JP2888481B2 - Ground hardening material lateral injection method and its equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended for stabilization of soft ground, foundation of structures, and supporting lining for excavation of horizontal shafts. The present invention relates to a method of laterally injecting a ground hardening material for forming a hardened pile layer extending laterally, a slime suction adjusting mechanism of an injection rod used for the method, and a variable ground pressure measuring sensor.

[0002]

In order to inject the ground hardening material laterally, an injection rod is inserted from the side surface of the ground to a predetermined depth in the horizontal direction, and the ground hardening material is injected from an injection nozzle provided on the side wall of the rod. While rotating the rod back and forth while cutting the surrounding soil with the hardening material jet and creating a hardened pile layer along the stirring injection trajectory, but there are many such as air injected with the hardening material jet Gas is enclosed around the formation layer.

[0003] In the case of vertical injection, these gases are discharged upward as an air lift from the gap of the rod insertion hole. However, in the case of side injection, the rod insertion direction is lateral, and a part of the gas is discharged from the gap between the soil particles. However, most of them are stored in the upper part of the formation layer, causing deformation of the formation hardening material layer and leakage of the injection density.

[0004] Further, when the ground pressure is increased by high-pressure injection of the hardening material, slime is pressed by the subsequent injection pressure, and a large amount of excess slime increasing the repulsive force near the nozzle is generated, so that injection becomes impossible. Ground pressure is detected by a pressure sensor, and excess slime is sucked and discharged through a slime suction hole to adjust slime.

[0005] However, when the injection pressure of the hardening material increases from the high-pressure injection to the ultra-high-pressure injection, the temperature in the injection ground may reach 50 degrees Celsius in the rod. It is a problem.

Furthermore, slime inhalation through the suction hole has depended on the fact that the slime that has lost its escape due to an increase in the ground pressure is naturally sucked into the suction hole. In order to maintain the pressure and the balance at a predetermined pressure, it has been a challenge to accurately grasp the ground pressure and to actively adjust the slime suction based on the pressure.

[0007]

According to the present invention, in order to discharge and remove the lift air stored in the upper part of the formation layer by lateral injection, a ring belt is provided at the tip of the injection rod, the rotation of the rod being cut off. The lift air is stored in the upper part of the hardened material layer formed in front of the rod that revolves while injecting the hardened material at high pressure by pivoting the intake rod up and down freely on the ring belt, The suction rod is set at a position following the receding hardening material injection nozzle, moves upward, and the suction rod that opens the suction port in the air storage space sucks and removes the stored air.

Further, in order to avoid a detection error of the pressure sensor due to an in-ground temperature rising due to high-pressure injection of the hardening material and obstacles in the slime, a low expansion coefficient liquid is filled between the sensor body and the exposed portion of the outer wall of the rod. Then, a pressure sensor was set by covering the sensing exposed portion with a cap made of an elastic material.

Further, the signal of the pressure sensor is transmitted to the outside operation unit by the transmitter, and the slime suction adjustment is operated by this signal, and the positive control of the slime suction is performed based on the accurate information of the ground pressure. It is something that can be done.

As means for this adjustment, an injection nozzle for injecting an air-fuel mixture jet in the discharge direction is provided in the suction path of the slime suction hole, and a throat packer for reducing the diameter of the discharge path in the injection direction is provided. It is intended to provide a mechanism for directly operating the jet injection and the path diameter reduction from the outside.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes an injection rod, which is provided at its tip with a ring belt 2 that blocks rotation of the rod. The ring belt 2 is shut off from the turning operation of the rod by a swivel structure, and the intake rod 21 implanted there is always configured to maintain the upper surface position in the propulsion direction of the rod.

The intake rod 21 has a double structure of a floatable outer shell and a flexible intake tube. The outer shell is pivotally connected to a ring belt by a hinge 22 so as to be movable up and down. To perform the undulating operation.

[0013] The intake tube is supported by the outer shell,
The base communicates with the intake path in the rod 1 through a through hole of a ring belt formed in the hinge.

The injection rod 1 has an injection nozzle 3 at a base side spaced from the ring belt 2 by a predetermined distance, a slime suction hole 4 at a back end thereof, and a pressure sensor 5 at a front end thereof.
Are set and communicate with the respective intra-rod paths.

First, a ground hardening material injection rod 1 is propelledly inserted into a side surface target ground, such as a horizontal shaft face, by a driving device that moves forward and backward, and a ring other than the ring belt 2 that is cut off from the turning operation at a predetermined depth. Is rotated, and the curing material is retracted while ejecting the curing agent from the ejection nozzle 3 at a high pressure.

The injection nozzle 3 is a superposition nozzle of the core nozzle and the surrounding nozzle. The ground hardening material is injected from the core nozzle and air is injected from the surrounding nozzle. The hardened material jet is large and the surrounding ground is cut and stirred to form the hardened material injection pile layer A having a large diameter.

As the rod 1 retreats, the hardening material jet cuts and agitates the surrounding soil, and the hardening material injection layer A is formed along the trajectory. Gas is enclosed around the formation layer,
The air pool B is formed above the hardened material injection layer by lifting.

When the air reservoir B is formed, the intake rod 21 set at a position following the injection nozzle 3 moves upward due to the buoyancy of the uncured hardened material to open an intake port in the air reservoir space and store the air. Inhale the air.

On the other hand, when the ground pressure rises together with the generation of slime due to the high-pressure injection of the hardening material from the injection nozzle 3, the pressure sensor 5 of the variable ground pressure measurement sensor set on the injection rod 1 senses this, and The fluctuation is converted into a signal and transmitted to the outside operation unit by the transmitter 54 of the coaxial cable.

Pressure sensor 5 set on injection rod 1
The sensing part 51 is covered by a cap 52 made of an elastic material, and in some situations, the surface of the cap is curved spherically. It is designed to avoid blockage.

A low-expansion liquid filling unit 53 is provided between the sensing unit 51 and the pressure sensor main body 5, and is filled with a liquid having a low expansion coefficient such as a mixed oil. The sensor is configured to accurately detect the ground pressure even if the ground temperature rises.

When the fluctuation signal of the ground pressure is received by the operation section outside the hole, and the occurrence of excessive slime is confirmed, water from the injection nozzle 41 set in the suction path of the slime suction hole 4 is operated by operation from outside the hole. A jet of air / air mixture is injected in the discharge direction to promote slime inhalation and absorb ground pressure.

Further, a throat packer 42 is provided in the suction path of the slime suction hole 4 to reduce the diameter of the discharge path in the injection direction and to reduce the diameter thereof. The inflation pressure is injected into the throat packer 42 by an operation from outside the hole, the discharge path is narrowed, and slime suction is suppressed to maintain an appropriate ground pressure.

According to the present invention, as described above, the stored air above the hardened material injection layer is reliably discharged, and the jet injection for promoting the slime suction in response to the fluctuation of the ground pressure detected by the pressure sensor 5 and the path for suppressing the slime suction are described. The diameter reduction of the ground is controlled from outside to effectively maintain the balance between the particle density of the ground and the injection amount of hardening material, enabling the formation of a hardened pile layer with a high density and a reliable injection area. It was made.

[0025]

[Brief description of the drawings]

FIG. 1 is a perspective side sectional view showing a main part of a structure of a hardening material injection rod.

FIG. 2 is a side view of a main part of a tip of a hardening material injection rod having a see-through cross-section of a target ground, showing a situation of forming an injection layer by removing a stored air by an intake rod and injecting a hardening material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection rod 2 Ring belt 21 Intake rod 22 Hinge 3 Hardening material injection nozzle 4 Slime suction hole 41 Air-mixed jet injection nozzle 42 Throat packer 5 Pressure sensor body 51 Sensor sensing unit 52 Elastic cap 53 Low expansion coefficient liquid filling unit 54 Transmitter 6 Slime inlet cleaning water outlet A Hardener injection layer B Air reservoir

Claims (4)

(57) [Claims] A ring belt is provided at the rod end where the rotation operation of the rod is blocked. An intake rod is pivotally mounted on the ring belt so as to be vertically movable, and an injection nozzle is provided on a side wall on the base side of the rod next to the ring belt. The ground hardening material injection rod that has been opened is propulsively inserted into the target ground in the side direction, and at the predetermined depth, the hardening material is sprayed at a high pressure and turned back and forth,
A method for laterally injecting hardened ground material, wherein lift air stored above a hardened material injection layer formed by the rotation trajectory of the hardened material jet is suctioned and removed with an intake rod. 2. A slime suction hole provided with a suction adjusting mechanism is opened at a predetermined interval from the injection nozzle, and a signal of a pressure sensor provided at the tip of the rod is transmitted to an operation unit outside the hole by a transmitter. The method for laterally injecting a ground hardening material according to claim 1, wherein the slime suction is controlled by the method. 3. A variable ground pressure sensor in which a low expansion coefficient liquid is sealed between a sensor body built in a rod and a sensing exposed portion of an outer wall of the rod, and the sensing exposed portion is covered with a cap made of an elastic material. 4. A throat for providing an injection nozzle for injecting an air-fuel mixture jet in a discharge direction in a suction path of a slime suction hole opened in a rod side wall, and for narrowing and reducing the discharge path in the injection direction to a throat shape. Set up a packer,
Adjusting slime by sucking and discharging surplus slime by externally controlling the mixture jet injection and path diameter reduction
Configured slime inhalation adjustment mechanism as