder portion 21 is located at the center of the base member 2. The axis of the central tubular portion 21 coincides with the center line C1 of the base member 2.

The guide cylinders 22 are arranged at equal intervals along the circumferential direction of the central cylinder 21 (that is, the circumferential direction of the center line C1). In the present embodiment, the guide cylinders 22 are arranged at intervals of 90 degrees. The axial center of the guide tubular portion 22 has a twisted positional relationship with respect to the axial center of the central tubular portion 21. Further, the axial centers of the guide cylinders 22 are twisted to each other with respect to the axial centers of other guide cylinders 22 adjacent to the central cylinder 21 in the circumferential direction.

Specifically, the axial center A1 of the guide cylinder portion 22a is in a twisted positional relationship with the axial center A2 of the guide cylinder portion 22b adjacent in the circumferential direction, and the axial center A2 of the guide cylinder portion 22b is in the circumferential direction. The axial center A3 of the adjacent guide cylinder 22c is in a twisted positional relationship with each other, and the axial center A3 of the guide tubular portion 22c is twisted with the axial center A4 of the guide tubular portion 22d adjacent in the circumferential direction. The axial center A4 of the guide cylinder portion 22d is in a twisted positional relationship with the axial center A1 of the guide cylinder portion 22a adjacent in the circumferential direction. That is, the four guide cylinders 22 are arranged along the circumferential direction of the central cylinder 21 so as to have a twisted positional relationship with each other.

The central cylinder portion 21 and the guide cylinder portion 22a are integrated by being connected at a connecting portion 23a extending in the axial center A1 direction. That is, the positional relationship between the central cylinder portion 21 and the guide cylinder portion 22a is fixed by the connecting portion 23a. Similarly, the central cylinder portion 21 and the guide cylinder portions 22b, 22c, 22d are integrated by being connected at the connecting portions 23b, 23c, 23d extending in the axial centers A2, A3, and A4, respectively. The connecting portions 23a, 23b, 23c and 23d are simply referred to as "connecting portion 23" unless otherwise specified. In the present embodiment, the respective connecting portions 23 are connected on the outer peripheral surface of the central tubular portion 21. However, the plurality of connecting portions 23 may be separated from each other as in the second embodiment described later.

The base member 2 in the present embodiment is cast steel in which the central tubular portion 21 and the plurality of guide tubular portions 22 are integrally formed by casting. That is, the base member 2 is a single member. In this way, by using a single member for the base member 2, the strength of the base member 2 can be improved as compared with the case where the central cylinder portion 21 and the plurality of guide cylinder portions 22 are joined as separate independent members. it can. Further, since it is molded by casting, even a complicated shape can be easily molded.

The central tubular portion 21 has ends 211 and 212 in the axial direction. The end portion 211 is an end portion that is on the upper side in the vertical direction when the base member 2 is installed on the ground surface. The end portion 211 is open upward, and the support column 3 can be inserted through the end portion 211. In the present embodiment, the end portion 212 is open downward, and the central cylinder portion 21 is a cylinder that is open upward and downward. However, the end 212 may be blocked by the bottom surface. Hereinafter, the end portion 211 is referred to as "upper end 211", and the end portion 212 is referred to as "lower end 212".

Through holes 213, 214, and 215 that penetrate the central tubular portion 21 in the radial direction are formed on the peripheral wall of the central tubular portion 21 on which the connecting portion 23 is not formed. Two through holes 213 are formed on one side (upper side in FIG. 3) in the axial direction with respect to the connecting portion 23. In other words, the through hole 213 is formed between the connecting portion 23 and the upper end 211 of the peripheral wall of the central tubular portion 21. Two through holes 214 are formed on one side in the axial direction from the connecting portion 23 and on the other side in the axial direction (lower side in FIG. 3) than the through holes 213. In other words, the through hole 214 is formed between the connecting portion 23 and the through hole 213 in the peripheral wall of the central tubular portion 21.

The diameter of the through hole 213 and the through hole 214 is, for example, 15 mm. The through hole 213 and the through hole 214 function as a drill guide hole for guiding the electric drill when drilling the support column 3 inserted through the central tubular portion 21. Further, the through hole 213 and the through hole 214 also function as bolt guide holes for inserting bolts from the outer peripheral side of the central tubular portion 21. The inserted bolt fixes the base member 2 and the support column 3 by fastening with a nut.

The through holes 215 are through holes extending in the circumferential direction of the central tubular portion 21, and two through holes 215 are formed on the peripheral wall of the central tubular portion 21. The through hole 215 is provided to reduce the weight of the base member 2. As the size of the through hole 215, an appropriate size is selected according to the weight of the base member 2 and the required strength of the central tubular portion 21. By providing the through hole 215 in the central cylinder portion 21 in this way, the weight of the base member 2 can be reduced, and in the construction of the pile foundation 1, the base member 2 can be easily carried by human power, so that the pile foundation 1 can be easily carried. The construction period of the construction can be shortened.

See FIG. The two through holes 213 are arranged on one side and the other side in the radial direction of the central tubular portion 21 at positions symmetrical with respect to the center line C1. By arranging the two through holes 213 at positions facing each other with the center line C1 in between in this way, after drilling the column 3 with an electric drill, one bolt is inserted through one through hole 213 and the other. It can be projected from the through hole 213 and fastened with a nut. Similarly, the two through holes 214 are arranged on one side and the other side in the radial direction of the central tubular portion 21 at positions symmetrical with respect to the center line C1.

In the present embodiment, the through hole 213 is formed directly above the through hole 214. However, the through hole 213 may be arranged not directly above the through hole 214. For example, the two through holes 214 may be formed above the connecting portions 23a and 23c, respectively, and the two through holes 213 may be formed above the connecting portions 23b and 23d, respectively. That is, the through hole 213 and the through hole 214 may be arranged at different angles of 90 degrees from each other.

See FIG. The support column 3 has a metal tube 31 and a fixture 32. The metal pipe 31 is a steel pipe in this embodiment. The diameter of the metal tube 31 is, for example, 80 mm to 100 mm, preferably 89 mm. The metal tube 31 has a wall thickness that can be drilled by a drill inserted through the through hole 213 or the through hole 214. Here, the "thickness that can be drilled by a drill" means a wall thickness that can be drilled within 30 seconds, preferably within 10 seconds by an electric drill that can be hand-held by a worker at the construction site of the foundation. Specifically, in the case of a steel pipe, it is 5 mm or less, for example, a wall thickness of 3 mm to 4 mm. As the wall thickness of the support column 3, an appropriate wall thickness is selected according to the drilling time by the drill and the strength required for the support column 3.

Further, the support column 3 has a wall thickness and a diameter that can be cut by a cutter. Specifically, it means a wall thickness that can be cut within 5 minutes, preferably within 1 minute, by an electric cutting tool (for example, an electric cutter, an electric saw, etc.) that can be held by a worker at a foundation construction site.

The fixture 32 is a mounting bracket for fastening with bolts to the mounting portion at the bottom of the house 91. The fixture 32 has a metal disk portion 321 and an fitting portion 322 that is fitted into the metal tube 31. A plurality of holes 323 for fastening bolts are formed in the disk portion 321. In the present embodiment, the fixture 32 and the metal tube 31 are integrated with each other, but the fixture 32 and the metal tube 31 may be a single member integrally formed.

See FIG. The strut 3 before being drilled is inserted into the hollow portion of the central tubular portion 21 of the base member 2. The support column 3 is located at the center of the central cylinder portion 21, and the axis of the support column 3 coincides with the axis of the central cylinder portion 21. That is, the axis of the support column 3 coincides with the center line C1 of the base member 2. The outer diameter of the support column 3 is equal to the inner diameter of the central cylinder portion 21 (or slightly smaller than the inner diameter of the central cylinder portion 21), and when the support column 3 is inserted through the central cylinder portion 21, the outer peripheral surface and the center of the support column 3 are formed. The inner peripheral surface of the tubular portion 21 is in contact with each other. At this time, the through holes 213 and 214 are closed by the support columns 3 on the inner peripheral surface side of the central tubular portion 21.

See FIG. The pile 4 is a metal pipe (for example, a steel pipe). The diameter of the pile 4 is, for example, 40 mm to 60 mm, preferably 49 mm. The wall thickness of the pile 4 is, for example, 2 mm to 4 mm, preferably 3 mm. The four piles 4 are inserted into the four guide cylinders 22, respectively. The outer diameter of the pile 4 is equal to the inner diameter of the guide cylinder 22 (or slightly smaller than the inner diameter of the guide cylinder 22), and when the pile 4 is inserted through the guide cylinder 22, the outer peripheral surface of the pile 4 and the guide The inner peripheral surface of the tubular portion 22 is in contact with each other. In this way, the pile 4 is fixed in the penetration angle into the ground by the guide cylinder portion 22 by coming into contact with the inner peripheral surface of the guide cylinder portion 22.

Since the guide cylinders 22 are in a twisted positional relationship, the piles 4 that penetrate into the ground via the guide cylinders 22 are also in a twisted positional relationship. Further, the piles 4 are arranged at a right angle of 90 degrees like the guide cylinder portion 22. Therefore, the base member 2 is supported in a well-balanced manner by the pile 4 guided into the ground by the guide cylinder portion 22.

[1.3 Construction method of pile foundation]
Next, the construction method of the pile foundation 1 described above will be described. The pile foundation 1 is constructed by a worker executing the construction method described below. FIG. 7 is a flowchart showing each process of the construction method of the pile foundation 1 according to the first embodiment. FIG. 8 is a flowchart showing the details of the preparation step S11 of FIG. FIG. 9 is an explanatory view showing a state of each step regarding the construction method of the pile foundation 1 according to the first embodiment. In FIG. 9, for the sake of simplicity, the ground G1 is shown as a horizontal plane.

See FIG. 7. In the construction method of the pile foundation 1, the preparation step S11 for preparing the base member 2 in which the support column 3 and the plurality of piles 4 are inserted, and the through holes 213 and 214 penetrating the central cylinder portion 21 in the radial direction are used. Then, a bolt is inserted into the hole of the pillar 3 drilled by the drilling step S12 and the pillar 3 which is drilled into the pillar 3 inserted through the central cylinder portion 21 by a drill through the through holes 213 and 214, and the central cylinder is inserted. The fixing step S13 for fixing the support column 3 to the portion 21 is executed.

See FIG. When the preparation step S11 is started, first, the worker installs the base member 2 on the ground G1 with the axial direction of the central cylinder portion 21 in the vertical direction (base member installation step S21). FIG. 9A is a diagram showing a state after the base member installation step S21 is completed. As shown in FIG. 9A, the central tubular portion 21 is installed on the ground G1 with the upper end 211 facing upward in the vertical direction, the lower end 212 facing downward in the vertical direction, and the lower end 212 in contact with the ground G1. Will be done. The base member 2 is manually carried by a worker and installed on the ground G1.

Next, the worker penetrates the four piles 4 into the ground via the four guide cylinders 22 (pile penetration step S22). The penetration of the pile 4 into the ground is performed by hitting the upper end portion of the pile 4 with an electric tool such as an electric hammer that can be held by an operator. FIG. 9B is a diagram showing a state in which a worker is penetrating a pile in the pile penetrating step S22.

By driving each of the piles 4 into the ground G1 along the axial centers A1, A2, A3, and A4 that are in a twisted positional relationship with each other, the base member 2 has its respective axial centers A1, A2, A3, It is supported by the pile 4 from the A4 direction. Therefore, the base member 2 is fixed to the ground G1 by the pile 4, and the base member 2 can be prevented from moving in the horizontal direction and the vertical direction. As a result, it is possible to secure a sufficient supporting force for erecting the support column 3 to be inserted into the base member 2 in the support column insertion step S24 described later.

Next, the worker cuts the support column 3 in the radial direction and adjusts the length of the support column 3 in the axial direction (support column preparation step S23). The worker prepares the support column 3 having a desired length in the axial direction by cutting the support column 3 in the radial direction with a hand-held electric cutter. Here, the length of the support column 3 in the axial direction becomes the height of the support column 3 after the support column 3 is inserted into the central tubular portion 21 by the support column insertion step S24 described later. In this respect, the support column preparation step S23 can be said to be an adjustment step for adjusting the height of the support column 3.

Next, after the pile penetration step S22 and the support column preparation step S23, the worker inserts the support column 3 whose length in the axial direction is adjusted into the central tubular portion 21 (support column insertion step S24). Since the outer diameter of the support column 3 is equal to the inner diameter of the central cylinder portion 21, the support column 3 is inserted into the central cylinder portion 21 while the outer peripheral surface of the support column 3 and the inner peripheral surface of the central cylinder portion 21 are in sliding contact with each other. FIG. 9C shows a state after the support column insertion step S24 is completed. As a result, the preparation step S11 is completed.

See FIG. 7. After the preparation step S11, the drilling step S12 is performed. In the drilling step S12, the worker inserts a hand-held electric drill in the radial direction from the through hole 213 to drill the peripheral surface of the support column 3. Similarly, an electric drill is inserted radially through the through hole 214 to drill the peripheral surface of the support column 3. In the present embodiment, the support columns 3 are drilled at one location each in the two through holes 213 and the two through holes 214. As a result, four holes are formed in the support column 3. The drilling step S12 ends when holes are formed in all the peripheral surfaces of the columns 3 corresponding to the through holes 213 and 214. FIG. 9D is a diagram showing a state in which the support column 3 is drilled in the drilling step S12.

Next, the fixing step S13 is performed. When the fixing step S13 is started, the two bolts 51 are inserted into the through holes 213 and 214, respectively, to fix the support column 3 to the central cylinder portion 21. Specifically, the bolt 51 is inserted from one through hole 213, and the end portion of the bolt 51 is projected from the other through hole 213 via the hole of the support column 3 drilled in the drilling step S12. Then, the nut is fastened to the protruding bolt 51. Similarly, the bolt 51 is inserted from one through hole 214, the end of the bolt is projected from the other through hole 214 via the hole of the support column 3, and the nut is fastened to the protruding bolt 51. FIG. 9E is a diagram showing a state in which the bolt 51 is inserted into the central cylinder portion 21 and the support column 3 in the fixing step S13. Here, the diameter of the bolt 51 is smaller than the diameter of the through holes 213 and 214, for example, 12 mm. Further, the length of the bolt 51 is longer than the outer diameter of the central cylinder portion 21, for example, 110 mm.

[1.4 Actions and effects of the first embodiment]
As described above, in the pile foundation 1 according to the first embodiment, the base member 2 is supported by a plurality of piles 4 inserted into the guide cylinder portion 22 of the base member 2. Further, the support column 3 inserted into the central tubular portion 21 of the base member 2 includes a metal tube 31 having a wall thickness that can be drilled by a drill inserted through the through holes 213 and 214. As a result, after the support column 3 is inserted into the base member 2 at the construction site, the support column 3 can be drilled with a drill. Such a pile foundation 1 is particularly useful when fixing the trailer house 9 to the ground having unevenness that is not leveled.

FIG. 10 is an explanatory view showing the operation of the pile foundation 1 according to the first embodiment of the present invention. In FIG. 10, the wheel 92 is not shown. The land on which the trailer house 9 is installed has grounds G2 and G3 having different heights. After executing the base member installation step S21 and the pile penetration step S22 at the construction site, the lengths (L1, L2) from each of the grounds G2 and G3 to the bolt mounting portion of the house 91 are measured, and the columns are prepared. In step S23, the column 3 is cut to a length corresponding to the length. Thereby, the height of the support column 3 in the vertical direction can be easily adjusted according to the shape of the ground surface.

After that, when the column insertion step S24, the drilling step S12, and the fixing step S13 are executed, a plurality of pile foundations 1 having the same height up to the bolt mounting portion of the house 91 are installed on the grounds G2 and G3. After that, the trailer house 9 is moved directly above the pile foundation 1, and the mounting portion of the house 91 and the fixture 32 are fixed with bolts so that the plurality of pile foundations 1 support the trailer house 9 which is a structure. Become.

All of the above processes can be performed with the tools on hand, and since it is not necessary to use a large-scale heavy machine, the cost for the construction can be suppressed. Moreover, since a concrete foundation is not used, the construction period can be shortened. Further, with the plurality of pile foundations 1, the trailer house 9 can be fixed to the ground even if the land is uneven or uneven as shown in FIG. Therefore, it is not necessary to perform ground maintenance (for example, preparation work such as leveling the ground) for stable installation of the trailer house 9, and the cost and construction period for installing the trailer house 9 as a temporary housing are reduced. Can be shortened.

When the trailer house 9 finishes its role in the land, the trailer house 9 is towed by a towing vehicle after removing the bolts that fasten the fixture 32 and the mounting portion of the house 91. You can easily move the trailer house 9 from the land. The trailer house 9 can then be reused for another purpose (for example, as a temporary housing in the event of another disaster). Since the base member 2 itself is not drilled or deformed at the time of construction, the base member 2 can also be reused after the columns 3 and piles 4 are pulled out. Therefore, the amount of waste after dismantling the temporary housing can be reduced as compared with the construction of the conventional temporary housing using wooden piles and concrete foundations. Therefore, the dismantling cost including the waste treatment cost can be reduced.

[2. Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following second embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

[2.1 Construction of pile foundation]
FIG. 11 is a perspective view of the pile foundation 1a according to the second embodiment looking down from diagonally above. FIG. 12 is a perspective view showing only a part of the base member 2a of the pile foundation 1a shown in FIG. FIG. 13 is a side view showing the pile foundation 1a seen from the direction of arrow XIII in FIG. FIG. 14 is a plan view showing only a part of the base member 2a of the pile foundation 1a seen from the direction of arrow XIV in FIG.

In the first embodiment, the base member 2 is a single member. On the other hand, in the second embodiment, the base member 2a is two divided members 61 in which the central tubular portion 21a is divided into one side and the other side in the radial direction. The two partition members 61 have the same shape as each other. Further, the base member 2a has a connecting tool 62 for connecting the two dividing members 61.

See FIGS. 12 and 13. FIG. 12 is a diagram showing only one split member 61 of the base member 2a. FIG. 13 is a side view showing a pile foundation 1a in a state where a support column 3a and a plurality of piles 4 are inserted into the base member 2a. The dividing member 61 has a half-cylinder portion 611 that covers the support column 3a from one side in the radial direction. The half-cylinder portion 611 has a semicircular shape as shown in FIG. As shown in FIG. 11, the central tubular portion 21a is formed by combining the two half-cylinder portions 611 in the circumferential direction. One dividing member 61 has two guide tubular portions 24 having a twisted positional relationship with the central tubular portion 21a, and one through hole 213a and one 214a.

In the dividing member 61, one through hole 213a is formed on one side in the axial direction (upper side in FIG. 13) with respect to the connecting portion 23. In other words, the through hole 213a is formed between the connecting portion 23 and the upper end 211 of the peripheral wall of the dividing member 61. In the dividing member 61, one through hole 214a is formed on the other side (lower side in FIG. 13) in the axial direction from the connecting portion 23. In other words, the through hole 214a is formed between the connecting portion 23 and the lower end 212 of the peripheral wall of the dividing member 61.

The connector 62 has a through hole 621 through which a bolt can be inserted as shown in FIG. The connector 62 is integrated with the dividing member 61. When the two dividing members 61 face each other on one side and the other side in the radial direction, the through holes 621 of the connecting tools 62 are located at the same position. Then, the two dividing members 61 can be connected by inserting a bolt into the through hole 621 and fastening the nut in a state where the two dividing members 61 are combined.

When the two dividing members 61 are connected by the connecting tool 62, the through holes 213a formed in the respective dividing members 61 face each other with the center line C1 as the center. Similarly, the two through holes 214a also face each other about the center line C1.

Of the guide cylinder portion 24, a through hole 241 having a shape extending in the axial direction is formed on the peripheral wall on which the connecting portion 23 is not formed. The through hole 241 is provided for reducing the weight of the base member 2a. As the size of the through hole 241 is selected, an appropriate size is selected according to the weight of the base member 2a and the required strength of the guide cylinder portion 24. By providing the through hole 241 in the guide cylinder portion 24 in this way, the weight of the base member 2a can be reduced, and in the construction of the pile foundation 1a, the base member 2a can be easily carried by human power, so that the pile foundation 1a can be easily carried. The construction period of the construction can be shortened.

The split member 61 in the present embodiment is cast steel in which a half-cylinder portion 611, two guide cylinder portions 24, and a connector 62 are integrally molded by casting. That is, one dividing member 61 is a single member. In this way, by using a single member for the split member 61, the split member is more than the case where the half-cylinder portion 611, the two guide cylinder portions 24 and the connecting tool 62 are joined as separate independent members by welding or the like. The strength of 61 can be improved.

See FIG. The support column 3 according to the first embodiment is inserted into the central cylinder portion 21 and then installed on the ground inside the central cylinder portion 21. On the other hand, the support column 3a according to the second embodiment is a pile (also referred to as a screw pipe or a spiral pipe) having a spiral structure at an end portion 33 different from the end portion to which the fixture 32 is connected. The support column 3a can drive the end portion 33 and a part of the metal pipe 31 on the end portion 33 side into the ground by using an electric tool such as an electric drill.

As described above, in the second embodiment, the two split members 61 are used as the base member 2a. Therefore, the weight of one member is lighter than that in the case where the base member is a single member, and the worker can easily carry the member manually. Therefore, the construction period of the pile foundation 1a can be shortened. Further, since the two dividing members 61 have the same shape, the number of points of the mold, the mold, and the like can be reduced, and the size of the mold, the mold, and the like can be reduced. Therefore, the manufacturing cost can be reduced. Further, by using the split member 61, flexible construction can be performed according to the situation at the site, as will be described later.

[2.2 Construction method of pile foundation]
Next, the construction method of the pile foundation 1a described above will be described. The pile foundation 1a is constructed by a worker executing the construction method described below. Since the construction method of the second embodiment is different from that of the first embodiment in the contents of the preparation step S11 and is common in other points, the description of the common points will be omitted. FIG. 15 is a flowchart showing details of the preparation step S11 according to the second embodiment. FIG. 16 is an explanatory view showing a state of each step regarding the construction method of the pile foundation 1a according to the second embodiment. In FIG. 16, for the sake of simplicity, the ground G1 is shown as a horizontal plane.

See FIG. When the preparation step S11 is started, first, with the axial direction of the support column 3a in the vertical direction, the worker penetrates the end portion 33 of the support column 3a and a part of the metal pipe 31 into the ground (support column penetration step S31). ). In the support column penetration step S31, the worker manually carries the support column 3a to the installation location of the support column 3a, and then pierces the end portion 33 of the support column 3a into the ground G1. Then, using an electric tool such as an electric screwdriver, the support column 3a is driven into the ground while being rotated in the circumferential direction along the spiral structure.

The length (height) of the portion of the support column 3a that protrudes above the ground in the axial direction is adjusted while driving the support column 3a into the ground. That is, when it is desired to shorten the length in the axial direction, the support column 3a is driven deeper. In this respect, the support column penetration step S31 also functions as an adjustment step for adjusting the height of the support column 3a. FIG. 16A is a diagram showing a state after the completion of the support column penetration step S31.

Next, the base member installation step S32 is performed. When the base member installation step S32 is started, the worker covers the portion of the support column 3a protruding above the ground with the two dividing members 61 from one side and the other side in the radial direction of the support column 3a, respectively. FIG. 16B is a diagram showing a state in which a portion of the support column 3a projecting above the ground is covered with two partitioning members 61. Next, the worker inserts a bolt into the through hole 621 of the connecting tool 62 and fastens the nut to connect the two dividing members 61 while covering the support column 3a. FIG. 16C is a diagram showing a state after connecting the two dividing members 61 with bolts. As described above, the base member installation step S32 is completed.

Next, the worker penetrates the four piles 4 into the ground via the four guide cylinders 24 (pile penetration step S33). The penetration of the pile 4 into the ground is performed by hitting the upper end portion of the pile 4 with an electric tool such as an electric hammer that can be held by an operator. FIG. 16D is a diagram showing a state in which a worker is penetrating a pile in the pile penetrating step S33.

As a result, the preparation step S11 according to the second embodiment is completed. After that, as in the first embodiment, the drilling step S12 of drilling the support column 3a inserted into the central cylinder portion 21a by a drill through the through holes 213a and 214a penetrating the central cylinder portion 21a in the radial direction. A fixing step S13 is performed in which the bolt 51 is inserted into the hole of the support column 3a drilled by the drilling step S12 via the through holes 213a and 214a, and the support column 3a is fixed to the central tubular portion 21a. 16 (e) is a diagram showing the state of the drilling step S12, and FIG. 16 (f) is a diagram showing the state of the fixing step S13.

[2.3 Actions and effects of the second embodiment]
As described above, in the second embodiment, after using the two dividing members 61 as the base member 2a and driving the support column 3a into the ground to adjust the length of the portion of the support column 3a that protrudes to the ground. , The base member 2a is installed and fixed to the support column 3a. Therefore, the length (height) of the support column 3a can be easily adjusted by the driving amount of the support column 3a. Further, the support column 3a includes a metal tube 31 having a wall thickness that can be drilled by a drill inserted through the through holes 213a and 214a. Therefore, since the metal pipe 31 can be drilled on any peripheral surface by a drill, even if the base member 2a is installed after adjusting the length according to the driving amount of the support column 3a, the drill is made on the support column 3a. The support column 3a and the base member 2a can be easily fixed by using the holes drilled by the above.

Since the outer diameter of the disk portion 321 of the fixture 32 is larger than the inner diameter of the central cylinder portion 21a, the central cylinder portion 21a cannot be inserted into the support column 3a in the state shown in FIG. 16A as it is. However, in the present embodiment, by using the base member 2a as the two dividing members 61, the columns 3a can be covered with the respective dividing members 61 from one side and the other side in the radial direction. Therefore, the fixture 32 can be used in a state of being fixed to the metal tube 31 in advance. As a result, the number of operations at the construction site can be reduced, and the construction period can be shortened.

[3. Modification example]
Although the embodiments of the present invention have been described above, the present invention can be modified in various ways other than the above-described embodiments. Hereinafter, a modified example according to the embodiment of the present invention will be described. In the following modification, the same components as those in the embodiment are designated by the same reference numerals and the description thereof will be omitted.

[3.1 Deformation example of structure]
In the first and second embodiments described above, the trailer house 9 with the wheels 92 is supported by a plurality of pile foundations 1. However, the structure supported by the pile foundation 1 is not limited to the trailer house 9. FIG. 17 is a schematic view showing a pile foundation 1 (a pile foundation similar to the pile foundation 1 according to the first embodiment) and a container house 9a supported by the pile foundation 1. The container house 9a has a house 91a. For example, the container house 9a is loaded on a truck bed or the like in an already assembled state and transported to the installation destination. A bolt mounting portion (not shown) is formed at the bottom of the house 91a, and by fastening the bottom of the house 91a and the upper part of the pile foundation 1 with bolts, the container house 9a is connected via the pile foundation 1. It is fixed to the ground G1.

[3.2 Deformation example of fixture]
The fixture 32 according to the first embodiment and the second embodiment described above has a disk portion 321. However, the practice of the present invention is not limited to this. FIG. 18 is a perspective view showing a support column 3b according to a modified example. The support column 3b is different from the support column 3 according to the first embodiment in that it has a metal rectangular plate portion 321a instead of the disk portion 321 and is common in other respects. Therefore, in FIG. 18, the same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. Note that FIG. 18 shows a state in which bolts 51 have already been inserted into the through holes 213 and 214 of the base member 2. The rectangular plate portion 321a is a rectangular plate. A plurality of holes 323a (two in FIG. 18) for fastening bolts are formed in the rectangular plate portion 323a. The structure can also be supported by such a support column 3b.

[3.3 Modification example of pile foundation construction method]
In the first and second embodiments described above, after fixing the plurality of pile foundations to the ground, the structure is fixed to the upper part of the pile foundations. However, the pile foundation 1a having the two split members 61 according to the second embodiment can be used for later reinforcing the foundation to which the structure is already fixed by the pile.

That is, in the second embodiment, the plurality of columns 3a are penetrated into the ground, and then the trailer house 9 is first placed on the upper part of the plurality of columns 3a in a state where the base member 2a is not installed, and the trailer house. 9 and the plurality of columns 3a are fastened with bolts. As a result, the trailer house 9 is supported by the plurality of columns 3a. Then, among the plurality of columns 3a supporting the trailer house 9, only a part of the columns 3a is used with the two dividing members 61 to install the base member, the pile penetration process S33, and the drilling process S12. And the fixing step S13 is performed to reinforce a part of the support columns 3a. For example, the base member 2a is selectively installed on the support column 3a to which a load is particularly applied and the support column 3a in which the ground penetrates into a soft position. The base member 2a may be installed on all the columns 3a.

Further, when the trailer house 9 needs to be installed immediately, the trailer house 9 is first fixed by a plurality of pillars 3a in the state where the base member 2a is not installed in the same manner as described above, and the trailer house 9 is being used as a temporary housing. If necessary, the split member 61 and the pile 4 can be used for reinforcement later.

By constructing in this way, flexible construction according to the situation at the site is possible, and since it is not necessary to reinforce the ground in advance, the construction period for installing a structure such as a trailer house 9 Can be shortened.

[4. Others]
It should be noted that at least a part of the above-described embodiment and various modifications may be arbitrarily combined with each other. In addition, the embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1, 1a Pile foundation 2, 2a Base member 21, 21a Central cylinder 211 End (upper end)
212 End (bottom)
213 Through hole 214 Through hole 215 Through hole 22, 22a, 22b, 22c, 22d, 24 Guide tube 23, 23a, 23b, 23c, 23d Connecting part 3, 3a, 3b Strut 31 Metal pipe 32 Fixture 321 Disc part 321a Rectangular plate part 322 Fitting part 323, 323a Hole 33 End part 4 Pile 51 Bolt 61 Dividing member 611 Half cylinder part 62 Connecting tool 621 Through hole 9 Trailer house 9a Container house 91, 91a House 92 Wheel 93 Towing tool G1, G2 , G3 Ground C1 Centerline A1, A2, A3, A4 Axial center An inclination angle (of guide tube)

Claims (8)

A base member in which a central cylinder portion and a plurality of guide cylinder portions having a twisted positional relationship with respect to the central cylinder portion are integrated.
A strut that can be inserted into the central cylinder,
A plurality of piles that can be inserted into the plurality of guide cylinders, respectively,
With
The central cylinder portion has a plurality of through holes penetrating the central cylinder portion in the radial direction.
The column is a pile foundation including a metal pipe having a wall thickness that can be drilled by a drill inserted through the through hole. The base member is a single member.
The pile foundation according to claim 1. The base member is two divided members obtained by dividing the central tubular portion into one side and the other side in the radial direction.
The two partitioning members each have the through hole.
Further provided with a connecting tool for connecting the two dividing members.
The pile foundation according to claim 1. The two partitioning members have the same shape as each other.
The pile foundation according to claim 3. A base member used as a member of a pile foundation
The central cylinder through which the support is inserted and
A guide cylinder that is integrated with the central cylinder and into which a plurality of piles are inserted,
With
The plurality of guide cylinders have a twisted positional relationship with respect to the central cylinder.
The central cylinder portion has a through hole that penetrates the central cylinder portion in the radial direction.
The support column including a metal tube having a wall thickness that can be drilled by a drill inserted through the through hole is inserted into the central cylinder portion.
Base member. Construction of a pile foundation using a base member in which a central cylinder through which a support is inserted and a guide cylinder through which a plurality of piles are inserted, which are in a twisted positional relationship with respect to the central cylinder, are integrated. It ’s a method,
A preparatory step for preparing the base member in a state where the support column and the plurality of piles are inserted, and
A drilling step of drilling into the support column inserted through the central cylinder by a drill through a through hole that penetrates the central cylinder in the radial direction.
A fixing step of inserting a bolt into the hole of the support column drilled by the drilling step through the through hole and fixing the support column to the central cylinder portion.
To prepare
Construction method of pile foundation. The base member is a single member and
The preparatory step is
A base member installation process in which the base member is installed on the ground with the axial direction of the central cylinder portion in the vertical direction.
After the base member installation step, a pile penetration step of penetrating the plurality of piles into the ground via the plurality of guide cylinders, and a pile penetration step of penetrating the plurality of piles into the ground, respectively.
A strut preparation step of cutting the strut in the radial direction to adjust the length of the strut in the axial direction, and a strut preparation step.
After the pile penetration step and the support column preparation step, a support column insertion step of inserting the support column into the central cylinder portion and a support column insertion step.
Have,
The method for constructing a pile foundation according to claim 6. The base member is two divided members obtained by dividing the central tubular portion into one side and the other side in the radial direction.
The preparatory step is
A strut intrusion step in which a part of the strut is penetrated into the ground with the axial direction of the strut as the vertical direction.
After the support column penetration step, the two dividing members are connected in a state where the portion of the support column that protrudes to the ground is covered by the two dividing members from one side and the other side in the radial direction of the support column, respectively. The base member installation process and
After the base member installation step, a pile penetration step of penetrating the plurality of piles into the ground via the plurality of guide cylinders, and a pile penetration step of penetrating the plurality of piles into the ground, respectively.
Have,
The method for constructing a pile foundation according to claim 6.

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