JPS61266719A - Method and apparatus for ground improving work by composite jet stream - Google Patents

Abstract

PURPOSE:To construct large-diameter homogenous columnar solid body by a method in which air and water are jetted through the nozzle of non-rotary hydraulic monitor and also cement milk is jetted from the nozzle of a rotary hydraulic monitor. CONSTITUTION:Compressed air, high-pressure water, and cement milk 7 are supplied through a triple tube 3 to a rotary hydraulic monitor 10. Both the monitors 10 and 20 are raised while supplying compressed air and high-pressure water to a non-rotary hydraulic monitor 20. Air-water jet stream C is jetted through the nozzle of the monitor 20 to form a vertical cut portion in the surrounding ground of a guide hole. Cement milk jet stream B1 is also jetted through the nozzle of the monitor 10 and air and water streams A1 and A2 are jetted, and they are joined together to form a composite jet stream A. The cut portion formed by the air and water jet streams C is widened by the composite jet stream A, and the ground is crushed and stirred by the jet stream A and mixed with the cement milk jet stream B2 to form a columnar solid body G.

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 method and Jell-Groudoe 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 ground improvement, water stopping, etc.

However, the diameter of the columnar solid bodies constructed by the high-speed air-water jets used in these applications is, for example, at a pressure of 400 Kfi/c.
i, flow f 150ff/min water jet and pressure 3KF
When using an air jet with a flow rate of I/cri, m1 vo/min, the distance varies depending on the quality of the soil to be improved, but is approximately 2 m to 2.5 m. 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 increase the size of the equipment and increase the weight of the surrounding area. Invitation,
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.

Further, 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 from the triple pipe swivel via a triple pipe, and the non-rotating hydraulic power monitor is fixed to the rotating hydraulic power monitor. A first nozzle that injects a composite jet of air and water that faces each other and intersects at an angle of 10 to 20 degrees in a plane including the axis, and an improvement material jet that is perpendicular to the axis and faces above and below the composite jet. A ground improvement device using a synthetic jet is characterized in that it has second and third nozzles that inject air and water jets, and a fourth nozzle that faces a non-rotating hydraulic power monitor and injects an axially perpendicular jet of air and water. provided.

[Operation and Effect of the Invention] Therefore, the jet of the fourth nozzle forms a notch in the ground,
The combined jet of the first nozzle has a longer effective range due to the synergistic effect of the mutual jets, which improves the crushing effect, and the intersection angle of 10 to 20 degrees increases the effective flying distance of the jet. Maximize. 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.

Triple pipe swivel 1 is equipped with compressed air, high pressure water and improvement material (
For example, an air hose 2a, a high-pressure hose 2b, and a grout hose 2C for supplying (for example, cement milk) are installed, and the compressed air, high-pressure water, and cement milk flow separately in the triple pipe 3 and are directed to the rotating hydraulic power monitor 10. 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, and the triple pipe 3 is supported rotatably in the range of 0 to 400 rpm by a rotary drive device 4. has been done.

In the lower half of the rotary hydraulic monitor 10, there is an air-water jet A that forms a combined air-water jet A that intersects at an intersection angle θ of 10 to 20 degrees on opposite sides in a plane that includes the axis of the rotary hydraulic monitor 10. The first nozzle 11 that injects A2 and A2
a, 11a and 11b, 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 set to increase.

Above and below this composite jet flow A, that is, between the first nozzle 11a and the non-rotating hydraulic power monitor 20, and at the lower end of the rotating hydraulic power monitor 10, there is a A second nozzle 13 and a third nozzle 14 are provided for injecting cement milk jets B1 and 82, respectively.

On the other hand, the non-rotating hydraulic power monitor 20 is provided with a fourth nozzle 21 configured similarly to the first nozzles 11a and 11b, which injects an axially perpendicular air-water jet C on the opposite side.

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 ctx is bored using a drilling device such as a drilling machine or an earth auger.

Next, as shown in FIG. 3, the rotary hydraulic power monitor 10 suspended from the triple tube swivel 1 via the triple tube 3 is inserted into the guide hole E to near the bottom by a truck crane F.

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, the rain hydraulic power monitor 10.20 is moved up and down, and the rotary hydraulic power monitor 10 is rotated by the rotary drive device 4.

Next, as shown in FIG. 4, the air hose 2a, high pressure hose 2b and grout hose 3C1 triple pipe swivel 1
, compressed air, high pressure water and cement milk are supplied to the rotating hydraulic power monitor 10 via the triple pipe 3, and the air hose 5a
, compressed air and high-pressure water are supplied to the non-rotating hydraulic power monitor 20 via the high-pressure hose 5b (Fig. 1), the rotating hydraulic power monitor 10 is rotated, and the non-rotating hydraulic power monitor 20 is not rotated, but both monitors 10 and 20 are connected. raise. By doing this, the fourth nozzle 2 of the non-rotating hydraulic power monitor 20
1, an air/water jet C is ejected horizontally, and this air/water jet C forms a vertical notch in the ground around the guide hole E as the non-rotating hydraulic power monitor 20 rises. 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 a cement milk jet B2 is jetted horizontally from the third nozzle 14, and these jets rise as the rotary hydraulic power monitor 10 rises.
The synthetic jet A spreads out the notch formed by the air/water jet C, crushing and agitating the ground around the guide hole E into a cylindrical shape. Cement milk is injected and stirred into the ground that has been crushed and stirred in this manner.

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 improves the crushing effect due to the mutual interference effect of the air/water jets A1 and A2, and the cement milk jet B1
is located between the air-water jet C and the synthetic jet PEA, so it mixes the cement milk and soil well and creates a columnar concrete.
1- Homogenize the solids G. Further, the intersection angle θ of 10 degrees to 20 degrees maximizes the effective flying distance of the synthetic jet IA 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 1] 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;
Figures 2 to 4 are drawings explaining the ground improvement method according to the present invention, in which Figure 2 shows the guide hole drilling process, Figure 3 shows the hydraulic monitor insertion process, and Figure 4 shows the columnar solid body construction process. FIG. A...Synthetic jet B1, B1...Cement milk jet C...Air/water jet E...Guide hole G...Columnar concrete solid body 1...Triple pipe swivel 3...Triple pipe 10... Rotating hydraulic power monitor 11a111b... First nozzle 1
3...Second nozzle 14...Third nozzle
20...Non-rotating hydraulic power monitor 21...Fourth nozzle Figure 2

Claims (2)

[Claims] (1) Insert a rotating hydraulic power monitor and a non-rotating hydraulic power monitor installed above the rotating hydraulic power monitor into a guide hole drilled in the ground in advance, and intersect in a plane containing the axis from multiple nozzles provided on the rotating monitor. At the same time, a synthetic jet of air and water is injected above and below the synthetic jet, and a jet of air and water perpendicular to the axis is injected from a plurality of nozzles provided on the non-rotating hydraulic monitor. This is a ground improvement method using a synthetic jet, which is characterized in that the ground is simultaneously pulled up from the ground, crushed and stirred by an air/water jet and a synthetic jet, and then further stirred by an improvement material jet to build a columnar solid body. (2) A non-rotating hydraulic monitor is installed coaxially with the rotating hydraulic monitor and fixed in the axial direction on the upper part of the rotating hydraulic monitor suspended from the triple pipe swivel via a triple pipe, and a plane containing the axis of the rotating hydraulic monitor is provided. The first injects synthetic jets of air and water that face each other and intersect at an angle of 10 to 20 degrees within the
and second and third nozzles that inject axially perpendicular improving material jets facing above and below the composite jet, and axially perpendicular air-water jets facing the non-rotating hydraulic power monitor. A ground improvement device using a synthetic jet, characterized by being provided with a fourth nozzle for spraying.