JP2005264454A - Construction method of pile foundation, and construction device for pile foundation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To construct a bearing pile of high reliability in constructing the pile in the ground by constructing a soil cement column inside a reinforced hole wall, supplying aggregate in addition to soil in an excavated hole, and carrying out mixing action with a solidifying material well. <P>SOLUTION: An excavating device 1 is provided with an auger device 11 at the lower end of a rod 10, and a flight member 12 is constituted as a nearly conical one. After excavating a pile hole by the auger device 11, action of pressing the soil toward the hole wall to reinforce it is performed while pulling up the auger device without rotation, and the solidifying material is injected into the lower part. After throwing soil to the upper part of the hole, the auger device is moved up and down while rotating to mix the solidifying material with the soil well. The soil cement column is thus constructed as a uniform one. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a construction method for a pile foundation and the like that supports the foundation of a building such as a house, and a construction device used for the construction, and in particular, without discharging the soil of the excavated pile hole to the ground surface, without applying pressure. Furthermore, the present invention relates to a construction method capable of constructing a strong cast-in-place pile by supplying solidified material, soil, aggregate (good quality soil), etc. to a gap remaining in a hole, mixing and stirring, and an apparatus used therefor.

Conventionally, when constructing a structure such as a house or other small building, the conditions such as the strength of the ground at the construction site are investigated, and the weight of the structure to be constructed is When it is judged that the strength cannot be supported, the pile foundation is used to increase the bearing capacity. In order to increase the bearing capacity of the ground, by placing existing piles such as concrete and steel pipe piles, while excavating the vertical hole, mixing cement milk etc. into the soil of the excavated hole, Means such as columnar ground improvement are used. In addition, various construction methods are used, such as placing an existing pile member into a hole in which the columnar ground has been improved and integrating it into a large-diameter pile. As a column member for supporting the foundation of the building on the ground, a commonly used construction method is known to use, for example, technical means as disclosed in the following document 1. In the conventional example, the soil in the excavation hole and the solidified material are mixed, and an existing pile is placed in a columnar member constructed as a structure of improved soil. Many examples are known as being capable of easily constructing a foundation based on a support pillar integrated with an existing pillar placed in (see, for example, Patent Document 1).
Japanese Patent Publication No.1-40173

  When the stratum that supports the foundation of the building is deep, it is necessary to use long steel pipe piles and so on. Furthermore, since a large amount of soil is generated when a foundation pile is constructed using a conventional method as disclosed in the above-mentioned conventional example, the treatment of the remaining soil becomes a problem. In addition, soil columns constructed by mixing cement milk etc. with soil can exhibit the ability to support a large load due to the large friction between the outer surface of the column and the soil wall of the hole. In addition, there is an unavoidable problem that a large amount of excess soil is generated when building the column.

  When excavating a pile hole, the present invention does not discharge the soil of the hole to the ground, but presses and compacts the soil against the hole wall to reinforce the hole wall, and the remaining soil and newly supplied bone The purpose is to provide a construction method for constructing a high-strength soil cement column by mixing a solidified material with a material (good quality soil) and mixing and stirring, and an apparatus therefor.

Claims 1 to 4 of the present invention relate to a construction method of a pile foundation. In the examples described below, members explained as auger devices are generic names of members generally called excavation blades and stirring blades. ing. In the present invention,
The invention of claim 1 excavates a pile hole perpendicularly to the ground using an auger device, and strengthens the hole wall by consolidating the soil of the excavated hole toward the hole wall;
The soil cement column is constructed without discharging the soil of the excavated hole to the ground by adding the solidified material and the insufficient aggregate to the soil remaining in the hole and kneading with a stirring means. It is characterized by.

The invention of claim 2 is a step of excavating a pile hole perpendicular to the ground using an auger device;
Injecting solidification material from the lower part of the excavation part while pulling up without rotating the auger device, and filling the solidification material in a predetermined range below the hole;
Pulling up the auger device to the ground without rotating, filling the space part above the pile hole with soil,
A process of inserting and rotating an auger device into the pile hole and mixing the solidified material and the soil,
It is characterized by constructing a soil cement column in which solidified material and soil are mixed.

The invention of claim 3 can perform the action of strengthening the hole wall by pressing the soil of the hole toward the wall of the hole by raising the auger device without rotating it,
While raising the auger device without rotating it, supplying the solidified material from the lower end of the rod without applying pressure into the ground, and filling the space formed in the lower portion of the auger device with the solidified material It is characterized by performing.
The invention of claim 4 uses a high-quality aggregate suitable for the properties of the solidified material as a material to be filled in the space above the pile hole after the auger device is pulled up, and the solidified material without applying pressure. And kneading.

The following invention relates to a pile foundation construction device,
In the invention of claim 5, the auger device for excavating the pile hole has a hole for ejecting a solidified material to a lower end portion of a hollow rod,
A predetermined range of the lower portion of the rod is provided with a flight member fixed with a plate-like member in the vertical direction and the circumferential direction,
The flight member is configured so that by raising the auger device without rotating, the soil of the hole is pressed against the wall of the hole, and the hole wall can be consolidated and strengthened. And

In the invention of claim 6, the auger device for excavating the pile hole has a hole for ejecting the solidified material at a lower end portion of a hollow rod connected to a device for supplying the solidified material.
In a predetermined range of the lower part of the rod, an approximately conical flight having a small diameter at the upper part and a large diameter at the lower part, and a drilling tooth device attached to the lower part of the large diameter flight,
It is supported by a movable vehicle device or a movable saddle device, and is configured to perform an operation of moving up and down while rotating the auger device and an operation of moving up without rotating. Features.

  Using the equipment configured as described above, the solidified material is filled in the lower part of the excavated pile hole, and then the soil is poured into the upper part of the hole and stirred by the stirring blade, so that the solidified material and the soil are removed. A uniformly mixed soil cement column can be constructed. When excavating the pile hole, drill it down to the expected depth and then pull it up at a low speed without rotating the auger device (stirring blade), without applying pressure to the space created at the bottom of the stirring blade. By filling the solidified material by pouring it in, the auger device strongly presses the soil against the wall of the hole and can simultaneously perform the action of strengthening the wall of the hole. Moreover, when applying this construction method, soil is not excluded from the excavated hole to the ground, and the soil can be used effectively.

  Then, as described above, after filling the solidified material to the middle part of the pile hole, raise only the stirring blade without rotation and pull it out from the pile hole, and put the soil on the upper part of the solidified material filled part Then, insert the auger device into the pile hole again, repeat the vertical movement while rotating the auger device, and thoroughly mix the soil and solidified material, so that a high quality column that does not cause uneven mixing Can be built. In addition, the auger device is lifted without rotating, and the wall is strengthened by pressing the soil against the wall of the excavated hole. With the operation of pulling up slowly, the hole wall can be consolidated by removing the space that is generated in the hole wall or where the soil on the wall is loose. Then, a column in which the solidified material injected into the hole, the soil remaining in the hole, and the aggregate to be added or the high-quality soil are mixed can be easily constructed without waste.

  When implementing the pile foundation construction method described below, 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. The pile foundation construction device is equipped with a solidification material supply mechanism for ejecting the solidification material from the ejection hole through the hollow portion of the middle rod and constructing the solidification material pillar in the excavation hole. . 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

  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 9 is supported by the winch 4a so as to be movable up and down. The upper device 9 moved up and down along the support member 5 is provided with a drive mechanism for driving the rod 10 of the excavator, and the auger device 11 provided at the lower portion of the rod 10 is rotated, The earth is excavated by excavating teeth (not shown) provided in the lower part of the flight 12.

  The rod 10 provided with the auger device 11 at the lower end is configured as a hollow rod, and the solidified material sent from the supply device 7 is supplied to the rod 10 through the supply pipe 8 connected to the upper device 9. Supply. And it provides so that a solidification material may be ejected from the hole 13 provided in the lower end part of the said rod 10, The said auger apparatus 11 is attached and comprised so that the flight 12 may be wound around the rod 10. FIG. Further, in the lower part of the flight 12, similarly to a conventionally used pile hole excavator, a drilling blade having a drilling blade attached to the tip is provided, so that the excavation action of the pile hole can be performed efficiently. It can also be comprised similarly to a well-known pile hole excavation apparatus.

  The flight 12 constituting the auger device 11 has a so-called substantially conical shape in which the upper part has a small diameter and the lower part has a large diameter so that it has a predetermined height in the vertical direction around the hollow rod 10. It is good to comprise like the conventional pile hole excavation apparatus. When the conical auger device 11 is raised without rotating, the soil at the top of the auger device is gradually pressed strongly toward the hole wall so as to follow the oblique auger device. As described above, by performing the operation of raising the auger device 11 at a low speed without rotating the auger device 11, the soil of the hole is made into the wall from the small diameter portion to the large diameter portion of the auger device. The action which pushes toward is performed. Eventually, the large diameter part of the auger device will strongly press the soil against the wall, and even if there are gaps or fragile parts in the hole wall due to the action of pressing the soil against the hole wall, The effect | action which strengthens a wall by the effect | action which presses the soil is provided, and it is made to improve the intensity | strength of the wall of a pile hole.

  As the auger device 11, instead of providing the screw-shaped flight 12, a plate-like member is attached at a predetermined interval to the rod so as to be substantially spiral, and the cone as a whole is provided. It may be configured to have a shape. In addition, in particular, when mixing and stirring the solidified material and soil in the hole, use a shape that forms a gap in the screw, rather than mixing using a screw-like flight. Thus, the mixing action can be performed more effectively. As the screw-like member having a gap, if a plate-like member is attached in a spiral shape with respect to the shaft with a gap, and configured as a substantially screw-shaped member, the stirring efficiency can be satisfactorily exhibited. In some cases.

  Next, the operation and process for constructing a cast-in-place pile (soil cement column) using the apparatus configured as described above will be described. FIGS. 2A to 2C illustrate a process from the excavation of the vertical hole by the auger device to the pulling up without rotating the auger device to strengthen the hole wall 16. First, as shown in FIG. 2A, the auger device 11 is rotated while being pressed by the rod 10 to excavate a pile hole 15 corresponding to the diameter of the auger device 11, and the pile hole 15 is formed at a predetermined depth. The state that has been reached is explained.

  Next, the auger device 11 is rotated at a low speed without rotating, and the auger device 11 is formed at the lower portion of the auger device 11 from the ejection hole 13 provided in the lower end portion of the rod 10. The operation of supplying the solidifying material so as not to cause a gap also in the space is continued, and the lower portion of the auger apparatus 11 is filled with the solidifying material. When supplying the solidified material, as shown in FIG. 2 (b), the solidification material is continued in accordance with the ascending operation of the auger device 11 until the height reaches the middle portion of the pile hole 15. And after that, the operation | movement which raises the auger apparatus 11 is continued, without supplying a solidification material, and the effect | action which strengthens a hole wall is performed.

  In the state where the auger device 11 is pulled up to the ground, as explained in FIG. 5C, the lower part of the pile hole 15 is filled with the solidification material 20, and the upper part of the hole is excavated. The soil 17 is left as it is. As described above, the operation of raising the auger device 11 without rotating it causes the soil to be strongly pressed against the hole wall 16 of the pile hole 15 to strengthen the wall. That is, when the conical auger device is lifted without rotation, the shape of the flight gradually increases in diameter, so that the soil in the hole is pressed toward the hole wall. In particular, since a lot of soil will be pushed into the weak part of the wall and the part where there are gaps in the formation, the wall becomes thicker, the gap does not occur, and it is surrounded by the reinforced hole wall, As will be described later, a support pile integrated with the ground can be constructed by constructing a soil cement column.

  2, the process proceeds to the step shown in FIG. 3. As described in FIGS. 2 (c) and 3 (a), the excavator 25 or the like is used to form the space above the pile hole 15. A new soil 18 is thrown into. The soil 18 to be supplied to the upper part of the pile hole 15 is not limited to the soil overflowing from the upper part of the hole 15, but the soil or the like scheduled to be excavated to construct the foundation (foundation) of the building. Use it according to the condition. The amount of the soil 18 to be newly added is adjusted as appropriate so that the final height of the column created by mixing with the solidifying material 20 in the hole 15 becomes the planned height of the soil cement column. It is constructed.

  As described above, a new soil 18 is put on the solidified material 20 filled in the lower part of the hole, and then the auger device 11 is inserted into the hole 15 as shown in FIG. In addition to rotating the rod, the auger device 11 is moved up and down a plurality of times to mix and stir the soil and the solidified material. And in the said hole 15, the high quality soil cement column 22 can be formed by stirring so that soil and the solidification material 20 may be mixed uniformly. As described above, the auger device is extracted from the hole, and when a predetermined time has elapsed, the solidifying material will be effective, so that it becomes a soil cement column that can support the foundation of a building or the like in a stable state, A building foundation can be constructed at the top of the column 21.

  In addition, as shown in the above embodiment, when a so-called soil cement column is constructed by mixing the soil of the excavated hole and the solidifying material, the solidifying material used for the construction of the column is not limited to cement milk. Any conventionally known solidifying material can be used. Furthermore, as the aggregate to be additionally input, even if it is available near the site, it can be used as it is even if it is mixed with some pebbles. The mixing ratio of the solidifying material and the soil can be appropriately set according to the result of the test using the soil in the field and the weight of the building or the like constructed on the foundation. In addition, the structure of the excavator, such as the flight structure of the auger device, and the attached equipment arranged around it, without modifying the devices that are generally used in the past, especially to deal with this construction method, It can be used as it is.

  Then, as described above, after using the auger device in which the excavation blade member and the stirring blade member are integrated, after the hole is dug down by the auger device, the auger device is raised at a low speed without rotating. The process of building a soil cement column can be carried out in a state where the wall of the hole is strengthened and the soil of the wall does not collapse. In addition, by using a lot of hole soil to reinforce the walls, additional aggregate and high-quality soil are added to the remaining hole, and the solidified material is not pressurized. Can be poured and mixed well with an auger device to build a homogeneous soil cement column. And since the method of injecting the high-pressure solidified material into the hole is not used, unlike the method of supplying the solidified material in the conventional method, the high-pressure solidified material is not ejected from the hole and mixed with the solidified material. Since the soil does not overflow, there is no need to take care of remaining soil after construction. Furthermore, since it is not necessary to use a pressure pump or a pressure-resistant hose as an attached device, the equipment can be simplified and the amount of solidifying material used can be reduced.

It is explanatory drawing which shows the structure of a construction apparatus. (A) thru | or (c) are explanatory drawings of the process raised after lowering an auger apparatus. (A) thru | or (c) is a figure explaining the process of constructing a soil cement column later on.

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, 9 Upper device, 10 Rod, 11 Auger device, 12 Flight, 13 Ejection hole, 15 Pile hole, 16 Hole wall,
17 excavated soil, 18 input soil,
20 drilling holes, 22 soil cement columns.

Claims (6)

Drilling a pile hole perpendicular to the ground using an auger device, and strengthening the hole wall by compacting the soil of the drilled hole toward the hole wall,
The soil cement column is constructed without discharging the soil of the excavated hole to the ground by adding the solidified material and the insufficient aggregate to the soil remaining in the hole and kneading with a stirring means. Pile foundation construction method characterized by Drilling a pile hole perpendicular to the ground using an auger device;
Injecting solidification material from the lower part of the excavation part while pulling up without rotating the auger device, and filling the solidification material in a predetermined range below the hole;
Pulling up the auger device to the ground without rotating, filling the space part above the pile hole with soil,
A process of inserting and rotating an auger device into the pile hole and mixing the solidified material and the soil,
A pile foundation construction method characterized by constructing a soil cement column in which solidified material and soil are mixed. By raising the auger device without rotating it, the soil of the hole can be pressed against the wall of the hole, and the hole wall can be strengthened.
While raising the auger device without rotating it, supplying the solidified material from the lower end of the rod without applying pressure into the ground, and filling the space formed in the lower portion of the auger device with the solidified material The pile foundation construction method according to claim 1, wherein the pile foundation construction method is performed.   After pulling up the auger device, as a material for filling the space above the pile hole, a high-quality aggregate suitable for the properties of the solidified material is used and kneaded with the solidified material without applying pressure. The construction method of a pile foundation according to claim 3. The auger device for excavating the pile hole has a hole for ejecting the solidified material to the lower end of the hollow rod,
A predetermined range of the lower portion of the rod is provided with a flight member fixed with a plate-like member in the vertical direction and the circumferential direction,
The flight member is configured so that by raising the auger device without rotating, the soil of the hole is pressed against the wall of the hole, and the hole wall can be consolidated and strengthened. Pile foundation construction equipment. The auger device for excavating the pile hole has a hole for ejecting the solidified material at the lower end of a hollow rod connected to a device for supplying the solidified material,
In a predetermined range of the lower part of the rod, an approximately conical flight having a small diameter at the upper part and a large diameter at the lower part, and a drilling tooth device attached to the lower part of the large diameter flight,
It is supported by a movable vehicle device or a movable saddle device, and is configured to perform an operation of moving up and down while rotating the auger device and an operation of moving up without rotating. Pile foundation construction device characterized.

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