Excavation volume measurement system and excavation volume measurement method

Abstract

This invention proposes an excavated soil volume measurement system and method that can accurately determine the weight, volume, and specific gravity of excavated soil generated in a slurry pressure balance shield tunneling system at an appropriate time. [Solution] The excavated soil volume measurement system 1 includes a screw conveyor 3 that discharges excavated soil from the chamber 24 of the shield machine 2, a soil pumping pipe 4 connected to the screw conveyor 3, a hopper 5 located outside the shaft into which the excavated soil transported via the soil pumping pipe 4 is fed, a weighing scale 51 that measures the weight of the hopper 5, and a three-dimensional measuring device 8 that measures the shape of the hopper 5 from above.

Description

Technical Field

[0001] The present invention relates to an earth volume measurement system and an excavation earth volume measurement method associated with shield construction.

Background Art

[0002] In an earth pressure balance shield, excavation is carried out while stabilizing the face by applying the earth pressure of the excavated earth and sand generated during tunnel excavation to the face. The earth pressure applied to the face is controlled by the earth pressure in the chamber. The control of the earth pressure in the chamber is performed by adjusting the thrust of the shield jack and the amount of earth discharged from the chamber in a state where the chamber is filled with excavated earth and sand. That is, in an earth pressure balance shield, the stability of the face is achieved by measuring and appropriately controlling the amount of earth discharged from the chamber. In addition, by comparing the measured value and the planned value of the earth discharge amount, the ground conditions of the face (for example, excessive intake of earth and sand, etc.) can also be grasped. Therefore, in shield construction, by measuring the excavation earth volume and reflecting the measurement result in the face earth pressure or the backfill injection amount, the improvement of the stability of the ground can be achieved, and thus the influence on the neighborhood can be made smaller.

[0003] Various methods are adopted for measuring the amount of earth discharged in an earth pressure balance shield. For example, in Patent Document 1, as a method for measuring the amount of earth discharged during shield tunneling, the weight of the contents is measured by measuring the weight of the skip hopper into which the excavated earth and sand are loaded, and the volume is calculated from the shape of the contents in the skip hopper measured by a three-dimensional shape measuring device. After measuring the weight and volume of the excavated earth and sand, it is discharged outside the tunnel pit by the skip hopper.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] It should be noted that the disposal costs for excavated soil are generally calculated by volume, with the specific gravity based on past performance also indicated. Since the excavated soil from earth pressure balance shield tunneling is often disposed of as sludge (=industrial waste), it would be preferable to calculate the costs by weight. However, the specific gravity of the excavated soil is not known in advance and fluctuates. Therefore, if there is a difference between the specific gravity based on past performance and the actual specific gravity, there is a risk of errors in the disposal costs.

[0006] The present invention aims to propose an excavated soil volume measurement system and method that can accurately determine the weight, volume, and specific gravity of excavated soil generated in a mud pressure balance shield tunneling system at an appropriate time. [Means for solving the problem]

[0007] The excavated soil volume measurement system of the present invention, which solves the aforementioned problems, comprises a screw conveyor for discharging excavated soil from the chamber of a shield machine, a soil transport means connected to the screw conveyor, and a hopper provided outside the shaft into which the excavated soil transported via the soil transport means is fed. The excavated soil volume measurement system comprises a weighing scale for measuring the weight of the hopper and a three-dimensional measuring device for measuring the shape of the hopper from above.

[0008] The method for measuring the amount of excavated soil using the excavated soil volume measurement system comprises a preparation step of measuring the hopper weight, which is the weight of the hopper at the start of excavation, and measuring the internal shape of the hopper at the start of excavation using the three-dimensional measuring device; a measurement step of measuring the weight of the hopper filled with soil, which is the weight of the hopper when excavated soil is loaded into it, and measuring the soil loading shape, which is the shape of the top surface of the hopper when excavated soil is loaded into it, using the three-dimensional measuring device; a weight calculation step of calculating the weight of excavated soil by subtracting the hopper weight from the weight of the hopper filled with soil; a volume calculation step of calculating the volume of excavated soil from the internal shape of the hopper and the soil loading shape; and a specific gravity calculation step of calculating the specific gravity of the excavated soil using the weight of the excavated soil and the volume of the excavated soil.

[0009] According to this excavated soil volume measurement system and method using it, the weight, volume, and specific gravity of the excavated soil generated in a mud pressure balance shield tunneling system can be accurately determined at an appropriate time by using a weighing scale to measure the weight of the hopper and a three-dimensional measuring device to measure the shape of the hopper from above.

[0010] When the means of transporting soil and sand is a soil and sand transport pipe, the volume of excavated soil and sand transported by the soil and sand transport pipe may be measured by a flow meter installed in the soil and sand transport pipe, or it may be calculated by the number of times the soil and sand transport pump is operated, or it may be calculated by the number of rotations of the screw conveyor. Furthermore, if the means of transporting soil and sand is a belt conveyor, the weight of the excavated soil and sand transported by the belt conveyor may be measured using a weighing scale installed on the belt conveyor, and the shape (volume) of the excavated soil and sand transported by the belt conveyor may be measured using a belt scanner.

[0011] The hopper should preferably have a volume capable of storing the excavated soil equivalent to one excavation ring. By using this hopper to calculate the specific gravity and volume of the excavated soil for each ring, and comparing the planned value with the measured value of the excavated soil for each ring, the ground conditions can be appropriately understood. [Effects of the Invention]

[0012] According to the excavated soil volume measurement system and method of the present invention, the weight, volume, and specific gravity of the excavated soil generated in a mud pressure balance shield can be accurately determined at an appropriate time. [Brief explanation of the drawing]

[0013] [Figure 1] This is a cross-sectional view showing an overview of an excavation volume measurement system according to an embodiment of the present invention. [Figure 2] This flowchart shows the procedure for measuring the volume of excavated soil according to an embodiment of the present invention. [Modes for carrying out the invention]

[0014] This embodiment describes the case in which a tunnel T is constructed using a mud pressure balance shield. In this embodiment, excavation is carried out while managing the amount of excavated soil using the excavation volume measurement system 1. Figure 1 shows an overview of the excavation volume measurement system 1. As shown in Figure 1, the excavated soil volume measurement system 1 includes a shield machine 2, a screw conveyor 3, a soil pumping pipe (soil transport means) 4, a hopper 5, a flow meter 6, a density meter 7, and a three-dimensional measuring device 8.

[0015] As shown in Figure 1, the shield machine 2 comprises a cutter head 21 located at the front end in the excavation direction, a main body 22 located behind the cutter head 21, a partition wall 23 formed at the front of the main body 22, and a plurality of shield jacks (not shown) located at the rear of the main body 22. The cutter head 21 rotates using the power of a motor to cut the ground G. The excavated soil generated by the cutting is taken into a chamber 24, which is the space between the cutter head 21 and the partition wall 23.

[0016] The screw conveyor 3 discharges excavated soil from the chamber 24 of the shield machine 2. The screw conveyor 3 comprises a casing 31 and a screw 32 located inside the casing 31. An soil intake port that opens within the chamber is formed at the tip (face-side end) of the screw conveyor 3, and a soil discharge port is formed at the rear end (port-side end) of the screw conveyor 3.

[0017] The soil pumping pipe 4 is made of steel and is connected to the soil discharge port formed at the tunnel entrance end of the screw conveyor 3. The soil pumping pipe 4 is a soil transport means that transports excavated soil discharged from the chamber 24 via the screw conveyor 3 to a hopper 5 located above ground. In this embodiment, the soil pumping pipe 4 is equipped with a flow meter 6 and a density meter 7. The flow meter 6 measures the volume of excavated soil pumped by the soil pumping pipe 4. The density meter 7 measures the density of excavated soil pumped by the soil pumping pipe 4. The flow meter 6 and the density meter 7 are communicatively connected to a control device (not shown), and the measurement results are transmitted to the control device.

[0018] Furthermore, the soil conveying pipe 4 is connected to the soil conveying pump 41. In this embodiment, a total of three soil conveying pumps 41, 41, 41 are provided: one at the joint between the soil conveying pipe 4 and the screw conveyor 3, and two in the section from the screw conveyor 3 to the hopper 5. Excavated soil is conveyed into the soil conveying pipe 4 towards the hopper 5 by the pressure of the soil conveying pump 41. The soil conveying pump 41 is equipped with a counter that measures the number of times the soil conveying pump 41 has been operated. The counter is connected to a control device (not shown) in a communication manner, and the measurement results are transmitted to the control device.

[0019] The hopper 5 is located outside the shaft S (above ground) and is used to store excavated soil transported via the soil pumping pipe 4. The hopper 5 in this embodiment has a volume capable of storing excavated soil equivalent to one tunnel length. The hopper 5 is also equipped with a weighing scale 51 for measuring its weight. The weighing scale 51 is connected to a control device (not shown) for communication, and the measurement results are transmitted to the control device.

[0020] In this embodiment, an earth and sand pit 9 is provided near the hopper 5 outside the vertical shaft S. The excavated earth and sand discharged from the hopper 5 is put into the earth and sand pit 9. The earth and sand pit 9 has a volume larger than the volume of the hopper 5 (for example, twice or more), and can store the excavated earth and sand generated by excavation for a plurality of rings. The excavated earth and sand stored in the earth and sand pit 9 is put into a transport vehicle and transported to a disposal site.

[0021] The three-dimensional measuring device 8 is provided above the hopper 5. The three-dimensional measuring device 8 is a device that measures the three-dimensional shape of an object. The three-dimensional measuring device 8 can be, for example, a LiDAR (Light Detection and Ranging) that measures scattered light with respect to laser irradiation, but is not limited thereto. The three-dimensional measuring device 8 measures the desired shape from above the hopper 5 by acquiring point cloud data of at least a part of the hopper 5 from above the hopper 5. The three-dimensional measuring device is communicably connected to a management device (not shown), and the measurement result is transmitted to the management device.

[0022] The tunnel is constructed by excavating the ground with the shield machine 2 and forming and arranging segment rings behind the shield machine 2 in the ground. The shield machine 2 advances by taking reaction force from the segment rings with the shield jacks. That is, the shield machine 2 advances one ring while assembling segment rings behind. Along with this, the excavated earth and sand for one ring of the excavation length is discharged from the chamber 24. At this time, the earth volume management of the excavated earth and sand discharged by the excavation of the shield machine 2 is performed.

[0023] Hereinafter, an earth volume measurement method using the earth volume measurement system 1 of this embodiment will be described. Fig. 2 shows the procedure of the earth volume measurement method. As shown in Fig. 2, the earth volume measurement method includes a preparation step S1, a measurement step S2, a weight calculation step S3, a volume calculation step S4, and a specific gravity calculation step S5.

[0024] Preparation step S1 involves measuring the weight of the hopper 5 at the start of excavation, which is the weight of the hopper 5 at the start of excavation, and measuring the internal shape of the hopper 5 at the start of excavation using a three-dimensional measuring device 8.

[0025] In measurement process S2, the weight of the hopper 5 with excavated soil inside is measured, and the shape of the top surface of the hopper 5 with excavated soil inside is measured using a three-dimensional measuring device 8. The measurement of the weight of the hopper and the shape of the soil inside is performed continuously in parallel with the tunnel excavation. After the measurement, the excavated soil in the hopper 5 is put into the soil pit 9.

[0026] The excavated soil discharged from the chamber 24 via the screw conveyor 3 is then transported to the hopper 5 via the soil pumping pipe 4.

[0027] In this embodiment, the volume of excavated soil is measured by the rotation speed of the screw conveyor 3 during excavation. Additionally, the volume of excavated soil is calculated by multiplying the number of pumping cycles (operations) of the soil pumping pump 41 connected to the soil pumping pipe 4 by the amount of soil pumped per pumping cycle. Furthermore, the volume of excavated soil is measured by accumulating the flow rate of the excavated soil that has passed through the flow meter 6 connected to the soil pumping pipe 4. According to the excavated soil volume measurement system 1 of this embodiment, the amount of excavated soil corresponding to each segment ring (excavation position) can be measured in the hopper 5. By determining the correlation (conversion formula or conversion coefficient) between the volume of excavated soil calculated from the rotation speed of the screw conveyor 3, the number of pumping cycles of the soil pumping pump 41 (preferably the soil pumping pump 41 installed at the joint between the soil pumping pipe 4 and the screw conveyor 3), and the measured value of the flow meter 6 from past data, and comparing this with newly acquired data, it becomes easy to detect, for example, when the rotation speed of the screw conveyor 3 shows an abnormal value, and the data showing an abnormal value can be supplemented with other data. Therefore, excavated soil volume management can be performed with high accuracy.

[0028] In the weight calculation process S3, the weight of excavated soil is calculated by subtracting the weight of the hopper at the start of excavation from the weight of the soil-filled hopper. In the volume calculation process S4, the volume of excavated soil is calculated from the shape of the hopper interior and the shape of the soil load at the start of excavation. In the specific gravity calculation process S5, the specific gravity of the excavated soil is calculated using the weight and volume of the excavated soil.

[0029] Furthermore, the accuracy of the measurement results is improved by simultaneously comparing the values ​​calculated using all soil volume measurement methods. For example, by determining the correlation (conversion formula or conversion coefficient) between the excavated soil volume calculated in volume calculation step S4 and the flow meter measurement value from past data, and comparing this with the correlation between the newly acquired excavated soil volume and the flow meter measurement value, it becomes easy to detect anomalies, and one of the anomaly values ​​can be compensated for using the other value. Similarly, by determining the correlation (conversion formula or conversion coefficient) between the specific gravity calculated in specific gravity calculation step S5 and the density meter measurement value (specific gravity) from past data, and comparing this with the correlation between the newly acquired specific gravity and the density meter measurement value, it becomes easy to detect anomalies, and one of the anomaly values ​​can be compensated for using the other value.

[0030] According to the excavated soil volume measurement system 1 and the excavated soil volume measurement method using the same of this embodiment, the weight scale 51 that measures the weight of the hopper 5 and the three-dimensional measuring device 8 that measures the shape of the hopper 5 from above the hopper 5 make it possible to accurately determine the weight, volume, and specific gravity of the excavated soil generated in a mud pressure balance shield at an appropriate time.

[0031] Furthermore, soil management involves calculating the specific gravity in addition to the weight of the excavated soil, making disposal management easier.

[0032] The volume of excavated soil transported by the soil transport pipe 4 is measured by a flow meter 6 installed in the soil transport pipe 4, converted by the number of pumping cycles (operations) of the soil transport pump 411, and further converted by the rotation speed of the screw conveyor 3. By comparing these measurement results with the measurement results from the hopper 5, it is possible to determine any abnormalities in the measuring instruments or changes in the properties of the excavated soil.

[0033] Furthermore, since it is equipped with a densimeter 7 for measuring the density of excavated soil, the measurement results of the densimeter can be compared with the values ​​calculated using the measurement results from the hopper 5 (measurement results of the weight of the soil-filled hopper and the shape of the soil loading), thereby allowing for the determination of abnormalities in each measuring instrument and changes in the properties of the excavated soil.

[0034] By calculating the amount of excavated soil per excavation length for one ring from the rotation speed of the screw conveyor 3 and comparing it with the planned amount of excavated soil, it is possible to check whether or not there is a collapse of the ground at the face of the tunnel. Therefore, by understanding in real time whether or not auxiliary construction methods are necessary, the impact on the surrounding ground can be minimized. By comparing the amount of excavated soil obtained from the rotation speed of the screw conveyor 3, the amount of excavated soil obtained from the number of pumping cycles of the soil pumping pump 41, and the measured values ​​of the flow meter 6 with the measurement results from the hopper 5 (measurement results of soil-filled hopper weight and soil loading shape), it is possible to easily identify the occurrence or warning signs of abnormal values.

[0035] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and each of the above-mentioned components can be modified as appropriate without departing from the spirit of the present invention. For example, in the above embodiment, a case was described in which a flow meter 6 and a density meter 7 are provided in the soil pumping pipe 4, but the flow meter 6 and density meter 7 may be provided only as needed. Furthermore, only one of the flow meter 6 or the density meter 7 may be installed.

[0036] The soil pumping pumps 41 may be installed as needed. The number and placement of the soil pumping pumps 41 may be determined appropriately according to factors such as the distance from the shield machine to the hopper and the excavation speed. Furthermore, it is not necessary for the soil pumping pumps 41 to have counters. Furthermore, volume measurement using the screw conveyor 3 can be performed as needed.

[0037] In the above embodiment, the case where the soil transport means is a soil pumping pipe 4 was described, but the soil transport means is not limited to a pipeline, and may be, for example, a belt conveyor. When using a belt conveyor as the soil transport means, it is desirable to measure the weight of the excavated soil using a weighing scale such as a belt scale or the measurement value of the screw conveyor 3, and to measure the volume of the excavated soil using a belt scanner. By doing so, the measurement results from the belt conveyor can be compared with the measurement results from the hopper 5 (measurement results of the weight of the soil-filled hopper and the shape of the soil load) to determine any abnormalities in each measuring instrument or changes in the properties of the excavated soil.

[0038] Hopper 5 does not necessarily need to have a volume capable of storing the excavated soil equivalent to one tunneling ring; the volume of hopper 5 can be determined as appropriate. Measurements in hopper 5 can be performed at any time regardless of the volume of hopper 5, so soil volume management is possible even if the volume of hopper 5 is small compared to the amount of excavated soil equivalent to one tunneling ring. If the volume of hopper 5 is less than the amount equivalent to one tunneling ring, excavation and measurement are carried out until hopper 5 is full, then excavation is stopped, the soil in hopper 5 is emptied, and then excavation and measurement are resumed. This process is repeated until one tunneling ring is completed.

[0039] In the above embodiment, the volume of excavated soil is measured using the screw conveyor 3 and the soil pumping pump 41, but the measurement of the volume of excavated soil using the screw conveyor 3 or the soil pumping pump 41 should be performed as needed. [Explanation of symbols]

[0040] 1. Excavation volume measurement system 2 Shield Units 21 Cutter head 22 Main body 23 Bulkhead 24 chambers 3 Screw conveyor 4. Soil and sand pumping pipe 41. Soil and sand pump 5 Hopper 6 Flowmeter 7 Density meter 8. Three-dimensional measuring device 9. Soil pit S1 Preparation process S2 measurement process S3 Weight calculation process S4 Volume calculation process S5 Specific gravity calculation process S Shaft T Tunnel

Claims

1. A screw conveyor that discharges excavated soil from the chamber of the shield machine, A means of transporting soil and sand connected to the screw conveyor, A hopper located outside the shaft into which the excavated soil transported via the soil transport means is fed, A weighing scale for measuring the weight of the hopper, An excavated soil volume measurement system characterized by comprising a three-dimensional measuring device for measuring the shape of the hopper from above the hopper.

2. The aforementioned means of transporting soil and sand is a soil and sand pumping pipe. The excavated soil volume measurement system according to claim 1, characterized in that it is equipped with a flow meter for measuring the volume of excavated soil being pumped by the soil pumping pipe.

3. The excavated soil volume measurement system according to claim 2, further comprising a soil pump connected to the soil pumping pipe and a counter for measuring the number of times the soil pump is operated.

4. The aforementioned means of transporting soil and sand is a belt conveyor. A weighing scale for measuring the weight of excavated soil transported by the aforementioned belt conveyor, The excavated soil volume measurement system according to claim 1, further comprising a belt scanner for measuring the shape of excavated soil transported by the belt conveyor.

5. A method for measuring the volume of excavated soil using the excavated soil volume measurement system described in claim 1, A preparatory step involves measuring the hopper weight, which is the weight of the hopper at the start of excavation, and measuring the internal shape of the hopper at the start of excavation using the three-dimensional measuring device. A measurement process comprising: measuring the weight of the hopper containing excavated soil, which is the weight of the hopper when the excavated soil is loaded into it; and measuring the shape of the top surface of the hopper when the excavated soil is loaded into it, using the three-dimensional measuring device; A weight calculation step to calculate the weight of excavated soil by subtracting the weight of the hopper from the weight of the soil-filled hopper, A volume calculation step for calculating the volume of excavated soil from the hopper internal shape and the soil loading shape, A method for measuring the volume of excavated soil, comprising a specific gravity calculation step of calculating the specific gravity of the excavated soil using the weight and volume of the excavated soil.

6. The aforementioned means of transporting soil and sand is a soil and sand pumping pipe. The method for measuring the volume of excavated soil according to claim 5, characterized in that the volume of excavated soil is measured by a flow meter connected to the soil pumping pipe.

7. The aforementioned means of transporting soil and sand is a soil and sand pumping pipe. The method for measuring the volume of excavated soil according to claim 5, characterized in that the volume of excavated soil is accumulated by the number of pumping cycles of a soil pump connected to the soil pumping pipe.

8. The aforementioned means of transporting soil and sand is a belt conveyor. The method for measuring the volume of excavated soil according to claim 5, characterized in that a weighing scale provided on the belt conveyor measures the weight of the excavated soil being transported by the belt conveyor, and a belt scanner measures the shape of the excavated soil being transported by the belt conveyor.

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