JPH0771027A - Preparing device of improved soil and working method thereof - Google Patents

Abstract

PURPOSE:To smoothly discharge slurry, by ejecting pressure water from a jet nozzle of discharge slurry into a slurry discharge path when sucking excess slurry from the suction opening on injecting a hardening agent and controlling an opening and closing cylinder. CONSTITUTION:An infection rod 11 of a hardening agent is moved forward while rotating on boring and the ground is excavated by an excavating bit 17 and at the same time, a specified volume of water is supplied from a water path 20 to a water guide path 30. But the pressure is low and a piston valve 25 can not be pushed down and hence, the pressure water passes through a boring water path 24 and opens a check valve 26 and injects water from a boring water nozzle 23. On the other hand, a relatively large volume of water is supplied into the water path 20 on injecting the hardening agent, while rotating and retracting the injection rod 11 for the agent. Thereby, the piston 32 is pushed down and a jet water path 29 for discharge slurry is opened and the boring water path 24 is closed. And water injection from the boring water nozzle 23 is stopped and the check valve 26 is opened. The pressure water from the water path 20 is ejected from the jet nozzle 28 for discharge slurry unto the discharge path 21 through the jet water path 29 for discharge slurry. The water pressure in the jet water path 29 acts on the water guide path 40 to push down the piston 39 and open the shutter 36 and the suction inlet 27 to suck discharge slurry.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement body forming apparatus and method for strengthening the ground by injecting a hardening agent into the ground to form a piled hardened ground improvement body in the ground. .

[0002]

2. Description of the Related Art Injecting a solution of a hardening agent such as cement milk from a hardening agent injection rod in the ground, and gradually pulling back the hardening agent injection rod while rotating the hardening agent injection rod, the pile shape is formed in the ground. A ground improvement method has been developed to create a hardened improved body.

As a problem of this construction method, in the ground where the water permeability is poor, the rise of the ground pressure at the injection point of the solution causes the ground surface to rise and adversely affect the adjacent structures, etc. May be limited to a small value. So, in order to prevent the rise of the ground pressure at the injection point, etc.,
Attempts have been made to release the internal pressure by providing a sludge suction port on the injection rod and discharging excess sludge such as excess solution and slime from the injection point to the surface through the suction port.

[0004] A hardener injection rod according to a conventional example that has been improved in this kind has a suction port for sludge that is opened on the peripheral surface of the hardener injection rod, and a discharge passage communicating with the suction port is injected with the hardener. It is provided in the rod, and this discharge path is connected to a vacuum suction device on the ground, and the vacuum suction device sucks and discharges sludge from the suction port. Further, for example, it is also considered that a pressure sensor for detecting the underground pressure is provided at the tip of the curing agent injection rod, and the vacuum suction device is operated according to the output of the pressure sensor.

[0005]

However, in the conventional one, a large lump of sludge is apt to be clogged with a large lump of sludge in the suction port opened in the hardening agent injection rod, and the lump of sludge is also discharged in the discharge passage. Sometimes obstructed smooth discharge.

In order to prevent clogging of the suction port, it is conceivable to install something like a shutter for opening and closing the suction port, but this shutter needs to be operated by remote control or automatically, and a drive therefor is required. Providing a new drive device such as a motor complicates the device configuration, not only increasing the cost but also creating a new cause of failure.

The present invention has been made in view of the above, and a ground improvement body capable of smoothly discharging sludge when necessary without using a special drive device such as a drive motor. The purpose is to provide a construction device and a construction method.

[0008]

A ground improvement body forming apparatus according to the present invention for achieving the above object is intended to improve the ground by a hardening agent injection rod in a drilled hole formed in the ground. In the ground improvement body creating device for creating one or more ground improvement bodies on the target ground by moving the hardening agent injection rod while injecting the hardening agent of 1. at a high pressure, the hardening agent injection rod has a peripheral surface thereof. A suction port for the sludge that is open to the ground, a discharge path that connects the suction port and communicates it with the ground, and a pressure is provided in the discharge path in the discharge direction at the tip of the discharge path. A sludge jet nozzle for injecting water, a sludge jet water passage for supplying high-pressure water to the sludge jet nozzle, a shutter for opening and closing the suction port, and a pressure in the sludge jet water passage. By Moving to is characterized in that comprises a opening and closing cylinder device for opening and closing the shutter.

Further, in the ground improvement body forming apparatus according to the present invention, the hardening agent injection rod further injects drilling water, and a drilling water nozzle that supplies high-pressure water to the drilling water nozzle. A hole water passage, a water passage for supplying pressurized water, and an alternative water supply for the sludge jet water passage and the drilling water passage operated by the pressure in the water passage. And a switching cylinder device for switching.

For example, the hardener injection rod is provided with a single-tube hardener injection nozzle for injecting in a direction perpendicular to the longitudinal axis of the rod on the peripheral wall surface, and the hardener injection nozzle injects only the hardener. . In addition, the curing agent injection nozzle has a double tube structure composed of a central core nozzle and a peripheral nozzle surrounding the core nozzle, so that the core nozzle ejects the curing agent and surrounds the high pressure air from the peripheral nozzle. To spray. Preferably, a pair of the curing agent injection nozzles are provided at an angular interval of 180 degrees in the circumferential direction and inject in opposite directions.

Further, the method for constructing a ground improvement body according to the present invention for achieving the above object, comprises a hardening agent for improving the ground by a hardening agent injection rod in a drilling hole formed in the ground. In the ground improvement body construction method, in which one or more ground improvement bodies are formed on the target ground by moving the hardening agent injection rod while injecting at high pressure, in the ground improvement body construction method, it is connected to the suction port of the sludge and communicated with the ground. When ejecting pressure water from the sludge jet nozzle provided at the position of the tip of the discharge passage into the discharge passage in the discharge direction, a shutter that covers the suction port by the pressure of the pressure water is used. It is characterized by opening.

Further, in the ground improvement body construction method according to the present invention, water injection from the sludge jet nozzle or water injection from the drilling water nozzle is selected depending on the pressure of the pressure water supplied to the water passage. The feature is that they are switched in one step.

[0013]

[Function] When the excess sludge is sucked from the suction port when injecting the hardening agent, the sludge of the sludge is crushed smoothly by injecting the pressure water from the sludge jet nozzle to the discharge channel of the sludge. Discharge is done. Simultaneously with the supply of the pressurized water to the sludge jet nozzle, the opening / closing cylinder device opens the shutter of the suction port. When the sludge is not sucked, the pressurized water is not supplied to the sludge jet nozzle, and the shutter is closed to prevent foreign matter from entering the suction port.

Further, the switching cylinder device for selectively switching the water supply to the sludge jet water passage and the drilling water passage automatically operates in accordance with the water pressure in the water passage to inject the drilling agent and the hardening agent. Change the work content required for.

On the other hand, while the structure of the single-tube hardener injection nozzle for injecting only the hardener is simple, the double-tube hardener injection nozzle is used to inject the hardener surrounded by high-pressure air. Therefore, the reaching distance of the curing agent can be extended. Further, the injection reaction forces are canceled by injecting in the anti-reverse direction, and bending of the rod is prevented.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 and 2 are schematic cross-sectional views of the tip portion of the hardening agent injection rod according to the embodiment of the present invention in the drilling step and the hardening agent injection step, respectively, and FIG. 3 shows the construction equipment according to the embodiment of the present invention. It is a schematic block diagram.

In FIG. 3, reference numeral 11 denotes a hardening agent injecting rod. The hardening agent injecting rod 11 is supported by a driving device 12, is rotationally driven around its longitudinal axis, and is moved forward and backward along the longitudinal axis. It is supposed to be done. Further, 13 is a high-pressure curing agent supply device, 14 is a high-pressure water supply device, and 15 is a sludge recovery device, each of which is connected to the curing agent injection rod 11. As each of these devices, those usually used for this type of ground improvement body forming device can be used.

The hardener injection rod 11 has a generally cylindrical shape and, as shown in FIG. 1, has an excavating bit 17 for drilling at the periphery of the most distal end thereof. A hardener flow path 18, a water flow path 20, and a sludge discharge path 21 are formed in the hardener injection rod 11, and these are each a high-pressure hardener supply device 13 installed on the ground at the base end, It is connected to the high-pressure water supply device 14 and the sludge recovery device 15.

A hardener injection nozzle 22 having a single pipe structure for injecting in a direction perpendicular to the rod longitudinal axis is provided on the peripheral wall surface of the tip of the hardener injection rod 11, and the hardener is supplied from the high pressure hardener supply device 13 to the hardener. The curing agent supplied through the flow path 18 is laterally ejected from the curing agent ejection nozzle 22.

At the center of the front end surface of the hardening agent injection rod 11, a drilling water nozzle 23 for jetting forward in the longitudinal direction of the rod is provided. The drilling water nozzle 23 communicates with the drilling water passage 24, and the drilling water passage 24 communicates with the water passage 20 via a piston valve 25 described later. A check valve 26 is provided at the tip of the drilling water passage 24 between the drilling water nozzle 23 and the drilling water passage 24. When water pressure is applied to the drilling water passage 24, the check valve 26 opens to release high pressure water. On the other hand, when the water pressure is not applied to the drilling water passage 24, the check valve 26 is closed to prevent backflow from the outside into the drilling water passage 24.

Further, a sludge suction port 27 is opened on the peripheral wall surface of the hardening agent injection rod 11, and this is the discharge passage 21.
Is in communication with. The hardener injection rod 11 has a discharge path 2
A nozzle 28 for a sludge jet that injects in the discharge path 21 in the discharge direction is provided at the position of the tip of the nozzle 1. Nozzle 28 for sludge jet is hardener injection rod 11
Is communicated with the water passage 29 for the sludge jet inside, and the water passage 29 for the sludge jet is further provided with the piston valve 25 and the introduction passage 3.
0 to the water passage 20.

The piston valve 25 is fitted into the sludge jet water passage 29 to close the valve body portion 31, the piston portion 32, and the end portion of the hole drilling water passage 24, which closes the valve body portion 31. And a valve stem portion 33 that operates. Piston valve 25
Has a piston portion 32 slidably inserted into a switching cylinder chamber 34 formed in the hardener injection rod 11 to form a switching cylinder device, and its valve rod portion 33 slides on a cylinder wall. Drilling water passage 2 freely penetrating
It faces the end of No. 4.

The compression spring 3 is provided in the switching cylinder chamber 34.
5, the piston part 32 is urged upward in FIG.
Normally, the piston valve 25 is positioned at the upper part by the spring force of the compression spring 35, and in this state, the valve body 31 is fitted into the sludge jet water passage 29 to close it and the tip of the valve rod portion 33. Separates from the drilling water passage 24 and opens it (state of FIG. 1). On the other hand, when the piston portion 32 is pushed down against the spring force by the water pressure supplied from the introduction passage 30, the valve body portion 31 separates from the sludge jet water passage 29 and opens it, and Stick 3
The tip of 3 comes into contact with the drilling water passage 24 to close it. Here, the predetermined pressure is applied to the piston portion 32.
The relationship between the pressure receiving area of the piston portion 32 and the spring force of the compression spring 35 is defined so that the piston portion 32 moves when it acts on.

A shutter 36 is provided at the sludge suction port 27 to open and close it. Shutter 36
An open / close rod 37 is connected to the open / close rod 37, and the open / close rod 37 is supported in the hardener injection rod 11 so as to be slidable in the longitudinal axis direction.
Further, the opening / closing cylinder chamber 3 is provided in the hardener injection rod 11.
8 is formed and a piston 39 is slidably inserted into the opening / closing cylinder chamber 38 to form an opening / closing cylinder device, and the opening / closing rod 37 is fixed to the piston 39. In addition, the cylinder chamber 38 above the piston 39
Communicates with the sludge jet water passage 29 through an introduction passage 40.

A compression spring 41 is installed in the opening / closing cylinder chamber 38 to urge the piston 39 upward in FIG.
Normally, the piston 39 is located at the upper part by the spring force of the compression spring 41, and the shutter 36 is also located at the upper part via the opening / closing rod 37 to close the suction port 27 in that state (FIG. 1).
State). On the other hand, when the pressure supplied from the introduction path 40 pushes the piston 39 downward against its spring force, the shutter 36 descends to open the suction port 27. In this case as well, the relationship between the pressure receiving area of the piston 39 and the spring force of the compression spring 41 is defined so that the piston 39 moves when a predetermined pressure acts on the introduction path 40.

In such a structure, when drilling holes, as shown in FIG. 1, the hardening agent injecting rod 11 advances while rotating, and excavates the ground by the excavating bit 17 at the tip, and at the same time, the water flow path 20. From a relatively small amount of water (eg 5
(Less than 0 liter / minute) is supplied. This water is introduced 3
However, since the pressure is low, the piston valve 25 cannot be pushed down, and the piston valve 25 closes the sludge jet water passage 29 and opens the drilling water passage 24. Therefore, the pressure water from the water flow path 20 does not go to the sludge jet water passage 29, and the shutter 36 causes the suction port 27.
While the closed state is maintained, the pressure water from the water flow path 20 passes through the drilling water passage 24, opens the check valve 26, and is jetted forward from the drilling water nozzle 23.

On the other hand, as shown in FIG. 2, when the curing agent is injected,
The curing agent injecting rod 11 retreats while rotating, the curing agent is supplied to the curing agent channel 18, and the curing agent is injected from the curing agent injection nozzle 22 into the drilled hole. A relatively large amount of water (for example, about 100 liters / minute) is supplied from the water flow path 20. This water is supplied to the introduction passage 30, and the water pressure causes the piston portion 32 to be pushed downward against its spring force to open the sludge jet water passage 29 and close the drilling water passage 24. Therefore, the drilling water nozzle 2
The water injection from 3 is stopped and the check valve 26 is closed, and the pressure water from the water flow passage 20 is injected into the discharge passage 21 from the sludge jet nozzle 28 through the water passage 29 for the sludge jet. Further, the water pressure in the sludge jet water passage 29 acts on the introduction passage 40 and pushes down the piston 39 to open the shutter 36 and open the suction port 27.

The sludge S is sucked from the opened suction port 27 toward the discharge passage 21, and the pressure water is jetted from the sludge jet nozzle 28 into the discharge passage 21.
The sludge is crushed and smooth suction is performed.

Further, in this embodiment, the injection of the curing agent is carried out by a nozzle having a simple single tube structure, so that the structure is simplified and a normal boring machine can be used.

Next, FIGS. 4 and 5 show another embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a tip portion of a curing agent injection rod according to another embodiment of the present invention, and FIG. 3 is a schematic configuration diagram of its construction equipment. The present embodiment is different from the above-described embodiment in the curing agent injection structure, and in the following description, the same parts as those in the above-mentioned embodiment are denoted by the same reference numerals and duplicate description will be omitted.

In FIG. 5, reference numeral 42 denotes a hardening agent injection rod according to this embodiment. In this apparatus, in addition to the drive device 12, the high pressure hardening agent supply device 13, the high pressure water supply device 14 and the sludge collecting device 15, , A high-pressure air supply device 16 is provided,
Each is connected to a hardening agent injection rod 42.

As shown in FIG. 4, the hardener injection rod 42
Inside the hardener flow path 18, the water flow path 20, the sludge discharge path 2
In addition to 1, an air flow path 19 is formed, and each of these has a high-pressure curing agent supply device 13, a high-pressure water supply device 14, a sludge recovery device 15, and a high-pressure air supply device 16 at the base end.
It is connected to the.

On the peripheral wall surface near the tip of the hardener injection rod 42, a hardener injection nozzle 43 for injecting in a direction perpendicular to the longitudinal axis of the rod is provided. In this embodiment, the hardening agent injection nozzle 43 has a double tube structure composed of a central core nozzle and a peripheral nozzle surrounding the core nozzle. The hardening agent flow passage 18 communicates with the core nozzle and the hardening nozzle is connected to the peripheral nozzle. The air flow path 19 communicates. Therefore, when the curing agent and the air are supplied from the high-pressure curing agent supply device 13 and the high-pressure air supply device 16, respectively, they are ejected from the curing agent injection nozzle 43 in a state in which the curing agent is surrounded by the air. Also,
A pair of curing agent injection nozzles 43 are provided at an angular interval of 180 degrees in the circumferential direction, and each injection reaction force is canceled by injecting in opposite directions.

According to the structure of the present embodiment as described above, by injecting the curing agent while surrounding it with air, it is possible to inject the curing agent to a distant place without damaging the injection pressure of the curing agent due to the effect of air inclusion. Therefore, a large-diameter ground improvement body can be created. Further, by injecting the curing agent in mutually opposite directions and canceling out the respective injection reaction forces, the force in the bending direction of the rod generated by the injection reaction force can be reduced, and the bending of the rod can be prevented. The bending phenomenon of the rod due to the injection reaction force is a problem particularly in a large-depth construction in which the rod length becomes long.
The rest of the configuration and operation are similar to those of the above-mentioned embodiment.

In the above description of the embodiments, an example of injecting the curing agent alone and an example of injecting the curing agent in a state in which the curing agent is surrounded by high pressure air are shown, but the present invention is not limited to this. Needless to say, it can be applied to various construction methods such as the case of using fresh water injection in combination.

[0036]

As described above in detail with reference to the embodiments, according to the present invention, the opening / closing cylinder device is operated by the pressure simultaneously with the supply of the pressure water to the sludge jet nozzle, and the suction port The shutter opens automatically,
The required opening and closing movement of the shutter can be obtained without requiring a special driving device, clogging of the suction port can be prevented, and the sludge can be discharged smoothly. Also, by providing a switching cylinder device that selectively switches the water supply to the sludge jet water passage and the drilling water passage, the water injection can be automatically switched according to the water pressure in the water passage. The efficiency of can be improved.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a tip portion of a curing agent injection rod according to an embodiment of the present invention in a hole making step.

FIG. 2 is a schematic cross-sectional view of a tip portion of a hardening agent injection rod according to an embodiment of the present invention in a hardening agent injection step.

FIG. 3 is a schematic configuration diagram of construction equipment according to an embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a hardener injection rod tip according to another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of construction equipment according to another embodiment of the present invention.

[Explanation of symbols]

 11, 42 Hardener injection rod 12 Drive device 13 High pressure hardener supply device 14 High pressure water supply device 15 Sludge recovery device 16 High pressure air supply device 17 Excavation bit 18 Hardener flow path 19 Air flow path 20 Water flow path 21 Discharge path 22, 43 Hardener injection nozzle 23 Drilling water nozzle 24 Drilling water passage 25 Piston valve 26 Check valve 27 Inlet port 28 Sludge jet nozzle 29 Sludge jet water passage 34 Switching cylinder chamber 35, 41 Compression spring 36 Shutter 38 Opening / closing cylinder chamber 39 Piston

Claims (7)

[Claims] 1. One or more by moving the hardening agent injection rod while injecting a hardening agent for improving the ground at a high pressure into the hole formed in the ground by the hardening agent injection rod. In the ground improvement body forming device for forming the ground improvement body of (1) on the target ground, the hardening agent injection rod is connected to the suction port of the sludge discharged to the peripheral surface thereof and the suction port to communicate it with the ground. A discharge passage, a nozzle for a sludge jet which is provided at a position of the tip of the discharge passage and injects pressure water into the discharge passage in the discharge direction, and high-pressure water is supplied to the nozzle for the sludge jet. A sludge jet water passage, a shutter that opens and closes the suction port, and an opening and closing cylinder device that is operated by pressure in the sludge jet water passage to open and close the shutter. That soil improvement material reclamation equipment. 2. The hardening agent injection rod further comprises a drilling water nozzle for injecting drilling water, a drilling water passage for supplying high-pressure water to the drilling water nozzle, and water for supplying pressurized water. A passage, and a switching cylinder device that is operated by the pressure in the water passage to selectively switch water supply from the water passage to the sludge jet water passage and the drilling water passage. The ground improvement body building apparatus according to claim 1. 3. The hardener injection rod is provided with a single-tube hardener injection nozzle for injecting in a direction perpendicular to the rod longitudinal axis on the peripheral wall surface, and the hardener injection nozzle injects only the hardener. The ground improvement body constructing apparatus according to claim 1 or 2, characterized in that. 4. The hardening agent injection rod is provided with a double tube structure hardening agent injection nozzle having a central core nozzle for injecting in a direction perpendicular to the longitudinal axis of the rod on a peripheral wall surface and a peripheral nozzle surrounding the core nozzle. 3. The ground improvement body creating apparatus according to claim 1, wherein the hardening agent is jetted from the core nozzle and high-pressure air is jetted from the peripheral nozzle so as to surround the hardening agent. 5. The curing agent injection nozzle is 180 in the circumferential direction.
5. A pair is provided with an angular interval of 4 degrees, and jets in directions opposite to each other.
The ground improvement body building device described. 6. One or more than one by moving the hardening agent injection rod while injecting a hardening agent for improving the ground into the drilled hole formed in the ground at a high pressure by the hardening agent injection rod. In the ground improvement body construction method for forming the ground improvement body on the target ground, from the sludge jet nozzle provided at the position of the tip of the discharge path that connects to the suction port of the sludge and communicates it with the ground. A method for constructing a soil improvement body, comprising: opening a shutter that covers the suction port by the pressure of the pressure water when the pressure water is jetted into the discharge path in the discharge direction. 7. The pressure of the pressure water supplied to the water passage,
7. The ground improvement body construction method according to claim 6, wherein water injection from the sludge jet nozzle and water injection from the drilling water nozzle are selectively switched.