Working-face-vicinity property measuring device

Abstract

Provided is a working-face-vicinity property measuring device in a shield tunneling machine or a tunnel boring machine, which can be used without boring from above ground, etc. A working-face-vicinity property measuring device 6 (6A, 6B, 6C, 6D, 6E) for use with an earth pressure type shield 1 serving as a shield tunneling machine comprises: an exploration jig 61 which is stored within the shield tunneling machine or a tunnel boring machine and which reaches a working-face vicinity FA; a jack 62 which serves as an advancing and retracting means for causing the exploration jig 61 to advance and retract between the shield tunneling machine or the tunnel boring machine and the working-face vicinity FA; and a displacement sensor 66 which detects an amount of displacement of the exploration jig 61. Among these components, the exploration jig 61 is stored within a fixed mixing blade 55 that projects into a chamber 16 from a separating wall 3 of the shield tunneling machine.

Description

Near-face property measuring device

[0001] The present invention relates to a device for measuring properties near a tunnel face, which is used to measure properties near a tunnel face, including displacement near the tunnel face, earth pressure near the tunnel face, pore water pressure near the tunnel face, pressure in a chamber, and / or pore water pressure in a chamber, from inside a tunnel boring machine, such as a shield machine or a tunnel boring machine.

[0002] Conventionally, in shield construction, ground deformation in front of and around the shield machine has been measured using inclinometers and other devices that utilize boreholes from the ground. In such cases, road restrictions arise due to environmental conditions on the ground, and measurements cannot be taken at any desired location due to soil cover issues. The present invention relates to a device that directly measures properties near the face, including displacement, earth pressure, and / or pore water pressure near the face (e.g., forward), at any desired location.

[0003] Here, "near the face" as used in this invention means the face surface that comes into contact with the shield machine cutter head, in front of the face (approximately 1D), and the area outside the outer periphery of the shield (approximately 1D) (D: outer diameter of excavation), but it is particularly preferable to be able to measure the characteristics of the face and in front of the face (approximately 1D).

[0004] For example, in an earth pressure shield tunnel boring machine, if the pressure inside the chamber is properly managed, the face will not displace significantly, and as a result, displacement of the surrounding ground can be suppressed. Conventional methods for managing mud pressure inside the chamber of an earth pressure shield include methods 1) and 2) shown below.

[0005] 1) A method of calculating active earth pressure, passive earth pressure, static earth pressure, etc. using an earth pressure calculation formula based on the soil constants (φ, C, γ, etc.) of the target ground estimated by a prior soil survey, the groundwater level, and the overburden load, and then setting and managing upper and lower limits of the mud soil pressure inside the chamber based on these values ​​(see, for example, Patent Document 1).

[0006] 2) A method of setting the controlled earth pressure based on the mud pressure in the chamber measured when the shield is stopped (see, for example, non-patent document 1).

[0007] JP 2012-233372 A, "Guidelines for safe and secure construction of shield tunnels," Shield Tunnel Construction Technology Review Committee, December 2021, p. 19

[0008] Issues with Method 1): Preliminary soil surveys are usually carried out by boring, and are often carried out at intervals of about 200m along the length of the route. Therefore, if soil conditions change during that time, it may not be possible to calculate the appropriate control pressure. In addition, because the earth pressure calculation formula itself is theoretical, it does not necessarily accurately calculate the earth pressure on the actual ground.

[0009] Furthermore, shield tunneling routes are almost always planned with road facilities on the ground, and since boring and measurement work from the ground would require road restrictions, it is not possible to frequently measure deformation of the ground near the tunnel face.In addition, the planned depth in urban areas is very deep, and there are often tunnel structures and lifelines in use between the tunnel and the ground, making it physically impossible to carry out the work.

[0010] Furthermore, when measuring the displacement in front of the shield machine using a boring measurement method, the measuring device must be retrieved before the shield machine reaches the measurement position, which requires a temporary interruption of excavation. There is also the risk that the borehole will become a waterway, causing problems such as the sudden outflow of muddy water.

[0011] Issues with method 2): The stopped mud pressure measured when the shield is stopped is thought to reflect the earth pressure acting on the face relatively accurately if the shield itself is not moving and the cutter does not have a face plate. However, if these conditions are not maintained, the stopped earth pressure does not necessarily represent the static earth pressure or active earth pressure of the ground.

[0012] With the pressure control method inside the chamber as described above, there is a possibility that an appropriate control pressure may not be set if the ground conditions or the like change.

[0013] Therefore, the present invention aims to provide a device for measuring properties near the tunnel face that can measure the ground properties around the tunnel face (especially in front of it) at any position regardless of the conditions on the ground or in the intermediate areas, and without interrupting or causing any problems to work, by directly measuring the properties near the tunnel face from inside a shield machine or a tunnel boring machine, rather than using a means for measuring displacement near the tunnel face from the ground.

[0014] In order to solve the above problems, the near-face property measurement device of the present invention is a near-face property measurement device used in a tunnel excavating machine, and comprises an exploration tool stored within the tunnel excavating machine and extending up to the vicinity of the face, an advance / retract means for moving the exploration tool back and forth between the tunnel excavating machine and the vicinity of the face, a displacement sensor for detecting the amount of displacement of the exploration tool, a pressure gauge for measuring earth pressure near the face, and / or a water pressure gauge for measuring pore water pressure near the face. Here, "inside the tunnel excavating machine" not only refers to the area behind the partition wall (the tunnel portal side), but also includes the cutter spokes, a storage box installed behind the cutter and in front of the partition wall, the cutter face plate, and the inside of the mixing blades.

[0015] In addition, the controlled earth pressure setting system of the present invention is a controlled earth pressure setting system for a tunnel boring machine, and comprises a pressure gauge that measures the mud pressure in a chamber, a mud pressure changing means that changes the mud pressure in the chamber, the above-mentioned near-face property measuring device, an analysis unit that analyzes the deformation characteristics of the ground based on the measured mud pressure and the measured face displacement, and a setting unit that sets the controlled earth pressure based on the analyzed deformation characteristics.

[0016] In this way, the near-face property measuring device of the present invention comprises an exploration tool that is stored within the tunnel boring machine and reaches the vicinity of the face, an advancing / retracting means for moving the exploration tool back and forth between the tunnel boring machine and the vicinity of the face, a displacement sensor that detects the amount of displacement of the exploration tool, an earth pressure meter that measures earth pressure near the face, and / or a water pressure meter that measures pore water pressure near the face. Therefore, the properties near the face can be accurately detected based on actual measured values ​​at any measurement position.

[0017] Furthermore, the system for setting the controlled earth pressure in a tunnel boring machine of the present invention comprises a pressure gauge that measures the mud pressure in the chamber, mud pressure changing means that changes the mud pressure in the chamber, the near-face property measuring device described above, an analysis unit that analyzes the deformation characteristics of the ground based on the measured mud pressure and the measured displacement near the face, and a setting unit that sets the controlled earth pressure based on the analyzed deformation characteristics. Therefore, the system for setting the controlled earth pressure in a tunnel boring machine is one that does not set the controlled earth pressure based on assumptions or estimates, but can confirm the validity of the controlled earth pressure by directly measuring the displacement near the face.

[0018] 1 is a cross-sectional view illustrating the internal structure of a shield tunneling machine. FIG. 1 is a cross-sectional view illustrating the configuration of the face vicinity property measuring device of Example 1 when stored. FIG. 1 is a cross-sectional view illustrating the configuration of the face vicinity property measuring device of Example 1 when reaching the face. FIG. 2 is an explanatory diagram illustrating variations in the shape of the tip of the exploration jig. FIG. 2 is a cross-sectional view illustrating the configuration of the face vicinity property measuring device of the first and second modified examples. FIG. 3 is a cross-sectional view illustrating the configuration of the face vicinity property measuring device of the third modified example when stored. FIG. 3 is an explanatory diagram illustrating the configuration of the face vicinity property measuring device of the third modified example. (a) is the configuration during the operation, and (b) is the configuration when reaching the face. FIG. 4 is an explanatory diagram illustrating the configuration of the face vicinity property measuring device of the fourth modified example. FIG. 4 is an explanatory diagram illustrating the configuration of the face vicinity property measuring device of the fifth modified example. FIG. 5 is a flowchart illustrating the procedure of a system for setting controlled earth pressure. FIG. 6 is a graph showing the relationship between mud pressure and horizontal displacement in a depressurization test.

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the components described in the following embodiments are merely examples and are not intended to limit the technical scope of the present invention to those. Note that, although the following description will use an earth pressure shield 1 as an example of a tunnel boring machine, the present invention can also be applied to other types of tunnel boring machines, such as a slurry shield, an earth pressure shield, an air bubble shield, a slurry shield, a thick slurry shield, and a tunnel boring machine.

[0020] (Configuration of a shield tunneling machine) Figure 1 is a longitudinal side view showing an embodiment of the present invention. As shown in Figure 1, the earth pressure shield 1 as a tunnel boring machine of this embodiment comprises a skin plate (shield main body cylinder) 2, a partition wall 3, a cutter head 5, a cutter rotation shaft 10, a cutter drive unit 12, a chamber 16, an earth removal device 17, a shield propulsion jack 18, mud-making material supply piping 21, a pressure gauge 22, a water pressure gauge 23, and a control unit 40 including an analysis unit 41 and a setting unit 42 arranged inside an operation chamber or the like.

[0021] The cutter head 5 has cutter spokes 51, a plurality of cutter bits 52 provided on the front surface of the cutter spokes 51, a fishtail bit 53 provided in the center of the front surface of the cutter spokes 51, and a plurality of stirring blades 54 provided on the back surface of the cutter spokes 51. The cutter head 5 is integrally attached to the cutter rotation shaft 10.

[0022] The cutter rotation shaft 10 is rotatably supported by a bearing 11 provided in the partition wall 3 and a bearing provided at the rear of a gear box 13 (described later). The cutter rotation shaft 10 is connected to a cutter drive unit 12. The cutter drive unit 12 has a gear box 13 installed on the rear side of the partition wall 3, a rotary drive source 14 connected to the gear box 13, and a reduction gear (disposed in the gear box 13; not shown) interposed between the output shaft of the rotary drive source 14 and the cutter rotation shaft 10.

[0023] The chamber 16 is formed by a space surrounded by the hood portion 2a of the skin plate 2, the partition wall 3, and the working face F. A screw conveyor, for example, is used as the earth removal device 17. The mud intake port of the earth removal device 17 is opened and installed so as to face the chamber 16. In this embodiment, the earth removal device 17 also functions as a mud pressure changing means.

[0024] Furthermore, an erector 15 for assembling the segments 90 is installed in the tail portion 2b of the skin plate 2. Furthermore, a plurality of shield propulsion jacks 18 are installed at required intervals in the circumferential direction inside the skin plate 2. In addition, a tail seal 19 is provided at the rear end of the skin plate 2.

[0025] (Configuration of near-face property measuring device 6) The earth pressure shield 1 as a shield tunneling machine in this embodiment is further equipped with a near-face property measuring device 6 that measures displacement at the face and / or near the face. Here, using Figures 2 and 3, an on-board measurement type near-face property measuring device 6 that measures the properties near the face from inside the machine will be described. Here, the properties near the face refer to at least one of the three properties: displacement near the face, earth pressure near the face, or pore water pressure near the face, and it is also possible for the device to measure two or more properties.

[0026] 2, the face vicinity property measuring device 6 of this embodiment is a rod-shaped probe jig 61 having a sufficient length to penetrate the partition wall 3 and the fixed mixing blade 55 and have a tip 610 reach, abut or penetrate the face vicinity FA, ​​and a hydraulic chuck 63 that grips / releases the probe jig 61 and moves / releases the probe jig 61 in accordance with the extension and contraction of jacks 62, 62 as advancing and retracting means, a detection unit 64 attached integrally to the end of the probe jig 61, a guide 65 that supports the sliding movement of the detection unit 64, a displacement sensor 66 that measures the displacement amount of the probe jig 61 by measuring the distance to the detection unit 64, a water stop device 67 for the probe jig 61, and water stop valves 68, 68A. Here, the face vicinity property measuring device 6 of this embodiment will be described in terms of measuring the "displacement" near the face as a property near the face.

[0027] That is, in this embodiment, the probe jig 61 is stored in the fixed agitator 55 that protrudes from the partition 3 into the chamber 16 and can be freely moved in and out (advance and retreat; enter and exit freely). That is, the fixed agitator 55 has a hole (through which the rod-shaped main body 613 of the probe jig 61 is inserted) formed through the center of the cross section along the axial direction. In this way, the probe jig 61 (the tip 610) moves and reaches from the tip of the fixed agitator 55 to the vicinity of the face FA, where it abuts or penetrates. In this embodiment, the probe jig is expressed as moving and reaching the vicinity of the face using the fixed agitator and abutting or penetrating, but if it has a similar shape (for example, a dedicated storage box 55A is separately prepared), it does not have to fulfill the purpose of the fixed agitator.

[0028] The detecting jig 61 is composed of a rod-shaped main body 613 and a tip 610 formed at the tip of the main body. The end of the main body is gripped by a hydraulic chuck 63. As will be described later with reference to Figures 4(a) to 4(f), the shape of the tip 610 may be a protruding conical portion 611a, or a shape combining an expanded flange portion 612 with the conical portion 611a at the center of the flange portion 612.

[0029] Therefore, when the hydraulic chuck 63 grips the detection jig 61, the detection jig 61 retreats when the jacks 62, 62 extend, and advances when the jack 62 retracts. When the hydraulic chuck 63 is released, the detection jig 61 is free. Therefore, in the open state (where the detection jig 61 can move freely), if the tip 610 of the detection jig 61 abuts or penetrates the face-near FA, the detection jig 61 moves (in the tunnel longitudinal direction) in accordance with the displacement of the face-near FA. As described below, in the present invention, the face-near FA protrudes slightly by reducing the mud pressure in the chamber 16, so the detection jig 61 moves in the tunnel longitudinal direction toward the tunnel portal.

[0030] (Operation Procedure) Next, using Figures 2 and 3, the operation procedure of the face vicinity property measuring device 6, which is equipped with the exploration tool 61, the jack 62 as an advance / retract means, and the displacement sensor 66, in the depressurization test of this embodiment will be described. 1. During shield tunneling, the exploration tool 61 is retracted to the position of the fixed mixing blade 55 (Figure 2). In other words, by extending the jack 62, the exploration tool 61 is housed at the tip of the fixed mixing blade 55. 2. After the shield stops, the exploration tool 61 is gripped by the hydraulic chuck 63 and slid to a position where the tip 610 abuts or penetrates the face F or face vicinity FA (see Figure 3). At this time, the jack 62 is retracted. 3. After the tip 610 of the exploration tool 61 abuts or penetrates the face F or face vicinity FA, ​​the hydraulic chuck 63 is released. This allows the detection jig 61 to move freely in the longitudinal direction of the tunnel (forward and backward directions) without being restricted. 4. The soil removal means (soil removal device 17) is operated at a slow speed to gradually reduce the mud pressure in the chamber 16. 5. As the pressure is reduced, the face F or the FA near the face is displaced, and this displacement pushes the detection jig 61 toward the inside of the shield. 6. The detection jig 61 is fitted with a measuring device (detection unit 64, displacement sensor 66) inside the shield. The amount of displacement is measured by the displacement sensor 66 via the detection unit 64. 7. The measurement value is sent from the displacement sensor 66 to the PC. At the same time, the mud pressure in the chamber 16 is measured by the pressure gauge 22 installed on the partition wall 3. 8. Using the above procedure, the relationship between the mud pressure in the chamber 16 and the amount of displacement of the face F or the FA near the face is determined. 9. The decompression test is stopped when all or part of the transition region (including the yield point) in the displacement near the face has been clarified. 10. Then, for example, the soil discharge means (soil discharge device 17) is reversed to return the mud and increase the mud pressure in the chamber 16 to its initial state. 11. The hydraulic chuck 63 grips the detecting jig 61 again and pulls it back by operating the jack 62, retracting the detecting jig 61 to the position of the fixed mixing blade 55 (see Figure 2). At this time, the jack 62 is extended.

[0031] 4A to 4F, various aspects of the tip 610 of the probe jig 61 will be described. Note that the tip 610 of the probe jig 61 is not limited to the examples and modified examples described below.

[0032] First, as shown in FIG. 4A, the tip 610 of the detecting jig 61 of the embodiment is configured with a conical portion 611a protruding from the tip.

[0033] 4(b), the tip 610 of the exploration jig 61 of the embodiment is composed of a flange 612 and a cone portion 611a protruding from the tip. The presence of the flange 612 makes it easier for the tip 610 to move together with the natural ground (towards the near side; towards the tunnel entrance).

[0034] 4(c), tip 610 of the modified example is composed of flange portion 612 and one (thin) arrow portion 611b with a conical "barb" at the tip. By having such a barb, tip 610 that has been stuck into the natural ground becomes one with the natural ground and is less likely to come out.

[0035] 4(d), tip 610 of another modified example is composed of flange portion 612 and multiple (here, two; thin diameter) arrow portions 611b, 611b each having a conical barb at the tip. The presence of multiple arrow portions 611b makes tip 610 more difficult to remove once it has penetrated the natural ground.

[0036] Next, as shown in Figure 4(e), the tip 610 of another modified example is composed of a flange portion 612 and a drill portion 611c having a drill shape at the tip. The presence of the drill portion 611c makes it difficult for the tip 610 to be inserted into the natural ground and become one with the natural ground. It is preferable that the drill portion 611c be able to rotate freely around its axis.

[0037] 4(f), the tip 610 of another modified example does not have a flange (612) and is composed of only one (thin) arrow portion 611b with a conical barb at the tip. In this way, the absence of a flange makes it easier to pass through the chamber 16.

[0038] (First Modification: Configuration of the Near-Face Property Measuring Device 6A) Next, the configuration of the near-face property measuring device 6A of the first modification will be described using Figure 5. As shown in the upper part of Figure 5, in the near-face property measuring device 6A of this modification, the cylinder portion 62a and rod portion 62b of the jack 62 serving as an advancing / retracting means are stored within the fixed mixing blade 55. That is, while in the embodiment the jack 62 is configured to be attached to the rear (inside the machine) of the partition wall 3, in this modification the jack 62 penetrates the partition wall 3 and is accommodated within the fixed mixing blade 55 or the storage box 55A. The near-face property measuring device 6A of this modification will be described in the case where it measures "displacement" near the face as a property near the face.

[0039] The rod portion 62b of the jack 62 serves as the detection jig 61, which protrudes from the tip of the fixed mixing blade 55 or the storage box 55A and reaches, abuts, or penetrates the vicinity of the face FA. Specifically, the displacement measurement method involves providing a through hole along the axial direction at the center of the cross section of the detection jig 61 (62b), into which the rod of the displacement sensor 66 is inserted. When the detection jig 61 slides back and forth, the relative displacement between the detection unit 64 attached to the detection jig 61 and the rod of the displacement sensor 66 can be measured.

[0040] The measurement procedure in this case is as follows: 1) During shield tunneling, the rod portion 62b of the detection jig 61 is stored in the fixed mixing blade 55 or the storage box 55A. 2) When the shield is stopped, the jack 62 is operated to extend the detection jig 61 (i.e., the rod portion 62b) forward and bring its tip into contact with or penetrate the FA near the face. 3) After the detection jig 61 is securely in contact with or penetrates the FA near the face, the hydraulic pressure of the jack 62 is released, allowing the detection jig 61 to move freely. 4) In this state, when the FA near the face is displaced, the detection jig 61 is pushed back, and the amount of displacement can be measured by the detection unit 64 and the displacement sensor 66. In this modified example, the cylinder portion 62a of the jack 62 that slides the detection jig 61 penetrates the partition wall and is located in the fixed mixing blade 55 or the storage box 55A, so the amount of protrusion behind the partition wall 3 can be further shortened compared to the embodiment.

[0041] (Second Modification: Configuration of Measuring Device 6B for Properties in the Vicinity of Face) Next, the configuration of Measuring Device 6B for Properties in the Vicinity of Face in a second modification will be described with reference to Fig. 5. As shown in the center of Fig. 5, in Measuring Device 6B for Properties in the Vicinity of Face in this modification, the cylinder portion 62a and rod portion 62b of the jack 62 serving as advancing and retreating means are stored in the cutter spokes 51. That is, while in the embodiment, the jack 62 is configured to be attached to the rear of the bulkhead 3 (on the inside of the machine), in this modification, the jack 62 is accommodated in the cutter spokes 51. The Measuring Device 6B for Properties in the Vicinity of Face in this modification will be described in the case where it measures the "displacement" of the face as a property of the face.

[0042] Furthermore, in this modified example, if the length of the near-face property measuring device 6B is longer than the depth of the cutter spokes 51, the rear of the near-face property measuring device 6B may be placed inside the (moving) mixing blade 54. In this case, as long as there is enough space to place the device (for example, using a storage box 54A), it does not have to fulfill the purpose of a (moving) mixing blade. The rod portion 62b of the jack 62 serves as the detection jig 61, and protrudes from the surface of the cutter spoke 51 on the face side and reaches, abuts, or penetrates the near-face FA.

[0043] As with the first modified example, the displacement measurement method involves providing a through-hole along the axial direction at the cross-sectional center of the detection jig 61 (62b), into which the rod of the displacement sensor 66 is inserted. When the cutter bit 52 is used as the tip 610, a through-hole is provided on the face side of the cutter spoke 51. When the detection jig 61 slides back and forth, the relative displacement between the detection unit 64 attached to the detection jig 61 and the rod of the displacement sensor 66 can be measured. The hydraulic oil line for driving the jack 62 and the signal line from the displacement sensor 66 run through the cutter rotation shaft 10 to the inside of the shield machine behind the bulkhead 3. The measurement procedure is similar to that of the near-face property measuring device 6A of the first modified example, and therefore will not be described here.

[0044] (Third Modification: Configuration of the Face Vicinity Property Measuring Device 6C) Next, the configuration of the face vicinity property measuring device 6C of the third modification will be described using Figure 6. As shown in Figure 6, the face vicinity property measuring device 6C of this modification has a jack 62 (cylinder portion 62a and rod portion 62b) serving as an advancing / retracting means and an exploration jig that moves back and forth from the inside of the machine through the partition wall 3 into the chamber 16. That is, while in the embodiment the jack 62 is configured to be attached to the rear of the partition wall 3 (the inside of the machine), in this modification the jack 62 (dual-purpose exploration jig 61) itself is moved back and forth by second jacks 69, 69 that serve as an inside advancing / retracting means. The face vicinity property measuring device 6C of this modification will be described in terms of the case where it measures the "displacement" of the face as a face property.

[0045] That is, in this modification, the jack 62 in the fixed mixing blade 55 or the storage box 55A described in the first modification has a sliding structure. Specifically, the jack 62 is held by second jacks 69, 69 serving as inboard advancing / retreating means via a bracket 70, and the second jacks 69, 69 are attached to the back side of the bulkhead 3 so as to receive a reaction force. Therefore, when the second jack 69 is extended, the jack 62 moves inboard, and when the second jack 69 is retracted, the jack 62 moves toward the face F. Then, when the second jack 69 is retracted and the jack 62 is located toward the face F, the jack 62 is extended so that the rod portion 62b abuts or penetrates the face vicinity FA.

[0046] As in the first and second modified examples, the displacement measurement method is such that a through-hole is provided in the center of the cross section of the detecting jig 61 (62b) along the axial direction, and the rod of the displacement sensor 66 is inserted into the through-hole. When the detecting jig 61 slides back and forth, the relative displacement between the detecting unit 64 attached to the detecting jig 61 and the rod of the displacement sensor 66 can be measured.

[0047] The measurement procedure in this case is as follows: 1) During shield tunneling, the rod portion 62b of the detection jig 61 is stored inside the bulkhead 3 (see Figure 6). 2) When the shield is stopped, the second jack 69 is retracted to move the jack 62 forward (see Figure 7(a)). 3) The jack 62 is then extended so that the rod portion 62b, i.e., the detection jig 61, reaches, abuts, or penetrates the vicinity of the tunnel face (see Figure 7(b)). 4) Once the detection jig 61 has reliably abutted or penetrated the tunnel face F, the hydraulic pressure of the jack 62 is released, allowing the detection jig 61 to move freely. 5) In this state, when the area FA near the tunnel face is displaced, the detection jig 61 is pushed back and the amount of displacement can be measured by the detection unit 64 and the displacement sensor 66.

[0048] By dividing the required stroke into two stages in this way, the amount of protrusion of the near-face property measuring device 6C into the machine is reduced. During excavation, the state shown in Figure 6 is maintained, so the fixed mixing blades (55) do not protrude into the chamber 16. This structure prevents deformation and damage to the near-face property measuring device 6C due to the gravel getting caught in the excavated ground.

[0049] (Fourth Modification: Configuration of the Near-Face Property Measuring Device 6D) Next, the configuration of the near-face property measuring device 6D of the fourth modification will be described using FIG. 8 . As shown in FIG. 8 , in the near-face property measuring device 6D of this modification, the cylinder portion 62a and rod portion 62b of the jack 62 serving as a moving means are housed within the cutter spokes 51 and the agitator 54. If the cutter spokes 51 are sufficiently large, the near-face property measuring device 6D can be housed within the cutter spokes 51 without using the agitator 54. Even if the cutter spokes 51 protrude rearward, it is not necessarily required to have the function of the agitator 54. For example, a storage box 54A large enough to store the device may be newly provided. That is, while in the embodiment, the jack 62 is configured to be attached to the rear (inside the machine) of the bulkhead 3, in this modification, the jack 62 is housed within the cutter spokes 51 and the agitator 54, or within the storage box 54A, as in the second modification. The near-face property measuring device 6D of this modified example will be described as measuring "earth pressure" near the face as the property near the face.

[0050] More specifically, in this modified example, the length of the near-face property measuring device 6D is longer than the depth of the cutter spokes 51, so the rear part of the near-face property measuring device 6D is arranged inside the (moving) mixing blade 54. The rod portion 62b of the jack 62 is integrated with the detection jig 61, and the cutter bit 52 installed on the face side of the detection jig 61 reaches, abuts, or penetrates the near-face FA.

[0051] In this modification, the tip 610 of the rod portion 62b is integral with the cutter bit 52. In this case, when not performing measurements, for example during excavation work, the tip 610 can be retracted further rearward than the other cutter bits 52, thereby preventing wear on the cutter bits 52 and damage to the measuring device. Furthermore, because the cutter spokes 51 rotate, measurements can be made at any position on the circumference, thereby expanding the range of measurement positions.

[0052] Furthermore, in the near-face property measuring device 6D of this embodiment, the tip 610 of the rod portion 62b is the cutter bit 52. Therefore, if the detecting jig 61 is configured to be extended to the position near the face FA and excavate before stopping excavation, it becomes possible to reliably abut the detecting jig 61 against the face even in hard ground that is difficult to penetrate.

[0053] Additionally, the near-face property measuring device 6D has, in addition to the displacement sensor 66 similar to that of the embodiment, an earth pressure meter 22A for measuring earth pressure near the face FA. In this modification, the earth pressure meter 22A is embedded in a recess provided in approximately the center of the cutter bit 52. As described above, the cutter bit 52 is attached to the face side (tip side) of the exploration jig 61 integrated with the jack 62, and therefore can be moved forward and backward by operation of the jack 62.

[0054] In this modified example, the case where the earth pressure gauge 22A is installed on the cutter bit 52 has been described, but the present invention is not limited to this, and a water pressure gauge 23A may be installed instead of the earth pressure gauge 22A to measure pore water pressure. These measuring instruments do not have to be placed in the center of the cutter bit 52 as described in the embodiment, and may be placed on the side of the cutter bit 52 or on the cutter spokes 51. In this case, it is more preferable to install them at the same depth position.

[0055] (Fifth Modification: Configuration of the Near-Face Property Measuring Device 6E) Next, the configuration of the near-face property measuring device 6E of the fifth modification will be described using FIG. 9 . As shown in FIG. 9 , in the near-face property measuring device 6E of this modification, the cylinder portion 62a and rod portion 62b of the jack 62 serving as the advancing / retracting means are stored within the cutter spokes 51 and (movable) agitator blade 54, or within the storage box 54A, as in the fourth modification. If the cutter spokes 51 are sufficiently large, they can be stored within the cutter spokes 51 without using an agitator blade or the like. Even if storage is required, the agitator blade function is not necessarily required; the device only needs to be large enough to store it. That is, while in the embodiment, the jack 62 was configured to be attached to the rear (inside the machine) of the bulkhead 3, in this modification, like the second and fourth modifications, the jack 62 is stored within the cutter spokes 51 and (movable) agitator blade 54, or within the storage box 54A. The near-face property measuring device 6E of this modified example will be described as measuring the "earth pressure" near the face and the "pressure in the chamber" as the properties near the face.

[0056] More specifically, in this modification, the length of the near-face property measuring device 6E is longer than the depth of the cutter spokes 51, so the rear part of the near-face property measuring device 6E is placed inside the (moving) stirring blade 54 or the storage box 54A. The rod portion 62b of the jack 62 is integrated with the detection jig 61, and the cutter bit 52 installed on the face side of the detection jig 61 reaches the near-face FA and abuts or penetrates it.

[0057] In this modification, the tip and trailing portion of the bit 52 have the same cross-sectional shape. This makes it easier to penetrate the vicinity of the face and also prevents the accidental ingestion of soil into the machine (cutter spokes) when retrieving and storing the near-face property device 6E (see Figure 9). Furthermore, as with the fourth modification, if the exploration tool 61 is configured to extend to the near-face FA position before stopping excavation, the exploration tool 61 can be reliably abutted against the face even in hard ground where penetration is difficult.

[0058] In this modification, the tip 610 of the rod portion 62b is integrated with the cutter bit 52. In this case, when not measuring, for example during excavation work, the tip 610 can be retracted further rearward than the other cutter bits 52, thereby preventing wear on the cutter bits 52 and damage to the measuring device. Furthermore, because the cutter spokes 51 rotate, measurements can be made at any position on the circumference, thereby expanding the range of measurement positions.

[0059] Additionally, the near-face property measuring device 6E has, in addition to the displacement sensor 66 similar to the embodiment, an earth pressure meter 22A for measuring earth pressure near the face FA. In this modification, the earth pressure meter 22A is embedded in a recess provided in approximately the center of the cutter bit 52, and one or more earth pressure meter 22A is also provided on the side of the bit (rearward of the tip position). As described above, the cutter bit 52 is attached to the face side (tip side) of the exploration jig 61 integrated with the jack 62, and can therefore be moved forward and backward by operation of the jack 62.

[0060] In this modified example, by inserting the cutter bit 52 into the vicinity of the face, it is possible to measure the earth pressure near the face and the pressure inside the chamber (mud pressure).

[0061] In this modification, the case where the earth pressure gauge 22A is installed on the cutter bit 52 has been described, but the present invention is not limited to this, and as in the fourth modification, the water pressure gauge 23A may be installed instead of the earth pressure gauge 22A to measure the pore water pressure. This makes it possible to measure the pore water pressure near the face and the pore water pressure in the chamber.

[0062] (Configuration of the Controlled Earth Pressure Setting System) The earth pressure shield 1 also includes a control unit 40 (see FIG. 1). The control unit 40 is, for example, a general-purpose personal computer having a memory, a CPU, an SSD, etc. The control unit 40 sets the controlled earth pressure of the earth pressure shield 1 and controls the excavation. That is, during excavation, the earth pressure is changed by discharging mud using the earth discharge device 17 (screw conveyor) as a mud pressure changing means, while the mud pressure is measured using the pressure gauge 22. Furthermore, water pressure is measured using the water pressure gauge 23. Of course, the functions of the analysis unit 41 and the setting unit 42, which will be described later, can be executed by a control unit (computing device; personal computer) separate from the control unit 40 that controls the excavation of the earth pressure shield 1. In this sense, the control unit can also be referred to as a "computing unit."

[0063] The control unit 40 of this embodiment further functions as an analysis unit 41 that analyzes the deformation characteristics of the ground based on the properties near the face, such as the measured mud pressure, the measured displacement near the face (e.g., horizontal displacement), and the measured pore water pressure, and as a setting unit 42 that sets the controlled earth pressure based on the analyzed deformation characteristics. The control unit 40 receives the earth pressure value from the pressure gauge 22 (22A), the pore water pressure value from the water pressure gauge 23 (23A), and the input value (displacement) from the displacement sensor 66 via a communication cable 43, and is also connected to input means such as a keyboard and a mouse. Furthermore, the control unit 40 is connected to a monitor or a separate PC for excavation management as output means. The functions of the analysis unit 41 and the setting unit 42 will be explained in the control flow described below.

[0064] The control earth pressure setting system S of the present invention is composed of the above-mentioned pressure gauge 22, water pressure gauge 23, earth removal device 17 as a mud pressure changing means, face vicinity property measuring device 6 (6A, 6B, 6C, 6D, 6E), and control unit 40 including analysis unit 41 and setting unit 42.

[0065] (Operation) Next, the flow of the controlled earth pressure setting system S of this embodiment will be described with reference to Figures 10 and 11. As shown in Figure 10, the flow of the controlled earth pressure setting system S is realized by executing the following steps S1 to S14.

[0066] Processing of initial values ​​(step S1) First, an initial value of the controlled earth pressure is set (step S2) based on the initial calculated earth pressure set by a boring test or the like (step S1). Then, the shield excavates according to this initial value of the controlled earth pressure (step S3). That is, in the initial stage after the shield starts excavating (before the decompression test is conducted), the controlled earth pressure is set based on the theoretical earth pressure calculated from the soil constants obtained from the preliminary soil survey. Alternatively, the mechanical constants of the ground obtained from the preliminary soil survey are given to the 3D-FEM model, and the controlled earth pressure is set from the relationship between the earth pressure and ground displacement.

[0067] Depressurization Test (Steps S4-S8) Next, with the shield machine stopped and not retreating, the mud pressure in the chamber is reduced (Step S4). That is, when excavation is stopped, such as during assembly of the segments 90, the screw conveyor is rotated slowly to gradually discharge the mud from the chamber 16 and reduce the pressure. During depressurization, the mud pressure is measured using the pressure gauge 22. At the same time, the water pressure is measured using the water pressure gauge 23 (23A). Furthermore, during depressurization, the displacement of the FA near the tunnel face is directly measured using the tunnel face property measurement device 6 (6A, 6B, 6C, 6D, 6E) (Step S5). Based on the measured mud pressure and the displacement near the tunnel face (e.g., horizontal displacement), the deformation characteristics are determined (Step S6). That is, the mud pressure-tunnel face displacement relationship is plotted on a graph to determine the deformation characteristics (see Figure 10). Once the deformation characteristics are determined, the mechanical constants of the ground are analyzed by back analysis (Step S7) (Step S8).

[0068] 3D-FEM model analysis (steps S9 to S12) Then, a 3D-FEM analysis is performed using the mechanical constants of the ground analyzed by the depressurization test (step S9). This 3D-FEM model analysis then predicts the impact on the surrounding ground and adjacent structures (step S10).

[0069] That is, once the deformation characteristics of the target ground are clarified by the depressurization test, the mechanical constants of the ground are calculated (Step S8) by back analysis of a ground model based on the in-situ boundary conditions such as the ground structure assumed from boring surveys and the measured water pressure (Step S7).The mechanical constants of the ground calculated in this way are used to perform a 3D-FEM analysis (Step S9).

[0070] As a result of the analysis, the presence or absence of harmful effects is determined by determining whether the amount of ground surface subsidence, etc. is below the allowable displacement amount (step S11). If harmful effects are found ("Yes" in step S11), the controlled earth pressure is changed (step S12) and the analysis is redone (steps S9 to S11). On the other hand, if harmless ("No" in step S11), the process returns to step S2, where the controlled earth pressure setting system S is executed at the next position and time.

[0071] Here, mechanical constants include, for example, Young's modulus, Poisson's ratio, angle of internal friction, and cohesion. A rational simulation of behavior can be performed by employing an FEM model based on the ground characteristics obtained based on this on-site behavior. Such a rational simulation based on on-site behavior makes it possible to predict ground surface subsidence and its impact on adjacent structures in advance and more accurately, minimizing the impact on the surrounding area or setting controlled earth pressures that correspond to regulatory values ​​for ground displacement, etc.

[0072] Analysis and Setting (Steps S13-S14) Once the ground deformation characteristics are understood, the yield point earth pressure is calculated by analysis from a mud earth pressure-displacement graph, as shown in Figure 11 (Step S13). That is, the analysis unit 41 of the control unit 40 determines the point where the gradient suddenly increases, considers this point as the yield point, and calculates the active earth pressure. For example, the least-squares method can be used to find an approximate line from multiple plots in the elastic region, and another approximate line from multiple plots in the plastic region, and the intersection of these lines can be used to determine the yield point. Alternatively, the appearance of consecutive plots that significantly deviate from the moving average can indicate that the transition region has been reached. If 3D-FEM model analysis is required due to the presence of nearby buildings, etc. (Step S14: "Required"), the impact on the surrounding ground and adjacent structures is predicted by 3D-FEM analysis (Step S10). If 3D-FEM model analysis is not required (Step S14: "Not Required"), the control earth pressure is reset based on the active earth pressure (Step S2). Specifically, it is necessary to ensure that the controlled earth pressure in the chamber 16 during excavation does not fall below the active earth pressure plus water pressure, so the active earth pressure plus water pressure is added, for example, by a factor of 0 to 20 kN / m ２ ) is set as the lower limit of the controlled earth pressure. On the other hand, the upper limit of the controlled earth pressure may be theoretically calculated using C and φ calculated back from the active earth pressure (yield point earth pressure), or may be set as a value that further takes into account the range of construction fluctuations in the above lower limit. On the other hand, if a 3D-FEM model analysis is required ("Required" in step S14), the 3D-FEM model analysis is performed (step S9).

[0073] In this way, the observed digital values ​​(observed values) are compared with the digital values ​​(analytical values) obtained from analysis using the model ground, and the model is constantly corrected to create a model ground that is consistent with changes in the ground as the shield face advances (the so-called "digital twin").

[0074] (Effects) Next, the effects achieved by the tunnel face vicinity property measuring devices 6, 6A, 6B, 6C, 6D, and 6E of this embodiment will be listed and explained.

[0075] (1) As described above, the near-face property measuring device 6 (6A, 6B, 6C, 6D, 6E) of this embodiment is a near-face property measuring device 6 (6A, 6B, 6C, 6D, 6E) used in an earth pressure shield 1 as a shield machine among tunnel boring machines, and is equipped with an exploration jig 61 that is stored within the shield machine, reaches the near-face FA, and abuts or penetrates the near-face area, a jack 62 as an advancing / retracting means for moving the exploration jig 61 back and forth between the shield machine and the near-face FA, and a displacement sensor 66 that detects the amount of displacement of the exploration jig 61. Therefore, the properties near the face can be accurately detected based on actual measurements at any measurement position.

[0076] That is, the tip of the detecting jig 61 reaches the FA near the face and abuts against or penetrates the FA near the face, so that the displacement near the face can be directly and accurately reflected by the detecting jig 61. In this case, since the distance from the partition wall 3 to the face F (i.e., the tip of the cutter bit 52) ​​is known in advance, the detecting jig 61 can be accurately pressed against or penetrated into the FA near the face.

[0077] (2) Furthermore, the near-face property measuring device 6, 6A is preferably configured such that the exploration jig 61 is stored in a fixed mixing blade 55 that protrudes from the partition wall 3 of the tunnel boring machine into the chamber 16, and the tip of the fixed mixing blade 55 reaches the near-face FA. Because this fixed mixing blade 55 protrudes into the chamber 16 from the partition wall 3 toward the face F, the stroke of the exploration jig 61 to the near-face FA can be shortened accordingly.

[0078] Therefore, the displacement of the FA near the face can be measured more accurately by the detection jig 61. In other words, since the distance from the tip of the fixed mixing blade 55 to the FA near the face is shorter than the distance from the surface of the partition wall 3 to the FA near the face, the distance that the detection jig 61 travels back and forth within the chamber 16 can be shortened. Furthermore, since the required stroke is smaller, the size of devices such as the jack 62 for sliding the detection jig 61 back and forth can be reduced. Because the interior of the shield behind the partition wall 3 is narrow, miniaturizing the device is advantageous.

[0079] (3) Furthermore, in the near-face property measuring device 6A, the jack 62 serving as the advancing / retracting means is preferably configured to be composed of a cylinder portion 62a and a rod portion 62b, and is stored within the fixed mixing blade 55, with the rod portion 62b also serving as the detecting jig 61 and configured to reach from the tip of the fixed mixing blade 55 to the near-face FA. By configuring it in this way, the length of the advancing / retracting means (i.e., the jack 62) that protrudes toward the tunnel mouth inside the shield machine can be further shortened. In other words, the amount of protrusion of the jack 62 inside the shield machine can be reduced by the amount of protrusion of the fixed mixing blade 55 into the chamber 16.

[0080] (4) Furthermore, the tunnel face vicinity property measuring device 6C preferably includes a jack 62 as an advancing / retracting means, which is composed of a cylinder portion 62a and a rod portion 62b, and further includes a second jack 69 as an in-machine advancing / retracting means for moving the cylinder portion 62a from the partition wall 3 of the tunnel boring machine into the chamber 16. In this way, by configuring the jack 62 to be slidable back and forth rather than being housed within the fixed mixing impeller 55, obstacles within the chamber 16 can be reduced. In other words, by dividing the required stroke into two stages, the amount of protrusion into the machine can be reduced. During excavation, the fixed mixing impeller does not protrude into the chamber 16, which prevents deformation or damage to the tunnel face vicinity property measuring device 6C due to large gravel or other particles getting caught in the excavated ground.

[0081] In addition, the near-face property measurement devices 6B, 6D, and 6E are preferably configured such that the detection jig 61 is stored within the cutter spokes 51 of the tunnel boring machine and can reach the near-face FA from the cutter spokes 51. By installing the detection jig 61 and the jack 62 in the cutter spokes 51 in this way, the stroke required to reach the near-face FA can be extremely short, making the near-face property measurement device 6 itself very short. Therefore, the detection jig 61 and the jack 62 can be placed inside the cutter spokes 51. In this way, if the measurement device is housed within the cutter spokes 51, the near-face property measurement device 6 can be placed in a narrow space within the shield machine. Furthermore, since the near-face property measurement device 6 can be moved by rotating the cutter head 5, measurement can be performed at any point on a circle of a certain radius from the center of the shield.

[0082] (5) Furthermore, although not shown, it is also preferable that the detection jig (61) is stored in the cutter head face plate, intermediate beam, and / or connecting member of the tunnel boring machine and configured to reach the face. In this way, by installing the detection jig 61 near the face, the stroke required to reach the face vicinity FA can be extremely short, and the length of the face vicinity property measurement device can also be extremely short. Therefore, the detection jig 61 can be stored inside the machine.

[0083] (6) Furthermore, it is preferable that the cutter spokes 51 have a (movable) stirring blade 54 or a storage box 54A on the rear side, and that at least a portion of the detection jig 61 or jack 62 is stored in the (movable) stirring blade 54 or the storage box 54A. If the near-face property measuring device 6 is larger than the depth of the cutter spokes 51, it can be placed inside the (movable) stirring blade 54 or the storage box 54A located behind the cutter spokes 51. In this case, the hydraulic oil line for driving the jack 62 and the signal line from the displacement sensor 66 are led through the center shaft (cutter rotation shaft 10) into the shield machine behind the bulkhead 3.

[0084] In this modified example, the near-face property measuring device 6 is housed inside the cutter spokes 51, so there is no need to place the measuring device in a narrow space inside the shield machine. In addition, the measuring device can be moved by rotating the cutter head 5, so it is possible to measure at any point on a circle of a certain radius from the center of the shield.

[0085] Furthermore, the face vicinity property measuring devices 6D and 6E further include a pressure gauge 22A for measuring the earth pressure in the face vicinity FA or a water pressure gauge 23A for measuring the pore water pressure in the face vicinity FA in the exploration jig 61, so that by measuring the earth pressure and pore water pressure in addition to the displacement, it becomes possible to analyze the properties around the face (ground) in more detail and accurately.

[0086] Furthermore, since the exploration jig 61 of the near-face property measuring device 6E has the same cross-sectional shape from the tip to the rear, it can easily penetrate into the near-face FA with a small load, expanding the range of options for advance / retract structure. It also prevents the erroneous intake of soil and sand when storing the exploration jig. Furthermore, since the measurement devices are located approximately in the center of the tip of the exploration jig 61 and on the side, it is possible to simultaneously measure the face properties near the face and inside the chamber.

[0087] (7) Furthermore, since the tip of the exploration jig 61 is a cutter bit 52, if the exploration jig 61 is configured to be extended to a position FA near the face before stopping excavation, it becomes possible to reliably abut the exploration jig 61 against the face even in hard ground that is difficult to penetrate.

[0088] (8) Furthermore, by further providing an in-chamber pressure gauge 22A that measures the pressure inside the chamber 16 of the earth pressure shield 1 as a tunnel boring machine, and / or an in-chamber water pressure gauge 23A that measures the pore water pressure inside the chamber 16, it becomes possible to analyze the properties inside the chamber 16 in more detail and accurately by measuring pressure and pore water pressure in addition to displacement.

[0089] (9) The controlled earth pressure setting system S of this embodiment is a controlled earth pressure setting system S for an earth pressure shield 1 as a tunnel boring machine, and includes a pressure gauge 22 that measures mud pressure in the chamber 16, an earth removal device 17 as a mud pressure changing means for changing the mud pressure in the chamber 16, a face vicinity property measuring device 6 (6A, 6B, 6C, 6D, 6E) that measures displacement of the face vicinity FA, ​​an analysis unit 41 that analyzes the deformation characteristics of the ground based on the measured mud pressure, the measured displacement of the face vicinity FA, ​​and the measured pore water pressure of the face vicinity FA, ​​and a setting unit 42 that sets the controlled earth pressure based on the analyzed deformation characteristics. Because of this configuration, the controlled earth pressure setting system S can set the controlled earth pressure by directly measuring the relationship between the mud pressure in the chamber and the displacement near the face, rather than setting the controlled earth pressure based on assumptions or estimates.

[0090] (10) Furthermore, when the tunnel boring machine is stopped, the mud pressure in chamber 16 is reduced by discharging a small amount of mud using earth removal device 17, which serves as a mud pressure changing means, and the active earth pressure can be found from the deformation of the ground by analysis unit 41. Therefore, when the shield machine is stopped from excavating—for example, when assembling segments—the pressure inside chamber 16 is slightly reduced, causing FA near the face to be slightly displaced toward chamber 16, and the active earth pressure can be directly found by analyzing the yield point from the transition region in the graph showing the relationship between mud pressure and displacement near the face.

[0091] (11) In addition, the analysis unit 41 estimates the mechanical constants of the ground by inverse analysis based on the analyzed deformation characteristics of the ground, updates the FEM model using the estimated mechanical constants of the ground, and uses the updated FEM model to predict the impact on the surrounding ground and / or structures. Therefore, although not completely in real time, by updating the FEM model at intervals that are close to real time and much shorter than conventional methods, the characteristics of the ground can be made much closer to the actual characteristics. As a result, predictions and impact assessments using the FEM model can be achieved with extremely high accuracy.

[0092] Although the embodiments and modifications of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments and modifications, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0093] For example, in the examples and modified examples, the near-face property measuring devices 6 (6A, 6B, 6C, 6D, 6E) have been described as being installed at predetermined positions, but this is not limiting. For example, in the examples and the first and third modified examples, the measuring devices may be installed midway between the shield center and the hood portion of the bulkhead 3, as shown in the figures, or may be installed closer to the hood portion. In the second modified example, the measuring devices may be installed at the middle of the cutter spokes 51, as shown in the figures, or near the shield center or near the tips of the cutter spokes 51. They may also be attached outward on the outermost periphery of the cutter spokes 51. Furthermore, they may be installed on the cutter head face plate or intermediate beam connecting members.

[0094] Furthermore, although not shown, the near-face property measuring device may be installed in a cutter head component such as a cutter head face plate, an intermediate beam, and / or a connecting member. In this case, the cutter head face plate, the intermediate beam, the connecting member, etc. constitute a part of the cutter head.

[0095] In addition, in the embodiment, the setting system S for controlled earth pressure using the face vicinity property measuring devices 6 (6A, 6B, 6C, 6D, 6E) has been described, but the present invention is not limited to this. For example, it can also be used in a system for detecting looseness of the face using the face vicinity property measuring devices 6 (6A, 6B, 6C, 6D, 6E).

[0096] REFERENCE SIGNS LIST 1: Earth pressure shield (tunnel boring machine) 2: Skin plate 2a: Hood section 2b: Tail section 3: Bulkhead 5: Cutter head 6: Measuring device for properties near the face (embodiment) 6A-6E: Measuring device for properties near the face (variant) 10: Cutter rotating shaft 11: Bearing 12: Cutter drive section 13: Gearbox 14: Rotation drive source 15: Erector 16: Chamber 17: Soil removal device 18: Shield propulsion jack 19: Tail seal 21: Mud-making material supply pipe 22, 22A: Pressure gauge 23, 23A: Water pressure gauge 40: Control section 41: Analysis section 42: Setting section 43: Communication cable 51: Cutter spoke 52: Cutter bit 53: Fishtail bit 54 : (Moving) mixing blade 54A: Storage box 55: Fixed mixing blade 55A: Storage box 61: Inspection jig 610: Tip 611a: Cone portion 611b: Arrow portion 611c: Drill portion 612: Flange portion 613: Main body portion 62: Jack 62a: Cylinder portion 62b: Rod portion 63: Hydraulic chuck 64: Detection portion 65: Guide 66: Displacement sensor 67: Water stop device 68: Valve (ball valve) 68A: Valve (ball valve) 68B: Release device (hydraulic chuck) 69: Second jack (machine inside advance / retract means) 70: Bracket 90: Segment S: Controlled earth pressure setting system F: Face FA: Vicinity of face

Claims

1. A face vicinity property measuring device used in a tunnel boring machine, comprising: a probing tool stored in the tunnel boring machine and reaching a position near the face; advancing and retreating means for advancing and retreating the probing tool between the inside of the tunnel boring machine and the position near the face; a displacement sensor for detecting the displacement amount of the probing tool, a pressure gauge for measuring the earth pressure near the face, and / or a water pressure gauge for measuring the pore water pressure near the face.

2. The face vicinity property measuring device according to claim 1, wherein the probing tool is stored in a fixed stirring blade protruding into the chamber from the partition wall of the tunnel boring machine or in a storage box, and is configured to reach the face from the tip of the fixed stirring blade or the storage box.

3. The face vicinity property measuring device according to claim 2, wherein the advancing and retreating means is composed of a cylinder part and a rod part, is stored in the fixed stirring blade or the storage box, and the rod part is also used as the probing tool and is configured to reach the face from the tip of the fixed stirring blade or the storage box.

4. The face vicinity property measuring device according to claim 1, wherein the advancing and retreating means is composed of a cylinder part and a rod part, and further comprises in-machine advancing and retreating means for advancing and retreating the cylinder part into and out of the chamber from the partition wall of the tunnel boring machine.

5. The face vicinity property measuring device according to claim 1, wherein the probing tool is stored in the cutter head face plate part, the intermediate beam, and / or the connecting material of the tunnel boring machine, and is configured to reach the face.

6. The cutter spoke has a moving stirring blade or a storage box on the rear side, and at least a part of the probing tool or the advancing and retreating means is stored in the moving stirring blade or the storage box. The face vicinity property measuring device according to claim 5.

7. The face vicinity property measuring device according to claim 5, wherein the tip of the probing tool is a cutter bit.

8. The face vicinity property measuring device according to claim 1, further comprising an in-chamber pressure gauge for measuring the pressure in the chamber of the tunnel boring machine and / or an in-chamber water pressure gauge for measuring the pore water pressure in the chamber.

9. A management earth pressure setting system for a tunnel boring machine, comprising: a pressure gauge for measuring the earth pressure in the chamber; an earth pressure changing means for changing the earth pressure in the chamber; a face vicinity property measuring device according to any one of claims 1 to 8; an analysis unit for analyzing the deformation characteristics of the ground based on the measured earth pressure, the measured displacement in the vicinity of the face, and the measured pore water pressure in the vicinity of the face; and a setting unit for setting the management earth pressure based on the analyzed deformation characteristics. A management earth pressure setting system.

10. The management earth pressure setting system according to claim 9, wherein when the tunnel boring machine stops, the earth pressure in the chamber is reduced by the earth pressure changing means, so that the active earth pressure can be obtained from the deformation of the ground by the analysis unit.

11. The analysis unit is configured to estimate the mechanical constants of the ground by inverse analysis based on the analyzed deformation characteristics of the ground, update the FEM model using the mechanical constants of the ground, and predict the influence on the surrounding ground and / or structures using the updated FEM model. The management earth pressure setting system according to claim 10.

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