JPH09296439A - Soil improvement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely and evenly mix a soil improvement material with excavated soil, by reflecting the soil improvement material jetted out of the jet nozzle at the front end of a easing pipe, toward the center of the excavated soil by a cutting and reflecting board. SOLUTION: Excavating blades 2 provided with cutters 21 at the lower end are radially extended from the front end of a casing pipe 1 provided with a cutter 11 at the front end thereof and an excavating and reflecting board 3 is fitted to the front end 2a of the excavating blades 2 and further, agitating blades 5 and stabilizing and agitating blades 6 are provided above the excavating blades 2. A jet nozzle opened to the cutting and reflecting board is provided at a little inside of the front end of the casing pipe 1. Soil is excavated by the cutters 11, 21 and the outer and inner cutter 31, 21a of the cutting and reflecting board 3 and a soil improvement material is jetted from the jet nozzle toward the excavated soil taken into the cutting and reflecting board 3. The improvement material is reflected to the center of the excavated soil by the jet receiver of the cutting and reflecting board 3 and securely and evenly mixed ray the agitating blades 5 and the stabilizing agitating blades 6.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a ground improvement device.

[0002]

As is well known, various foundation piles (improved piles) have been developed for the purpose of preventing liquefaction, settlement and stabilization of soft ground, and some of them have already been put to practical use. There is. Along with this, related technologies such as an apparatus for constructing various foundation piles or a ground improvement apparatus using the foundation piles have made great progress in recent years. A typical structure of a ground improvement device (referred to as a ground improvement device) using this foundation pile will be described.
That is, this ground improvement device forms a hole in the ground (in the ground) through a casing pipe, or cuts into the ground through a bladed blade (or a rotary cylinder, a stabilizer, etc.). Form a hole (excavate vertically in the ground through a rotating cylinder) and inject (inject or press-fit) a predetermined improving material such as cement milk into the excavated soil (excavated earth and sand) in the hole. It is a structure to build a foundation pile by doing so.

In connection with the above-mentioned prior art, the present applicant proposes the following ground improvement device in "Underground casing and method for improving ground by combined use of jets" in Japanese Patent Laid-Open No. 6-284740. The gist of the invention is to provide an excavating blade provided with a rotor or an underground casing (hereinafter referred to as an underground casing) at the tip of a casing pipe, and a large number of blades between the underground casing and the casing pipe. It is provided with a stirring blade and a stabilizer / stirring blade above the excavation blade and on the peripheral surface of the casing pipe. The excavated soil (excavation soil) is underground while excavating the sediment with the multiple blades. It is taken into the casing, the improved body is injected (high pressure injection) from the injection port of the casing pipe into the taken excavated soil, the both are stirred and mixed to produce improved soil, and this excavation and improved soil are produced. It is characterized in that the improved pile body is constructed by repeating the above.

[0004]

The invention of Japanese Patent Application No. 6-284740 described in detail above is characterized in that it can sufficiently exhibit its function in ordinary soil and construct an excellent improved pile body. However, it was found that a problem remains on the ground of cohesive soil. That is, the improving material is injected into the excavated soil in the underground casing, but a large amount of the excavated soil remains in the underground casing, and the large amount of the excavated soil and the improving material are kneaded to form a large dango shape ( Lumps) are formed. In this way, once the lumps are formed, they hinder the excavation / drilling of the underground casing, which causes a problem that the subsequent excavation and stirring / mixing cannot be performed. On the other hand, if the improving material is not reliably injected toward the inside of the underground casing, for example, it is injected along the inner wall side of the underground casing, and is agitated and mixed only on the inner wall side, There is a lump in the underground casing, and there is the same problem as described above.

[0005]

In view of the above, the present invention ensures that the improved material is reflected in the direction of the center of the excavated soil to ensure sufficient agitation and mixing of the two to avoid the occurrence of lumps. Or excavated soil mixed with improved materials (improved soil)
Surely to eliminate the anti-digging (toward the ground) efficiently,
The following configuration is adopted for the purpose of the above.

That is, the ground improvement device of the present invention is provided with a casing pipe having an injection port at its tip slightly inside, and at the tip of the casing pipe and extending in the radial direction of the casing pipe. Several excavating blades, a number of blades respectively provided at the lower ends of the several excavating blades, a cutting plate / reflecting plate respectively provided at the blade tips of the excavating blades, and the case
It is composed of a stabilizer and a stirring blade provided on the single pipe and a stirring blade.

A ground improvement device according to another invention is a casing pipe having an injection port at a slightly inner end thereof, an auger screw provided below the casing pipe and on a peripheral surface of the casing pipe, A large number of blades respectively provided at the lower end of the auger screw, a cutting plate and a reflecting plate provided at the spiral blade end of the auger screw, a stabilizer-cum stirring blade and a stirring blade provided at the casing pipe, It is composed of.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The operation of the present invention will be described below.
First, in the example shown in FIGS. 1 to 3, the casing pipe is rotated via a driving machine (not shown). The blade at the tip of the casing pipe (which is provided if necessary) that rotates with the rotation of the casing pipe, the blade provided on the excavation blade, and the blade edges of the inner and outer blades of the cutting plate and the reflecting plate penetrate the ground. Excavate.

Then, an improving material (such as an improving material in which water and cement are mixed, an improving material in which water, cement and bentonite are mixed, etc.) is injected from an injection port provided slightly inside the tip of the casing pipe. While (there is also a method of using compressed air injection in combination with an improved material such as this sprayed water and cement mixed material, an improved material with water mixed with cement and bentonite, etc.) Take in the cutting plate and the reflection plate and stir and mix both. By the spray receiver provided inside the cutting plate and reflector, the improvement material can be surely diffused toward the center of the excavated soil, and can be substantially uniformly penetrated into the excavated soil. The feature is that intensive injection into the vicinity can be avoided. Therefore, the improvement material is surely sprayed into the excavated soil taken into the cutting plate / reflector, so that the excavated soil and the improvement material can be surely and uniformly stirred and mixed, and as a result, the excellent improvement soil can be obtained. Can be generated, and the occurrence of lumps can be avoided.

As described above, excavation and agitation / mixing are sequentially performed to advance the present apparatus to produce improved soil, and the improved soil is further agitated by the agitating blade and / or the stabilizer / agitating blade. Stir-mixed to form a good improved pile.

A stabilizer / stirring vane is attached to the wall surface of the drilled hole to allow the underground casing to be excavated in the vertical direction and to have an improved diameter (cutting plate / reflecting plate inner and outer blade edges). According to the above, the improved pile body having a predetermined standard (setting) is constructed. Further, it has a secondary effect that the resistance at the time of pulling out the device (there may be the injection of the improving material) can be minimized.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings.

In the example of FIGS. 1 to 3, the ground improvement apparatus of the present invention is provided at 1 (not shown) in a ground improvement machine, a civil engineering work such as an excavator, or a drive section (drive device) provided in a construction work machine. Further, the casing pipe is provided with a blade 11 (provided as necessary) at the tip thereof, and has an injection port 111 slightly inside the tip of the casing pipe 1. Further, the casing pipe 1 has an excavation blade 2 extending at the tip thereof and in the radial direction of the casing pipe 1, and a large number of blades 21 for excavation provided at the lower end of the excavation blade 2. And a cutting plate / reflecting plate 3 provided on the blade tip 2a of the excavation blade 2,
The stirring pipe 1 and the stirring blade 6 and the stirring blade 5 provided on the casing pipe 1 are respectively provided.

The injection port 111 is constructed so as to open slightly toward the inside of the tip of the casing pipe 1 and toward the cutting plate / reflecting plate 3, and the casing is opened through this injection port 111. The improvement material supplied to the pipe 1 was excavated by the blade 11 of the excavation blade 2, the blade 21 of the casing pipe 1, the outer blade 31 of the cutting plate / reflector 3 and the inner blade 31a (described later). Reflected toward the excavated soil and toward the center of the excavated soil, the mixture is agitated and mixed with the excavated soil to produce improved soil. In addition, the blades 11, 21, the outer blade 31, and the inner blade 31a provided at the lower end of the excavation blade 2 can be used to crush underground obstacles and stir and mix with the excavated soil.

The jet receiver 4 inside the cutting plate / reflector 3
Avoids spraying only on the outer peripheral surface of the excavated soil of the improved material or toward the wall surface of the drilled hole B, and ensures reliable and efficient reflection toward the center of the excavated soil as described above. The structure is such that efficient stirring and mixing can be achieved. Moreover, it is possible to achieve uniform diffusion of the improved material and ensure that it penetrates into the excavated soil. The cutting plate / reflecting plate 3 has cutting inner and outer blades 31a and 31 at the tip thereof.

Further, by the stirring force of the stirring blades 5, excellent improved piles are formed through uniform stirring and mixing of the excavated soil and the improving material. Further, an appropriate number of stabilizers / stirring blades 6 are provided above the stirring blades 5.
The radial free edge 61 of the combined stirring blade 6 and the cutting edges of the inner and outer blades 31a and 31 of the cutting plate / reflector 3 have the same radial positional relationship (the same vertical positional relationship). Then, an improved pile body having an improved diameter A having the same diameter as that of the stabilizer / stirring blade 6 is constructed. In the figure, 7 indicates an improved body supply pipe provided in the casing pipe, and C indicates improved soil.

Next, in another example shown in FIG. 4 (hereinafter, the same members have the same reference numerals and names), 10 is an auger screw for excavating and stirring, which is provided at the tip of the casing pipe 1. The spiral blade tip 10a of 10 is provided with a pair of cutting plate and reflecting plate 3. The cutting plate / reflecting plate 3 is optionally provided with an injection receiver 4 (not shown). Reference numeral 100 in the figure denotes an excavating blade provided at the lower end of the auger screw 10. The rest of the configuration is almost the same as the above example.

[0018]

EFFECTS OF THE INVENTION According to the present invention, by providing a cutting plate and a reflecting plate on the excavation blade, the improved material can be reliably injected toward the center of the excavated earth and sand, and by this, the improved material and the excavated soil can be reliably and uniformly distributed. Mixing and stirring is possible.

Further, according to the present invention, by providing the jet receiver inside the cutting plate / reflector plate, there is an effect that reliable stirring and mixing is achieved, and no clumps of cohesive soil are generated and efficient stirring and mixing is achieved.

Further, the present invention is an excellent improvement by installing a stabilizer / stirring blade having the same diameter as the improved diameter (drilling hole formed by the cutting edges of the inner and outer blades provided on the leading edge of the cutting plate / reflector). There are practical benefits such as the construction of piles and low resistance when pulled out.

[Brief description of drawings]

FIG. 1 is a schematic view showing an operating state of stirring and mixing, which is an example of the present apparatus.

FIG. 2 is a schematic diagram showing a drawing-out operation state such as stirring and mixing of the present apparatus shown in FIG.

3 is an enlarged front view showing a portion of an injection port of the present apparatus shown in FIG.

FIG. 4 is a schematic view showing another example of the apparatus and showing an operating state of stirring and mixing.

[Explanation of symbols]

 1 Casing Pipe 11 Blade 111 Jet Port 2 Excavation Blade 2a Blade Tip 21 Blade 3 Cutting Plate / Reflector 31 Outer Blade 31a Inner Blade 4 Injection Receptor 5 Stirring Blade 6 Stabilizer-Stirring Blade 61 Free Edge 7 Improved Body Supply Pipe 10 Auger screw 10a Spiral blade tip 100 Blade A Improved diameter B Drilling C Improved soil

Claims (3)

[Claims] 1. A casing pipe having an injection port at its tip slightly inside, a plurality of excavating blades at the tip of the casing pipe and extending in the radial direction of the casing pipe, A large number of blades respectively provided at the lower ends of several excavating blades, a cutting plate / reflecting plate respectively provided at the blade tips of the excavating blades, a stabilizer / agitating blade and stirring provided at the casing pipe. Ground improvement device consisting of wings. 2. A casing pipe having an injection port at its tip slightly inside, an auger screw provided below the casing pipe and on the peripheral surface of the casing pipe, and a lower end of the auger screw. A ground improvement device comprising a large number of blades, a cutting plate / reflector provided on the spiral blade tip of the auger screw, and a stabilizer / stirring blade and stirring blade provided on the casing pipe. . 3. The ground improvement device according to claim 1 or 2, wherein an injection receiver is provided inside the cutting plate / reflector.