JP7158010B2 - High-pressure injection method rod - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rod used in a high-pressure jetting method, which is a type of consolidation improvement method among soft ground countermeasures. More particularly, the present invention relates to a rod used in a high-pressure injection construction method for injecting solidifying material at high pressure to improve soft ground, and particularly to a rod capable of efficiently discharging slime.

Known high-pressure injection methods include a mechanical agitation method, a high-pressure injection method, a mechanical agitation combination method, and the like for creating improved columns in the ground. This high pressure injection method includes a single pipe method that injects a solidifying material, a double pipe method of "air + grout injection", "air + water injection, grout injection", "air + water injection, air + grout injection", or A triple pipe construction method of "water injection, air + grout injection" and the like are known. In the high pressure injection method for creating a cylindrical improved body, for example, when drilling with a casing, after the drilling is completed, a building rod is inserted into the casing, the casing is pulled out, and the rod is pulled up to form the improved body. It is intended to carry out the development work of. During construction of the improved body, slime consisting of excess soil particles, water, etc. is drained into the slime bit on the ground surface through the gap between the drilled hole drilled in the casing and the outer peripheral surface of the rod.

If this slime cannot be drained smoothly, it is impossible to create a large-diameter, high-quality improved body. Therefore, smooth discharge of the slime is an important construction condition in order to create a large-diameter, high-quality improved body. It has also been proposed that the rod is composed of multiple pipes, an outer guide pipe and an inner injection rod are inserted into this guide pipe, and the gap between the guide pipe and the inner injection rod is used as a discharge path for discharging mud. (Patent Document 1). Moreover, in order to promote the discharge of slime into the slime bit, a rod with spiral blades provided on its outer circumference and fed by a screw has also been proposed (Patent Document 2).

JP-A-7-166533 Japanese Patent Application Laid-Open No. 2001-131954

However, when a multi-pipe rod as shown in Patent Document 1 is used to discharge sludge from the gap, pebbles such as gravel are mixed in the sludge discharge because the multi-pipe has a narrow gap. Then, there is a problem that pebbles or the like are caught in this gap, causing clogging, and smooth sludge cannot be discharged. In addition, in the case of the device having spiral blades as in Patent Document 2, if pebbles such as gravel are mixed in the sludge discharge, the pebbles are removed between the spiral blades or between the spiral blades and the sludge discharge. There is a problem of getting caught between holes, and it is not always possible to drain mud smoothly.

The present invention achieves the following objects against the above background.
SUMMARY OF THE INVENTION An object of the present invention is to provide a rod for a high-pressure injection method that can smoothly discharge slime in the high-pressure injection method, which is a consolidation improvement method.
Another object of the present invention is to provide a high-pressure injection method rod that can stir slime when it is discharged in the high-pressure injection method, which is a consolidation improvement method.

The high-pressure injection method rod of the present invention 1 is a high-pressure injection method that injects a solidifying material into the ground to create a solidification improvement body, and the solidification material is applied to the ground at the lower end to create the solidification improvement body. A building rod having a monitor for jetting, and one or more planes parallel to the axis of the building rod are formed on the outer periphery of the building rod, and the plane is aligned with the axis of the building rod. Three surfaces are formed on the outer periphery at equal angular positions, and are characterized by being composed of partial arcuate surfaces of a cylindrical shape alternately arranged at the equal angular positions with the three surfaces.

The high-pressure injection construction method of the second aspect of the present invention is characterized in that in the first aspect of the present invention, it has an excavating blade arranged on the outer periphery of the construction rod for cutting a drilled hole to be drilled before constructing the consolidated improvement body. do.

The rod of the high-pressure injection construction method of the present invention can smoothly discharge slime by increasing the flow area, and can agitate the slime when it is discharged.

FIG. 1 is a cross-sectional view showing a model of the underground when forming a columnar solidification improvement body in the high-pressure injection method. FIG. 2 is a cross-sectional view of a unit rod that constitutes a building rod. 3 is a cross-sectional view of a unit rod, FIG. 3(a) is a cross-sectional view cut along line AA in FIG. 2, and FIG. 3(b) is a cross-sectional view cut along line BB in FIG. is. FIG. 4 is a sectional view of a joint portion when unit rods are connected. 5A and 5B are diagrams showing a monitor and an excavating blade for the high-pressure injection method, FIG. 5A is a cross-sectional view of the injection nozzle, and FIG. 5B is a bottom view of FIG. 5A.

A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a model of the underground when forming a columnar solidification improvement body in the high-pressure injection method. The double pipe construction method will be described as an example of the high pressure injection construction method described in the present embodiment. After gripping the construction rod 3, which is a double pipe, by the grasping / driving device 2 of the soil improvement machine 1, while rotating this construction rod 3, pull it up along the leader 4 of the soil improvement machine 1 and consolidate. An improved body 10 is constructed. A cement-based solidifying material pressurized by a high-pressure jet grout pump (not shown) and compressed air pressurized by a pneumatic pump are passed through a double-tube swivel (not shown) to the solidifying material and compressed air. Air is supplied through the building rods 3 . Compressed air is added to the pressurized solidifying material, and the compressed air is jetted to the ground at high pressure to form a consolidated improvement body 10.例文帳に追加The solidifying material and air are supplied through the interior of the construction rod 3 as will be described later.

The slime 7 consisting of excess soil particles, water, etc. discharged during the formation of the solidification improver 10 is discharged from the gap 5 between the formation rod 3, the drilled hole 6 and the outer peripheral surface of the formation rod 3. It rises and is drained into the slime bit 8 on the ground surface. In order to smoothly discharge the slime 7, the size of the gap 5 should be made as large as possible. However, if the gap 5 is made larger than necessary, it is not possible to create a uniform and high-quality consolidated improved body 10 . FIG. 2 is a cross-sectional view of a unit rod that constitutes a building rod. 3 is a cross-sectional view of a unit rod, FIG. 3(a) is a cross-sectional view cut along line AA in FIG. 2, and FIG. 3(b) is a cross-sectional view cut along line BB in FIG. is. FIG. 4 is a sectional view of a joint portion when unit rods are connected.

The construction rod 3 is used by connecting unit rods 10 of a predetermined length with joints provided at both ends thereof and assembling them to a desired length. The unit rod 10 has a hexagonal male joint portion 11 at one end and a hexagonal female joint 12 at the other end. The cross-sectional shape obtained by cutting the outer pipe 13, which is the unit rod 10, perpendicular to the axis line is an irregular hexagon (see FIG. 3(b)). In the outer shape of the cross section of the outer pipe 13 cut perpendicular to the axis, an equilateral triangular surface 14 and a circular arc surface 15 appear in a straight line. An inner pipe 21 is arranged at the center of the unit rod 10 . This inner pipe 21 is a hollow pipe for passing the solidifying material pressurized to a high pressure. The hexagonal male joint portion 11 constitutes a male joint for sequentially connecting the unit rods 10 to a required length. A portion of the hexagonal joint 16 that constitutes the outer shell of the hexagonal male joint portion 11 is composed of square tube portions 17 and 18 having a hexagonal cross section and a cylindrical small diameter portion 19 .

Two connecting pin insertion holes 20 are formed in the rectangular tubular portion 18 of the hexagonal joint 16 . After inserting the hexagonal male joint portion 11 into the hexagonal female joint 12, the connecting pin insertion hole 20 inserts a later-described connecting pin 30 (see FIG. 3A) to connect the hexagonal male joint portion 11 and the hexagonal female joint 12 together. is fixed. A joint inner pipe 22 is arranged at the center of the hexagonal joint 16 . One end of the joint inner pipe 22 is connected to one end of the inner pipe 21 . On the other hand, the outer cylinder 25 of the hexagonal female joint 12 has the same outer shape as the outer pipe 13 described above. The through-holes in the outer cylinder 25 are composed of hexagonal square holes 26 and 27 and a circular small circular hole 28 . The square hole portions 26, 27 and the small circular hole portion 28 correspond to the square tube portions 17, 18 and the small diameter portion 19 of the hexagonal male joint portion 11, respectively, and their respective axial positions and angles are adjusted during connection. is inserted with

In the square hole portion 27 of the hexagonal female joint 12, pin holes 29, which are through holes for inserting connection pins 30 (FIG. 3(a)), are arranged at two locations at different angles of 60 degrees. FIG. 4 shows two unit rods 10 connected together, and is a cross-sectional view showing a state in which a hexagonal male joint portion 11 and a hexagonal female joint 12 are connected. The distal end of the joint inner pipe 22 is inserted into and connected to the inner pipe connecting portion 35 at one end of the inner pipe 21 . Since the O-ring 36 is arranged in the connecting portion 35 , the solidifying material will not leak from the connecting portion 35 . An air passage 40 is formed on the outer circumference of the joint inner pipe 22 in a state where the hexagonal male joint portion 11 and the hexagonal female joint 12 are connected. As described above, the air passage 40 is for passing compressed air when the cement-based solidifying material is injected at high pressure to form the solidification improver 10, and when the compressed air is added to form the solidification improver 10. is a passage.

5A and 5B are diagrams showing a monitor and an excavating blade for the high-pressure injection method, FIG. 5A is a cross-sectional view of the injection nozzle, and FIG. 5B is a bottom view of FIG. 5A. The solidifying material nozzle 45 is an injection nozzle for injecting a high pressure onto the ground. The solidifying material nozzle 45 communicates with a solidifying material supply path 46 connected to the inner pipe 21 . The high-pressure solidifying material supplied from the solidifying material supply path 46 is jetted to the outer periphery of the solidifying material nozzle 45 while rotating. An air nozzle 47 is arranged around the solidifying material nozzle 45 . Compressed air supplied to the air nozzle 47 is supplied from the air passage 40 formed on the outer circumference of the inner pipe 14 . The pressurized solidifying material is jetted from the solidifying material nozzle 45, and compressed air is jetted along the periphery of the solidifying material to form the solidification improvement body 10. As shown in FIG.

Three excavation blades 50 are fixed to the hexagonal arc surface 15 at the tip of the construction rod 3 . Prior to forming the consolidation improver 10 , the drill hole 6 shown in FIG. 1 is first drilled with a drill bit 50 . The size of the inner diameter of the drilling hole 6 is substantially the same as the outer diameter of the excavating blade 50 . The slime 7 rises from the gap 5 between the drilling hole 6 and the outer peripheral surface of the construction rod 3 and is discharged into the slime bit 8 on the ground surface. At this time, the outer surface of the forming rod 3 has a flat surface and an arc surface, which are composed of an equilateral triangular plane 14 and an arc surface 15 appearing in a straight line in the cross section. A gap 5 between the outer peripheral surface of the rod 3 is large. Furthermore, since the slime 7 is agitated by the flat surface 14 of the outer surface of the construction rod 3, clogging due to pebbles or the like being caught is reduced. That is, the flat surface 14 of the outer surface of the building rod 3 functions as a kind of stirring blade.

[Other embodiments]
The embodiment described above is a double pipe construction method in which a hardening material is injected while compressed air is applied in the high pressure injection construction method. However, the invention is not limited to this double pipe construction method. The present invention is intended to increase the area of the gap 5 between the outer peripheral surface of the construction rod 3 and the excavation hole 6 and to stir the slime, and is not limited to the double pipe construction method, single pipe construction method, triple pipe construction method. etc. can also be applied. In addition, three planes parallel to the axis line were formed at equal angular intervals on the outer peripheral surface of the construction rod 3 described above. However, as long as it is one or more planes, two planes may be used. In addition, although it is combined with a cylindrical surface, a hexagonal prism without a cylindrical surface may be used.

DESCRIPTION OF SYMBOLS 1... Soil improvement machine 3... Construction rod 6... Excavation hole 8... Slime bit 10... Consolidation improvement body 11... Hexagonal male joint part 12... Hexagonal female joint 13... Outer pipe 14... Surface 15... Circular surface 16... Hexagonal joint 17 , 18... Rectangular tubular portion 19... Small diameter portion 21... Inner pipe 22... Inner pipe for joint 25... Outer cylinder 30... Connection pin 35... Connecting part 45... Solidifying material nozzle 47... Air nozzle 50... Excavation blade

Claims (2)

In the high-pressure injection method that injects a solidification material into the ground to create an improved solidification body,
a forming rod having a monitor at its lower end for spraying the solidification material onto the ground for forming a consolidated improved body;
One or more planes parallel to the axis of the construction rod are formed on the outer periphery of the construction rod ,
The construction rod has three planes formed at equal angular positions on the outer periphery of the axis of the construction rod. A rod of a high-pressure injection method characterized by: In the rod of the high-pressure injection method according to claim 1,
A high-pressure jetting rod, comprising: a drilling blade disposed on the outer circumference of the building rod for drilling a hole to be drilled before building the consolidated improvement body.

Images