JPH0213119B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a slurry shield excavation method for maintaining earth pressure within a face within a desired range.

(Prior art) In this type of mud type shield excavation method, it is desirable that the face be stabilized in a manner that is compatible with the properties of the excavated soil, and that the excavated soil be stably discharged. It is necessary to always maintain the earth pressure within the face within a desired range that can counter the earth pressure from the ground and groundwater pressure.

Conventional methods for stabilizing the face include:
For example, the same amount of excavated soil as taken into the face is discharged outside the face, or the earth pressure from the ground and groundwater pressure are measured with an earth pressure meter and the slurry material is adjusted accordingly. There are things to inject.

(Problem to be Solved by the Invention) However, in the former case of the conventional method described above, the plastic flow state and its distribution within the face differ depending on the properties of the excavated soil, so it is difficult to keep the volume of discharged soil constant. In addition to being difficult to do so, the earth pressure within the face also fluctuates, leading to unstable excavation in which the shield machine excavates intermittently. Furthermore, in the latter case of the conventional construction method described above, the earth pressure differs depending on the measurement location, so it has the disadvantage that it is difficult to accurately maintain the earth pressure balance.

Therefore, the present invention aims to provide a slurry shield excavation method to improve these problems.

(Means for Solving the Problems) The present invention focuses on the fact that when the plastic flow state and its distribution within the face become constant, the rotational torque of the cutter and the earth pressure can be maintained constant. The gist of this is to detect the rotational torque of the cutter, which varies depending on the properties within the face, and to compare the detected value with a preset reference value. The plastic flow state within the face is adjusted to increase the amount of slurry injection material injected, and to decrease the amount of slurry injection material when the detected value is smaller than the standard value, thereby reducing the amount of rock that moves within the face. This is a mud-type shield excavation method that maintains the earth pressure within the desired range to counter the earth pressure and groundwater pressure from the ground.

(Example) The present invention will be explained below based on the illustrated example. First, to explain the device used to carry out the present invention, a shielding machine 1 is provided with a cutter 2, a drive device 3 for the cutter, a cutter torque detection device 5, and a propulsion jack 4 for the shielding machine 1 on the front.
A screw conveyor 6 for transporting excavated earth and sand from the center of the shield machine 1 is connected to a transport conveyor 7, and the rear end thereof reaches an input path to a crusher 8.

Next, the excavated soil crushed within a certain particle size in this crusher 8 is introduced into a pressure pump chamber 9 by an arbitrary conveyance device, and a conveyance pipe 10 is guided outside from the pressure pump chamber 9. , a flow meter 11 and a pipe pressure detector 10a are placed at appropriate locations in the middle.
10b is provided.

The end of the conveying pipe 10 is communicated with a vibrating sieve 13 attached to the upper part of a mud storage tank 12 installed outside the tunnel,
The vibrating sieve machine 13 separates excavated soil to be used as residual soil and excavated soil to be reused as injection material,
The injection material is put into the slurry material in the mud storage tank 12, and is passed from the mud storage tank 12 through the pressure pump 16 to the injection pipe 1.
Extend 7 into the hole.

The injection pipe 17 branches into two directions from the middle, and one side communicates with the pressure pump chamber 9 via an injection material pump 18, an injection pump 19, and a flow rate detector 20. The other side of the injection pipe 17 also passes from the injection material pump 21 to the injection pump 22 to the flow rate detector 23, and its extended tip has a jet hole near the cutter 2, which is the tip of the face of the shield machine 1. There is.

In addition to installing a detector 24 for the injection pressure inside the pipe at an appropriate location near the tip of the injection pipe 17, it is also used to drive the shielding machine 1, detect the flow rate and pressure of the conveying pipe 10, and drive the injection pump 22 of the press-in pipe 17. , flow rate, injection pressure, etc., can be controlled remotely while being monitored by indicators 26 installed on an electrically connected operation panel 25. Reference numeral 14 in the drawing is a mixer for slurry material, 1
5 is a hoppa of leftover soil.

Next, the operation of the above-mentioned device will be explained. By extending the propulsion jack 4 to propel the shield machine 1 and rotating the cutter 2 with the drive device 3, the ground in front of the face is excavated and the excavated earth and sand is taken into the face partitioned by the bulkhead. be included. The excavated soil is mixed with a necessary amount of slurry injection material, and is made into a desired plastic flow state and discharged to the outside of the face by the screw conveyor 6. This excavated earth and sand is transferred to conveyor 7.
After being conveyed to the pressure pump room 9 via the crusher 8 and further mixed with the added slurry injection material to obtain a desired fluid state suitable for pipe transportation, it is passed through the conveyor pipe 10 to a vibrating sieve on the ground. 13.

A part of the soil sieved by the vibrating sieve machine 13 is
Sludge mixer 14 for reuse as injection material
The slurry is mixed with the slurry material and stored in the mud storage tank 12 as a slurry injection material, and the remaining soil is processed as residual soil via the residual soil hopper 15.

This slurry injection material is supplied to the pressure pump 16 and the injection pipe 1.
7 to each injection pump 18, 21 equipped with a pump rotation speed detector and stored therein, and the necessary amount of slurry injection material is delivered to the above-mentioned face and pressure pump chamber 9 via each injection material pump 19, 22. are injected into each.

The slurry injection material injected into the face is stirred into a mixed state with the excavated soil by the rotation of the cutter 2, and is brought into a uniform desired plastic fluid state in a short time,
The inside of the face is brought to a desired range of earth pressure capable of countering earth pressure from the ground and groundwater pressure.

Next, in the above device, when the propulsion jack 4 that presses the bulkhead of the face receives a reaction force from the bulkhead, the operating panel 25 monitors the change in the hydraulic pressure of the propulsion jack 4.
By measuring the elongation speed, the propulsion speed of the shield machine 4 can be determined.

Further, the cutter torque detection device 5 detects the rotational torque of the drive device 3 that rotationally drives the cutter 2 on the operation panel 2.
By measuring at step 5, the rotational torque of the cutter 2 which varies depending on the properties of the face can be detected, and the mixed earth pressure of the excavated earth and sand and the slurry injection material within the face can be determined.

Further, the pressure detector 24 measures the injection pressure of the slurry injection material supplied to the face, the flow rate detectors 20 and 23 measure the flow rate of the slurry injection material supplied to the pressure pump chamber 9 and the face, and the flow meter 11 measures the injection pressure of the slurry injection material supplied to the pressure pump chamber 9 and the face. From room 9 to transfer room 1
The amount of discharged earth and sand pumped out at zero is detected, and can be measured using the operation panel 25.

Each data detected in this way is displayed on the indicator 26 on the operation panel 25, and the data of the detected cutter rotation torque is displayed on the operation panel 25.
The cutter rotation torque is compared with a reference value set in advance in No. 5, and at least the rotational speed of the injection pump 22 is increased or decreased to reach the reference value, and the amount of slurry injection material injected into the face is adjusted.

For example, when the rotational torque of the cutter 2 becomes larger than the standard value in coarse-grained soil such as gravel, the rotational speed of the injection pump 22 is increased to automatically adjust the injection amount of slurry injection material to be mixed with the excavated soil. In addition, in soft ground with a large content of fine particles, the number of revolutions of the injection pump 22 is decreased to automatically reduce the injection amount of the slurry injection material.

In this way, the amount of slurry injection material injected into the face is automatically adjusted to an appropriate amount in response to an increase or decrease in the rotational torque of the cutter 2, and the plastic flow state within the face, which varies depending on the properties of the excavated soil, is adjusted to inject the slurry into the ground. Since the earth pressure is maintained within a desired range that can withstand earth pressure from It can be done.

By constantly monitoring the flow rates in the pressure feed pipe 10 and the injection pipe 17, changes and abnormalities in the amount of excavated soil and excavation conditions can be accurately grasped, and in cooperation with the adjustment of the slurry injection material, accurate construction management can be achieved. It can be performed.

(Effects of the Invention) As described above, in the slurry shield excavation method of the present invention, the properties of the face are determined from the rotational torque of the cutter, and the amount of slurry injection material injected is increased or decreased depending on the properties of the face. By adjusting the plastic flow state, the earth pressure within the face can always be maintained within a desired range that can counter earth pressure from the ground and groundwater pressure.

Therefore, the face can be stabilized more easily and reliably than in the conventional construction method described above, so that good excavation and pipe transportation of earth and sand can be performed.

[Brief explanation of drawings]

The drawing is an overall side view showing an embodiment of an apparatus for carrying out the construction method of the present invention. [Explanation of symbols], 1... Shield machine, 2... Katsuta, 3... Drive device, 4... Propulsion jack, 5
... Cutting torque detection device, 6 ... Screw conveyor, 7 ... Conveyor conveyor, 8 ... Crushing machine, 9
...Pressure pump room, 10 ... Conveying pipe, 11 ... Flow meter, 12 ... Sludge storage tank, 13 ... Vibrating sieve machine, 14
...Sludge mixer, 15...Residue hopper, 16...
...Pressure pump, 17... Injection tube, 18... Infusion material pump, 19... Infusion pump, 20... Flow rate detector, 21... Injection material pump, 22... Infusion pump, 23...... Flow rate detector, 24...pressure detector,
25...Operation panel, 26...Indicator.

Claims (1)

[Claims] 1 The slurry injection material is injected into the face blocked by the bulkhead of the shield machine, and stirred and mixed with the earth and sand excavated by a cutter, and the earth pressure counteracts the collapse of the ground, and the fluidized excavated earth is brought to the ground. In the pipe-transported slurry shield excavation method, the rotational torque of the cutter, which varies depending on the properties of the face, is detected, and the detected value is compared with a preset reference value,
If the detected value is larger than the reference value, the injection amount of the slurry injection material is increased, and if the detected value is smaller than the reference value, the injection amount of the slurry injection material is decreased to reduce the plastic flow in the face. A slurry shield excavation method characterized by adjusting the condition and maintaining the earth pressure within a desired range within the face.