JP2929553B2 - Control method of shield device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a technique that is effective when applied to automatic control of a shield device used for tunnel excavation.

[Conventional technology]

In the shield method, a steel cylinder called a shield having a cross section slightly larger than the tunnel outer diameter is pushed into the ground, and a cutter (cutting blade) is used at this tip.
Excavation is performed while rotating the, and a support member having an arc-shaped cross section called a segment is assembled in a ring shape at the rear end, and the tunnel is dug while suppressing collapse of the excavated surface.

The forward movement of the shield device is realized by pushing down the distal end face of the segment assembled in a ring shape with a hydraulic jack called a shield jack, and advancing the cutter face by utilizing this reaction force.

[Problems to be solved by the invention]

By the way, in the prior art, there is also known a system in which measurement data such as the speed and stroke of a shield jack during excavation work, a screw rotation speed and a rotation load are centrally managed by a main controller such as a microcomputer. The measured data is simply displayed on a display such as a CRT or the like, and the control in the next excavation process is determined exclusively depending on the feeling and skill of the worker.

However, this results in variations in the tunnel excavation route depending on the operator, and the accuracy also greatly differs depending on the skill of the operator. If there are many mistakes made by the workers, many meanders occur in the tunnel after the excavation, and the quality of the construction is reduced.

Further, in controlling each part of the shield device that excavates underground, it is necessary to comprehensively control each device such as a cutting blade, a screw, and a shield jack. For example, excessively amplifying only the output of some devices may break the mechanical balance inside the tunnel formed by excavating the shield, and may cause a disaster such as a road surface collapse accident.

The present invention has been made in view of the above problems, and has as its object to realize a highly reliable and highly safe shield construction without requiring any skill.

[Means for solving the problem]

The present invention provides a method for rotating a cutter head provided at the tip to excavate underground, assembling a segment at a rear end into a ring shape, and reacting the extension force of a jack abutted on the end face of the segment by the reaction force against the stretching force of the jack. In the shield device for moving the head forward, the gist is to calculate the management value by multivariate analysis of the measurement data in any section where the excavation has already been completed, and to control the shield device in the next excavation process based on this management value. I do.

[Action]

In the multivariate analysis, the multivariate analysis is performed based on measurement data such as earth pressure, speed and stroke of a shield jack, rotation speed and rotation load of a screw, and rotation speed of a cutting blade.

Next, each management value is calculated by sequentially substituting random numbers into the management items of the calculation formula obtained above so as to minimize the constant term.

Then, operation control of the shield jack, the cutting blade, and the like is executed based on this management value.

As described above, after performing a large number of variable analyzes based on the measurement data, the control of each unit is calculated by substituting random numbers, so that a high-precision management value can be obtained, and the operation reliability of each unit such as the shield jack can be improved. Can be enhanced.

As a result, high-precision tunnel excavation can be realized without depending on the feeling of a skilled person.

〔Example〕

FIG. 1 is a cross-sectional view showing the overall structure of a shield device according to one embodiment of the present invention, FIG. 2 is a flowchart showing a control procedure of this embodiment, and FIG. 3 is a graph showing a data extraction method of the embodiment. FIG.

The shield device 1 of the present embodiment is used for a so-called muddy water shield method, and includes a cutter head 3 provided with a cutting blade 2 at a front end, a girder portion 4 and a tail portion 5 at a rear end.

The cutting blade 2 is given a rotating force by a hydraulic motor 6 for driving installed in the cutter head 3 and excavates a ground wall in contact with a front surface thereof. The excavated earth and sand is configured to be guided into the cutter head 3 by the cutting blade 2. The inside of the cutter head 3 is separated from the other parts by a partition as a tank chamber 7, and the tank chamber 7 is provided with a nozzle 8 into which muddy water 9 is introduced from the ground. The tank has a function of dissolving the excavated earth and sand in the muddy water 9 in the tank chamber 7. The tank chamber 7 is provided with a rotary screw 10 for stirring mud 9 in the chamber, and has a structure to promote the dissolution of earth and sand in the tank chamber 7.

Then, high-concentration muddy water obtained by dissolving earth and sand in the tank chamber 7
Reference numeral 19 denotes a structure in which water is drained through a drain pipe 12 extending to the ground via a drain port 11. In other words, the excavated soil becomes highly concentrated muddy water 19 and is efficiently discharged to the ground.

In the girder part 4, a plurality (for example, eight in this embodiment) of hydraulic shield jacks 15 are arranged in a direction parallel to the axial direction along the inner peripheral surface thereof (only one in the figure). Illustrated). Each of these shield jacks 15 has a structure that can be independently expanded and contracted by injection of hydraulic pressure. The tip of the shield jack 15 is connected to the cutter head 3, and the rear end is a segment described later.
It faces 16 axial end faces.

In the girder unit 4, a position detection device 13 including a gyro compass and a level meter, and a microcomputer as a main control device 14 including an internal storage device such as a memory and an external storage device such as a magnetic recording device are provided. Is installed. It is desirable that these electronic / electric devices are installed at a predetermined height from the bottom surface of the girder unit 4 so as not to be contaminated by the muddy water 9 (19).

As described above, shield jack 15, screw 10
The cutting blade 2 is provided with a speed sensor, a stroke sensor, a torque sensor, and the like (not shown). Measurement data such as earth pressure, shield jack speed and troke, screw rotation speed and load, and rotation speed of the cutting blade are provided. The information is input to the main control device 14 at any time.

An erector 18 is provided in the tail portion 5 for constructing a segment 16 for supporting an excavated cross section by combining piece members 17 each having an arc-shaped cross section. The erector 18 has a structure that can rotate 360 ° about the axis, and is configured to sequentially connect the ring-shaped segments 16 along the inner cross section of the excavation.

The shield device 1 is configured such that the rear end of the shield jack 15 is brought into contact with the axial end face of the already constructed segment 16 and the shield jack 15 is extended, so that the cutter head 3 is advanced by the reaction force. It has become.
Therefore, the excavation direction and angle can be changed by selectively operating the shield jack 15.

In this embodiment, the control of the excavation direction is performed as follows.

First, an arbitrary section x is set by the main control unit in a state where a certain excavation work is completed (201). This section x
In this case, it is desirable that the section be excavated smoothly without meandering or accident of the shield. As shown in FIG. 3, the measurement data at this time is calculated by the standard deviation excluding the section of 10 cm at the start and 10 cm at the end of each excavation ring where the earth pressure data is generally unstable (202).

Next, a multivariate analysis is performed (203). Here, an arithmetic expression used for the multiple regression model in the following regression analysis is prepared.

Y = aX1 + bX2 + cX3 + dX4 +... A In the above equation, Y is the earth pressure (face pressure) applied to the cutting blade, that is, the objective variable used in the regression analysis, and X1, X2, X3, X4, It shows measurement data excluding earth pressure, that is, explanatory variables used for regression analysis. Specifically, these explanatory variables are management items for controlling each device of the shield device. For example, it is possible to exemplify a screw rotation speed, a jack speed, and a gate opening amount for determining an amount of excavated earth and sand. The number of management items to be set is not particularly limited.
.., A, b, c,... Are regression coefficients in the regression analysis. Further, A is a constant term representing an error, and its expected value is 0. In this embodiment, based on good excavation data obtained earlier in section x,
.. And specific variables are substituted for the objective variables Y, and coefficients such as a, b, and c are determined by regression analysis. Store in an external storage device.

Next, in the above equation, the coefficients a, b, c,.
Are substituted, and the determination of the multivariate analysis is performed based on the contribution ratio (204).

Next, using the above formula as it is, the X1, X2, X3, X4,.
Is used as a management item, and random numbers are sequentially substituted into this management item (205).

This random number is obtained by a random number generation routine prepared by the main control device 14 in advance. At this time, since the earth pressure Y (objective variable) is a fixed value, the value of the constant term A differs depending on the random number to be substituted.

The above-mentioned substitution of random numbers is repeated, for example, several thousand times, and for each management item, each management value for which the constant term A is the minimum value is calculated (206).

Then, data analysis is further performed to set a 95% confidence interval width for each management item. Then, a control signal is output using the confidence interval as a control width (207). The hydraulic motor 6, the screw 10, the shield jack 15 and the like are controlled by the control signal, and the next excavation step is executed. Each part of the shield device is controlled in a well-balanced manner by each management item calculated by the multivariate analysis and provided with a certain confidence interval.

The control described above is performed, for example, every several tens of cm,
It is repeated every time a ring is formed. Although the control timing varies depending on the precision required for the construction, it goes without saying that the shorter the interval between the control timings, the higher the accuracy of the control.

〔The invention's effect〕

According to the present invention, each part of the shield device is controlled by automatic control without depending on the intuition of a skilled person, so that tunnel excavation with high precision can be realized, and each part of the shield device is controlled in a well-balanced manner. Safe tunnel excavation without accidents such as sinking can be realized.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a sectional view showing the entire structure of a shield device, FIG. 2 is a flowchart showing a control procedure, and FIG. 3 is a data extraction method. FIG. DESCRIPTION OF SYMBOLS 1 ... Shield apparatus, 2 ... Cutting blade, 3 ... Cutter head,
4 ... Girder part, 5 ... Tail part, 6 ... Hydraulic motor, 7 ...
Tank chamber, 8 nozzle, 10 screw, 11 drain
12… Drain pipe, 13… Position detection equipment, 14… Main controller, 15…
Shield jack, 16… segment, 17… piece member,
18 ... Electr, 19 ... Muddy.

Claims (1)

(57) [Claims] 1. A cutter head mounted on a tip is rotated to excavate underground, and a segment is assembled in a ring shape at a rear end, and a reaction force against an extension force of a jack abutted on the end face of the segment is used. A control method of a shield device for advancing a cutter head, wherein a management value is calculated by multivariate analysis of measurement data in an arbitrary section that has already been excavated, and a random number is assigned to a management item determined by the multivariate analysis. A control method for a shield device, characterized by sequentially determining a management value such that a constant term has a minimum value.