JPH06306848A - Construction method for agitated mixed reinforcing body - Google Patents

Abstract

PURPOSE:To make a rod function as a load resistant body by leaving and fixing the rod in an agitated mixed reinforcing body formed by agitating and mixing excavated soil and a solidifying body in the ground while excavating the ground. CONSTITUTION:A solidifying material is supplied through a shaft passage together with excavated soil by an agitating vane 13 of an excavating agitating hollow rod 1, and an agitated mixed reinforcing body 2 is constructed. When it reaches a prescribed depth, the rod 1 is separated from a boring machine 3, and is left in the reinforcing body 2. After the reinforcing body 2 is hardened, a rotary shaft 11 of the reinforcing body 2 projecting to the ground surface side is fixed to a concrete wall body 5 or the like. In this case, an excavating vane 12 and the agitating vane 13 of the excavating agitating hollow rod 11 function as a load resistant body to check slipping-out of the rod 1, and exhibit extremely large pullout resistance force. Thereby, since the possibility that agitated mixed soil before it is hardened slips out of a hole together with the excavating agitating hollow rod is eliminated, it is constructed safely while avoiding looseness of the peripheral ground or ground subsidence.

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 stir-mixture reinforcing body containing a core material for reinforcing ground immediately after cutting or general ground.

[0002]

2. Description of the Related Art In order to prevent the cut slope from collapsing,
Alternatively, various construction methods have been developed for reinforcing general ground.

[0003]

[Problems to be Solved by the Invention] When the above-mentioned conventional ground reinforcement technique is used, for example, when construction is carried out in the immediate vicinity of the railway being used, there are the following problems.

<B> It is difficult to carry out the reinforcement work without affecting the surrounding ground.

<B> If the method of improving the sediment with a particularly large diameter is used, it is likely to cause the collapse of the surrounding sediment, which is dangerous.

<C> A device for improving earth and sand with a small diameter reduces the risk, but the number of constructions becomes enormous and the construction takes time and effort.

<D> The applicant has previously proposed a ground reinforcement technique suitable for this type of application as Japanese Patent Application No. 4-56541. In this method, the ground is stirred and mixed while discharging the solidifying material such as cement milk from the tip of the drilling and stirring rod to build a stirring and mixing reinforcement in the ground, and then the drilling and stirring rod is pulled out and the center of the stirring and mixing reinforcement is extracted. This is a method in which a core material such as a reinforcing bar is inserted into the portion to perform the construction. In this construction technology, it is technically difficult to position the core material at the center of the stirring and mixing reinforcement body, and it is also difficult to confirm the position of the core material from the outside. This is even more noticeable when constructing. This is caused not only by the rigidity of the core material and the bending of the core material due to the weight of the core material, but also by the bending of the core material due to collision with a hard object such as gravel. for that reason,
There is an urgent need to develop a technique for locating the core material in the center of the stirring and mixing reinforcement. Further, there is room for improvement in terms of construction efficiency because the core material insertion step is performed after the stirring and mixing reinforcement body is constructed. Further, when the excavation stirring rod is pulled out, the stirring mixed soil in the vicinity of the hole mouth is easily discharged, and it takes time to repair the hole mouth. Furthermore, there is a risk that the agitated mixed soil will come out together with the extraction of the excavated agitating rod.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to allow a core material to be inserted at an accurate position, improve the construction efficiency, and prevent coagulation of stirred mixed soil. It is intended to provide a method of constructing a stirrer / mixing reinforcement, which has a high pullout resistance of the core material.

[0009]

[Means for Solving the Problems] That is, according to the present invention, an excavation stirring hollow rod having a stirring blade at the tip of a rotary shaft discharges the solidifying material to form a hole, and the stirring blade forms the ground material and the solidifying material. Is a method for constructing a stirring and mixing reinforcement body, in which a stirring and mixing reinforcement body is constructed by stirring and mixing, and the excavation and stirring hollow rod is left with the rotary shaft being positioned in the stirring and mixing reinforcement body.

[0010]

Therefore, according to the present invention, since the excavated soil and the solidifying material are agitated and mixed in the ground while excavating the ground, a large-diameter agitation and mixing reinforcement body is constructed while avoiding the collapse of the surrounding ground. You can do it. <B> Since the hollow rod for excavation and stirring used for excavation and stirring is left in the ground without being collected and is used as the core material, the core material can be positioned at the center of the stirring and mixing reinforcement body. <C> Since the stirring hollow rod is not collected, discharge of the stirring mixed soil at the hole mouth can be avoided, and repair work for the hole mouth becomes unnecessary.

[0011]

Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings.

<A> Drilling stirring and discharge FIG. 1 shows a stirring and mixing reinforcement 2 using a hollow rod 1 for drilling and stirring.
The construction example of is shown. The hollow rod 1 for excavating and stirring is a member having both the function of excavating and stirring earth and sand and the function as a core material. To do. The excavation blade 12 and the stirring blade 13 are fixed to the rotary shaft 11, and rotate as the rotary shaft 11 rotates. If necessary, a co-rotation preventing blade 14 having a diameter larger than those of both blades 12 and 13 may be provided, or the stirring blade 13 may be omitted depending on the soil quality. In this case, the co-rotation preventing blade 14 is arranged at a position intermediate between the both blades 12 and 13 in a state of allowing free rotation. The excavation stirring hollow rod 1 has a discharge port formed at the tip of the rotating shaft 11 so that the solidified material such as cement milk supplied through the shaft of the rotating shaft 11 can be discharged from the vicinity of the stirring blade 13. ing. The discharge port may be formed at a part of the stirring blade 13 in addition to being opened at the tip of the rotary shaft 11 or the side surface of the tip part.

The base end of the rotary shaft 11 constituting the hollow shaft 1 for excavation and stirring is set on a well-known boring machine 3, and a swivel 4 is provided so that a solidifying material such as cement milk can be supplied to the shaft of the rotary shaft 11. Put on.

Then, the excavating and stirring hollow rod 1 is rotated to start the excavation of the ground, and at the same time, the supply of the solidifying material such as cement milk is started through the axis of the rotary shaft 11. As a result, the drilling process by the rotation of the excavation blade 12, the discharging process of the solidifying material, and the stirring and mixing process of the soil and the solidifying material by the stirring blade 13 proceed in parallel, and the passing trace of the stirring blade 13 is obtained. A large diameter stirring and mixing reinforcement body 2 (soil mortar), in which the soil and the solidifying material are mixed by stirring, is built toward the ground. The co-rotation preventing vanes 14 arranged on the rotating shaft in a state of allowing free rotation prevent the earth and sand from co-rotating with the stirring vanes 13. In the process of building the stirring and mixing reinforcement body 2,
Since the rotation center of the excavation stirring hollow rod 1 and the center (axial center) of the stirring / mixing reinforcing member 2 coincide with each other, the rotating shaft 11 is always located at the center of the stirring / mixing reinforcing member 2.

<B> Setting of core material After the stirring and mixing reinforcement body 2 is built to a predetermined depth, the rotation of the excavation and stirring hollow rod 1 and the supply of the solidifying material are stopped. In the present invention, since the excavating and stirring hollow rod 1 used for construction is also utilized as the core material, the excavating and stirring hollow rod 1 is separated from the boring machine 3 and left in the stirring and mixing reinforcement 2.
Since the rotation center of the excavation stirring hollow rod 1 and the center (axial center) of the stirring / mixing reinforcement 2 coincide with each other, the rotating shaft 11 is always located at the center of the stirring / mixing reinforcement 2 in the process of constructing the stirring / mixing reinforcement 2. It will be. Therefore, the rotating shaft 11 constituting the core material for excavating and stirring hollow rod 1 exactly coincides with the center of the mixing and stirring reinforcement body 2, and it is not necessary to confirm this from the outside.

<C> Fixing of the core material (FIG. 2) After the stirring and mixing reinforcement body 2 is cured, the rotating shaft 11 of the stirring and mixing reinforcement body 2 protruding to the surface side is fixed to the concrete wall body 5 or the like. The excavation blade 12 and the stirring blade 13 of the excavation stirring hollow rod 1 function as a load-bearing body that prevents the excavation stirring hollow rod 1 from coming out.

[0017]

As described above, the present invention has the following effects.

<A> The excavating and stirring hollow rod used for constructing the stirring and mixing reinforcement is left in the ground without being recovered. Therefore, there is no concern that the stir-mixed soil before hardening will come out of the hole together with the hollow hollow rod for excavation, and the loosening of the surrounding ground and the ground subsidence can be avoided and the construction can be performed safely. Moreover, since the agitated mixed soil at the hole mouth is not discharged, the repair work is not required.

<B> Since it is not necessary to extract the hollow rod for excavation and stirring, the construction efficiency is improved and the construction period can be greatly shortened.

<C> Since the hollow shaft for excavation and stirring whose rotating shaft is always located at the center of the stirrer / mixer when used is used as the core of the stirrer / stirrer, the center of the stirrer / mixer is accurately adjusted. It can be installed in any position. When the core material is arranged at the center of the stirring and mixing reinforcement, it is extremely advantageous in transmitting the pulling force generated in the core material to the surrounding ground through the stirring and mixing body.

<D> Since the stirring and mixing reinforcement having a large cross section is built in the ground to increase the frictional resistance with the surrounding ground, the total length of the stirring and mixing reinforcement can be short. Therefore, it is possible to easily perform construction even in a site where the drilling length is restricted or the height is restricted, such as a site near a railway, a road, or a building.

<E> In addition to the adhesive force between the peripheral surface of the rotating shaft and the stirring and mixing reinforcement, the pulling resistance of the excavating and stirring hollow rod after the construction is used as a load-bearing member for restricting the excavation blade and the stirring blade from coming out. Since it functions, an extremely large pull-out resistance force can be exerted when a tensile force acts on the core material.

[Brief description of drawings]

[Figure 1] Explanatory drawing of a hollow rod for excavation and stirring during construction

[FIG. 2] An explanatory view of a completed state in which the hollow rod for excavation and stirring is fixed to the concrete wall body as a core material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukihiko Tamura 2-22-15-106 Katsuradai, Midori-ku, Yokohama-shi, Kanagawa (72) Inventor Kosei Fukuda 2-4-1 Akasaka, Minato-ku, Tokyo Tenox Co., Ltd. (72) Inventor Shigeru Yoshida 2-4-1, Akasaka, Minato-ku, Tokyo Inside Tenox Co., Ltd. (72) Inventor Kamifumi Kamae 2-4-1-1, Akasaka, Minato-ku, Tokyo Inside Tenox Co., Ltd.

Claims (1)

[Claims] 1. A drilling and stirring hollow rod equipped with a stirring blade at the tip of a rotary shaft for drilling holes while discharging the solidifying material, and stirring and mixing the ground material and the solidifying material with the stirring blade to form a stirring and mixing reinforcement. A method of constructing a stirring and mixing reinforcement body, which is constructed and the excavation and stirring hollow rod is left with the rotary shaft positioned in the stirring and mixing reinforcement body.