JP2000265456A - Establishment method for mixed and solidified reinforcing pile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength of a pile. SOLUTION: An improvement material such as sand, a solidifying agent and present ground soil are mixed stirring at a original position of the ground which should be improved. These stirring and mixing are continuously performed from a predetermined depth to a ground level, thereby a mixed and solidified reinforcing pile which consists of a mixture of the improvement material, the solidifying agent and the present ground soil is established. Moreover, when stirring and mixing while pilling out, a construction machine is used, and the construction machine is provided with a stirring device having an agitating blade 9 which has larger than a diameter of a casing 3 and a solidifying agent delivering port 10 in a tip end part of a stirring shaft 8, an improvement material supplying device such as a hopper 7, a rotative casing 3, and a forced lift device 6 for the casing, etc. In that case, the casing 3 filled the improvement material at least in its tip end part is forced into a predetermined depth while rotating. Sequentially, the improvement material is exhausted flowing down from the tip end part of the casing 3 while pulling out the casing 3, and the improvement material, the solidifying agent and the present ground soil are mixed stirring at an outside of the tip end part of the casing 3 while delivering the solidifying agent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a reinforced mixed solidified pile with further improved pile strength.

[0002]

2. Description of the Related Art Conventionally, as a method of improving soft ground,
A mixing and solidifying method is known in which a solidifying material such as cement milk and mortar and soft soil are stirred and mixed in situ in the ground, and the soft soil is consolidated using chemical bonding to solidify and improve the ground. ing. In this method, the solidified material and the solidified material are stirred and mixed by discharging and solidifying the solidified material from a stirring shaft having a stirring blade at the tip, and the solidified material is formed.

[0003]

However, conventionally, depending on the soil properties of the original ground, the solidification reaction is hindered, and sufficient pile strength may not be obtained, and further improvement in pile strength has been demanded. In order to solve this, it is conceivable to increase the amount of cement or mix an expensive enhancer,
There is a limit from the viewpoint of cost effectiveness, and its practicality is low.

[0004] Accordingly, an object of the present invention is to provide a method for constructing a reinforced mixed solidified pile in which the pile strength is further improved.

[0005]

That is, according to the present invention, an improving material such as sand, a solidifying material, and an original ground are mixed under stirring at the original position of the ground to be improved, and the mixed mixing is performed from a predetermined depth to the surface of the ground. This is a method for constructing a reinforced mixed solidified pile, characterized in that solidified piles composed of a mixture of an improved material, a solidified material, and original ground soil are formed continuously.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention includes the following embodiments. In the above configuration of the present invention, a stirrer having a stirring blade having a diameter larger than the casing diameter and a solidified material discharge port at the tip end of the stirrer shaft at the time of drawing stirring and mixing, an improved material supply device such as a hopper, and a rotatable casing And using a construction machine equipped with a forced lifting device such as a casing,
While rotating the casing filled with the improving material at least at the distal end portion, it penetrates to a predetermined depth, and then pulls out the casing, discharges the improving material down from the casing distal end, and discharges the solidified material while improving the outside of the casing distal end,
An embodiment in which the solidified material and the original ground are stirred and mixed is preferable. In this case, the stirring blade is preferably provided so as to protrude from the tip of the casing.

[0007] In another embodiment, a stirrer is foldable and a construction machine equipped with a stirrer shaft vertical moving device is used.
The stirring blade is folded and penetrated in a state housed in the casing, and the stirring blade is protruded from the tip of the casing by a stirring shaft vertical movement device during stirring and mixing, and the stirring blade is developed by rotation or the like to have a diameter larger than the casing diameter. It can be configured as follows.

In the above embodiment, a plurality of stages of stirring blades are provided in the length direction of the stirring shaft, and the stirring blade near the lower end of the stirring shaft has a larger diameter than that of the upper portion. The stirring blades of the stages may be provided at different angles for each stage.

Further, when the casing is penetrated and / or pulled out, it is preferable to discharge the ground in an amount corresponding to the total amount of the improving material and the solidifying material to be supplied. It is.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view showing an example of a construction machine for carrying out the present invention, partially cut away.

In FIG. 1, 1 is a construction machine main body, 2 is a leader erected on the front of the construction machine main body 1, and 3 is a casing. The upper end of the casing 3 is rotatably connected to the reader 2 via a casing rotating device 4 with a swivel mechanism. A stirring drive device 5 and a forced lifting device 6 for forcibly raising and lowering the casing 3 are provided at an upper portion of the casing rotating device 4, and an improving material supply hopper 7 is provided at an uppermost portion. The forced lifting device 6 is, for example, a rack and pinion type that can obtain a reaction force from the leader 2 at the time of penetration and withdrawal. Although FIG. 1 shows the device arrangement as described above, the device arrangement is arbitrary, and the present invention is not limited to this.

A stirrer for discharging the solidified material and stirring and mixing the improved material, the solidified material and the original ground includes a stirring drive device 5, a stirring shaft 8 connected to the drive device 5, and penetrating through the casing 3.
A stirring blade 9 is provided at the tip of the stirring shaft 8 and protrudes from the tip of the casing 3 and has a diameter larger than the diameter of the casing 3, and a discharge port 10 for the solidified material located near the stirring blade 9. The stirring shaft 8 is a hollow tube, and supplies the solidified material supplied through the solidified material supply pipe 11 to the discharge port 10. The discharge port 10 may be opened at the lowermost end of the stirring shaft 8, may be opened at the middle of the stirring blade 9, or may be opened at the stirring shaft 8.
May be opened over a plurality of stages in the length direction.

In order to improve the soft ground by using the construction machine shown in FIG. 1, first, the casing 3 is set at a predetermined position, and a predetermined amount of the improving material such as sand or gravel is put into the casing 3 from the improving material supply hopper 7. , Slag, crushed stone, excavated soil, etc. The improving material filled in the tip part in the casing 3 is as follows:
Prevent the ground soil from entering the casing 3. Casing 3
While being rotated by the casing rotating device 4, the forcible penetrating device 6 forcibly penetrates to a predetermined depth. At the time of penetration, the stirring blade 9 advances in the ground soil in conjunction with the casing 3.

Next, the casing 3 is pulled out by the forcible elevating device 6 while rotating the stirring blade 9, and the improved material is discharged from the casing 3 and discharged therefrom.
A solidifying material, for example, cement milk, cement mortar, or the like is supplied through the discharge port and discharged from the discharge port 10. The agitating blade 9 having a diameter larger than the diameter of the casing 3 agitates and mixes the improved material and the solidified material with respect to the original ground corresponding to the effective diameter, thereby improving the strength of the diameter larger than the diameter of the casing 3. A solidified pile can be created. In addition, the casing 3 may or may not rotate at the time of withdrawal.

As described above, by continuously ejecting and stirring and mixing the solidified material while pulling out the casing 3 from a predetermined depth to the surface of the ground, the casing 3 is made of a mixture of the improved material, the solidified material and the original ground. A pile with a diameter larger than the diameter is formed, and the solidified material contained in the pile is strongly bonded to the improved material and the local soil by a hydration reaction or a pozzolan reaction, and a high-strength solidified pile can be created.

In the above description, the stirring blade 9 projecting from the front end of the casing 3 and having a diameter larger than the diameter of the casing 3 is described.
Although an example using the above is described, a foldable stirring blade accommodated in the casing 3 may be used instead of such a stirring blade 9.

For example, the stirring blade is a foldable stirring blade, and a stirrer is folded and housed in a casing using a construction machine equipped with a stirring shaft vertical moving device capable of forcibly moving the stirring shaft up and down by hydraulic pressure or the like. The stirrer blades may be made to protrude from the tip of the casing by the vertical motion device at the time of stirring and mixing, and the stirring blades may be expanded by rotation or the like to have a diameter larger than the diameter of the casing.

As an example of such a stirring blade, there is a folding blade 9A that closes by directional rotation and expands by directional rotation as shown in FIG. Another example of a folding wing may be a pantograph wing.

In order to increase the efficiency of stirring and mixing, it is preferable to provide a plurality of stages of stirring blades 9 in the length direction of the stirring shaft 8, but this stirring blade 9 may have a twist, or may have a twist as shown in FIG. As shown, the stirring blade 9D near the lower end has a larger diameter than the stirring blades 9C and 9B at the upper part, or the stirring blades 9E, 9F and 9G are provided at different angles for each stage as shown in FIG. Or a combination thereof.

In the present invention, since the improved material and the solidified material are put into the ground, the ground around the solidified pile may be pushed and the ground may be displaced. In ground improvement near an existing building or the like, it is preferable to discharge an amount substantially corresponding to the total amount of the improving material and the solidifying material to be supplied in consideration of the occurrence of ground displacement. As a method for discharging the soil, a conventionally known method can be applied. For example, a spiral blade may be provided on the outer periphery of the casing, and the soil may be discharged to the ground surface along the spiral blade during penetration and / or removal.

[0021]

According to the method for constructing a reinforced mixed solidified pile according to the present invention described above, the improved material such as sand, the solidified material such as cement milk and the original ground are mixed and stirred in situ on the ground to be improved. Thus, a high-strength solidified pile made of a mixture of the improved material, the solidified material and the original ground soil can be efficiently formed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view showing an example of a construction machine for carrying out the present invention.

FIG. 2 is a drawing showing an example of a deployable folding wing.

FIG. 3 is a drawing showing an example in which a plurality of stages of stirring blades having different diameters are provided.

FIG. 4 is a view showing an example in which a plurality of stirring blades are provided at different angles.

[Description of Signs] 1 Construction machine main body 2 Leader 3 Casing 4 Casing rotating device 5 Stirring drive device 6 Forced lifting device 7 Improved material supply hopper 8 Stirring shaft 9 Stirrer blade 10 Discharge port 11 Solidified material supply pipe

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2D040 AB05 AB07 BA06 BA08 BB03 BC01 BD05 CA01 CA04 CA09 CB03 DA12 DB07 EA01 EA07 EA17 EA18 EA21 2D041 AA01 BA03 CA01 CB01 DA11

Claims (7)

[Claims] An improved material such as sand, a solidified material, and an original ground soil are stirred and mixed at the original position of the ground to be improved, and the mixed mixing is continuously performed from a predetermined depth to the surface of the ground, and the improved material, solidified A method for forming a reinforced mixed solidified pile, comprising forming a solidified pile made of a mixture of wood and raw soil. 2. A stirrer having a stirrer blade having a diameter larger than the diameter of a casing and a solidified material discharge port at a tip end of a stirrer shaft at the time of drawing stirring and mixing, an improved material supply device such as a hopper, a rotatable casing and a casing. Using a construction machine equipped with a forced elevating device, the casing filled with the improving material at least at the tip portion penetrates to a predetermined depth while rotating, and then the improving material flows down and discharged from the casing tip while pulling out the casing, and the solidified material 2. The method of claim 1, wherein the agitating and mixing of the improved material, the solidified material and the ground soil is performed outside the tip of the casing while discharging. 3. The method according to claim 2, wherein the stirring blade is provided so as to protrude from a tip of the casing. 4. The stirring blade is a foldable stirring blade,
3. The stirrer is folded into the casing by using the construction machine according to claim 2 provided with a stirrer shaft vertically moving device, and penetrates the casing. 3. The method according to claim 2, wherein the stirring blade is expanded by rotation or the like so as to have a diameter larger than the diameter of the casing. 5. The reinforced mixed solidified pile according to claim 3, wherein the stirring shaft is provided with a plurality of stages of stirring blades in its length direction, and the stirring blade near the lower end of the stirring shaft has a larger diameter than that of the upper portion. Construction method. 6. The method according to claim 3, wherein a plurality of stages of stirring blades are provided at different angles for each stage. 7. A reinforced mixed solidified pile according to any one of claims 1 to 6, wherein when the casing is penetrated and / or pulled out, an amount corresponding to the total amount of the improving material and the solidifying material to be supplied is discharged. Construction method.