JP2023013173A - Chamber internal pressure control system for mud pressure shield machine and chamber internal pressure control method - Google Patents

Abstract

To provide a chamber internal pressure control system for a mud pressure shield machine and a chamber internal pressure control method capable of highly accurately controlling the pressure of mud in the entire chamber of the mud pressure shield machine.SOLUTION: A chamber internal pressure control system 50 in a mud pressure shield machine has a plurality of pressure sensors 20 attached to a bulkhead 13 from a top to a bottom in the height direction, and an evaluation device 30 for evaluating suitability of internal pressure of a chamber 14. The evaluation device 30 has an acquisition unit 302 that acquires measurement data from each of the pressure sensors 20, a calculation unit 304 that obtains a regression line relating to the pressure gradient over the height direction using the measurement data over the height direction, a storage unit 310 for storing a theoretical face pressure line for the face pressure gradient across the height of a cutter head 12, and an evaluation unit 306 that evaluates the suitability of the internal pressure of the chamber 14 using the regression line and the theoretical face pressure line.SELECTED DRAWING: Figure 1

Description

The present invention relates to a chamber internal pressure control system and a chamber internal pressure control method for a mud pressure shield machine.

Slurry shields (slurry pressurized shields) have been more advantageous than mud pressure shields in the construction of large cross-section shield tunnels with an outer diameter of 10 m or more, for example, from the viewpoint of stable maintenance of the face and efficiency of soil removal. and has been generally applied.
Regarding the stable maintenance of the face, in the case of a slurry shield, the mud water adjusted at the plant on the ground is sent to the chamber on the back of the cutter head through the mud pipe, and the mud water pressure from the face (face soil It is easy to stably hold the face because it is opposed to the pressure). On the other hand, in the case of the mud pressure shield, the excavated soil excavated by the cutter head is taken into the chamber, and the excavated soil and additives are agitated and plastically fluidized to generate highly impermeable mud. However, the earth pressure due to this mud is made to counter the face earth pressure. Therefore, if the mud is not uniformly and sufficiently plastically fluidized in the entire area of the chamber, the entire surface of the cutter head cannot counteract the face earth pressure with mud pressure, resulting in ground subsidence and other effects on the surrounding environment. may become a matter of concern.
In a conventional shield machine, multiple pressure sensors (soil pressure gauges) are attached to the bulkhead that forms the chamber, and the measured values of the pressure sensors at the center and near the center of the shield machine are mainly monitored to detect the pressure of the mud. are managing. However, in such mud pressure management based only on the measured values of one or more pressure sensors, it is not possible to specify the mud pressure throughout the chamber, and the mud is kept as uniform and sufficient as possible throughout the chamber. It is extremely difficult to identify whether or not plastic fluidization occurs.
When applying a mud pressure shield in the construction of the above-mentioned large-section shield tunnel, it becomes more difficult to uniformly and sufficiently plastically flow the mud in the entire chamber behind the large-section cutter head. This is one of the reasons why the earth pressure shield construction method is difficult to apply in the construction of large-section shield tunnels.
On the other hand, the slurry shield construction method requires the installation of sludge pipes and sludge discharge pipes, and requires soil and water separation equipment in the vertical shaft and on the ground. The construction cost tends to be higher than that of the pressure shield construction method, and this problem can become even more pronounced in the construction of large-section shield tunnels.

From the above, there is a demand for a mud pressure shield construction method that is excellent in the stability of the face and can be applied to the construction of large-section shield tunnels. In other words, in order to realize such an earth pressure shield construction method, a system or method capable of highly accurately controlling the pressure of mud in the entire chamber of the earth pressure shield tunneling machine (in-chamber pressure control) is required.

Here, Patent Literature 1 proposes a shield construction method in which excavated earth and sand are used to excavate while resisting ground pressure (face pressure). Specifically, in the chamber of the shield machine, the soil excavated by the cutter of the shield machine is mixed with an additive material to liquefy. is detected by a plurality of pressure sensors to obtain the pressure gradient, and the addition rate of the additive is adjusted according to the difference between this pressure gradient and the estimated ground pressure gradient. This is a shield construction method that adjusts the discharge amount of liquid earth and sand according to the difference with the mountain pressure, and discharges the liquid earth and sand with a sealed pump that has a liquid blocking function.

JP-A-3-5592

According to the shield construction method described in Patent Document 1, the pressure in the chamber is detected by a plurality of pressure sensors to obtain the pressure gradient, and the additive material is added according to the difference between this pressure gradient and the estimated ground pressure gradient. Although it states that the addition rate is adjusted, there is no description of a system or method that enables highly accurate control of the mud pressure throughout the chamber.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a chamber internal pressure control system and a chamber internal pressure control method for a mud pressure shield machine that can control the pressure of mud throughout the chamber of the earth pressure shield machine with high accuracy. and

In order to achieve the above object, one aspect of the chamber internal pressure control system for a mud pressure shield machine according to the present invention includes:
A mud pressure shield tunneling machine in which excavated soil taken in a chamber between a cutter head and a bulkhead and additives are agitated and plastically fluidized to form mud, and the pressure of the mud counteracts the face pressure. A chamber pressure management system in
a plurality of pressure sensors attached to the bulkhead from above to below in the height direction;
and an evaluation device for evaluating suitability of the chamber internal pressure,
The evaluation device is
an acquisition unit that acquires measurement data from each of the plurality of pressure sensors;
a calculation unit that uses the measurement data in the height direction to determine a regression line related to the pressure gradient in the height direction;
a storage unit for storing a theoretical face pressure line for a face pressure gradient across the height of the cutter head;
and an evaluation unit that evaluates the appropriateness of the chamber internal pressure using the regression line and the theoretical face pressure line.

According to this aspect, the evaluation device acquires measurement data from a plurality of pressure sensors attached in the height direction from the top to the bottom of the bulkhead, and the evaluation device detects mud (impermeable soil) in the height direction Determine the regression line for the pressure gradient of the sludge), and evaluate the adequacy of the chamber pressure using the theoretical face pressure line (slope) and the regression line (slope) for the face pressure gradient over the height direction of the cutter head. Thus, it is possible to confirm and evaluate whether or not the face pressure is properly maintained by the mud pressure.
Here, the evaluation device may be installed inside the earth pressure shield machine, or may be installed in the management building on the ground. Acquisition of measurement data by the acquisition unit includes reception of measurement data by wire or wirelessly.

In addition, "attached to the bulkhead from above to below in the height direction" means, for example, from the upper end or near the upper end of the bulkhead to the lower end or near the lower end at intervals in the height direction. For example, a plurality of pressure sensors may be attached at intervals in the circumferential direction along the contour line of the bulkhead which is circular in front view. A plurality of vertically spaced pressure sensors may be mounted at a central location on the bulkhead, or even a plurality of horizontally mounted pressure sensors may be mounted at each height level.
In addition, "using the regression line and the theoretical face pressure line" means that the regression line and the theoretical face pressure line are directly compared, or a threshold range with a predetermined width is set around the theoretical face pressure line, This involves comparing the threshold range to the regression line (and thus indirectly comparing the regression line to the theoretical face pressure line).
Furthermore, there are various methods for setting the theoretical face pressure line. ), or by multiplying the overburden loads at the upper and lower levels of the cutter head by a predetermined ratio.
For example, when the regression line falls within a threshold range with a predetermined width around the theoretical face pressure line, it can be evaluated that the face pressure is properly maintained.

In another aspect of the chamber internal pressure control system for a mud pressure shield tunneling machine according to the present invention,
The storage unit stores an upper limit line and a lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure straight line,
The evaluation unit determines whether or not the regression line exists between the upper limit line and the lower limit line, and evaluates as the first eligible if it exists between the upper limit line and the lower limit line.

According to this aspect, the evaluation unit determines whether or not a regression line exists between the upper limit line and the lower limit line, which are the upper and lower threshold lines set based on the theoretical face pressure line. In this case, it is possible to confirm and evaluate with high accuracy whether or not the face pressure is properly maintained by the mud pressure.
Here, the method of setting the upper limit line and the lower limit line, which are the upper and lower threshold lines, can be set variously according to the nature of the ground and the degree of importance of the influence on the surrounding environment. and ±30% can be set as the upper limit line and the lower limit line. These upper and lower lines are generally straight lines, but the theoretical face pressure differs depending on the tunnel construction position, and the upper and lower lines set based on the theoretical face pressure also differ. When both the theoretical face pressure and the upper and lower limit lines are shown in the control chart along the axial direction, all of these lines are waveforms.

In another aspect of the chamber internal pressure control system for a mud pressure shield tunneling machine according to the present invention,
The calculation unit obtains the difference between the regression line and the measurement data of each pressure sensor to calculate the standard deviation,
The storage unit further stores a threshold for the standard deviation,
The evaluation unit compares the standard deviation with the threshold value, and evaluates the sample as second qualified when the standard deviation is equal to or less than the threshold value.

According to this aspect, the difference (deviation) between the regression line and the measurement data of each pressure sensor is obtained to calculate the standard deviation regarding the deviation in the height direction, and if the standard deviation is equal to or less than the threshold, the second eligibility is determined. By evaluating, it is possible to appropriately evaluate the linearity of the measurement data polygonal line formed by connecting the values of each pressure sensor in the height direction of the bulkhead, and when the measurement data polygonal line has good linearity, It can be evaluated that the mud is uniformly and sufficiently plastically fluidized throughout the chamber.
That is, when a regression line exists between the upper limit line and the lower limit line, which are the upper and lower thresholds set based on the theoretical face pressure line, by evaluating it as the first eligibility, the mud pressure shield tunneling machine during excavation It can be confirmed and evaluated that the face pressure is properly maintained by the mud pressure, and the standard deviation regarding the difference between the measurement data broken line and the regression line in the height direction is less than the threshold. By doing so, it is possible to confirm and evaluate that the mud is uniformly and sufficiently plastically fluidized throughout the chamber.
By executing the two-stage (two types) evaluation in this way, it is possible to highly accurately control the pressure of mud in the entire chamber of the mud pressure shield machine.

Here, the method of setting the threshold for the standard deviation can also be set in various ways according to the nature of the natural ground, the degree of importance of the influence on the surrounding environment, and the like.
Moreover, the smaller the standard deviation value, the higher the linearity of the measurement data polygonal line, and the closer it is to the regression line. In addition, if the difference (deviation) at all height levels is large, the standard deviation will naturally be large, and it will not be possible to be evaluated as second eligible. Due to this, the standard deviation becomes large, and it may not be possible to evaluate as the second eligible.

In addition, one aspect of the chamber pressure control method for a mud pressure shield tunneling machine according to the present invention is as follows:
A mud pressure shield tunneling machine in which excavated soil taken in a chamber between a cutter head and a bulkhead and additives are agitated and plastically fluidized to form mud, and the pressure of the mud counteracts the face pressure. A chamber internal pressure control method in
a measurement acquisition step of acquiring measurement data from each of a plurality of pressure sensors attached to the bulkhead in the height direction from above to below;
a calculation step of obtaining a regression line relating to the pressure gradient over the height direction using the measurement data over the height direction;
and an evaluation step of evaluating suitability of the chamber pressure using the regression line and a theoretical face pressure line relating to the face pressure gradient over the height direction of the cutter head.

According to this aspect, using measurement data from a plurality of pressure sensors attached over the height direction from the top to the bottom of the bulkhead, a regression line regarding the pressure gradient over the height direction is obtained, and the By evaluating the appropriateness of the chamber pressure using the theoretical face pressure line and regression line regarding the face pressure gradient over the height direction, it is confirmed and evaluated whether the face pressure is properly maintained by the mud pressure. be able to.

Further, in another aspect of the chamber internal pressure control method for a mud pressure shield tunneling machine according to the present invention,
In the calculating step, the difference between the regression line and the measurement data of each pressure sensor is obtained to calculate the standard deviation,
In the evaluation step, it is determined whether or not the regression line exists between an upper limit line and a lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure line. 1 Evaluate as eligible, compare the standard deviation with a threshold for the standard deviation, and evaluate as second eligible if the standard deviation is equal to or less than the threshold.

According to this aspect, when there is a regression line between the upper and lower threshold lines set based on the theoretical face pressure line, the mud pressure shield excavation is evaluated as the first eligibility. When it is possible to confirm and evaluate that the face pressure is properly maintained by the mud pressure during excavation of the machine, and the standard deviation of the difference between the regression line and the measurement data of each pressure sensor is less than the threshold , it can be confirmed and evaluated that the mud is uniformly and sufficiently plastically fluidized throughout the chamber. These two-stage evaluation methods make it possible to control the pressure of mud in the entire chamber of the mud pressure shield tunneling machine with high accuracy.

According to the mud pressure shield machine chamber internal pressure control system and the chamber internal pressure control method of the present invention, the mud pressure control in the entire chamber of the mud pressure shield machine can be performed with high accuracy.

1 is a diagram showing an example of the overall configuration of a chamber internal pressure management system according to an embodiment; FIG. It is a figure which shows an example of the hardware constitutions of an evaluation apparatus. It is a figure which shows an example of the functional structure of an evaluation apparatus. It is a figure explaining how to obtain|require the standard deviation based on the difference of a regression line and the measurement data of each pressure sensor. It is a figure which shows both a measurement data polygonal line, a theoretical face pressure straight line, a regression line, etc. FIG. FIG. 2 is a control chart showing both the chamber internal pressure gradient (waveform), the upper limit line (upper limit waveform), and the lower limit line (lower limit waveform) at each construction position of the tunnel. It is a figure which shows the example where standard deviation is below the threshold value and the linearity of a measurement data polygonal line is favorable. Both (a) and (b) are diagrams showing examples in which the standard deviation exceeds the threshold value and the linearity of the measurement data polygonal line is poor. 4 is a control chart showing the linearity of the pressure gradient (waveform) in the chamber at each construction position of the tunnel.

A chamber internal pressure control system and a chamber internal pressure control method for a mud pressure shield machine according to an embodiment will be described below with reference to the accompanying drawings. In addition, in the present specification and drawings, substantially the same components may be denoted by the same reference numerals, thereby omitting duplicate descriptions.

[Chamber Inner Pressure Management System and Chamber Inner Pressure Management Method According to Embodiment]
An example of a chamber internal pressure control system and a chamber internal pressure control method for a mud pressure shield machine according to an embodiment will be described with reference to FIGS. 1 to 8. FIG. Here, FIG. 1 is a diagram showing an example of the overall configuration of the chamber internal pressure management system according to the embodiment.

The chamber internal pressure control system 50 includes a plurality of pressure sensors 20 attached to the bulkhead 13 constituting the earth pressure shield tunneling machine 10 over the height direction from the top to the bottom, and the earth pressure shield tunneling system. and an evaluation device 30 which is inside the steel shell 11 of the machine 10 and evaluates whether the pressure in the chamber is appropriate. Here, the evaluation device 30 will be described as being installed inside the earth pressure shield machine 10, but the evaluation device 30 may be installed in an administration building (not shown) on the ground, or the earth pressure shield Both the excavator 10 and the management building may be equipped with evaluation devices, and both evaluation devices may be connected so as to be able to transmit and receive data.

A mud pressure shield machine 10 has a steel shell 11 and a cutter head 12 in front of the steel shell 11 in the excavation direction. The mud pressure shield machine 10 of the illustrated example will be described below as a large cross-section shield machine with a cutter head 12 having an outer diameter of 10 m or more (especially about 15 m or more), but the cutter head has an outer diameter of less than 10 m. of small and medium-sized shield machines may be applied.

Inside the steel shell 11, there are a bulkhead 13 forming a chamber 14 together with the back surface of the cutter head 12, a hydraulic drive motor 18 for rotationally driving the cutter head 12, an erector device 17 for assembling the segments S in a ring shape, a segment A shield jack 16 that applies a reaction force to the ring to excavate the mud pressure shield tunneling machine 10, a screw conveyor 15 that conveys the excavated soil taken into the chamber 14 via the cutter head 12 to the rear in the excavation direction, and a tail seal. A back-filling injection device 19 and the like for injecting the back-filling injection material J are provided. Here, a pressure sensor (not shown) for directly measuring the face pressure Pk may be attached to the cutter head 12 .

A plurality of stirring blades 12a are attached to the back surface of the cutter head 12 and protrude into the chamber 14. As the cutter head 12 rotates in the X direction, the earth and sand on the face K are taken into the chamber 14 as excavated soil and rotated. Impermeable mud D is generated by agitating the excavated soil and the additive material with the stirring blades 12a for plastic fluidization. Here, the additive is supplied to the chamber 14 from the rear side of the bulkhead 13 through a supply pipe (not shown).

In the mud pressure shield tunneling machine 10 , the mud pressure of the plastically fluidized mud D counters the face pressure Pk acting on the cutter head 12 . As the mud pressure shield tunneling machine 10 excavates in the ground G, the soil properties change, the groundwater level changes, and the earth covering load changes, so that the face pressure Pk also changes. Therefore, in the mud pressure shield machine 10, the amount of excavated soil taken into the chamber 14, the amount of mud D discharged from the chamber 14, Furthermore, the face pressure Pk, which changes according to excavation, is maintained while adjusting the supply amount of the additive material.

The bulkhead 13 has a circular shape when viewed from the front, and a plurality of pressure sensors 20 are attached along the contour line of the bulkhead 13 at intervals in the circumferential direction, thereby forming the bulkhead as shown in FIG. 13 over the height direction from above to below.

Measurement data on mud pressure at each height level measured by a plurality of pressure sensors 20 attached over the height direction of the bulkhead 13 is transmitted to the evaluation device 30 . Here, the evaluation device 30 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a diagram showing an example of the hardware configuration of the evaluation device, and FIG. 3 is a diagram showing an example of the functional configuration of the evaluation device.

As shown in FIG. 2, the evaluation device 30 is configured by an information processing device (computer) such as a personal computer (PC). A computer constituting the evaluation device 30 includes a CPU (Central Processing Unit) 31, a main memory device 32, an auxiliary memory device 33, an input/output IF (interface) 34, and a communication IF 35, which are interconnected by a connection bus 36. ing. The main memory device 32 and the auxiliary memory device 33 are computer-readable recording media. In addition, the above components may be provided individually, or some components may not be provided.

The CPU 31 is also called MPU (Microprocessor) or processor, and the CPU 31 may be a single processor or a multiprocessor. The CPU 31 is a central processing unit that controls the entire evaluation device 30 made up of a computer. For example, the CPU 31 develops a program stored in the auxiliary storage device 33 so that it can be executed in the work area of the main storage device 32, and controls peripheral devices through the execution of the program, thereby performing a function that meets a predetermined purpose. I will provide a.

The main storage device 32 stores computer programs executed by the CPU 31, data processed by the CPU 31, and the like. The main storage device 32 includes, for example, flash memory, RAM (Random Access Memory), and ROM (Read Only Memory). The auxiliary storage device 33 stores various programs and various data in a readable and writable recording medium, and is also called an external storage device. The auxiliary storage device 33 stores, for example, an OS (Operating System), various programs, various tables, and the like. The OS includes, for example, a communication interface program for exchanging data with an external device or the like connected via the communication IF 35 . The external devices include, for example, each pressure sensor 20 attached to the bulkhead 13, a pressure sensor (not shown) attached to the cutter head 12, and a position sensor such as a gyro provided inside the mud pressure shield excavator 10. (not shown), and a personal computer (not shown) for construction management in the administration building connected to the network.

The auxiliary storage device 33 is used, for example, as a storage area that assists the main storage device 32, and stores computer programs executed by the CPU 31, data processed by the CPU 31, and the like. The auxiliary storage device 33 is a silicon disk including a nonvolatile semiconductor memory (flash memory, EPROM (Erasable Programmable ROM)), a hard disk drive (HDD) device, a solid state drive device, or the like. Examples of the auxiliary storage device 33 include drive devices for removable recording media such as a CD drive device, a DVD drive device, and a BD drive device. ) memory, SD (Secure Digital) memory card, and the like.

The input/output IF 34 is an interface for inputting/outputting data with devices connected to the evaluation device 30 . The input/output IF 34 is connected to, for example, a keyboard, a pointing device such as a touch panel or a mouse, and an input device such as a microphone. The evaluation device 30 receives operation instructions and the like from the operator who operates the input device via the input/output IF 34 .

Further, the input/output IF 34 is connected to, for example, a display device such as a liquid crystal display (LCD) or an organic EL panel (EL: electroluminescence), and an output device such as a printer and a speaker. For example, measurement data relating to mud pressure and face pressure transmitted from each pressure sensor 20 attached to the bulkhead 13 and a pressure sensor (not shown) attached to the cutter head 12 is acquired (received). , is displayed. In addition, based on the regression line regarding the pressure gradient of the mud pressure calculated by the evaluation device 30 based on the measurement data, the theoretical face pressure line regarding the face pressure gradient over the height direction of the cutter head 12, and the theoretical face pressure line An upper limit line and a lower limit line, etc., which are set upper and lower thresholds, are displayed on the same screen.

The communication IF 35 is an interface with the network to which the evaluation device 30 is connected. The communication IF 35 receives measurements from the pressure sensor 20 via various networks such as a public network such as the Internet, a wireless network such as a mobile phone network, a dedicated network such as a VPN (Virtual Private Network), a LAN (Local Area Network), and the like. Data is received, and this measurement data and various evaluation result data evaluated by the evaluation device 30 based on the measurement data are transmitted to a personal computer in a management building or the like. Note that each pressure sensor 20 and the evaluation device 30 may be connected by wire so that data can be transmitted and received.

As shown in FIG. 3 , the evaluation device 30 provides various functions of at least an acquisition unit 302 , a calculation unit 304 , an evaluation unit 306 , a display unit 308 , and a storage unit 310 by executing programs by the CPU 31 . Here, at least part of the processing functions may be provided by a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), or the like. gate array), a numerical processor, a dedicated LSI (large scale integration) such as an image processor, or other digital circuits.

The acquisition unit 302 includes measurement data regarding the mud pressure in the chamber 14 measured by each pressure sensor 20, and measurement data regarding the face pressure if the cutter head 12 is equipped with a pressure sensor for measuring the face pressure. It is received at any time and stored in the storage unit 310 at any time. For example, if the cutter head 12 is equipped with a pressure sensor that measures the face pressure, this pressure sensor, like the pressure sensor 20 attached to the bulkhead 13, is also connected to the cutter head 12 by a plurality of pressure sensors. It is preferable that it is attached over the height direction from the upper part to the lower part of the lever.

Thus, the measurement of the mud pressure by each pressure sensor 20 and the transmission and reception of measurement data from each pressure sensor 20 to the acquisition unit 302 are included in the measurement acquisition process of the chamber internal pressure control method according to the embodiment.

The calculation unit 304 calculates a regression line relating to the pressure gradient of the mud pressure over the height direction using measurement data from each pressure sensor 20 provided over the height direction of the bulkhead 13 .

The regression line can be calculated by applying, for example, the method of least squares to a polygonal measurement data line formed by connecting the measurement data at the positions of the pressure sensors 20 in the height direction of the bulkhead 13 .

The calculation unit 304 further obtains the difference between the regression line and the measurement data of each pressure sensor 20 to calculate the standard deviation.

Here, FIG. 4 is a diagram explaining how to obtain the standard deviation based on the difference between the regression line and the measurement data of each pressure sensor. As shown in FIG. 4, a measurement data polygonal line is created based on measurement data from a plurality of (five in the illustrated example) pressure sensors 20 in the height direction of the bulkhead 13, and the measurement data polygonal line is used to create a regression line. is created, and the difference (deviation) between each measurement data and the regression line, s1, s2, . The standard deviation s is obtained by calculating the square root of the value obtained.

Thus, using the data measured by each pressure sensor 20, calculating the regression line regarding the pressure gradient of the mud pressure over the height direction of the bulkhead 13, and the regression line and the measurement data of each pressure sensor 20 Calculating the standard deviation by obtaining the difference is included in the calculating step of the chamber internal pressure control method according to the embodiment.

The storage unit 310 stores a theoretical face pressure line relating to the face pressure gradient over the height direction of the cutter head 12 . This theoretical face pressure straight line is obtained by using boring data, existing soil data, etc. of the ground G to be constructed, and the upper level and the lower level of the cutter head 12 that change according to the excavation of the mud pressure shield machine 10. Set by calculating each static earth pressure (including water pressure). Alternatively, the theoretical face pressure straight line can be set by multiplying the overburden loads at the upper and lower levels of the cutter head by a predetermined ratio (70%, 80%, etc.). Furthermore, based on measurement data relating to the face pressure measured by a plurality of pressure sensors attached to the cutter head 12, the calculation unit 304, for example, creates a theoretical face pressure straight line and stores the created theoretical face pressure straight line. It may be stored in unit 310 .

In addition to the theoretical face pressure line, the storage unit 310 stores an upper limit line and a lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure line. The method of setting the upper limit line and the lower limit line is, for example, ±20% or ±30% of the theoretical face pressure line as the upper limit line and the lower limit line, depending on the nature of the ground and the importance of the impact on the surrounding environment. be.

The storage unit 310 stores the theoretical face pressure line, the upper limit line and the lower limit line based thereon, and the threshold value for the standard deviation. The setting of the threshold for this standard deviation is also set according to the nature of the natural ground, the degree of importance of the influence on the surrounding environment, and the like.

The evaluation unit 306 determines whether or not a regression line relating to the pressure gradient of mud pressure exists between the upper limit line and the lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure line. Evaluate as first eligible if present.

Here, FIG. 5 is a diagram showing both the measurement data polygonal line, the theoretical face pressure line, the regression line, etc. at a construction position with a tunnel. In the example shown in FIG. 5, the slope of the theoretical face pressure line based on the static earth pressure line at this construction position is 18 kPa/m, and the slope of the regression line is 21 kPa/m, which is +15% of the theoretical face pressure line. ing. When the upper limit line, which is the threshold line, is set to about 20%, the evaluation unit 306 evaluates that the mud pressure at this construction position maintains the face pressure stably, and is evaluated as the first eligible. It will be. Various graphs shown in FIG. 5 are displayed on the display unit 308 of the evaluation device 30 .

FIG. 6 is a control chart showing both the chamber internal pressure gradient (waveform), the upper limit line (upper limit waveform), and the lower limit line (lower limit waveform) at each tunnel construction position (along the tunnel axial direction). . This control chart is displayed on the display unit 308 of the evaluation device 30 .

The theoretical face pressure differs depending on the construction position of the tunnel, and the upper limit line and lower limit line set based on the theoretical face pressure also differ. When both the upper limit line and the lower limit line are shown, both of these lines become waveforms as shown. Here, in the control chart of the illustrated example, each construction position of the tunnel is assigned to the ring No. of the segment ring. , and the width of the segment (1 m, 2 m, etc.) is indicated by the ring number. By multiplying by , for example, the position of a tunnel from a vertical shaft (not shown) is identified.

The illustrated upper limit line and lower limit line are set at ±20% of the theoretical face pressure line. In this control chart, Ring No. The regression line falls below the lower limit line around 710 to 720, and the evaluation unit 306 does not evaluate as the first qualified.

In this way, when a regression line exists between the upper limit line and the lower limit line, which are upper and lower thresholds set based on the theoretical face pressure line, the earth pressure shield tunneling machine 10 is evaluated as being first qualified. It is possible to appropriately confirm and evaluate whether or not the face pressure Pk is properly maintained by the mud pressure during excavation.

The evaluation unit 306 further compares the standard deviation calculated by the calculation unit 304 with a threshold for this standard deviation, and evaluates as second qualified when the standard deviation is equal to or less than the threshold.

Here, FIG. 7A is a diagram showing an example in which the standard deviation is below the threshold and the linearity of the measurement data polygonal line is good. It is a figure which shows the example which exceeds a threshold value and the linearity of a measurement data polygonal line is bad.

Since the standard deviation is based on the difference between the regression line and the measurement data of each pressure sensor, it is an index showing the linearity of the measurement data polygonal line. It means that the mud is uniformly and sufficiently plastically fluidized over the height direction.

In the example shown in FIG. 7A, the measurement data polygonal line shows almost the same linearity as the regression line, so the standard deviation is small, and the mud in the chamber 14 is uniformly and sufficiently plastically fluidized as much as possible. indicates In the case of the example shown in FIG. 7A, the evaluator 306 evaluates it as second eligible.

On the other hand, in the example shown in FIG. 7B (a), for example, the difference between the two measurement data and the regression line is large, and it is difficult to say that it has linearity approximating the regression line. It is not estimated that the mud in chamber 14 is as uniform as possible and sufficiently plastically fluidized.

In addition, in the example shown in FIG. 7B (b), the measurement data polygonal line has a large zigzag line across the regression line, which is also difficult to say that it has linearity similar to the regression line. Therefore, the standard deviation becomes large, and it cannot be evaluated that the mud in the chamber 14 is uniformly and sufficiently plastically fluidized.

FIG. 8 is a control chart showing the linearity of the chamber internal pressure gradient (waveform) at each construction position of the tunnel. In the example shown in FIG. 8, 25 kPa is set as the standard deviation threshold.

Similar to the regression line and the theoretical face pressure line shown in FIG. 6, the standard deviation also has a waveform as shown in the example. This control chart is also displayed on the display unit 308 of the evaluation device 30 .

In the illustrated example, the standard deviation is below the threshold at all construction positions of the tunnel, and it is evaluated that the mud is uniformly and sufficiently plastically fluidized throughout the construction section and throughout the chamber 14. At section 306, it will be evaluated as second eligible.

In this way, the difference between the regression line and the measurement data of each pressure sensor is obtained to calculate the standard deviation regarding the deviation in the height direction. It is possible to appropriately evaluate the linearity of the measurement data polygonal line formed by connecting the values of each pressure sensor 20 over the height direction of the bulkhead 13, and when the measurement data polygonal line has good linearity, the inside of the chamber 14 It can be evaluated that the mud is uniformly and sufficiently plastically fluidized over the entire area.

Therefore, in the evaluation unit 306, when there is a regression line between the upper limit line and the lower limit line, which are the upper and lower thresholds set based on the theoretical face pressure line, it is evaluated as the first eligibility, so that the mud pressure shield excavation Confirm and evaluate that the face pressure is properly maintained by the mud pressure during excavation of the machine, and if the standard deviation regarding the difference between the measurement data polygonal line and the regression line in the height direction is less than the threshold By evaluating the second qualification, it is confirmed and evaluated that the mud is uniformly and sufficiently plastically fluidized throughout the chamber.

Execution of the two-stage evaluation by the evaluation unit 306 described above is included in the evaluation process of the chamber internal pressure control method according to the embodiment.

According to the chamber internal pressure control system 50 and the chamber internal pressure control method shown in the figure, the mud pressure control in the entire area of the chamber 14 of the mud pressure shield machine 10 is highly controlled by performing a two-stage (two types) evaluation. It can be done with precision.

It should be noted that other embodiments may be possible in which other components are combined with the configurations described in the above embodiments, and the present invention is not limited to the configurations shown here. Regarding this point, it is possible to change without departing from the gist of the present invention, and it can be determined appropriately according to the application form.

10: Mud Pressure Shield Machine (Shield Machine)
11: Main body (steel shell)
12: Cutter head 12a: Stirring blade 13: Bulkhead 14: Chamber 15: Screw conveyor 16: Shield jack 17: Erector device 18: Hydraulic drive motor 19: Back-filling injection device 20: Pressure sensor 30: Evaluation device 50: Inside the chamber Pressure control system (chamber pressure control system for mud pressure shield machine)
302: Acquisition unit 304: Calculation unit 306: Evaluation unit 308: Display unit 310: Storage unit G: Natural ground (ground)
K: Face Pk: Face pressure D: Mud S: Segment J: Backfill injection material

Claims (5)

A mud pressure shield tunneling machine in which excavated soil taken in a chamber between a cutter head and a bulkhead and additives are agitated and plastically fluidized to form mud, and the pressure of the mud counteracts the face pressure. A chamber pressure management system in
a plurality of pressure sensors attached to the bulkhead from above to below in the height direction;
and an evaluation device for evaluating suitability of the chamber internal pressure,
The evaluation device is
an acquisition unit that acquires measurement data from each of the plurality of pressure sensors;
a calculation unit that uses the measurement data in the height direction to determine a regression line related to the pressure gradient in the height direction;
a storage unit for storing a theoretical face pressure line for a face pressure gradient across the height of the cutter head;
A chamber internal pressure control system for a mud pressure shield tunneling machine, comprising an evaluation unit that evaluates whether the chamber internal pressure is appropriate using the regression line and the theoretical face pressure line. The storage unit stores an upper limit line and a lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure straight line,
The evaluation unit determines whether or not the regression line exists between the upper limit line and the lower limit line, and evaluates as the first eligible if it exists between the upper limit line and the lower limit line. A chamber internal pressure control system for the described mud pressure shield machine. The calculation unit obtains the difference between the regression line and the measurement data of each pressure sensor to calculate the standard deviation,
The storage unit further stores a threshold for the standard deviation,
3. The earth pressure shield excavation according to claim 1, wherein the evaluation unit compares the standard deviation with the threshold value, and evaluates the second qualified vehicle when the standard deviation is equal to or less than the threshold value. Machine chamber pressure control system. A mud pressure shield tunneling machine in which excavated soil taken in a chamber between a cutter head and a bulkhead and additives are agitated and plastically fluidized to form mud, and the pressure of the mud counteracts the face pressure. A chamber internal pressure control method in
a measurement acquisition step of acquiring measurement data from each of a plurality of pressure sensors attached to the bulkhead in the height direction from above to below;
a calculation step of obtaining a regression line relating to the pressure gradient over the height direction using the measurement data over the height direction;
and an evaluation step of evaluating the appropriateness of the chamber pressure using the regression line and a theoretical face pressure line relating to the face pressure gradient over the height direction of the cutter head. A chamber internal pressure control method for a shield machine. In the calculating step, the difference between the regression line and the measurement data of each pressure sensor is obtained to calculate the standard deviation,
In the evaluation step, it is determined whether or not the regression line exists between an upper limit line and a lower limit line, which are upper and lower threshold lines set based on the theoretical face pressure line. 1 Evaluate as eligible, and compare the standard deviation with a threshold value related to the standard deviation, and evaluate as the second eligible if the standard deviation is less than or equal to the threshold. A chamber internal pressure control method for a mud pressure shield tunneling machine.

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