JPH10195862A - Soil improving apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold down energy loss of jetted improvement material to the minimum to enable soil improvement as designated in a soil improvement apparatus in which a nozzle for jetting a large jet amount of improvement material is provided in a monitor part in such a manner as to be well-balanced in a jet grout construction method such as JSG method, CJG construction method or the like. SOLUTION: In a monitor part 8', a supply path 10... for improvement material is formed with the center curvature radius ranging from 20mm-40mm, and smoothly curved from the vertical direction to the horizontal direction in a 90-degree arc in the inside of the monitor part 8 with the outside diameter of 90mm-120mm. A ring-shaped spacer shim type piece 13 which is made of teflon and has a thickness of 1mm or less is interposed between the end part of the supply path 10... for improvement material and a nozzle 11 screw- connected to the end part to be pressed tightly like a metal touch and brought into face contact with the improvement material supply path 10... of the nozzle 11 to prevent energym loss of improvement material such as flowing cement milk or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The disclosed technology relates to a ground improvement work in which a high-pressure injection pump supplies a large amount of hardened material such as cement milk, water, air, etc., through a supply passage in a rod and ejects the same into the ground. It belongs to the technical field of the structure of the monitor unit of the ground improvement device.

[0002]

2. Description of the Related Art As is well known, in Japan, which is an island nation, has many mountain forests, and is located near a complicated and long coastline, it is not only for agricultural and livestock use. In addition, the plains used for residential areas and various industrial facilities are extremely narrow and limited.Therefore, in the inland areas, the soft ground in the basins such as shallow coasts, rivers, lakes and marshes can be improved and used effectively. Technology is extremely important, and various ground improvement technologies have been researched and developed for practical use since ancient times.

[0003] Among them, a material such as cement milk or the like, which is pressurized by a high-pressure pump such as a high-pressure injection stirring method such as a so-called JSG method or a CJG method, or water or air, is fed and enclosed. Injecting into the ground without losing energy from the nozzle formed by extending from the monitor part provided in the part is the most important in order to secure the design and creation of improved structures in the ground It is one of the conditions.

That is, as shown in FIG. 6, an improving material such as cement milk in a monitor section 8 connected and connected to a rod (not shown) via a joint is supplied to a nozzle 11 provided to extend from the tip thereof. On the other hand, it is surrounded by a supply passage 4 for a fluid such as air or water, and is ejected into the ground to be ejected and supplied in any process of ascending and descending while rotating a rod, thereby forming a predetermined columnar structure. We are trying to create it.

If the injection amount of the improving material is about 100 l / min or less per minute, the injection of the improving material into the ground is performed at right angles from the improving material supply passage 10 as shown in FIG. The embodiment in which the nozzle 11 is provided sideways was sufficiently practical.

However, in recent soil improvement, when it is desired to increase the diameter of a columnar structure formed in the ground, a large amount of an improved material to be pumped through a rod may be required. It has come to be desired.

For example, as described above, the improvement material and water used in the JSG method and the CJG method have been less than 100 l / min (for example, 60 l / min) as described above. Being over 200 l, 400 l and 600
l, which is designed and manufactured to promote the enlargement of the formation diameter of structures in the ground,
The large-volume feeding of such improved materials and water has limitations and limitations on the diameter of the rod and the diameter of the monitor due to mechanical devices, so that an increase in the flow velocity is inevitable. The feed passage 10 formed in the monitor section 8
Turbulence is inevitably generated at a right angle portion of the nozzle 11 and
This caused a loss of energy that erupted into the ground.

That is, as shown in FIG. 7, in a ground improvement apparatus used in a conventional high-pressure injection stirring method, a rod 1 that rotates and moves up and down is connected to a predetermined length through joints 2, 2, 2,. A passage 3 for feeding an improving material such as cement milk and a supply passage 4 for air and the like formed concentrically with the passage 3 are formed in the rod 1 in a double pipe system. And feed the cement milk improving material 6 or water 7 from the same, and form two supply passages 10 and 10 through a branch part 9 in a monitor part 8 connected to a lower end of the rod 1 and a right angle to the terminal part. Nozzles 11, 11 extending sideways
From the material 6 such as cement milk, or water 7 etc., and rotate around (or ascend) around it around
A rod-shaped structure is jetted into the ground as a jet 12 and injected into the ground to form a columnar structure in the ground.

Therefore, since the monitor section 8 has the structure of the predetermined number of nozzles 11, 11... Extending in a right angle, the monitor section 8 is designed to form two systems of rectifying passages 10, 10. The structure becomes complicated, and the length of the monitor unit 8 becomes long because the two flow straightening passages 10 and 10 leading to the nozzle 11 are formed to a predetermined length via the branching unit 9, and the design is complicated. As a result, the monitor unit 8 has to be large and over 100 kg in weight and expensive, and the problem is that the monitor unit 8 becomes longer and larger in size.

[0010] Thus, the close connection between the nozzle 11 and the supply passage in the monitor section 8 prevents damage (insect-eating state) caused by the swirling current caused by the flowing improving material. Therefore, precision grinding and finish polishing in the metal touch state of the damaged portion are necessary, and the forming process requires extremely high skill and complicated processes, the work is complicated, and as a result, There is a disadvantage in that it leads to an increase in cost, and there is a bottleneck in that the nozzle portion of the monitor part is damaged (worm-eating state) during the ground improvement work, resulting in poor durability.

[0011]

SUMMARY OF THE INVENTION The object of the invention of this application is to improve the material supplied from a high-injection high-pressure pump based on the prior art described above and to inject the improved material into the ground from a monitor provided below the rod. The technical problem to be solved is to solve the problems of wear resistance such as energy loss and nozzle damage due to the bending of the supply passage in the monitor, and the diameter of the monitor part is almost the same as the rod diameter. The nozzles provided on the sides of the monitor are arranged in a well-balanced manner, and while being at right angles to the horizontal direction, the damage (worm biting) phenomenon is suppressed, the loss of injection energy is suppressed, and the durability is good. It is an object of the present invention to provide an excellent soil improvement device which is advantageous in the field of application of civil engineering in the construction industry by making the ground improvement as designed well.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the structure of the invention of the present application, in order to solve the above-mentioned problems, a threaded joint is provided at a predetermined length with a predetermined number of steps. A predetermined number of nozzles are provided in a well-balanced manner on the side of the monitor unit connected to and connected to the distal end portion of the rod having substantially the same diameter (or slightly larger diameter) as the rod.
At least one piece of a ring-shaped spacer made of shim type Teflon and having a thickness of 1 mm or less is formed in a flat plate shape or a male type in which a side surface is tapered at a portion connected to the nozzle from the supply passage of the improving material. When the nozzle is tightened by being interposed in a scalpel type mode, a tight metal touch is made to prevent leakage, preventing damage and worm worming. The curvature supply passage of the curving supply passage of the improving material provided in the part is formed in a well-balanced manner within the range of 20 mm to 40 mm, and the feeding pressure of the improving material such as cement milk is 250 kg.
f / cm ^{2 to} 350 kgf / cm ² and feed rate is 300 to
About 500 l / min, fluid such as air is 6 kgf / cm ² -12
Technical measures were taken to ensure that the feed rate was in the range of about kgf / cm ^{2 and} about 4 to 12 m ² / min.

[0013]

In order to perform a predetermined ground improvement, when a predetermined columnar structure is formed on the ground to be improved, the inner pipe of a rod penetrated into the ground is swept through a swivel joint to form a cement. Feeding pressure of 250kgf for improving materials such as milk
/ Cm ² -350kgf / cm ² , feed rate is 300-50
Pressure is supplied at about 0 l / min, and air or other fluid is supplied to the outer pipe concentrically provided on the inner pipe via a swivel joint at a supply pressure of about 6 kgf / cm ^{2 to} 12 kgf / cm ² . An improved material supply passage formed by pumping at an amount of about 4 to 12 m ² / min and connected to the tip of the rod and connected to the monitor section having a diameter of about 90 mm to 120 mm without interference with each other. When the radius of curvature is within the range of 20 mm to 40 mm, the tip is smoothly curved, bent horizontally at right angles to the monitor, ejected into the ground through a nozzle, and rotated upward (or downward). It is injected to form a columnar structure as an improvement body in the ground, and at that time, a Teflon-made structure interposed between the tip of the curved portion of the supply passage of the improvement material inside the monitor and the nozzle. Shim type 1
mm or less ring-shaped spacer piece is flat, or the side is formed in a tapered shape, male type, or female type is interposed and screwed into the nozzle,
It is tightened in a tight metal touch so as not to cause damage (worm-eating state) due to the generation of a vortex from the supply passage of the improving material to the nozzle.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the invention of the present application will be described as follows.

The monitor connected to the rod is 90mm-1
The diameter is 20 mm, and even within the diameter, the supply passages of the improving material are curved so as not to interfere with each other, are formed with a radius of curvature of 20 mm to 40 mm, and the front end thereof is horizontally perpendicular to the nozzle. When connecting and connecting, the shim type piece of the ring-shaped spacer has a thickness of 1 mm or less and at least one piece, male or female type when viewed from the nozzle formed flat or tapered on the side The nozzle is securely tightened with a metal touch in the supply passage of the nozzle improvement material, and the material is made of Teflon, etc. And distortion are also corrected, and the tightening of the supply passage of the improving material and the nozzle is improved.

[0016]

1 to 5 show an embodiment of the invention of this application.
This will be described below.

It is to be noted that the same parts as those in FIG.

The embodiment shown in FIG. 1 is an embodiment of a ground improvement device A (A), A '(B) which forms the center of the gist of the invention of this application. In the embodiment shown in FIG. Rod 1
Are connected to a predetermined length via joints 2, 2, 2 of a predetermined number of stages, and a monitor 8 'is integrally connected and extended at the end of the joint via a joint 2'.

In the embodiment shown in FIG. 1A, cement milk 6 as an improving material is supplied from the upper swivel joint 5 to the inner pipe 3 of the rod 1, and an air fluid 7 Is supplied to an outer tube 4 concentrically provided on the inner tube 3, and the inner tube 3 and the outer tube 4 are connected to a branch portion 9 ′ immediately below the first-stage joint 2.
Are divided into two systems, an inner pipe 10 'and an outer pipe 10 respectively.
In the monitor section 8 ', the two supply passages 10' and 10 '' gradually and smoothly intersect and intersect with each other in a non-interfering manner, and are largely curved in the horizontal direction by 90 °.
1.

The monitor section 8 'is formed immediately below the lowermost joint 2' of the rod 1. In this embodiment, the outer diameter φ of the rod 1 is 90 mm, and the outer diameter of the monitor section 8 'is 90 mm. φ is 106 mm, and the monitor part 8 ′ is not large in diameter and length with respect to the rod 1, as shown in FIG. The supply passage 10 '''' is made of tungsten carbide and its center line has a radius of curvature of 20 mm or more.
Within a range of 40 mm, a 90 ° curve can be formed sufficiently smoothly from the vertical direction to the horizontal direction within a diameter of the monitor section of 90 mm to 120 mm.

A portion where the fluid supply passages 10 ″, 10 ′ ″ are bent at 90 ° is liable to be damaged by the generation of eddy currents. As shown in FIG. In addition, the eddy current becomes severe, causing a large energy loss, and the damage is enlarged, a hole is opened, and there is a problem of durability (durability problem).

Therefore, by integrally forming this portion with a tungsten carbide carbide, wear resistance can be improved, damage due to eddy current can be prevented, and energy loss can be minimized.

The feed pressure of the improving material 6 fed from a large-capacity high-pressure feed pump (not shown) is 250 kgf / cm ² -3.
It is about 50 kgf / cm ² , and the feed rate is 300 to 500 l / min (experiment has shown that if it is out of this range, energy due to eddy currents is generated or a structure with a set diameter cannot be formed). Supply pressure of air fluid 7 6kgf /
cm2 ~12kgf / cm2 or so, the amount of feed is 4 to 12 m ² N /
It is set to be within the range of about a minute (experiment has shown that effective injection of the improving material cannot be carried out outside this range).

In the embodiment shown in FIG. 1B, the outer diameter φ of the rod 1 is similar to the embodiment shown in FIG.
Is 90 mm, and the outer diameter of the monitor section 8 ′ is 90 mm to 12 mm.
0 mm, and the radius of curvature of the center line of the improvement member 10 ″ ′ from the vertical state to the horizontal state in the monitor part 8 ′ is 20 mm.
mm to 40 mm, and the feed pressure of the cement milk modifier 6 fed from the swivel joint 5 is 250 mm.
kgf / cm ² 〜300kgf / cm ² , feed rate 300 ～
500 l / min, the supply amount is about 300-500 l / min, and the supply pressure of the air supply passage 7 is 60 kgf / cm ² -12 kg.
f / cm ² and the feed rate are in the range of about 4 to 12 m ² / min, similar to the embodiment of FIG.
The bifurcated portion 9 ″ which is bifurcated from the inner pipe 3 of the supply passage of the concentric improving material and the concentric outer pipe 4 of the fluid supply passage to the monitor part 8 ′ has the form shown in FIG. The only difference is that the point located on the lower side near the monitor section 8 'is different. In both of the embodiments shown in FIGS. 1A and 1B, the improved material is formed by smoothly bending 90 ° from the vertical direction to the horizontal direction without interfering with each other in the monitor 8 ′. The supply passage 10 '''and the fluid supply passage 10''''are formed so that the radius of curvature R of the center line thereof is smoothly within the range of 20 mm to 40 mm and is connected to the nozzle 11 in FIGS. As shown in 3, it is made of Teflon and has a thickness of 1 mm
The following ring-shaped spacer piece 13 is interposed in a metal-touch manner, and is tightly pressed by screwing the nozzle 11 in close contact. During the jetting, the vortex is suppressed as much as possible, and the abrasion (worm erosion) of the nozzle 11 and the supply passage 10 ″ ′ for the improving material due to the vortex is stopped.

Even if the inner peripheral portion of the Teflon ring-shaped spacer piece 13 slightly bulges toward the improving material supply passage 10 '''through the tightening of the nozzle 11 due to the interposition of the piece 13 of the ring-shaped spacer, continuous operation is continued. Wear in a very short time due to the improvement material such as cement milk which flows and blows out, and corrects a slight gap and distortion in the work formation at the boundary portion by the ring-shaped spacer piece 13, and the high-pressure injection of the improvement material As designed.

The ring-shaped spacer piece 13 shown in FIGS. 2 and 3 is a doughnut-shaped flat narrow piece of 1 mm or less, but as shown in FIG. It is also possible to adopt a shim type piece 13 '.

The embodiment shown in FIGS. 4 and 5 is a dish-shaped embodiment in which a ring-shaped spacer as a piece of the shim type has a tapered side surface.
In the embodiment shown in FIG. 4, a strong tightening state is maintained in a mounting state at the time of tightening. The embodiment shown in FIG. 4 is a male type viewed from the nozzle 11 side. Is a female type.

Nevertheless, the press-fitting effect of bringing the end of the supply passage 10 '''of the improving material into the monitor portion 8' into close contact with the nozzle 11 in a metal-touch manner is promoted, and cutting and polishing are performed. It can correct slight gaps and distortions in the formation of work, etc., suppresses pressure loss (energy loss) due to damage (insect eating) due to the improvement material, and create columnar structures for ground improvement in the ground as designed Is made possible.

Since the improved material ejected from the nozzle 11 is ejected horizontally to the rod 1 in a direction perpendicular to the rod 1,
The construction efficiency is good, and it is possible to construct a large-diameter columnar structure as designed.

In the embodiment shown in FIGS. 4 and 5, not only one ring-shaped spacer as a piece but also two or more ring-shaped spacers as shown in FIGS. It is needless to say that a design mode of adopting a shim type laminated state is also possible.

It should be noted that the embodiments of the invention of this application are not limited to the above-described embodiments, and for example, it is possible to employ a process-forming method such as providing a step on the surface of a ring-shaped spacer. Various aspects can be adopted.

[0032]

As described above, according to the invention of the present application, basically, the improvement material by the high-pressure pump having a large injection amount of the improvement material such as the JSG method or the CJG method is jetted to the side to improve the ground to be ground. In a ground improvement device for forming a columnar structure as an improved body, a double pipe for supplying a fluid such as air at a predetermined pressure to an inner pipe provided with an improving material in an inner pipe and an outer pipe concentrically provided in the inner pipe. A monitor is connected to the tip of the rod, and the inner pipe and the outer pipe are branched into a plurality of pipes such as a two-system pipe at the upper part of the monitor, and smoothly bent in the monitor. Then 90
° The ground improvement device connected to the ejection nozzle in a balanced manner by changing the direction, wherein the supply passages of the respective improvement materials of a plurality of systems in the monitor section bend 90 ° without interfering with each other,
By being extended in the lateral direction and connected to the nozzle, the flowing improving material does not generate a vortex or the like in the monitor portion, and particularly, the diameter φ of the monitor portion is close to the same small diameter as the rod. By setting the radius of curvature of the supply passage of the improving material to 20 mm to 40 mm to 90 mm to 120 mm, the supply passage of the improving material in the monitor section can be passed, pumped,
An excellent effect is obtained in that the supplied improving material is reliably jetted in the horizontal and horizontal directions without generating a vortex, and a large-diameter columnar structure as designed can be reliably formed.

[0033] A shim-type Teflon-made ring-shaped spacer piece having a thickness of 1 mm or less is interposed in the connection portion between the supply passage of each improvement material and the nozzle in the monitor section, so that the improvement material is improved. The point that the work on the work such as metal touch of the end of the supply passage and the nozzle has to be performed with extremely high precision is possible because the interposition of the ring-shaped spacer can correct the slight gap and distortion generated in the work. Therefore, damage (insect eating) due to the improving material flowing through the boundary portion during operation is prevented, energy loss of the jet grout is prevented, and the tightening state of the surface contact between the supply passage of the improving material and the metal touch of the nozzle is prevented. Excellent effect is achieved, that is, energy loss can be eliminated and ground improvement can be performed efficiently.

The ring-shaped spacer is made of Teflon by interposing a piece of the ring-shaped spacer in a dish shape having a tapered side surface and a male type or a female type as viewed from the nozzle side. In combination with this, there is an advantage that the press-fitting effect when the screw of the nozzle is tightened is increased, and from this point also, an excellent effect that the energy loss of the jet grout ejected is prevented is prevented.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of an embodiment of a ground improvement device according to the invention of the present application, (a) is a partial longitudinal sectional view of one embodiment,
(B) is a partial cross-sectional side view of another embodiment.

FIG. 2 is a partial cross-sectional schematic side view of a mode of fitting nozzles in a monitor unit.

FIG. 3 is a perspective view of one embodiment of a ring-shaped spacer in a nozzle, and FIG. 3C is a cross-sectional view of one embodiment;
(D) is a perspective view of a shim-type ring-shaped spacer, and (E) is a cross-sectional view of one embodiment of a multi-layered ring-shaped spacer.

FIG. 4 is an embodiment of another ring-shaped spacer;
(F), (g), (h) are (c), (d),
It is a mode figure corresponding to (e).

FIG. 5 is a diagram showing another embodiment.
(L) is a mode diagram corresponding to (C), (D), and (E) in FIG. 3.

FIG. 6 is a vertical cross-sectional view of a portion where a nozzle for supplying an improving material and a nozzle are provided in a monitor section of a conventional general mode.

FIG. 7 is a partial longitudinal sectional view of a conventional rod and a monitor unit.

[Explanation of symbols]

6 improvement material 3 improvement material supply passage (inner tube) 7 high-pressure fluid 4 fluid supply passage (outer tube) 1 rod 2, 2 'joint 11 nozzle 8 monitor unit A, A' ground improvement device 10 ''' Supply passage 13, 13 ', 13'',m13''', 13 '''', 13 ''
'''Ring spacer (Shim type piece)

Claims (4)

[Claims] 1. A double-pipe type rod having a supply passage of a high-pressure-improved improving material and an inner pipe having a high-pressure fluid supply passage as an outer pipe is connected to the inner pipe by a predetermined number of joints. In a ground improvement apparatus in which a monitor portion having a plurality of ejection nozzles laterally balanced in a circumferential direction is connected and connected to a tip portion, a supply passage of each of a plurality of systems of improving materials in the monitor portion is smoothly curved. ° is connected to the nozzle extending laterally, the diameter of the monitor part is formed in a range of 90 mm to 120 mm, and the radius of curvature of the center line of the supply passage of the improving material is formed in the range of 20 mm to 40 mm. supply passage feeding pressure 250kgf / cm ² ~350kgf / cm ² approximately at feed rate is 3
About 500 to 500 l / min, the supply passage of the high-pressure fluid has a supply pressure of about ⁶ kgf / cm ² to 12 kgf / cm ² , and the supply amount is 4 to 12 kgf / cm ²
A ground improvement device characterized by being formed so as to have a flow rate of about m ² N / min. 2. A part of the supply passage of the improving material in the monitor part, wherein a part which is smoothly curved and bent 90 ° in a lateral direction is made of tungsten carbide and is integrally formed. The ground improvement device as described. 3. A ring-shaped spacer made of a thin Teflon shim-type piece having a thickness of 1 mm or less is provided at a connecting portion between the supply passage of the improving material in the monitor portion and the nozzle, in a metal-touch manner. The ground improvement apparatus according to claim 1, wherein the ground improvement apparatus is interposed in a pressed state. 4. The apparatus according to claim 3, wherein said ring-shaped spacer is formed in a dish shape having a tapered side surface.
The ground improvement device as described.