JPH0790838A - Underground slurry discharge engineering and its device - Google Patents

Abstract

PURPOSE:To discharge and transport a sucked slurry by discharge energy of a water jet itself by injecting the water jet from an injection nozzle installed in a sucked slurry delivery route in the slurry discharge direction. CONSTITUTION:On a head end part of a slurry suction pipe 1, a multi-purpose high pressure injection nozzle A is installed. Thereafter, a slurry suction port 2 is opened with a specified interval. Additionally, a prevention net 21 to prevent intrusion of foreign matter is attached. Thereafter, the suction pipe 1 is inserted into an objective ground. When a water jet is injected from the nozzle A with high pressure in the discharge direction, negative pressure is generated in a discharge route 3 and a slurry in the circumference of the suction pipe 1 is sucked Simultaneously, by carrier force of the water jet in the route 3, the sucked slurry is discharged. Additionally, injection pressure is adjusted in accordance with ground internal pressure measured by a ground internal pressure sensor 6. Additionally, by a forming an ejector part 41 in the route 3, effect of the water jet is strengthened. Consequently, it is possible to discharge the slurry efficiently and to improve efficiency in respect of work and cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is ancillary to the construction of underground structures for the purpose of stabilizing soft ground, foundations of structures, and supporting the ground, etc., and slurries underground soil to unload it. The present invention relates to an underground slurry discharge method and an apparatus for discharging surplus slurry generated during excavation and injection of injection material.

[0002]

2. Description of the Related Art Conventionally, in the high-pressure injection injection method which requires the discharge of excess slurry and the high-pressure injection excavation method in which ground soil is slurried to be unloaded, the discharge of the slurry is mainly a multipurpose insertion pipe. There have been adopted methods of utilizing a gap with the ground around the rod, providing a slurry discharge path in the multipurpose insertion tube, or separately providing a casing with holes.

When the space between the insertion rod and the ground is used, there is no problem if the depth is shallow and the injection amount per minute is small, but the performance of the high-pressure pump is improved and a large amount of high-pressure injection is obtained. Nowadays, when the discharge is suppressed, it is compressed by the subsequent injection pressure, and a large amount of excess slurry that increases the repulsive force near the nozzle is generated.

In the case of providing a unique slurry discharge path in the multipurpose insertion pipe or in the case of separately drilling the casing, the deeper the depth, the lower the ground pressure of the target ground or the negative pressure of the discharge path. Cannot discharge the slurry completely, and the problem is how to enhance the carrying capacity.

As a countermeasure against this problem of strengthening the carrying force, collection by a suction pump from the multipurpose insertion tube insertion port is proposed, and further, an air ejection mechanism for enhancing the lift effect is provided in the slurry discharge path, Although it has been proposed to inject an air-mixed jet in the direction of discharging the slurry, the diameter of the discharging route in the actual construction requires a discharging pipe having a diameter of 75 mm or more.

On the other hand, as the injection of the ground hardening material by ultra-high pressure develops, the balance between the injection amount of the hardening material and the particle density of the ground becomes important, and the slurry treatment greatly affects the construction result. However, no special consideration has been given so far.

[0007]

The conventional multi-purpose insertion pipe is provided with the vertical direction when the multi-purpose insertion pipe is installed in order to provide an air ejection mechanism for strengthening the lift effect in the slurry discharge path or to inject a mixed air jet in the slurry discharge direction. When the multi-purpose insertion pipe is inserted horizontally, the air rising function stays in the path as it is, although the effect can be expected if the air rising function is directly connected to the slurry discharge force. Therefore, the movement of the air itself in the discharge direction becomes a problem.

Further, when the discharge path becomes longer in distance, the diameter of the pipe constituting the discharge path must be further increased, and in the case of air having a low mass or a mixed air jet by a normal injection force. , Insufficient as carrier energy in the discharge route of slurry with high viscosity including clods and gravel, it cannot cope with the sudden increase of the ground pressure inside the target ground due to the ultra-high pressure injection of the multipurpose insertion pipe, and the discharge route is clogged. There are also problems.

Further, the relationship between the target ground ground pressure and the slurry discharge amount due to the ultra-high pressure injection of the multipurpose insertion pipe differs depending on the purpose of inserting the multipurpose insertion pipe, but the balance according to the purpose must always be maintained. The conventional method does not have the adjusting means.

[0010]

The present invention addresses the above problems and discharges the water jet itself by injecting a water jet from the injection nozzle provided in the suction slurry discharge path at a high pressure in the slurry discharge direction. It is designed to discharge and convey the inhaled slurry by energy, and at the same time, to maintain the balance between the target ground underground pressure and the amount of slurry discharge by equipping the jet pressure adjusting means of the water jet. It solved this by the method of.

That is, a suction pipe provided with a slurry suction port having a discharge path at the tip is inserted into the target ground, and a water jet is ejected from the injection nozzle provided in the discharge path toward the slurry discharge direction to 100 kilograms per square. A high pressure of 400 to 400 kilograms per square centimeter was used to eject the inhalation slurry by the jet energy.

Further, a pressure sensor is provided at the tip of the suction pipe, and while measuring and grasping the ground pressure of the inserted target ground, the water jet injection pressure in the discharge route is adjusted according to this, and further, The slurry discharge path of the suction pipe is connected to the slurry processing mechanism, and the gas-liquid separation mechanism is set near the slurry discharge port connected from the discharge path to the processing mechanism so that the system from the slurry suction to the slurry processing can be systematized. It is the one.

Regarding the energy enhancement of the water jet, the jet nozzle provided in the discharge path is set to an inclination angle so that the water jet is jetted as a swirl flow, and the jet of the water jet is made in correspondence with the smoothness of the slurry transfer. The cohesive soil melting agent was added to the fluid.

[0014]

[Function] When a water jet is jetted from the jet nozzle provided in the discharge path at a high pressure of 100 kilograms per square centimeter to 400 kilograms per square centimeter toward the slurry ejection direction, a suction effect is generated at the slurry inlet and the water is ejected. A negative pressure is generated in the path, and the slurry around the suction pipe is sucked by the ground pressure of the target ground or the negative pressure of the discharge path, and the suction slurry is conveyed to the discharge port by the conveying force of the water jet in the discharge path.

The slurry conveyed to the discharge port is separated from the mixed gas by the gas-liquid separation mechanism set therein, and further sent to the processing mechanism to filter the water content, and the solid content is formed into a sludge cake. To be done.

If the jet nozzle provided in the discharge path is set to an inclination angle as necessary and the water jet is jetted as a swirling flow, the slurry conveying force is further enhanced.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 is a slurry suction pipe that also serves as a multipurpose insertion pipe, and a multipurpose high-pressure injection nozzle A is set on the side wall of the tip end, and a slurry suction port 2 is opened at a predetermined interval from this. A preventive net 21 for preventing foreign matter from entering the suction port 2 as needed.
Is set.

The multipurpose insertion pipe is a ground hardening material injection rod, a high-pressure injection drilling pipe, etc., which is equipped with a high-pressure injection nozzle and is inserted into the target ground to inject the ground hardening material and fresh water from the injection nozzle at an ultrahigh pressure to remove the surrounding soil. With the function of excavating and stirring,
It is supported by the operating mechanism B according to the purpose, and moves forward, backward,
It is given operations such as rotation. Of course, a slurry suction pipe independent of the multipurpose insertion pipe may be used.

The slurry suction port 2 has a discharge path 3 in which the injection nozzle 4 is directed in the slurry discharge direction.
Is provided, and the water jet is directed in the slurry discharge direction.
It injects at a high pressure of 100 kilograms per square centimeter to 400 kilograms per square centimeter to suck the slurry around the suction pipe and discharge the suction slurry by the transport force of the water jet in the discharge path.

The nozzle diameter of the injection nozzle 4 is about 2.0 mm to 3.2 mm with respect to the discharge path pipe diameter of 30 mm to 75 mm, and the discharged slurry is 210 liters to 416 liters per minute. If you set it with an inclination angle, the water jet will be injected as swirling turbulence,
Transport power is strengthened.

Jet water supply pipe 5 for supplying jet water
The pressure is controlled by the operation mechanism 51 on the ground, and the water jet injection pressure in the discharge path is adjusted according to the ground pressure of the target ground measured and grasped by the pressure sensor 6 set at the tip of the slurry suction pipe 1. If necessary, a viscous soil melting agent is added to the jet fluid of the water jet depending on the soil properties of the target ground.

The discharge path 3 has a narrowed portion 42 in which the path is rapidly narrowed at a predetermined location and an open portion that gradually expands in the discharge direction.
An ejector unit 41 composed of 43 is provided to restrict the slurry transport flow and enhance the effect of the water jet. In addition, a mixing chamber for the slurry and the water jet is provided in front of the ejector section 41 as needed.

The slurry carried by the water jet through the discharge path 3 to the discharge port is separated from the mixed gas by the gas-liquid separation mechanism 31 set therein, and is further sent to the filter press 32 which is a processing mechanism. Only the filtered water that has been dehydrated and made into a cake and filtered flows through and is discharged from the drainage section.

[0024]

Since the present invention is configured as described above, the slurry by excavation and the slurry by injecting the hardening material can be efficiently discharged through a dedicated discharge route, and the discharge rate of the discharged slurry can be changed according to the purpose of construction. Emissions are adjusted and managed, and a systematic process is realized until the processing of the slurry, which has the effect of increasing efficiency in terms of both work and cost.

[0025]

[Brief description of drawings]

FIG. 1 is an overall explanatory view showing a construction situation in which an injection work using a multipurpose insertion tube is taken as an example in an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional explanatory view of the tip portion showing the basic mechanism of the slurry suction pipe.

[Fig. 3] Enlarged vertical cross-sectional side view showing the structure of the ejector part set in the discharge route. 1 Slurry suction pipe also serving as a multipurpose insertion pipe 2 Slurry suction port 21 Foreign matter intrusion prevention net 3 Discharge route 31 Gas-liquid separation Mechanism 32 Filter press 4 Injection nozzle 41 Slurry discharge path Ejector section 42 Discharge path narrowed section 43 Discharge path open section 5 Jet water supply pipe 51 Jet water pressure operating mechanism 6 Ground pressure sensor A Multi-purpose high-pressure injection nozzle B Multi-purpose insertion pipe operation Mechanism C Ground hardening material injection layer

Claims (7)

[Claims] 1. A suction pipe provided with a slurry suction port having a discharge path at its tip is inserted into the target ground, and a water jet is injected at high pressure in the slurry discharge direction from an injection nozzle provided in the suction slurry discharge path. The method for sucking the slurry around the suction pipe and discharging the suction slurry by the conveying force of the water jet in the discharge path 2. A pressure sensor is provided at the tip of the suction pipe,
The underground slurry discharge method according to claim 1, wherein the underground pressure of the target ground is measured and grasped, and the water jet injection pressure in the discharge route is adjusted accordingly. 3. The underground slurry discharging method according to claim 1, wherein the jet nozzle provided in the slurry discharging path is set to an inclination angle and the water jet is jetted as a swirling flow. 4. The underground slurry discharging method according to claim 1, wherein the viscous soil melting agent is added to the jet fluid of the water jet. 5. A suction pipe having a slurry suction port provided at a tip end thereof and having a discharge passage having a discharge nozzle provided with a spray nozzle whose discharge hole is directed in the slurry discharge direction, and an operating mechanism for adjusting the spray pressure of the spray nozzle. Underground slurry discharge device consisting of 6. The ejector part, which comprises a narrowed part that rapidly narrows the path and an open part that gradually expands in the discharge direction, is provided in the slurry discharge path of the suction pipe. Underground slurry discharge device 7. The gas-liquid separation mechanism is set so that the slurry discharge path of the suction pipe is connected to the slurry processing mechanism, and the slurry discharge mechanism connected to the processing mechanism from the discharge path is set near the slurry discharge mechanism. Item 6) Underground slurry discharge device