Automatic additive control system, method for automatically controlling injection rate of additive, and program

Abstract

To automatically set an optimum injection rate of an additive according to viscosity of excavated soil in a chamber provided in a shield machine or near a face in earth pressure shield tunneling.SOLUTION: An automatic additive control system for automatically controlling an injection rate of an additive to be injected into a chamber provided in a shield machine or into excavated soil near a working face while excavating natural ground with the shield machine, comprises an injection rate setting device for controlling the injection rate of the additive to be injected into the excavated soil. The injection rate setting device includes: a viscosity acquisition unit for calculating a measured viscosity representative value based on viscosity measurement values for a predetermined period of the excavated soil; and an injection rate prediction unit for obtaining a predicted injection rate of the additive based on the measured viscosity representative value and prediction information related to the injection rate of the additive. The prediction information is information created based on an actual injection rate of the additive added in the past and an actual viscosity representative value calculated based on the actual viscosity for a predetermined period of the excavated soil into which the additive was injected.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an automatic additive control system, a method for automatically controlling the injection rate of an additive, and a program for automatically controlling the injection rate of an additive injected into a chamber provided in a shield tunneling machine or into excavated soil near the face. [Background technology]

[0002] The earth pressure shield tunneling method is a method in which a chamber installed in a shield tunneling machine is filled with excavated soil excavated by a cutter head, and additives are injected as necessary, and the resulting earth pressure is used to excavate the ground while stabilizing the tunnel face. In order to maintain the stability of the tunnel face, it is necessary to properly manage the plastic flow state of the excavated soil filled in the chamber. For this reason, for example, Patent Document 1 discloses a device for measuring the soil flow in the chamber.

[0003] In order to maintain a good plastic flow state of the excavated soil, it is necessary to inject an additive suitable for the soil quality of the excavated soil at an appropriate injection rate. For this reason, the machine operator of the shield tunneling machine operates the shield tunneling machine while manually adjusting the injection rate while grasping the plastic flow state of the excavated soil, referring to the soil discharge state of the excavated soil, the face pressure state and cutter torque value during excavation, and the viscosity, which is one of the indicators of the fluidity of the excavated soil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4156480 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the discharged soil is affected by the blowout prevention material added by the screw, and so its properties are different from those of the excavated soil in the chamber. Fluctuations in face pressure are affected not only by the properties of the excavated soil in the chamber, but also by screw control. Cutter torque values ​​are affected not only by the soil in the chamber, but also by the soil in front of the excavation. In comparison, the viscosity of the excavated soil directly represents the properties of the soil in the chamber, but it takes a lot of experience to set an appropriate injection rate of additives according to changes in viscosity.

[0006] In this way, adjusting the injection rate is a complicated task, and performing it in conjunction with the directional control and earth pressure control of the shield tunneling machine places a heavy burden on the machine operator, making it an issue to find ways to reduce that burden.In addition, there has been a shortage of skilled machine operators in recent years, and there was a need to develop a method that would enable even inexperienced machine operators to accurately adjust the injection rate of additives.

[0007] The present invention has been developed in consideration of such problems, and its main objective is to automatically set the optimal injection rate of additive in accordance with the viscosity of the excavated soil in a chamber provided in a shield tunneling machine or near the face in an earth pressure shield tunneling method. [Means for solving the problem]

[0008] In order to achieve this objective, the automatic additive control system of the present invention is an automatic additive control system that automatically controls the injection rate of an additive to be injected into a chamber provided in a shield machine or into excavated soil near the face while the shield machine is excavating the natural ground, and is equipped with an injection rate setting device that controls the injection rate of the additive to be injected into the excavated soil, and the injection rate setting device includes a viscosity acquisition unit that calculates a measured viscosity representative value based on the viscosity measurement value of the excavated soil for a predetermined period of time, and an injection rate prediction unit that acquires a predicted injection rate of the additive based on the measured viscosity representative value and prediction information related to the injection rate of the additive, and is characterized in that the prediction information is information created based on the actual injection rate of the additive added in the past and the actual viscosity representative value calculated based on the actual viscosity of the excavated soil for a predetermined period of time into which the additive was injected.

[0009] The additive automatic control system of the present invention is characterized in that the measured viscosity representative value is a moving average of the viscosity measured values ​​measured intermittently over a specified period of time, and the actual viscosity representative value is a moving average of the actual viscosities measured intermittently over a specified period of time.

[0010] The automatic additive control system of the present invention is characterized in that the prediction information has upper and lower limit values ​​for the measured viscosity representative value corresponding to the predicted injection rate.

[0011] The automatic additive control system of the present invention is characterized in that the injection rate setting device includes a prediction information creation unit that creates the prediction information.

[0012] The automatic additive control system of the present invention is characterized by including a viscosity measuring device that measures the viscosity measurement value of the excavated soil.

[0013] The automatic additive control system of the present invention is characterized in that the viscosity measuring device has a measuring section within the chamber.

[0014] The automatic control method for the injection rate of additives of the present invention is a method for automatically controlling the injection rate of additives to be injected into a chamber provided in a shield machine or into excavated soil near a face while the shield machine is excavating natural ground, and includes the steps of: calculating a representative measured viscosity value based on viscosity measurement values ​​of the excavated soil for a predetermined period of time; and obtaining a predicted injection rate of the additives based on the representative measured viscosity value and prediction information related to the injection rate of the additives, wherein the prediction information is information created based on the actual injection rate of the additives added in the past and the representative actual viscosity value calculated based on the actual viscosity of the excavated soil for a predetermined period of time into which the additives have been injected.

[0015] The method for automatically controlling the injection rate of an additive of the present invention is characterized in that the measured viscosity representative value is a moving average of the viscosity measured values ​​measured intermittently over a specified period of time, and the actual viscosity representative value is a moving average of the actual viscosities measured intermittently over a specified period of time.

[0016] The method for automatically controlling the injection rate of an additive of the present invention is characterized in that the prediction information sets upper and lower limit values ​​for the measured viscosity representative value corresponding to the predicted injection rate.

[0017] The method for automatically controlling the injection rate of an additive according to the present invention is characterized by including a step of creating the prediction information.

[0018] The computer program of the present invention is characterized by causing a computer to execute the method of automatically controlling the injection rate of an additive of the present invention.

[0019] According to the automatic additive control system, and the automatic additive injection rate control method and program of the present invention, a predicted injection rate appropriate for the viscosity of the excavated soil can be automatically obtained based on a representative measured viscosity value calculated based on the viscosity measurement value of the excavated soil and predicted information related to the additive injection rate, thereby eliminating the need for the work of controlling the additive injection rate, which has previously been performed by a machine operator, and making it possible to save labor.

[0020] This allows the machine operator to focus more on other management items necessary for excavating the ground, such as directional control of the shield machine and control of earth pressure, enabling reliable control of the shield machine. On the other hand, if the directional control and earth pressure control of the shield machine are also automated and linked, automatic operation of the shield machine can be achieved, making it possible to reduce the number of machine operators required.

[0021] In addition, by acquiring prediction information regarding the injection rate of the additive based on the actual injection rate of the additive added in the past and the representative actual viscosity value calculated based on the actual viscosity of the excavated soil to which the additive was injected for a specified period, even an inexperienced machine operator can inject the additive optimally for the soil quality to be excavated. In this case, by using the representative actual viscosity value, it becomes possible to calculate a predicted injection rate that reflects the viscosity trend of the excavated soil for a specified period.

[0022] Furthermore, by setting upper and lower limit values ​​for the measured viscosity representative value corresponding to the predicted injection rate in the prediction information, the variation in the measured viscosity representative value can be absorbed as long as it is within the range of the upper and lower limits, and the predicted injection rate can be obtained with stable accuracy. Effect of the Invention

[0023] According to the present invention, it is possible to automatically set the optimal injection rate of additive according to the viscosity of the excavated soil in a chamber provided in a shield tunneling machine or near the face as a predicted injection rate based on a representative measured viscosity value calculated based on the viscosity measurement value of the excavated soil and predicted information related to the injection rate of additive. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram showing an outline of a shield machine and an automatic additive control system according to the present invention. [Diagram 2] FIG. 2 is a diagram showing a shield machine and a soil flow control mechanism of the present invention. [Diagram 3] FIG. 1 is a diagram showing the configuration of an automatic additive control system of the present invention. [Figure 4] 1 is a flow chart showing the procedure for constructing a tunnel while automatically controlling the addition rate of the additive material of the present invention. [Diagram 5] FIG. 13 is a diagram showing past performance data used to obtain prediction information in the present invention. [Figure 6] FIG. 2 shows a predicted injection rate threshold table (prediction information) of the present invention, and a graph verifying the predicted injection rate threshold table. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] The present invention automatically controls the injection rate of additives injected into a chamber or into excavated soil near a tunnel face during shield construction using an earth pressure shield tunneling method, while a shield machine is excavating the natural ground. The following describes in detail the automatic additive control system, the method for automatically controlling the injection rate of additives, and the program with reference to Figs. 1 to 6, taking as an example a case where an aerated material is injected as additive into excavated soil near a tunnel face.

[0026] Before this, an outline of a shield tunneling machine 10, an additive injection facility 20, and shield construction using these devices to excavate natural ground, as shown in FIG. 1, will be given.

[0027] <<Shield tunneling machine>> As shown in FIG. 1, the shield tunneling machine 10 comprises an electric motor 11 for driving the cutter, a cutter head 12, a shield body 13, a partition wall 14, a chamber 15, a screw conveyor 16, a shield jack 17, and rear equipment 18.

[0028] As shown in Fig. 2(a), the cutter head 12 is formed in a circular shape when viewed from the side of the working face A, and has a plurality of cutter spokes 121 extending radially from a central axis. A plurality of cutter bits 122, which are metal excavation tools, are attached to the surface of each cutter spoke 121 facing the working face A. As shown in Fig. 1, a chamber 15 is provided on the rear side of the cutter head 12.

[0029] The chamber 15 is a space into which excavated soil and sand that is continuously generated by the cutter head 12 excavating the natural ground is taken in, and is partitioned by the partition 14 and a hood portion 131, which is a cylindrical outer shell located on the front side (face A side) of the shield body 13. In addition, a screw conveyor 16 that penetrates the partition 14 and discharges the excavated soil and sand taken into the chamber 15 is provided.

[0030] The shield jacks 17 are provided in multiple circumferential directions on the rear side (tail side) of the shield body 13, and extend with the spreader 171 pressed against the segment ring 30 to press the cutter head 12 against the face A. The segment ring 30 is formed by assembling multiple segments in a continuous circumferential direction using an erector (not shown).

[0031] The shield machine 10 having the above configuration cuts the tunnel face A by pressing the cutter head 12 against the tunnel face A with the shield jack 17 while rotating with the cutter drive electric motor 11. At this time, using the additive injection equipment 20 described later, aerated material M1 is injected near the tunnel face A as shown in Fig. 2(b), and the chamber 15 is filled with the excavated soil generated by cutting.

[0032] The shield machine 10 excavates while stabilizing the face A due to the earth pressure of the excavated soil into which the foam material M1 has been injected and mixed. Then, by extending the rod of the shield jack 17 by the amount cut by the cutter head 12, a reaction force is obtained from the segment ring 30 to obtain propulsive force.

[0033] After the shield machine 10 has excavated in this manner, the rod of the shield jack 17 is contracted to form a space between the segment ring 30 and a new segment ring 30 is assembled. The shield construction involves repeating the above process to sequentially connect the segment rings 30, thereby constructing a tunnel lining underground.

[0034] The rear equipment 18, located inside the tunnel lining to which this segment ring 30 is connected, is equipped with a shield machine operation panel 19 for the shield machine 10 operated by a machine operator, and additive injection equipment 20, as shown in Figure 1.

[0035] ≪≪Additive injection equipment≫≫ The additive injection equipment 20 is a device that injects foaming material M0 and foam material M1 made from compressed air into the chamber 15, and as shown in Figure 1, it is equipped with an additive control device 21, an additive storage tank 22, an additive injection pump 23, a compressor 24, and an additive operation panel 25.

[0036] The foaming material M0 is produced by an additive production device (not shown) installed on the ground or the like, and is stored in an additive storage tank 22, and then pumped to an additive line 231 by an additive injection pump 23. Compressed air supplied from a compressor 24 via an air line 241 is joined in the additive line 231, and is injected near the face A as foaming material M1.

[0037] The injection amount of foaming material M0 supplied from the additive storage tank 22 to the additive injection pump 23 is controlled by the additive control device 21 based on the injection rate input via communication means from the additive operation panel 25. The additive operation panel 25 is provided together with the shield machine operation panel 19, and is used by the machine operator to determine the injection rate of the foaming material M1 with reference to the viscosity, which is one of the indicators that express the fluidity of the excavated soil filling the chamber, and to input this manually.

[0038] In this embodiment, the task of inputting the injection rate of the aerated material M1 into the additive material control device 21 can be performed not only manually by a machine operator via the additive material operation panel 25, but also automatically using the additive material automatic control system 40.

[0039] The additive automatic control system 40 is a system that uses prediction information created based on past performance data related to the injection rate of the foam material M1 to obtain a predicted injection rate of the foam material M1 suitable for the viscosity of the excavated soil and sand, and outputs the obtained predicted injection rate to the additive injection equipment 20. The additive automatic control system 40 and the prediction information will be described in detail below.

[0040] <<Additive automatic control system>> As shown in FIG. 1, the automatic additive control system 40 is composed of a soil flow control mechanism 50 and an injection rate setting device 60.

[0041] <<Sediment Flow Management Organization>> 2(b), the soil flow control mechanism 50 is equipped with a flapper 51 installed on the bulkhead 14 of the shield machine 10, and is a device that uses this flapper 51 to evaluate the plastic fluidity of the excavated soil filling the chamber 15. In this embodiment, this device is used as a viscosity measuring device.

[0042] The flapper 51 is composed of a shaft 511 protruding from the partition wall 14 into the chamber 15, and a flapper blade 512 attached near the tip of the shaft 511. In Fig. 2(a), an example is given in which the flappers 51 are provided in four places, but the number may be any number, and in most cases only one is provided. The installation position is set in consideration of the positional relationship with the equipment that mixes the excavated soil in the chamber 15 (for example, mixing blades, fixed blades, agitators, etc.).

[0043] The following two methods are provided for obtaining viscosity measurements of the excavated soil filling the chamber 15 using the above-mentioned flapper 51.

[0044] <Method of obtaining viscosity measurement value: Part 1> The viscosity measurement value is obtained from a torque value corresponding to the rotational resistance generated when the flapper blade 512 is rotated around the shaft 511.

[0045] 2(b), the soil flow control mechanism 50 includes the above-mentioned flapper 51, electric motor 52, and data processing device 53. The rotational torque when the electric motor 52 is driven to rotate the flapper blade 512 around the axis of the shaft 511 in the excavated soil by a predetermined angle is measured based on the power of the electric motor 52. This is obtained as a torque value corresponding to the rotational resistance of the flapper blade 512.

[0046] The data processing device 53 calculates the viscosity of the excavated soil in the chamber 15 based on the strain rate obtained from this torque value and the viscosity equation, and outputs this as a viscosity measurement value of the excavated soil in the chamber 15. The method of calculating viscosity based on the strain rate and the viscosity equation is described in Reference 1 (Reference 1: Japanese Patent No. 4156480).

[0047] <Method of obtaining viscosity measurement value: Part 2> A strain gauge is provided on the shaft 511 of the flapper 51, and the viscosity measurement value is obtained from the deformation amount of the shaft 511.

[0048] A hollow tube is used for the shaft 511, and multiple strain gauges are provided using the inner space. Multiple strain gauges are arranged at equal intervals around the circumference of the shaft 511, and multiple gauges are also arranged in the radial direction. This allows the amount of deformation to be measured when the excavated soil flowing inside the chamber 15 collides with the shaft 511 and causes the shaft 511 to deform.

[0049] The data processing device 53 calculates the viscosity of the excavated soil in the chamber 15 based on the strain rate obtained from this deformation amount and the viscosity equation, and outputs this as a viscosity measurement value of the excavated soil in the chamber 15. The method of calculating viscosity based on the strain rate and the viscosity equation is described in Reference 2 (Reference 2: Japanese Patent No. 4769264).

[0050] ≪≪Injection rate setting device≫≫ The injection rate setting device 60 may be any of a notebook PC, a tablet terminal, a smartphone, etc., and as shown in Figure 3, it is equipped with an input device 61, an output device 62, a central processing unit 63, a storage device 64, and a main memory 65.

[0051] Examples of the input device 61 include a keyboard, a scanner, and a switch, and examples of the output device 62 include a display and a printer. The central processing unit 63 is a computer having a CPU, a GPU, a ROM, a RAM, and a hardware interface. The storage device 64 is made up of a semiconductor memory or a hard disk drive, and stores, for example, a performance data file 641, a forecast information file 642, and the like, as will be described in detail later.

[0052] The main memory 65 temporarily stores certain programs and data that can be executed by the central processing unit 63, and is equipped with, for example, a viscosity acquisition unit 651, an injection rate prediction unit 652, an injection rate output unit 653, and a prediction information creation unit 654.

[0053] Although details will be described later, the viscosity acquisition unit 651 acquires a measured viscosity representative value based on viscosity measurement values ​​of the excavated soil for a predetermined period measured by the soil flow control mechanism 50. The injection rate prediction unit 652 acquires a predicted injection rate of the aerated material M1 based on the measured viscosity representative value acquired by the viscosity acquisition unit 651 and prediction information created based on past performance data related to the injection rate of the aerated material M1. The injection rate output unit 653 outputs the predicted injection rate acquired by the injection rate prediction unit 652 to the additive control device 21 of the additive injection equipment 20.

[0054] The prediction information creation unit 654 creates prediction information by utilizing past performance data related to the injection rate of the foam material M1. The prediction information is not limited to this, and may be created separately by other means and stored in the memory device 64 of the injection rate setting device 60. A program for realizing these functions on the injection rate setting device 60 is stored in the central processing unit 63.

[0055] The soil flow management mechanism 50 and injection rate setting device 60 of the additive automatic control system 40, the shield machine operation panel 19 of the shield tunneling machine 10, and the additive control device 21 and additive operation panel 25 of the additive injection equipment 20 are connected via communication means to enable data transmission and reception between them. The communication means may be either wired or wireless, or may be a combination of these.

[0056] <<Forecast Information>> The prediction information is information used when the injection rate prediction unit 652 described above obtains a predicted injection rate of the aerated foam material M1, and any method of obtaining the information may be used so long as it can predict a suitable addition rate that ensures the plastic flowability and watertightness of the excavated soil within the chamber 15 and the ability to prevent adhesion to the shield tunneling machine 10. For example, the procedure for obtaining the prediction information using past performance data obtained when the machine operator manually set the injection rate of the aerated foam material M1 in the preceding excavation area is as follows.

[0057] 5(a) plots the actual grouting rate and the actual viscosity representative value when the shield machine 10 excavates the range of ring numbers 270 to 340 of the segment ring 30. The actual grouting rate is an adjustment value of the grouting rate appropriately adjusted by the machine operator while excavating the natural ground while injecting the aerated foam material M1 at a preset grouting rate.

[0058] The representative actual viscosity value is a moving average of the actual viscosity, the latest data being the actual viscosity of the excavated soil and sand that the machine operator used as a reference when deciding the actual injection rate. There is no limit to the period or number of data points for obtaining the moving average, but for example, time-series data of viscosity measurements obtained intermittently (e.g., every 5 minutes) during the period when one segment ring 30 is excavated is used.

[0059] In this way, when the representative actual viscosity value (moving average of the actual viscosity) is used to obtain the prediction information, a predicted injection rate that reflects the actual viscosity trend over a predetermined period can be obtained even if the actual viscosity has temporary variations. In other words, the viscosity variations that the machine operator takes into account when determining whether or not to change the injection rate can be reflected in the prediction information.

[0060] By performing regression analysis using the actual viscosity representative value and the actual injection rate obtained as described above, a regression equation L is obtained in which the injection rate is the objective variable and the viscosity is the explanatory variable, as shown in Fig. 5(b). Although it is possible to use the obtained regression equation L as prediction information, here, a predicted injection rate threshold value table is created based on the obtained regression equation L, and this is applied as prediction information.

[0061] <Predicted injection rate threshold table> The predicted injection rate threshold table is a correspondence table that associates predicted injection rates with viscosity measurement values, and as shown in Fig. 6(a), upper and lower limit values ​​for the viscosity measurement values ​​are set for each predicted injection rate displayed in 1% increments. By setting the upper and lower limit values ​​for the viscosity measurement values ​​in this way, predicted injection rates can be obtained in 1% increments, just like a machine operator.

[0062] Furthermore, even if there is variation in the measured viscosity representative value acquired by the viscosity acquisition unit 651, the predicted injection rate can be acquired while minimizing the influence of the variation, so long as it is within the range between the set upper and lower limits. With such a predicted injection rate threshold table, for example, when the measured viscosity representative value is 50,000 Pa.s, the optimal predicted injection rate can be predicted to be 27%. Note that when the predicted injection rate threshold table is applied, the upper limit is treated as being less than the upper limit, and the lower limit is treated as being equal to or greater than the lower limit.

[0063] In order to evaluate the above predicted injection rate threshold table, the actual viscosity representative values ​​plotted in Fig. 5(a) were applied to the predicted injection rate threshold table to obtain the predicted injection rate, which is shown in Fig. 6(b). As shown in Fig. 6(b), the predicted injection rate obtained using the predicted injection rate threshold table and the actual injection rate determined by the machine operator are generally consistent.

[0064] For example, looking at the range of ring numbers 280-290 of segment ring 30 where the actual grouting rate is increasing, the predicted grouting rate is also increasing similarly, and it can be seen that the predicted grouting rate is a good representation of the operation of the machine operator. Therefore, if the aerated material M1 is injected into the excavated soil near the face A at the predicted grouting rate obtained using the predicted grouting rate threshold table, plastic flow and water cutoff are ensured within chamber 15, and the function of preventing adhesion to the shield tunneling machine 10 is also ensured.

[0065] A method for constructing a tunnel by employing the above-mentioned predicted injection rate threshold table and the automatic additive control system 40 to automatically control the injection rate of the foam material M1 while excavating the natural ground with the shield machine 10 will be described below according to the flow shown in Fig. 4. Additionally, the automatic injection rate control method for the foam material M1 and the injection rate setting device 60 will be described in detail with reference to the configuration diagram of the injection rate setting device 60 in Fig. 3.

[0066] How to build a tunnel When the shield machine 10 starts excavating the natural ground, the natural ground is cut by the cutter bits 122 of the cutter head 12, and the excavated soil is continuously generated, filling the chamber 15. In addition, the aerated material M1 is injected into the excavated soil via the additive injection equipment 20 at a preset injection rate.

[0067] In this state, the soil flow control mechanism 50 measures and calculates the viscosity inside the chamber 15, and outputs the resulting viscosity measurement value to at least the shield machine operation panel 19 of the shield machine 10 and the injection rate setting device 60. The viscosity measurement value is output intermittently (for example, at 5-minute intervals).

[0068] <<Collecting performance data: STEP 1>> The actual injection rate of the foam material M1, which is changed or adjusted by the machine operator with respect to the preset injection rate, and the actual viscosity that the machine operator used as a reference when setting this actual injection rate are collected as performance data. Here, the viscosity measurement value measured by the soil flow control mechanism 50 is treated as the actual viscosity.

[0069] The machine operator judges whether or not it is necessary to change the injection rate of the foam material M1 while referring to the viscosity measurement value output to the shield machine operation panel 19. If it is judged that a change is necessary, the changed injection rate is set as the actual injection rate and inputted to the additive material control device 21 via the additive operation panel 25.

[0070] The additive control device 21 then pumps the foaming material M0, an amount of which satisfies the input actual injection rate, from the additive storage tank 22 to the additive line 231 via the additive injection pump 23. This is mixed with air supplied from a compressor and injected from the cutter head 12 toward the face. The combination of the actual injection rate set by the machine operator and the viscosity measurement value (actual viscosity) is accumulated as performance data.

[0071] Any method of accumulating performance data may be used, but for example, the additive operation panel 25 and the injection rate setting device 60 are connected via a communication means so that when a machine operator inputs an actual injection rate into the additive operation panel 25, the actual injection rate is output from the additive operation panel 25 to the injection rate setting device 60. Similarly, the sediment flow control mechanism 50 and the injection rate setting device 60 are connected via a communication means so that a viscosity measurement value (actual viscosity) is output from the data processing device 53 of the sediment flow control mechanism 50 to the injection rate setting device 60.

[0072] When the actual data is input to the injection rate setting device 60 in this manner, the central processing unit 63, in response to a command from the viscosity acquisition unit 651, accumulates the actual injection rate and actual viscosity in the actual data file 641, and stores it in the storage device 64. The above operation of accumulating the actual data is repeated until the number of data pieces required to create a predicted injection rate threshold table (prediction information) is reached.

[0073] <<Creating forecast information: STEP 2>> When the required number of data items has been accumulated, the central processing unit 63 creates a predicted injection rate threshold table (prediction information) in response to a command from the prediction information creation unit 654. The creation procedure is as explained above in <<Prediction Information>> and <<Prediction Injection Rate Threshold Table>>. The created predicted injection rate threshold table is stored in the prediction information file 642 of the storage device 64.

[0074] <<Automatic control of additive injection rate: STEP 3>> Once the predicted injection rate threshold table is stored in the memory device 64, the machine operator inputs command information to the injection rate setting device 60, for example, via the input device 61, to start automatic control of the injection rate of the foam material M1.

[0075] <Prediction of expected injection rate: STEP 3-1> Then, the central processing unit 63 receives a command from the viscosity acquisition unit 651 to acquire the viscosity measurement values ​​that are intermittently input, and calculates a measured viscosity representative value based on the acquired viscosity measurement values.

[0076] The measured viscosity representative value is a moving average of viscosity measurement values, with the latest data being calculated each time a viscosity measurement value that is measured intermittently is obtained. There is no limit to the period or number of data for obtaining the moving average, but for example, time-series data of viscosity measurement values ​​obtained intermittently (e.g., at 5-minute intervals) during the period of excavating one ring of the segment ring 30 is used. When the measured viscosity representative value is calculated, the central processing unit 63 receives a command from the injection rate prediction unit 652 to obtain a predicted injection rate.

[0077] The predicted grout rate is obtained by applying the measured viscosity representative value to the predicted grout rate threshold table created in STEP 2 each time the measured viscosity representative value is calculated. In this way, the predicted grout rate is also obtained by using a moving average of the viscosity measurement values, rather than the viscosity measurement values ​​measured intermittently. This makes it possible to minimize the impact of temporary variations caused by the inclusion of clay lumps or large gravel.

[0078] <<Output of predicted injection rate: STEP3-2>> When the predicted injection rate is acquired, the central processing unit 63, in response to a command from the injection rate output unit 653, compares the injection rate of the aerated material M1 currently being injected into the excavated soil near the face A via the injection rate setting device 60 with the calculated predicted injection rate. If the two are different, the acquired predicted injection rate is output to the additive control device 21 of the additive injection equipment 20.

[0079] As a result, the injection rate of the aerated foam material M1 injected into the excavated soil near the face A via the injection rate setting device 60 is changed and adjusted to the predicted injection rate. On the other hand, if the injection rate of the aerated foam material M1 currently being injected is the same as the calculated predicted injection rate, the predicted injection rate is not output, and the current injection rate is maintained. In this way, the injection rate control of the aerated foam material M1 is automated.

[0080] If the above predicted injection rate threshold table is created using past performance data from experienced machine operators, it will be possible to inject the aerated material M1 that is optimal for the soil quality to be excavated, even if the operation of the shield tunneling machine 10 is taken over by an inexperienced machine operator during the period when the injection rate of the aerated material M1 is automatically controlled.

[0081] <Confirming the predicted injection rate: STEP 3-3> The data such as the viscosity measurement value, the measured viscosity representative value, and the predicted injection rate obtained in (STEP 3-1) and (STEP 3-2) above are stored in a performance data file 641 and a prediction information file 642 in the storage device 64. The data is also output to an output device 62 such as a display. Alternatively, the data is output to the shield machine operation panel 19 of the shield machine 10.

[0082] This allows the machine operator to constantly monitor how the injection rate of the foam material M1 is automatically controlled, as well as the measured viscosity of the excavated soil filling the chamber 15, which varies over that period. Therefore, if the predicted injection rate obtained by the injection rate setting device 60 for the time-series data of the viscosity of the excavated soil deviates from the empirical value of the machine operator, the machine operator can temporarily halt the automatic control.

[0083] For example, command information for temporarily suspending the automatic control of the injection rate of the foam material M1 is input to the injection rate setting device 60 via the input device 61. Thus, the operation of outputting the predicted injection rate acquired by the injection rate setting device 60 to the additive material control device 21 of the additive material injection equipment 20 is stopped. Then, returning to the above (STEP 1), the machine operator corrects the injection rate of the foam material M1 and resumes the work of inputting it to the additive material control device 21 via the additive material operation panel 25.

[0084] By continuing this operation, performance data by the operator is accumulated, and the predicted injection rate threshold table is created again in the procedure of (STEP 2) above. At this time, the accumulated performance data treats the injection rate set by the machine operator as the actual injection rate. Also, the viscosity measurement value at the time the machine operator sets the injection rate is treated as the actual viscosity. After creating a new predicted injection rate threshold table in this way, this predicted injection rate threshold table is used to resume automatic control of the injection rate of the foam material M1 in the procedure of (STEP 3) above.

[0085] <Achieving the planned point for changing additives: STEP 3-4> When the excavation work by the shield machine 10 progresses and a point is reached where an instruction to change the type of additive is displayed on the excavation plan or the like, automatic control of the injection rate by the injection rate setting device 60 is temporarily suspended. This is because the predicted injection rate threshold value table needs to be re-created every time the additive is changed.

[0086] Therefore, we return to the above (STEP 1) and have the machine operator set the injection rate with the changed type of additive, accumulate performance data, and then recreate the predicted injection rate threshold table using the above procedure (STEP 2). In this case, too, the accumulated performance data treats the injection rate set by the machine operator as the actual injection rate. Also, the viscosity measurement value at the time the machine operator sets the injection rate is treated as the actual viscosity.

[0087] After the predicted injection rate threshold table corresponding to the changed type of additive is created, this predicted injection rate threshold table is used to resume automatic control of the injection rate of the additive in the above procedure (STEP 3). The above process is repeated until the shield machine 10 reaches the planned end point of excavation.

[0088] According to the above-mentioned additive automatic control system 40, and the method and program for automatically controlling the injection rate of additives, the soil properties of the excavated soil in the chamber 15 are obtained as viscosity measurement values, and a measured viscosity representative value is calculated from the viscosity measurement values. Next, a predicted injection rate of the foam material M1 is obtained based on the measured viscosity representative value and the predicted injection rate threshold table, and output to the additive control device 21 of the additive injection equipment 20.

[0089] In this way, because control of the injection rate of the foam material M1 can be automated, it is possible to omit the work previously performed by the machine operator of determining the injection rate of the foam material M1 (ratio of the amount of foam material to the amount of excavated soil) and inputting the determined injection rate into the additive material control device 21 via the additive material operation panel 25. This makes it possible to reduce the labor required by the machine operator, allowing them to focus more on other management items necessary for excavating the natural ground, such as directional control of the shield machine 10 and control of earth pressure, and enables reliable control of the shield machine 10.

[0090] On the other hand, if the directional control and earth pressure control of the shield tunneling machine 10 are also automated and linked together, automatic operation of the shield tunneling machine 10 can be achieved, which can also reduce the number of machine operators required.

[0091] Furthermore, if predictive information regarding the injection rate of the foam material M1 is obtained based on the results of a regression analysis using the actual injection rate of the additive added in the past by an experienced machine operator and a representative actual viscosity value calculated based on the actual viscosity of the excavated soil into which the additive was injected over a specified period of time, even an inexperienced machine operator will be able to inject the optimal additive according to the soil properties of the excavated soil.

[0092] The automatic additive control system, the automatic additive injection rate control method, and the program of the present invention are not limited to the above-described embodiments, and it goes without saying that various modifications are possible without departing from the spirit of the present invention.

[0093] For example, in this embodiment, the injection rate of the foam material M1 is automatically controlled using the additive automatic control system 40, but the present invention can be applied to any additive used in earth pressure shield construction, including not only foam material M1 but also mineral-based, surfactant-based, superabsorbent resin-based, water-soluble polymer-based, etc.

[0094] In addition, the soil flow control mechanism 50 described with reference to Figure 2 is used as the viscosity measuring device, but any viscosity measuring device can be used as long as it has the function of intermittently measuring the viscosity of the excavated soil filled in the chamber 15.

[0095] Furthermore, as explained with reference to the flow chart in Fig. 4, the step (STEP 2) of acquiring the predicted injection rate threshold value table is performed immediately before the step (STEP 3) of automating the work of controlling the injection rate of the foam material M1, but this is not limiting. For example, if there has been a tunnel construction project in the past in which the soil conditions were similar and the same type of additive was used, the predicted injection rate threshold value table may be created using the construction data.

[0096] In addition, the representative actual viscosity value used in creating the predicted injection rate threshold table is the latest data of actual viscosity that the machine operator used as a reference when deciding on the actual injection rate, and a moving average of actual viscosities intermittently obtained immediately before that during the period of excavation equivalent to one ring of the segment ring 30 is used. At this time, for example, if there is an abnormal value, this data may be deleted to calculate the moving average, or maximum and minimum thresholds may be set, and data above the maximum threshold and data below the minimum threshold may be deleted to calculate the moving average.

[0097] Alternatively, any method may be used to calculate the representative actual viscosity value, such as the moving median, as long as it is a calculation method that can reflect the viscosity trend over a predetermined period of time, taking into consideration the case where temporary variations occur due to the presence of clay lumps or large gravel in the excavated soil in the chamber 15. This also applies to the representative measured viscosity value of the excavated soil, which is applied to the predicted injection rate threshold table when obtaining the predicted injection rate. [Explanation of symbols]

[0098] 10 Shield tunneling machine 11 Cutter drive electric motor 12 Cutter head 121 Cutter Spoke 122 Cutter Bit 13 Shield body 131 Food Section 14 Bulkhead 15 Chambers 16 Screw conveyor 17 Shield Jack 171 Spreader 18 Rear equipment 19 Shield machine operation panel 20 Additive injection equipment 21 Additive control device 22 Additive storage tank 23 Additive injection pump 231 Additive Line 24 Compressor 241 Airlines 25 Control panel for additives 30 Segment Ring 40 Additive automatic control system 50 Sediment Flow Management Mechanism (Viscosity Measuring Device) 51 Flapper (measurement part) 511 Shaft 512 Flapper Wing 52 Electric Motor 53 Data Processing Device 60 Injection rate setting device 61 Input Devices 62 Output Device 63 Central Processing Unit 64 Storage device 641 Performance data file 642 Forecast Information File 65 Main memory 651 Viscosity acquisition part 652 Injection rate prediction section 653 Injection rate output section 654 Forecast Information Creation Department M0 foam material M1 Foam material (additive)

Claims

1. An automatic additive control system that automatically controls an injection rate of an additive to be injected into a chamber provided in a shield machine or into excavated soil near a face while the shield machine is excavating a natural ground, An injection rate setting device is provided for controlling the injection rate of the additive to be injected into the excavated soil, The injection rate setting device is A viscosity acquisition unit that calculates a representative measured viscosity value based on viscosity measurements of the excavated soil over a predetermined period of time; an injection rate prediction unit that obtains a predicted injection rate of the additive based on the measured viscosity representative value and prediction information related to the injection rate of the additive, An automatic additive control system characterized in that the prediction information is information created based on an actual injection rate of the additive added in the past and a representative actual viscosity value calculated based on the actual viscosity of the excavated soil into which the additive was injected for a specified period of time.

2. In the additive automatic control system according to claim 1, the representative measured viscosity value is a moving average of the viscosity measured values ​​intermittently measured over a predetermined period of time; An additive automatic control system, characterized in that the representative value of actual viscosity is a moving average of the actual viscosity measured intermittently over a predetermined period of time.

3. In the additive automatic control system according to claim 1, An automatic additive control system, characterized in that upper and lower limit values ​​of the measured viscosity representative value corresponding to the predicted injection rate are set in the prediction information.

4. In the additive automatic control system according to claim 1, An automatic additive control system, characterized in that the injection rate setting device includes a prediction information creation unit that creates the prediction information.

5. In the additive automatic control system according to claim 1, An automatic additive control system comprising a viscosity measuring device that measures the viscosity value of the excavated soil.

6. In the additive automatic control system according to claim 5, An automatic additive control system, characterized in that the viscosity measuring device has a measuring section within the chamber.

7. A method for automatically controlling an injection rate of an additive, which automatically controls an injection rate of an additive to be injected into a chamber provided in a shield machine or into excavated soil near a face while the shield machine is excavating a natural ground, comprising: A step of calculating a representative viscosity value based on viscosity measurements of the excavated soil for a predetermined period of time; and acquiring a predicted injection rate of the additive based on the measured viscosity representative value and prediction information related to the injection rate of the additive, A method for automatically controlling the injection rate of an additive, characterized in that the prediction information is information created based on an actual injection rate of the additive added in the past and a representative actual viscosity value calculated based on the actual viscosity of the excavated soil into which the additive has been injected for a specified period of time.

8. The method for automatically controlling an injection rate of an additive according to claim 7, the representative measured viscosity value is a moving average of the viscosity measured values ​​intermittently measured over a predetermined period of time; A method for automatically controlling the injection rate of an additive, characterized in that the representative value of the actual viscosity is a moving average of the actual viscosity measured intermittently over a predetermined period of time.

9. The method for automatically controlling an injection rate of an additive according to claim 7, A method for automatically controlling an injection rate of an additive, characterized in that upper and lower limit values ​​of the measured viscosity representative value corresponding to the predicted injection rate are set in the prediction information.

10. The method for automatically controlling an injection rate of an additive according to claim 7, A method for automatically controlling an injection rate of an additive, comprising the step of creating the prediction information.

11. A computer program that causes a computer to execute the method for automatically controlling an additive injection rate according to any one of claims 7 to 10.

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