JPH0455516A - Deep layer mixing processing machine and pile cap construction with its machine - Google Patents

Abstract

PURPOSE:To improve workability by providing the tip section of a rotary blade shaft with a lower section agitating-blade, to provide a position near a ground surface, with an upper section agitating-blade, and by providing a position near the lower section agitating-blade, with a slurry outlet. CONSTITUTION:By the lower section agitating-blade 3 of an earth auger 1, ground 24 is excavated and at the same time, from the tip section of a rotary blade shaft 2, the slurry 4 of ground stabilizer is discharged and is mixed with excavated earth, and the pile section 25 of a diameter (d)is formed. After that, by an upper section agitating-blade 20, the ground surface section Of the ground 24 is excavated and at the same time, slurry 21 is discharged to be mixed with the excavated earth, and the upper section cap section 23 of a diameter D is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a deep mixing machine used in a deep mixing method, which is a type of ground improvement method, and a pile cap method carried out by the deep mixing machine. Pause.

2. Description of the Related Art In a conventional deep mixing processing machine, as illustrated in FIG. 5, a stirring blade 3 is installed at the lower end of a rotary blade shaft 2 that is supported vertically downward and rotationally driven by an earth auger 1 on the ground. In addition, the rotary blade shaft 2 has a pipe structure capable of discharging a slurry 4 such as a ground stabilizer from its lower end, etc., and is configured to mix the earth and sand and the slurry 4 in situ while being rotatably excavated by the stirring blades 3. It is said that

Therefore, the piles were constructed using the above-mentioned deep mixing machine and had uniform diameters that remained constant from the top to the bottom.

Problem to be solved by the present invention I) Since the improved piles 5 constructed by a conventional deep mixing machine are uniform diameter piles whose diameters do not change, their arrangement pitch is large and sparse (therefore, the ground improvement rate is is small) If embankment 6 is placed on top of improved pile 5...
As a result of aging, the embankment 6 gradually sinks in between the piles,
There was a drawback that uneven settlement occurred on the surface of the embankment 6. 7 in the figure indicates the supporting layer ground.

■) Conventionally, as a countermeasure to solve the disadvantage of uneven settlement mentioned above, for example, two improved upper piles 5 were used as shown in Figure 7 A and B.
, 81st construction method of ``joining'' that configures 5 pieces into an overlapping whale, or the 81st! ! ms above the head of improved pile 5 as in
Many construction methods have been implemented in which so-called geotextiles 8, such as nets, sheets, etc., are laid horizontally. However, the former construction method has the disadvantage that the number of improvement piles 5 increases and the improvement rate of the ground increases dramatically, which increases the number of construction steps, lengthens the construction period, and increases costs. The latter construction method also had the disadvantage of consuming Thiotextile 8 and increasing the cost due to the increase in the laying process.

m) Conventionally, as a method of constructing road embankments with little subsidence in areas where there is a lot of highly organic tributary ground, pile caps such as concrete piles or pine piles 9 cast into the ground have been used as shown in Figure 9. Reinforced concrete floor slab 1 as a head connection in the section
0 and place the embankment 6 on top of it, or as shown in Figure 10, place a concrete cap 11 on the head of the pine pile 9.
, and place embankment 6 on top of it, or connect reinforcing bars 12 and geotextile 8 to the pile head as shown in Figure 11.
There are many methods that have been implemented, such as constructing an embankment and placing an embankment 6 on top of it.

In addition, when continuous wall-shaped improvement piles are required in offshore construction using the conventional deep mixing machine (Fig. 5) described above, two adjacent piles as shown in Fig. 12 A and B are used.
In addition to this improvement, a construction method has also been implemented in which an overlapping pile cap 13 is constructed on the head of the pile 5.5, and the same effect and effect as the pile cap construction method on the 10th surface is expected.

However, in the case of this construction method, one set of improved piles 5 and two pile caps 13, 13 on both sides thereof constitutes one set, and in short, three steps are required, so the construction takes a lot of effort. Moreover, since the pile 5 and the pile cap 13 are connected to each other for improvement purposes, the reliability of the joint between the two is not perfect.

The above-mentioned problems are issues to be solved by the present invention.

Means for Solving the Problems (First to Third Inventions) As a means for solving the r1 problem of the prior art described above, a deep mixing machine according to the present invention is provided as shown in it!1 of the drawings.
~No. 31! As shown in the examples in IA and B, a lower stirring blade 3 is installed at the tip of a rotary blade shaft 2 having a tube structure capable of discharging a soil stabilizer slurry, and an upper stirring blade 20 is installed near the ground surface. installed.

The lower stirring blade 3 has a length corresponding to the pile diameter d, and the lower stirring blade 20 has a length equivalent to the cap diameter. It is characterized in that a downward or sideways slurry discharge port is provided near the blade 20 (FIG. 1).

Moreover, the upper stirring blade 20 of the deep mixing processing machine of the present invention is
The position of the upper 111I stirring blade 20 is variable in the vertical direction along the rotary blade shaft 2 (Fig. 2), and the upper 111I stirring blade 20 is bent in a specific rotation direction, but has one straight blade in the reverse direction. 3A and B), each of which has a blade tip constituted by a single-foldable enlarged blade piece 22 that has a rod-like shape.

How this ring-N mixing treatment machine works! 124, the pile portion 25 and the cap portion 23 can be constructed in one step (see Figure 1 and Figures 4A and 4B).

At the time of rotary excavation of the ground 24 by the large-diameter upper stirring blade 20, the ground 24 has already been rotatably excavated and mixed in an area corresponding to the pile diameter d by the small-diameter lower stirring blade 3, and is generally soft. In the surface layer of the ground, the strength of the ground is weak and the overburden pressure is small, so the excavation resistance torque is not very large, and the upper stirring blade 2o can perform smooth rotational excavation. Good mixing processing is possible even without intentionally discharging the stabilizer slurry.

The upper stirring blade 20 whose position is variable in the vertical direction along the rotary blade shaft 2 can be freely adapted to cases where the improvement depth H of the cap portion 23 differs depending on the location.

The single-folding enlarged blade piece 22 rotates forward and backward, making it the upper stirring blade 1! Since the actual lengths of the I20 are different, when stored on the ground, the enlarged blade pieces 22 can be bent to make management compact.

(Fourth invention) The pile cap construction method using a deep mixing treatment machine according to the fourth invention, as shown in the examples in FIGS. A lower stirring blade 3 is installed at the tip of the shaft 2, an upper stirring blade 20 is installed near the ground surface, the lower stirring blade 3 has a length corresponding to the pile diameter d, and the lower stirring blade 20 is installed at a position near the ground surface. is a deep mixing machine having a length corresponding to the diameter of the cap part and having a slurry discharge port located at least in the vicinity of the lower stirring blade 3 (upper stirring blade 20 if necessary). Akebono scrapes in the direction. To do this, first, the ground 24 is rotatably excavated with the lower stirring blade 3, and the rotary blade shaft 2
A step of forming a pile portion 2δ by mixing with slurry 4 of a soil stabilizer discharged downward or sideways from the tip of the upper stirring blade. In step 20, the ground surface of the ground 24 is rotatably excavated to a predetermined depth, and if necessary (if the amount of slurry in step 3 is insufficient to the lower stirring blade), the slurry 21 of the ground stabilizer is discharged to perform a mixing process. The method is characterized by comprising the steps of: forming an upper cap portion 23;

The lower stirring blade 3 rotates in advance and excavates the slurry 4.
The subsequent upper stirring blade 2o again rotatably excavates the ground surface portion of the ground 24 that has been mixed with slurry 2.
1 is discharged and mixed to form the cap portion 23, the pile portion 25 and the cap portion 23 become an integrated improved soil structure, and complete reliability can be obtained at the joint.

The large-diameter cap portion 23 has the same effect as increasing the ground improvement rate, and by constructing the adjacent cap portions 23 in a bonding relationship (Fig. 4 A and B), uneven settlement can be prevented with less man-hours. It is possible to ms the embankment ground that does not grow.

Embodiments Next, embodiments of the present invention shown in Sections 11 to 4 A and B will be described.

1st I! The deep mixing treatment machine shown in I is an earth auger 1 on the ground that is supported vertically downward and driven to rotate, and a lower agitation unit is installed at the tip of a rotary blade shaft 2 with a tube structure capable of discharging soil stabilizer slurry. The blade 3 is installed and the ground surface (
An upper stirring blade 20 is installed near G-L). The lower stirring blade 3 has a length corresponding to the diameter d (d is usually about 100 cm to 150 cm+) of the small diameter pile portion 25, and the upper stirring blade 20 has a length corresponding to the diameter d of the small diameter pile portion 25.
The length corresponds to the diameter D of No. 3 (D is usually about 200 cm to 300 cm). A discharge port for the slurry 4 is provided downward from the tip (lower end) of the rotary blade shaft 2 (or laterally from a position approximately at the same level as the lower stirring blade 3). Furthermore, if necessary, a horizontal discharge port for the slurry 21 may be provided at approximately the same level as the upper stirring blade 20. In this case, the supply and stop of the slurry 4.21 is controlled by separate systems to the two slurry discharge ports.

The upper stirring blade 20 can be attached to the rotary blade shaft 2 by fixing the position, or by using a sliding key or the like, as shown in FIG. The installation position is made variable in the vertical direction along the rotating blade shaft 2, thereby increasing the improved depth H of the cap portion 23.
It is convenient to implement the system with a configuration that can accommodate different cases depending on the location. And also the upper stirring blade 20
As shown in FIGS. 3A and 3B, it is also convenient to configure approximately half the length of the distal end side as a single-foldable enlarged blade piece 22 rotatably connected by a pin 26. It is. Furthermore, at the connecting portion of the enlarged blade piece 22 with the bottle 26, there is a stopper that stops the enlarged blade piece 22 in a straight bar-like position when the upper stirring blade 20 rotates counterclockwise as shown in FIG. 3B. 27 is installed, and in this state, the large-diameter cap portion 23 can be rotary excavated and mixed with the slurry 21. On the other hand, when the upper stirring blade 20 rotates clockwise as shown in FIG. 3A, or when it is stored when the rotation is stopped, the enlarged blade piece 22 bends at the position of the bottle 26, making it possible to store the blade in a compact manner. It is preferable to use a configuration that can save space.

In the pile cap construction method carried out by the deep mixing machine with the above configuration, as shown in Fig. 1, the earth auger 1 is first installed at a predetermined position on the ground 24, and the lower stirring blade 3 is used to stir the ground 24. Rotate the tail vertically downward.

At the same time, a soil stabilizer slurry 4 is discharged from the tip of the rotary blade shaft 2 and mixed with the excavated soil to form a pile portion 25 of diameter d of improved soil. In this way, the construction of the pile portion 26 by the lower stirring blade 3 is advanced in the depth direction of the ground 24, and when a predetermined depth (for example, the position of the support layer ground 7) is reached, the subsequent upper stirring blade 20 reaches the ground surface GL. As it is, the ground surface portion of the ground 24 is rotatably excavated in the depth direction, and a mixing process is performed using the slurry 4 discharged from the position of the preceding lower stirring blade 3. however,
If the amount of the slurry 4 is insufficient, the slurry 21 is accordingly discharged sideways from a position approximately at the same level as the upper stirring blade 20 to sufficiently mix it with the excavated soil, and the upper cap is made of improved soil. A portion 23 is formed.

The upper cap portion 23 is formed by rotary excavating the improved soil that has been previously mixed by the lower stirring blade 3 and mixing it with the slurry 21, so that the pile portion 25 and the upper cap portion 23 are is formed as an integrated improved soil structure. The pile portion 25 has a diameter dltloOc+g~150C depending on the length of the lower stirring blade 3.
It is assumed to be the first place, and usually from the ground surface G-L to the supporting layer ground 7
It is formed as a deep mixing process to a depth reaching . The upper cap portion 23 on the ground surface is connected to the upper stirring blade 2.
Depending on the length of 0, the diameter is 200011~300c
m, and the depth H is approximately 2 m.

In particular, the construction of this pile cap method is as shown in Figure 4A.
As illustrated in FIG. 1B, a pile portion 25 is formed by placing the upper caps 23 in contact with each other or in close proximity to each other, and an embankment 6 is placed on the upper cap portion 23 to create a housing site or construct a road.

Effects of the present invention According to the deep mixing treatment machine and the pile cap construction method using the deep mixing machine according to the present invention, the formation of the pile portion 25 using improved soil and the formation of the upper cap portion 23 are performed in one construction step. It has excellent performance and efficiency. Moreover, since the pile portion 25 and the upper cap portion 23 are formed of improved soil that is integrated into one piece, the reliability of the joint is completely ensured, and an excellent product of Shinaga can be formed.

In addition, since the large-diameter upper cap portion 23 provides a support effect equivalent to increasing the actual improvement rate, there is no need to worry about uneven settlement of the embankment 6 placed on top of it, resulting in a highly stable residential area with no worries about subsidence. Land development and roads can be constructed with high quality and at low cost.

4. I! ! Brief explanation of the drawings 1111 Fig. 28 is an elevational view showing the deep mixing treatment machine according to the present invention and the form of improved soil constructed by the machine. I is a perspective view showing an example of the configuration of the upper stirring blade, No. 31! l
A and B are plan views showing different embodiments of the upper stirring blade;
Figures 4A and 4B are an elevation view and a plan view partially showing the construction status of the Bailkya Mbue method, No. 51! 1 is an elevation view showing a conventional deep mixing treatment machine, Figure 6 is an elevation view showing an example of construction of a deep mixing treatment machine, and Figures 7A and B are elevation views showing different construction examples. The plan view, Figure 8, is an elevation view showing a further different construction example, Figure 91! ! ~Figure 11 is an elevation view showing an example of the construction of a conventional road embankment; Figure 12A;
B is an elevation view and a plan view showing an example of construction of a continuous wall-shaped improved pile using a conventional deep mixing machine.

4.21... Slurry 2... Rotating vane shaft 20.
...Upper blade shaft 22...Enlarged blade piece 24...
Ground 23... Upper cap part 25...
・Pile part L remains (>1:1 low ML6) Fig. 5 Fig. Fig. Fig. Fig. Fig. A

Claims (1)

[Scope of Claims] [1] A lower stirring blade is installed at the tip of a rotary blade shaft having a tube structure capable of discharging a slurry of soil stabilizer, and an upper stirring blade is installed near the ground surface, The lower stirring blade has a length equivalent to the diameter of the pile part, the upper stirring blade has a length equivalent to the diameter of the cap part, and the slurry discharge port is provided at least in the vicinity of the lower stirring blade. Features: Deep mixing processing machine. [2] The deep mixing processing machine according to claim 1, wherein the upper stirring blade is variable in its position in the vertical direction along the rotary blade axis. [3] The upper stirring blade is characterized in that the tip of the blade is composed of a single-folding enlarged blade piece that bends in a specific rotational direction but becomes a straight rod-like shape in the reverse direction. A deep mixing processing machine according to claim 1 or 2. [4] A) A lower stirring blade is installed at the tip of the rotary blade shaft with a tube structure that can discharge soil stabilizer slurry, an upper stirring blade is installed near the ground surface, and a lower stirring blade is installed near the ground surface. A deep mixing machine has a length equivalent to the pile diameter, the upper stirring blade has a length equivalent to the cap diameter, and a slurry discharge port is provided at least in the vicinity of the lower stirring blade. excavating in the depth direction, and (b) first rotating the ground with the lower stirring blade and mixing it with slurry of a ground stabilizer discharged downward or sideways from the tip of the rotary blade shaft to form a pile portion; , C) At the stage where the pile part is formed to a predetermined depth in the ground, the upper stirring blade is used to rotatably excavate the ground surface part of the ground to a predetermined depth, and if necessary, a slurry of a soil stabilizer is discharged to carry out a mixing treatment. 1. A pile cap construction method using a deep mixing processing machine, characterized by comprising the steps of: forming an upper cap portion using a deep mixing process;