JPH07103552B2 - Joint between improved ground and Yamadome wall and its construction method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint between an improved ground and a mountain retaining wall suitable for constructing a basement portion of a building or an independent underground structure, and a construction method thereof.

[0002]

2. Description of the Related Art Conventionally, it has been practiced to construct a mountain retaining wall or to improve the ground for a portion to be root-cut. However, as shown in FIG. 7, the portion where the ground improvement 1 is applied becomes a hard ground, so in order to prepare the mountain retaining wall 2 in preparation for root cutting, a steel sheet pile is placed at a position slightly away from the ground improvement 1. I am doing it. In addition, the reverse construction procedure also brings about a similar state, and if the earth retaining wall 2 reaches the predetermined depth, the purpose of the earth retaining wall is achieved.
It was not necessary to consider the relationship with.

[0003]

As described above, the ground improvement 1
If there is a gap 3 on the unimproved ground between the part of the ground and the retaining wall 2, it will cause boiling, heaving, etc., or displacement of the retaining wall at this part. Even if it is used as a substitute for a replacement beam, it cannot be dealt with.

In order to deal with such a situation, it is conceivable to grout the space 3 so as to make the ground improvement 1 and the earth retaining wall 2 integral with each other, or to provide the earth retaining wall 2 with an earth anchor or the like. However, the number of processes increases by that amount, laborious work is required, and the construction cost rises. Also, reliability remains a problem.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional examples and to eliminate the risk of boiling, heaving, etc.
Another object of the present invention is to provide a highly reliable joint between an improved ground and a mountain retaining wall and a construction method thereof, which does not cause any trouble even when the improved ground is used as a substitute beam for replacement.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention is to construct a soil cement pile retaining wall at the end of an improved ground area improved by deep mixing without any gap between the improved ground and the improved ground. , And deep mixed ground improvement is performed up to the planned construction part of the soil cement retaining wall, and the planned construction part of this soil cement retaining wall is pre-excavated with a rock auger, and the excavated portion is soil cement retaining wall with a multi-axis auger etc The main point is to construct the.

[0007]

According to the present invention, since there is no gap between the soil area improved by deep mixing and the soil cement pile retaining wall, there is no voiding or heaving. Further, the ground improved by deep mixing and the soil cement pile retaining wall surface are well compatible with each other, and high water stopping performance can be obtained.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a plan view showing an embodiment of the improved ground of the present invention, and FIG. 2 is a side view of the same as above, after root cutting.

Reference numeral 4 in the figure is an improved ground which is an improvement of the viscous ground similar to the above-mentioned conventional example. The improved ground 4 uses a stirring blade having a strong stirring ability, and the mortar at the present position in the viscous soil layer, This is an improvement by the deep-layer mixing method in which a treatment material such as cement milk is kneaded and the treatment is performed by utilizing the chemical consolidation action of the cohesive soil and the treatment agent.

There are various methods for the deep layer mixing treatment method. As an example thereof is shown in FIG. 4, a deep layer mixing treatment machine 5 is used, and the hardening material from the hardening material plant 7 is used in this deep layer mixing treatment machine 5. Columnar body 8 improved by mixing 6 with the ground and stirring
Will be created in the ground. The columnar bodies 8 are constructed at intervals, and later, the columnar bodies 8 are constructed by further wrapping the columnar bodies 8 in a similar manner.

The improved ground 4 improved by the deep layer mixing has an end portion up to a planned construction portion of a soil cement pile retaining wall 9 described later.

Next, in the improved ground 4, a portion of the soil cement pile retaining wall 9 to be constructed is combined with an excavating casing having an excavating blade and an auger excavator inside the excavating casing to form a core of the soil in the excavating casing. The rock auger is used to excavate the inside of the machine and cut the inside with an auger excavator. Also, in some cases
Pre-drilling may be performed with an auger excavator that is not equipped with a plug.

In this way, a rock auger or a case
The portion previously excavated by the auger excavator without a ring becomes soft in a state in which holes are lined up as shown in FIG. It should be noted that this hole can be appropriately selected depending on the strength of the improved ground 4, such as holes drilled every other hole or holes drilled continuously.

Then, in this soft excavation portion 10, FIG.
The soil cement mountain retaining wall 9 is constructed with a multi-axis auger 11 as shown in FIG. This soil cement pile retaining wall 9 is constructed by the so-called soil cement continuous wall construction method, and the soft excavated portion 10 is drilled in a column shape with a multi-axis auger 11,
A mixture of cement milk, bentonite, etc. is discharged from the tip of the kneading shaft and mixed with in-situ soil in the ground to continuously form pillars made of soil cement.

Before the soil cement is completely hardened, H-shaped steel 12 as a stress bearing material is arranged at appropriate intervals.

In this way, the area of the improved ground 4 improved by deep mixing and the soil cement pile retaining wall 2 are
There is no gap between them and it can be completely joined,
As shown in FIG. 2, even when the improved ground 4 is root-cut and spanned with beams and the like, the hole surface of the improved ground 4 and the surface of the soil cement pile retaining wall 9 are made of the same material and are well-known to each other Will also be expensive.

[0017]

As described above, in the joint between the improved ground and the mountain retaining wall of the present invention and the construction method thereof, there is no gap between the improved ground area and the mountain retaining wall, and the joint is complete. , There is no risk of boiling or heaving,
In addition, even when the improved ground is used as a substitute beam, it does not cause any trouble and is highly reliable.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a joint between an improved ground and a mountain retaining wall according to the present invention.

FIG. 2 is a side view after root cutting showing one embodiment of the joint between the improved ground and the mountain retaining wall of the present invention.

FIG. 3 is a plan view of a process in the middle showing an embodiment of a method of constructing the joint between the improved ground and the mountain retaining wall of the present invention.

FIG. 4 is a side view showing a deep layer mixing processing method.

FIG. 5 is a front view of a main part of a multi-axis auger for constructing a soil cement retaining wall.

FIG. 6 is an overall side view of a multi-axis auger for constructing a soil cement retaining wall.

FIG. 7 is a plan view showing a conventional example.

[Explanation of symbols]

 1 ... Ground improvement 2 ... Mountain retaining wall 3 ... Spacing 4 ... Improved ground 5 ... Deep mixing processor 6 ... Hardening material 7 ... Hardening material plant 8 ... Columnar body 9 ... Soil cement earth retaining wall 10 ... Excavation part 11 ... Multi-axis auger 12 … H-shaped steel

Claims (2)

[Claims] 1. A joint between an improved ground and a mountain retaining wall, characterized in that at the end of the improved ground area improved by deep mixing, a soil cement mountain retaining wall is constructed in this area without any clearance with the improved ground. 2. The deep-mixed ground improvement is performed up to the construction planned portion of the soil cement earth retaining wall, and the construction planned portion of the soil cement earth retaining wall is previously excavated by a rock auger,
A method for constructing a joint between an improved ground and a mountain retaining wall, which comprises constructing a soil cement mountain retaining wall with a multi-axis auger or the like at the excavated portion.