JPH0235090B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a ground improvement method using a synthetic jet that crushes and stirs the ground and rocks using a synthetic jet, and also injects improving materials and builds columnar solid bodies to improve the ground. Concerning construction methods and methods.

[Prior art] Column jet construction method and jet ground construction method are known as construction methods that improve the ground by crushing and stirring the ground and rocks using high-speed jets and injecting improving materials to build columnar solid bodies. Widely used for water, etc.

However, the diameter of the columnar solids created by the high-speed air-water jets used in these applications is limited to
Kg/cm ² , water jet with flow rate 50/min and pressure 3
When using ^an air jet with a flow rate of 1 m ³ /min, approximately 2 m
It is about 2.5m. Moreover, when the soil is clayey, heterogeneous columnar solids containing soil clods may be formed.

In order to improve these shortcomings and build homogeneous columnar solids with a larger diameter, increasing the output of the pump and increasing the pressure and flow rate of the water jet will lead to an increase in the size and weight of the equipment. Furthermore, attaching a stirring blade or the like to the underwater monitor to improve the stirring effect and achieve homogenization inevitably increases the diameter of the guide hole, which is undesirable as it increases the cost required for drilling.

[Object of the Invention] Accordingly, the object of the present invention is to provide a method for ground improvement using a synthetic jet that can construct a large-diameter, homogeneous columnar solidified body, and an apparatus for carrying out the method.

[Configuration of the Invention] According to the present invention, a rotating hydraulic power monitor and a non-rotating hydraulic power monitor provided above the rotating hydraulic power monitor are inserted into a guide hole drilled in advance in the ground, and a plurality of nozzles provided on the rotating monitor are inserted into a guide hole drilled in the ground in advance. A synthetic jet of air and water that intersects in a plane including the axis from the air and a jet of improvement material perpendicular to the axis are injected above and below the synthetic jet, and air perpendicular to the axis is injected from multiple nozzles installed on a non-rotating hydraulic monitor. By using a synthetic jet, which is characterized in that both monitors are simultaneously pulled up from the ground while injecting a water jet, and the ground that has been fractured and stirred by an air/water jet and a synthetic jet is further stirred by an improvement material jet and a columnar solid body is built. Ground improvement methods are provided.

Furthermore, according to the present invention, a non-rotating hydraulic power monitor is provided coaxially and fixed in the axial direction with the upper rotating hydraulic power monitor of the rotating hydraulic power monitor suspended through the triple pipe swivel, and a first nozzle that injects a synthetic jet of air and water that faces each other and intersects at an angle of 10 to 20 degrees in a plane containing Provided is a ground improvement device using a synthetic jet, characterized in that second and third nozzles are provided to inject air and water, and a fourth nozzle is provided that faces a non-rotating hydraulic power monitor and injects an axially perpendicular air-water jet. has been done.

[Operations and Effects of the Invention] Therefore, the jet of the fourth nozzle forms a notch in the ground, and the combined jet of the first nozzle has a longer effective range due to the synergistic effect of the mutual jets. This improves the crushing effect, and an intersection angle of 10 to 20 degrees maximizes the effective flight distance of the jet. In other words, since a composite jet is created at a certain distance from the nozzle exit, the flying distance is increased.
As a result, the free surface of the ground is widened by the cut formed by the fourth nozzle, which is crushed and stirred by the combined jet of the first nozzle, so the stirring effect is significantly improved. Mix the improvement material well with the soil. As a result, a homogeneous columnar solid body with a large diameter can be constructed.

[Preferred Embodiment] When carrying out the present invention, it is preferable that the triple tube swivel be configured to be able to rotate at high speed. In this way, construction efficiency can be improved.

[Example] An apparatus for carrying out the present invention will be described below with reference to FIG.

In FIG. 1, a rotary hydraulic power monitor 10 is suspended from a triple pipe swivel 1 via a triple pipe 3, and an annular rotated hydraulic power monitor 20 is attached to the upper part of the rotary hydraulic power monitor 10 by a fixing means (not shown). It is provided coaxially with the monitor 10 and fixed in the axial direction.

The triple pipe swivel 1 is connected to an air hose 2a, a high pressure hose 2b, and a grout hose 2c for supplying compressed air, high pressure water, and improving material (for example, cement milk). The water flows separately to the rotating hydraulic power monitor 10, and the non-rotating hydraulic power monitor 20 is connected to an air hose 5a for supplying compressed air and a high pressure hose 5b for supplying high pressure water. It is rotatably supported by a rotary drive device 4 within a range of 0 to 400 rpm.

In the lower half of the rotary hydraulic power monitor 10, there is an air/water jet A1 forming a combined air/water jet A that intersects at an intersection angle θ of 10 to 20 degrees on opposite sides in a plane including the axis of the rotary hydraulic power monitor 10. and the first nozzles 11a, 11a and 11 that inject A2.
b, 11b are provided. Although these first nozzles are not shown, a high-speed air jet is ejected from a ring-shaped nozzle that surrounds a well-known nozzle that ejects a high-pressure water jet, and the high-speed air jet wraps the high-pressure water jet to increase the flight distance of the high-pressure water jet. It is starting to increase.

Above and below this composite jet A, that is, the first
Between the nozzle 11a and the non-rotating hydraulic monitor 20 and at the lower end of the rotating hydraulic monitor 10, axially perpendicular cement milk jets B1 and B2 are formed on opposite sides in a plane containing the axis of the rotating hydraulic monitor 10.
A second nozzle 13 and a third nozzle 14 are respectively provided for injecting.

On the other hand, the non-rotating hydraulic power monitor 20 has a first nozzle 1 that injects an axially perpendicular air-water jet C to the opposite side.
Fourth nozzle 2 configured similarly to 1a and 11b
1 is provided.

Next, a construction method according to the present invention will be explained with reference to FIGS. 2 to 4.

In the construction method according to the present invention, first, as shown in FIG. 2, a guide hole E having a diameter of 15 to 20 cm is bored using a drilling device D such as a drilling machine or an earth auger.

Next, as shown in Figure 3, the truck crane F
The rotary hydraulic power monitor 10 suspended from the triple pipe swivel 1 via the triple pipe 3 is inserted into the guide hole E up to the vicinity of the bottom. At this time, the non-rotating hydraulic power monitor 20 is also inserted at the same time. Therefore, by moving the triple pipe swivel 1 up and down by the truck crane F, both hydraulic power monitors 10 and 20 are moved up and down, and the rotary hydraulic power monitor 10 is rotated by the rotary drive device 4.

Next, as shown in FIG.
a, high pressure hose 2b and ground hose 3c,
Compressed air is supplied through triple pipe swivel 1 and triple pipe 3,
High pressure water and cement milk are supplied to the rotating hydraulic power monitor 10, and the air hose 5a and high pressure hose 5b are
(Fig. 1), compressed air and high pressure water are supplied to the non-rotating hydraulic power monitor 20, and the rotating hydraulic power monitor 10
is rotated, and both monitors 10 and 20 are raised without rotating the non-rotating hydraulic power monitor 20. By doing this, the air/water jet C is injected horizontally from the fourth nozzle 21 of the non-rotating hydraulic power monitor 20, and as the non-rotating hydraulic power monitor 20 rises, the air/water jet C flows through the guide hole. Form one vertical cut in the ground around E. On the other hand, a cement milk jet B1 is jetted horizontally from the second nozzle 13 of the rotary hydraulic power monitor, and downward and upward air-water jets A1 and A2 are jetted from the first nozzles 11a and 11b, so that the angle of intersection θ is A synthetic jet A is formed, and the third nozzle 14
A cement milk jet B2 is injected horizontally from the rotary hydraulic power monitor 1.
0 rises, the synthetic jet A expands the notch formed by the air/water jet C, crushing and stirring the ground around the guide hole E into a columnar shape. Cement milk is injected and stirred into the ground that has been crushed and stirred in this way.

This cement milk and a part of the soil are mixed and solidified after a certain period of time, and a columnar concrete solid body G is constructed. At this time, the synthetic jet A is air/water jet A1,
The crushing effect is improved by the mutual interference effect of A2,
Moreover, since the cement milk jet B1 is located between the air/water jet C and the synthetic jet A, the cement milk and the soil are well stirred and the columnar concrete solids G are homogenized. Also, the intersection angle θ of 10 degrees or 20 degrees
maximizes the effective flying distance of the synthetic jet A and increases the diameter of the columnar concrete solid body. Note that, depending on the soil quality, the same effects can be obtained even if the cement milk jets B1 and B1 are omitted and both the composite jet A and the air/water jet C are replaced with air/cement milk jets.

[Summary] As explained above, according to the present invention, a notch is formed in the ground by the jet of the fourth nozzle, and the notch is expanded by the synthetic jet of the first nozzle, thereby improving the crushing and stirring effect. . As a result, a large diameter and homogeneous columnar solid body can be constructed.

[Brief explanation of drawings]

Fig. 1 is a side view showing a ground improvement device implementing the present invention, Figs. 2 to 4 are drawings explaining the ground improvement method according to the present invention, Fig. 2 shows the guide hole drilling process, and Fig. 3 shows the process of drilling guide holes. FIG. 4 is a diagram showing a hydraulic monitor insertion process, and FIG. 4 is a diagram showing a columnar solid body construction process. A... Synthetic jet, B1, B1... Cement milk jet, C... Air water jet, E... Guide hole,
G... Columnar concrete compact, 1... Triple pipe swivel, 3... Triple pipe, 10... Rotating hydraulic power monitor, 11a, 11b... First nozzle, 13...
Second nozzle, 14...Third nozzle, 20...
Non-rotating hydraulic power monitor, 21...fourth nozzle.

Claims (1)

[Claims] 1. A rotary hydraulic power monitor and a non-rotating hydraulic power monitor provided above the rotary hydraulic power monitor are inserted into a guide hole drilled in advance in the ground, and a plurality of nozzles provided on the rotating monitor are inserted into the shaft. A composite jet of air and water that intersects in a plane and a jet of improvement material perpendicular to the axis above and below the composite jet are injected, and a jet of air and water perpendicular to the axis is injected from multiple nozzles provided on a non-rotating hydraulic monitor. This is a ground improvement method using synthetic jets, which is characterized in that both monitors are simultaneously lifted from the ground, and the ground that has been fractured and stirred by an air/water jet and a synthetic jet is further stirred by an improvement material jet and a columnar solid body is built. 2. A non-rotating hydraulic power monitor is provided above the rotating hydraulic power monitor suspended from a triple pipe swivel via a triple pipe, coaxially with the rotating hydraulic power monitor and fixed in the axial direction. A first nozzle that injects a composite jet of air and water that faces each other and intersects at an intersection angle of 10 to 20 degrees, and a second nozzle that injects an axially perpendicular reforming material jet oppositely above and below the composite jet. a third nozzle;
A ground improvement device using a synthetic jet, characterized in that a fourth nozzle is provided that injects an axially perpendicular jet of air and water facing a non-rotating hydraulic power monitor.