Discrimination system for soil distribution on working face by shield machine

Abstract

To provide a discrimination system for soil distribution on a working face allowing excavation management of a shield machine in a more stable state through accurate and exact comprehension on a state of the ground of the working face under excavation with a cutter head.SOLUTION: A discrimination system for soil distribution includes an acceleration sensor 14 attached on a cutter bit 16 and a computer 20, wherein the computer 20 is provided with a vibration data storage unit 21 for storing excavation vibration data upon cutting a working face 12 with the cutter bit 16 per rotational angle of the cutter head 13; and a vibration data display unit 22 for displaying excavation vibration data stored in the vibration data storage unit 21 as a plurality of annular excavation vibration distributions 23a, 23b concentric with a circle imitating the working face cross section. Boundary parts with different soil in grounds 12a, 12b, 12c of the working face 12 are discriminated from a vibration fluctuated place 24a on the plurality of annular excavation distributions 23a, 23b displayed on the vibration data display unit 22.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a system for determining the soil distribution at a tunnel face using a shield tunneling machine, and in particular to a system for determining the soil distribution at a tunnel face using a shield tunneling machine that is installed in a closed-type shield tunneling machine and enables the soil distribution of the ground at the tunnel face to be determined. [Background technology]

[0002] In recent years, for example, in urban areas, there has been a demand for longer shield tunnels due to shaft land issues and congestion with underground buried objects. When constructing longer shield tunnels, the soil quality of the ground at the tunnel face often changes as the shield machine excavates. Furthermore, when the shield machine excavates the boundary between layers of different soil types, for example, layered vertically or horizontally, different soil types may appear simultaneously on the same tunnel face being cut.

[0003] When a shield machine excavates an area where ground has different soil types, for example, if one type of ground is bedrock or the like and is significantly harder than the other type of ground, and the soil conditions at the tunnel face are not properly understood, the shield machine is likely to run over or skid on the hard ground, making it difficult to accurately maintain the vertical and horizontal alignment of the shield tunnel. For this reason, there is a need for technology that allows the shield machine to stably manage its excavation in accordance with the ground conditions by understanding the soil conditions at the tunnel face as a whole and controlling it to prevent running over or skidding on the hard ground, for example by increasing the amount of overcut by the copy cutter in areas of hard ground.

[0004] In particular, with conventional sealed shield tunneling machines, which rotate the cutter head attached to the tip of the shield body to excavate while cutting the face, changes in the soil quality at the face are generally evaluated by, for example, examining the properties of the cut soil discharged from a compartment, or measuring the earth pressure at the face and the cutter torque value of the cutter head.However, with such evaluation methods, it is difficult to grasp the soil quality at the face as a whole and properly distinguish the distribution of different soil types at the face.

[0005] For this reason, the applicant of the present application has proposed, for example in Patent Document 1 described below, a system for determining the soil distribution at the face of a shield tunnel using a simple configuration that enables the ground condition at the face of the tunnel to be accurately grasped in real time and across the entire tunnel while the cutter head is cutting, thereby enabling more stable management of the shield tunneling machine's excavation.

[0006] The system for determining the soil type distribution at the face using a shield tunneling machine described in Patent Document 1 comprises an acceleration sensor attached to the outer periphery of the cutter head and a computer connected to the acceleration sensor. The computer is equipped with a vibration data memory unit that stores cutting vibration data sent from the acceleration sensor when the face is cut by a bit for each predetermined rotation angle of the cutter head, and a vibration data display unit that displays the cutting vibration data for each rotation angle stored by the vibration data memory unit as a cutting vibration distribution distributed circumferentially around a circle that resembles the face cross section.The system makes it possible to determine the boundary between different soil types in the ground at the face from the points where the wave state of the distribution in the circumferential cutting vibration distribution displayed by the vibration data display unit changes. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6342723 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the face soil quality distribution discrimination system described in Patent Document 1, the acceleration sensor is attached to the outer edge of the cutter head, separated from the bit, and mainly measures vibrations from the outer bit only.In addition, the measurement value includes vibrations from bits surrounding the outer bit, as well as vibrations transmitted through the cutter head, which creates technical issues such as difficulty in accurately detecting vibrations in some ground conditions, and the boundary between ground of different soil types can only be roughly displayed using straight lines.Therefore, there is a need for the development of a new discrimination system that can resolve these technical issues.

[0009] The object of the present invention is to provide a system for determining the soil distribution at the tunnel face using a shield machine, which enables more accurate and detailed understanding of the ground conditions at the tunnel face during cutting by a cutter head in real time when constructing a shield tunnel, thereby enabling more stable management of the shield machine's excavation. [Means for solving the problem]

[0010] The present invention is a system for determining soil type distribution at a shield tunneling face by a shield tunneling machine, which is provided on an enclosed shield tunneling machine that has a rotating cutter head at the tip of the shield body and excavates while cutting the face with a plurality of bits attached to the cutter head, and which is capable of determining the soil type distribution of the ground at the face. The system comprises an acceleration sensor integrally attached to each of two or more acceleration detection bits selected from a plurality of bits fixed to a front plate of a cutter spoke that constitutes the cutter head in a state of protruding forward from the front plate, and a computer connected to these acceleration sensors, and the two or more acceleration detection bits include a peripheral acceleration detection bit arranged on the outer periphery of the cutter head and a middle acceleration detection bit arranged in an intermediate region between the center of the cutter head and the outer periphery, and the computer is configured to detect the acceleration sensors of the peripheral acceleration detection bits. The system is equipped with a vibration data storage unit that stores cutting vibration data sent from the acceleration sensors attached to the outer acceleration detection bit and the intermediate acceleration detection bit when cutting the face using these acceleration detection bits for each predetermined rotation angle of the cutter head, and a vibration data display unit that displays the cutting vibration data for each rotation angle stored by the vibration data storage unit from the outer acceleration detection bit and the intermediate acceleration detection bit as a plurality of concentric ring-shaped cutting vibration distributions distributed in the circumferential direction of a circle that resembles the face cross section, and the above-mentioned object has been achieved by providing a system for determining face soil type distribution using a shield machine that can determine the boundary areas between different soil types in the ground at the face from the locations where the wave state of the distribution changes in the plurality of concentric ring-shaped cutting vibration distributions displayed by the vibration data display unit.

[0011] Furthermore, in the system for determining face soil distribution using a shield tunneling machine of the present invention, it is preferable that the vibration data display unit displays the distribution of vibration acceleration for each rotation angle as the cutting vibration distribution in multiple concentric rings.

[0012] In addition, in the system for determining the soil distribution at the face using a shield tunneling machine of the present invention, an auxiliary acceleration sensor connected to the computer is attached to the inner wall surface of the shield body, and the vibration data display unit preferably displays the cutting vibration data for each rotation angle as a plurality of concentric rings of the cutting vibration distribution, with noise and mechanical vibrations removed using the main body vibration data sent from the auxiliary acceleration sensor.

[0013] Furthermore, in the system for determining face soil distribution using a shield tunneling machine of the present invention, the acceleration sensor is preferably configured to be able to detect cutting vibration data in at least two directions that are perpendicular to each other, and is attached to the outer acceleration detection bit and the intermediate acceleration detection bit with a first detection direction aligned with the circumferential direction of rotation of the cutter head and a second detection direction aligned with a direction perpendicular to the head surface of the cutter head at the portion where the acceleration sensor is attached.

[0014] Furthermore, in the system for determining face soil distribution using a shield tunneling machine of the present invention, it is preferable that the intermediate acceleration detection bit to which the acceleration sensor is attached is attached at one location in the intermediate region between the center and outer periphery of the cutter head, or at two locations at different radial distances from the center.

[0015] In addition, in the system for determining face soil distribution using a shield machine of the present invention, it is preferable that the outer periphery acceleration detection bit and the middle acceleration detection bit are arranged and attached to the same cutter spoke.

[0016] Furthermore, in the system for determining face soil quality distribution using a shield tunneling machine of the present invention, the computer is preferably equipped with a boundary line display unit, and the boundary line display unit is preferably configured to display, as the boundary between different soil types in the ground at the face of the tunnel, a broken line connecting the points of change in the wave state of each adjacent pair of distributions in the multiple concentric ring-shaped cutting vibration distributions displayed by the vibration data display unit. [Effects of the Invention]

[0017] According to the system for determining soil distribution at the face using a shield tunneling machine of the present invention, when constructing a shield tunnel, it is possible to grasp the ground condition at the face of the tunnel being cut by the cutter head in real time, on a planar basis, with greater accuracy and precision, thereby enabling the excavation management of the shield tunneling machine to be carried out in an even more stable manner. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an explanatory diagram illustrating the configuration of a system for determining face soil distribution using a shield machine according to a preferred embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a front view of the shield tunneling machine. [Figure 3] FIG. 3 is an enlarged cross-sectional view taken along the line AA in FIG. 2. [Figure 4] 1(a) is a partially cutaway front view illustrating the acceleration detection bit, FIG. 1(b) is a cross-sectional view taken along BB in FIG. 1(a), and FIG. 1(c) is a top view of FIG. 1(a) viewed from above. [Figure 5] (a) is a cross-sectional view along CC in (b) of the detection jig housing the acceleration sensor before the lid plate is attached, (b) is a cross-sectional view along DD in (a) with the lid plate attached, (c) is an enlarged cross-sectional view along EE in (a) with the lid plate attached, and (d) is an enlarged cross-sectional view along FF in (a). [Figure 6] (a) is a front view explaining the acceleration sensor, (b) is a side view of (a) seen from the left, (c) is a side view of (a) seen from the right, and (d) is a top view of (a) seen from above. [Figure 7] 10 is an explanatory diagram illustrating an example of a display screen by a vibration data display unit and a boundary line display unit. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] As shown in FIG. 1, a system 10 for determining soil type distribution at a face using a shield machine according to a preferred embodiment of the present invention is used in construction work to construct a shield tunnel using a sealed shield machine, such as a mud pressure type shield machine 11. This system makes it possible to accurately grasp the condition of ground 12a, 12b, 12c at a face 12 during cutting in real time across the entire surface. For example, when the shield machine 11 excavates a boundary portion between ground 12a, 12b, 12c of different soil types, it is possible to accurately grasp the condition of one ground. Even when the soil of the ground 12a is bedrock or the like and is considerably harder than the soil of the other grounds 12b, 12c, which are made up of sandy soil, clayey soil, etc., the shield machine 11 can be controlled to prevent climbing over or sliding sideways on the hard ground 12a by, for example, increasing the amount of overcut by the copy cutter 16a (see Figure 2) in the hard ground 12a, thereby enabling more stable excavation management according to the conditions of the ground 12a, 12b, 12c.

[0020] In other words, in urban areas, for example, where there is a demand for longer shield tunnels to be constructed using not only large-diameter shield machines but also small- and medium-diameter shield machines due to issues such as shaft land availability and congestion with underground buried objects, and when constructing longer shield tunnels, it is expected that the shield machine 11 will often be used to excavate the boundary areas of overlapping ground 12a, 12b, 12c of different soil types.Therefore, even if ground 12a, 12b, 12c of different soil types appear simultaneously on the same cutting face 12, the discrimination system 10 of this embodiment is able to accurately grasp the condition of the ground 12a, 12b, 12c on the face 12 and avoid, for example, climbing over or sliding on hard ground 12a, thereby making it possible to accurately maintain the longitudinal and horizontal alignment of the shield tunnel.

[0021] Furthermore, as shown in Figures 2 and 4(a) to (c), the discrimination system 10 of this embodiment uses an acceleration sensor 14 (see Figures 4(a) and (b)) integrally provided on a bit 16 (acceleration detection bits 41, 42) attached to the cutter head 13 of the shield tunneling machine 11, and is able to grasp the condition of the ground 12a, 12b, 12c on the working face 12 being cut by the cutter head 13 in real time, on a planar basis, with greater accuracy and precision, preferably while referring to a columnar diagram of the surrounding ground.

[0022] The system 10 for determining the soil distribution at the face using a shield machine in this embodiment is, as shown in Figures 1 to 4, a determination system that is installed on an enclosed shield machine 11 that has a rotating cutter head 13 at the tip of the shield body 15 and excavates while cutting the face 12 using a plurality of bits 16 attached to the cutter head 13, and is capable of determining the soil distribution of the ground 12a, 12b, 12c at the face 12, and is equipped with acceleration sensors 14 (see Figures 4(a) and (b)) that are integrally attached to two or more acceleration detection bits 41, 42 (see Figure 2) selected from the plurality of bits 16 that are fixed to the front panel 43a of the cutter spokes 43 that constitute the cutter head 13 in a state of protruding forward from the front panel 43a, and a computer 20 (see Figure 1) connected to these acceleration sensors 14. The two or more acceleration detection bits 41, 42 include an outer peripheral acceleration detection bit 41 arranged on the outer periphery of the cutter head 13 and an intermediate acceleration detection bit 42 arranged in an intermediate region between the center and outer periphery of the cutter head 13. The computer 20 is equipped with a vibration data storage unit 21 that stores cutting vibration data sent from the acceleration sensors 14 attached to the outer peripheral acceleration detection bit 41 and the intermediate acceleration detection bit 42 when cutting the cutting face 12 with these acceleration detection bits 41, 42 for each predetermined rotation angle of the cutter head, and a vibration data display unit 22 that displays the cutting vibration data for each rotation angle stored by the outer peripheral acceleration detection bit 41 and the intermediate acceleration detection bit 42 in the vibration data storage unit 21 as a plurality of concentric annular cutting vibration distributions 23a, 23b (see FIG. 7) distributed in the circumferential direction of a circle simulating the cutting face cross section. The boundary portions of different soil types in the ground 12a, 12b, 12c of the working face 12 can be identified from the points 24a, 24b where the wave state of the distribution fluctuates in the circumferential cutting vibration distributions 23a, 23b displayed by the vibration data display unit 22.

[0023] In addition, in the system 10 for determining the soil distribution at the face using a shield tunneling machine of this embodiment, the vibration data display unit 22 is configured to display the distribution of vibration acceleration (ground response acceleration during cutting) for each rotation angle as multiple concentric ring-shaped cutting vibration distributions 23a, 23b.

[0024] Furthermore, in the system 10 for determining the soil distribution at the face using a shield tunneling machine of this embodiment, as shown in Figure 1, an auxiliary acceleration sensor 18 connected to a computer 20 is attached to the inner wall surface of the shield main body 15, preferably to the back part of a partition 17 provided on the shield main body 15, and the vibration data display unit 22 is configured to display the cutting vibration data for each rotation angle as multiple concentric ring-shaped cutting vibration distributions 23a, 23b, with noise and mechanical vibrations removed using the main body vibration data sent from the auxiliary acceleration sensor 18.

[0025] In this embodiment, the shield machine 11 is a sealed shield machine, such as a known mud pressure type shield machine. In the mud pressure type shield machine 11, a partition wall 17 is provided behind the cutter head 13 at the tip of the shield body 15 to form a compartment 19 that is filled by mud pressure, and the center shaft 13a of the cutter head 13 is attached and supported by this partition wall 17. Also provided inside the shield body 15 are a mud removal mechanism (not shown), a rotary drive motor (not shown), a shield jack (not shown), an erector (not shown), etc.

[0026] The computer 20 constituting the discrimination system 10 of this embodiment is a known device that functions as a database server, and can be, for example, a personal computer. The database server computer 20 includes a CPU, ROM, RAM, an interface, storage means, input means, display means, output means, etc. The CPU of the database server controls the overall operation of the database server using the RAM as a work area in accordance with a control program stored in the ROM. Various computer programs are stored in the ROM, allowing the CPU to function as storage means, input means, display means, output means, etc. The CPU also stores cutting vibration data sent from the acceleration sensor 14 together with the rotation angle of the cutter head 13 via a vibration data storage unit 21 (described later), and displays the cutting vibration data stored in the vibration data storage unit 21 on a display 20a as cutting vibration distributions 23a and 23b distributed in the circumferential direction via a vibration data display unit 22, or outputs the data from a printer (not shown).

[0027] In this embodiment, the computer 20 incorporates a known shield tunneling management system capable of centrally managing measurement values collected from various measuring instruments used in the shield tunneling method and survey values entered via input means. The shield tunneling management system has functions such as centrally managing measurement values collected from various measuring instruments used in the shield tunneling method, organizing the information, and providing it to engineers and workers to support on-site construction management, estimating the condition of the ground, the condition of excavated soil, and the installation status of the shield tunneling machine based on changes over time and the results of statistical processing, and calculating the position of the shield tunneling machine and segments by inputting measurement results and determining the deviation from the baseline. The "Shield Tunneling Management System" manufactured by Sensou Kobo Co., Ltd. can be preferably used as such a shield tunneling management system.

[0028] Furthermore, in this embodiment, the computer 20 is installed in an operation control room 30 located on the ground, and the computer 20 installed in the operation control room 30 is connected to various measuring instruments, the acceleration sensor 14 and auxiliary acceleration sensor 18 described below, for example, via acceleration sensor amplifiers 25a, 25b, and via a known transmission system 29 equipped with a control panel 26 made of PCL, a sequencer panel 27, a remote operation panel 28, etc.

[0029] The acceleration sensor 14 and auxiliary acceleration sensor 18, which together with the computer 20 constitute the discrimination system 10 of this embodiment, can be various known acceleration sensors that detect acceleration, which is the rate of change of velocity over time (time derivative). Acceleration sensors are used to measure the value of acceleration itself or detect the application of an external force, using the physical law that the acceleration acting on an object is proportional to the external force applied. The acceleration sensor 14 and auxiliary acceleration sensor 18 can be various acceleration sensors that can detect tilt, vibration, movement, impact, fall, etc., as well as scientific experiments that require high-precision measurements, gravity measurement, earthquake measurement, etc. More specifically, various types of three-axis piezoelectric acceleration detectors manufactured by Showa Sokki Co., Ltd., which can accurately detect vibration magnitude, frequency, etc., can be used as such acceleration sensors.

[0030] In this embodiment, the acceleration sensor 14 is attached and fixed integrally to the bits 16 arranged on the cutter head 13 of the shield tunneling machine 11, preferably to each of the outer acceleration detection bit 41 and the middle acceleration detection bit 42 (see Figure 2), by the acceleration sensor attachment structure 40 shown in Figures 4(a) to (c).

[0031] That is, in this embodiment, the mounting structure 40 for an acceleration sensor in a shield tunneling machine is a mounting structure for mounting and fixing the acceleration sensor 14 as a unit to the bit 16 (acceleration detection bits 41, 42) arranged on the cutter head 13 (see Figure 2) in a shield tunneling machine 11 equipped with a face soil distribution discrimination system 10 (see Figure 1) including an acceleration sensor 14 attached to the cutter head 13 and a computer 20 connected to the acceleration sensor 14, and as shown in Figures 3 and 4(a) and (b), the acceleration detection bits 41, 42 on which the acceleration sensor 14 is mounted are fixed to the front plate 43a of the cutter spokes 43 (see Figure 2) that constitute the cutter head 13, in a state where they protrude forward from the front plate 43a. As shown in Figures 5(a) to 5(d), the acceleration sensor 14 is fixedly housed in the inner tip portion of a detection jig 44, which is made of a metal base portion 45 and a mounting portion 46 extending from the base portion 45. The detection jig 44 is attached to the acceleration detection bits 41, 42 via the detection jig 44. Mounting holes 43b, into which the mounting portions 46 of the detection jig 44 are inserted and fixed, are formed in the front plate 43a of the cutter spoke 43 at the mounting positions of the acceleration detection bits 41, 42. The mounting holes 43b penetrate the mounting bases 41a, 42a of the acceleration detection bits 41, 42 to a depth that penetrates the mounting holes 43b. A plurality of bolt fastening holes 43c are formed on the back side of the base portion 45 of the detection jig 44, surrounding the mounting portion 46. A plurality of bolt insertion holes 45a are formed in the base portion 45 of the detection jig 44, surrounding the mounting portion 46. The mounting stand 46 is inserted and attached into the mounting fixing hole 43b, the bolt insertion hole 45a is aligned with the bolt fastening hole 43c, and the base part 45 is placed on the front plate 43a from the back side. Then, the detection jig 44 is fastened and fixed to the front plate 43a using the fastening bolt 47, whereby the acceleration sensor 14 is attached and fixed as a unit to the fixing bases 41a, 42a of the acceleration detection bits 41, 42.

[0032] In addition, in this embodiment, a cable 48, which is a wiring that connects to the acceleration sensor 14, is arranged inside the mounting upright portion 46 via a connector 49 attached to the base portion 45 of the detection jig 44, and is also extended through the hollow interior 43d of the cutter spoke 43 (see Figure 3) to be connected to the computer 20.

[0033] Furthermore, in this embodiment, the acceleration detection bits 41, 42 to which the acceleration sensor 14 is attached are the leading bits 16b that are fixed to the surface of the front plate 43a of the cutter spoke 43 and cut the natural ground first.

[0034] In this embodiment, the cutter head 13 to which the acceleration sensor 14 is attached has a circular front shape with a radius of, for example, approximately 6800 mm, as shown in FIG. 2. It includes a disk-shaped center drum 13b with a fishtail bit 13c attached, which is integrally joined to the center shaft 13a (see FIG. 1), and twelve cutter spokes 43 extending radially outward from the center drum 13b. The twelve cutter spokes 43 are integrally connected to each other by an annular outer support ring 13d arranged concentrically with the center drum 13b, thereby firmly supporting the rotational reaction force generated when cutting the ground 12a, 12b, and 12c. In the cutter head 13, the opening areas surrounded by each pair of adjacent cutter spokes 43, the center drum 13b, and the outer support ring 13d each form an opening 13e for taking in soil and sand. The cut soil and gravel from the ground 12a, 12b, 12c of the working face 12 cut by the multiple bits 16 attached to the cutter head 13 is taken into the rear compartment 19 through these soil intake openings 13e.

[0035] In this embodiment, the twelve cutter spokes 43 each have a hollow cross-sectional shape, for example, an isosceles trapezoidal shape, as shown in Fig. 3, and preferably have a hollow interior 43d large enough for an operator to enter. This allows an operator to perform predetermined tasks in the hollow interior 43d as needed, and also allows various wiring and piping to be installed. The hollow interior 43d of each cutter spoke 43 communicates with the interior of the center drum 13b and the center shaft 13a, and the installed wiring and piping can be extended to the rear of the partition wall 17 via, for example, a rotary joint provided in the center shaft 13a.

[0036] Furthermore, in this embodiment, each cutter spoke 43 and outer peripheral support ring 13d has a leading bit 16b fixed to the surface of the front plate 43a, which cuts the ground before the other bits 16, as well as a plurality of known bits 16, such as a main bit, trim bit, scraper bit, copy cutter 16a, etc., which are arranged in predetermined positions and attached as a unit using a known joining method.

[0037] In this embodiment, in each cutter spoke 43, the multiple leading bits 16b fixed to the surface of the front plate 43a are arranged in two rows in a staggered pattern, connected together at a predetermined radial interval, as shown in Figure 2, and as shown in Figures 3 and 4(a) and (b), each fixing base is fixed to the front plate 43a of the cutter spoke 43 (see Figure 2) by welding or the like, and is attached in a state where it protrudes forward from the front plate 43a of the cutter spoke 43. In this embodiment, of these leading bits 16b, for example, one selected leading bit 16b arranged on one or two cutter spokes 43 on the outer periphery of the cutter head 13 is designated as the outer periphery acceleration detection bit 41, and preferably one or two selected leading bits 16b arranged on the same cutter spoke 43 in the intermediate region between the center and outer periphery of the cutter head 13 are designated as the intermediate acceleration detection bit 42, and the acceleration sensor 14 is integrally attached to each of these acceleration detection bits 41, 42 by the above-described attachment structure 40 using the detection jig 44. Vibration characteristics differ for each cutter spoke 43, but by preferably arranging the outer periphery acceleration detection bit 41 and the intermediate acceleration detection bit 42 on the same cutter spoke 43, it is possible to ignore the difference in vibration characteristics. As shown by the ▽ mark in Figure 2, in this embodiment, in each of preferably two selected cutter spokes 43, one outer peripheral acceleration detection bit 41 and one intermediate acceleration detection bit 42 are provided by the leading bit 16b, with the same radial distance from the center.

[0038] Here, as the plurality of leading bits 16b, some of which become acceleration detection bits 41, 42, it is preferable to use, for example, a product name "Stamina Bit" (manufactured by Okumura Corporation), which has a configuration similar to that of the excavator cutter bit described in Design Registration No. 1533573. The leading bits 16b (acceleration detection bits 41, 42) made of "Stamina Bit" are made of tip portions 41b, 42b made of superalloy and shank portions 41c, 42c made of steel, and have the function of striking and disturbing the ground with the tip portions 41b, 42b. The acceleration detection bits 41, 42 of the preceding bit 16b are firmly attached to the cutter spoke 43 by joining, by welding or the like, the fastening bases 41a, 42a, made of steel, similar to the shanks 41c, 42c, to the front plate 43a of the cutter spoke 43 at the attachment positions of the acceleration detection bits 41, 42, where the attachment holes 43b and bolt fastening holes 43c are formed. At the attachment positions of the acceleration detection bits 41, 42, the attachment holes 43b formed in the front plate 43a of the cutter spoke 43 are circular through-holes with a diameter of, for example, approximately 30 mm. The bolt fastening holes 43c formed on the back side of the front plate 43a of the cutter spoke 43 are female threaded holes with a thread diameter of, for example, approximately 12 mm, and are preferably formed in four locations at equal angular intervals of 90° in the circumferential direction in the outer peripheral region surrounding the attachment holes 43b (see FIG. 5(b)). Furthermore, in the center of the bottom surface of the fixing bases 41a, 42a of the acceleration sensing bits 41, 42, bite holes 41d, 42d, preferably having the same inner diameter as the mounting and fixing hole 43b, are formed as openings as part of the mounting and fixing hole 43b.

[0039] The acceleration detection bits 41, 42 are fixed to the front plate 43a of the cutter spoke 43 with their longitudinal directions L aligned circumferentially about the center of the cutter head 13 (see FIG. 2) and with the biting holes 41d, 42d of the fixing bases 41a, 42a aligned with the mounting holes 43b of the front plate 43a. As a result, when the acceleration detection bits 41, 42 are attached to the front plate 43a of the cutter spoke 43, the mounting holes 43b, into which the mounting erect portions 46 of the detection jig 44 are inserted and fixed, are formed to a depth reaching the biting holes 41d, 42d in the fixing bases 41a, 42a of the acceleration detection bits 41, 42.

[0040] In this embodiment, as shown in FIGS. 4(a) to 4(c) and 5(a) to 5(d), the acceleration sensor 14 is housed in the inner tip portion of a detection jig 44, which is made of a metal base portion 45 and a mounting portion 46, and is attached to the acceleration detection bits 41, 42 via the detection jig 44. The detection jig 44 is preferably a steel metal piece, and the base portion 45 has a disk shape with a diameter of, for example, approximately 100 mm and a thickness of, for example, approximately 16 mm. A circular fitting hole 45b is formed through the center of the base portion 45, into which the upright end portion 46a of the mounting portion 46 is fitted and fixed. Furthermore, the outer circumferential region surrounding the fitting hole 45b and the upright end portion 46a of the mounting portion 46 fitted therein has four bolt insertion holes 45a, preferably at equal angular intervals of 90° in the circumferential direction (see FIG. 5(b)).

[0041] On the other hand, the mounting upright portion 46 of the detection jig 44 is configured to include a cylindrical upright base end portion 46a and a tip-side notched cross-sectional portion 46b, which is located tip-side of the upright base end portion 46a and has a cross-sectional shape in which the side of the circular cross-section is notched in an arch-like shape. The mounting upright portion 46 is joined to the base portion 45 by adhesive or welding, with the base end of the upright base end portion 46a fitted into the fitting hole 45a of the base portion 45, thereby forming the detection jig 44 integrated with the base portion 45, with the tip-side portion of the upright base end portion 46a and the tip-side notched cross-sectional portion 46b standing perpendicularly from the base portion 45.

[0042] A connector connection hole 46c, for example, having a female thread ridge, is formed at the base end of the standing base end portion 46a fitted into the base portion 45 of the standing mounting portion 46. The connector connection hole 46c is for connecting a connector 49 that draws a cable 48 extending through the hollow interior 43d of the cutter spoke 43 into the inside of the detection jig 44. A wiring insertion hole 46e (see FIG. 5(d)) having a semi-oval cross section, for example, is formed at the tip end portion of the standing base end portion 46a that protrudes from the base portion 45, on the opposite side of the connector connection hole 46c across the bridge member 46d. A wiring routing groove 46f (see FIG. 5(c)) having a semi-oval cross section, for example, is formed in the cutout surface of the tip end side cutout cross-sectional shape portion 46b of the standing mounting portion 46, except for the tip end portion, and is continuous with the wiring insertion hole 46e of the standing base end portion 46a. At the tip end portion of the wiring arrangement groove 46f of the tip end cutout cross-sectional shape portion 46b, a sensor mounting portion 46g having a rectangular hollow cross-sectional shape is formed, which can accommodate the acceleration sensor 14, which preferably has a hexahedral shape, in a state where it is positioned so that it cannot rotate.

[0043] Furthermore, in the central part of the arch-shaped cutout surface in the tip-side cutout cross-sectional portion 46b of the mounting upright portion 46, the band-shaped opening surface of the above-mentioned wiring arrangement groove 46f extends in the upright direction and opens, and on both sides of the wiring arrangement groove 46f, screw holes 46h with a screw diameter of, for example, about 2 mm are formed in a total of six places, for example, three places on each side, at a predetermined interval in the upright direction. For example, by working inside the hollow interior 43d of the cutter spoke 43, the cable 48 arranged inside the hollow interior 43d is pulled into the wiring insertion hole 46e and wiring arrangement groove 46f via the connector 49 and the link member 46d (see FIGS. 4(a) and 4(b)), and the acceleration sensor 14 is attached to the tip of the cable 48. After that, with the cable 48 and the acceleration sensor 14 housed in the wiring arrangement groove 46f and the sensor mounting portion 46g, a cover plate 46i (see FIGS. 5(b) and 5(c)) is attached so as to cover the band-shaped opening surface of the wiring arrangement groove 46f by screwing fixing screws 46j into the screw holes 46h on both sides of the wiring arrangement groove 46f. This makes it possible to precisely and stably position the acceleration sensor 14, which is connected to the computer 20 via the cable 48, at the tip of the mounting stand 46, and then house and fix it as a single unit inside the detection jig 44, which consists of the metal base part 45 and the mounting stand 46 that stands up from the base part 45.

[0044] In this embodiment, a cable 48 and an acceleration sensor 14 connected to the computer 20 are placed in the wiring insertion hole 46e of the upright base end portion 46a and the wiring routing groove 46f of the tip-side notched cross-sectional portion 46b, and the band-shaped opening of the wiring routing groove 46f is covered with the cover plate 46i. Then, by filling and hardening a filling and hardening agent into the wiring insertion hole 46e and the wiring routing groove 46f, it is possible to eliminate gaps around the cable 48 and the acceleration sensor 14. This makes it possible to accurately position and fix the acceleration sensor 14 and the cable 48 inside the detection jig 44 in a more stable state.

[0045] In this embodiment, the acceleration sensor 14 is, for example, a triaxial piezoelectric acceleration detector, and is therefore capable of detecting cutting vibration data in three directions, preferably at least two directions perpendicular to each other. The acceleration sensor 14 has a hexahedral shape with six faces arranged at right angles to each other, as shown in Figures 6(a) to 6(d), for example, and is capable of detecting cutting vibration data in each of the three directions, which are the X, Y, and Z directions perpendicular to each face. In addition, the acceleration sensor 14 is accommodated in a sensor mounting portion 46g having a rectangular hollow cross-sectional shape at the tip of the wiring arrangement groove 46f formed in the cutout cross-sectional shape portion 46b of the detection jig 44, and is thereby positioned and fixed so that, for example, the Z direction faces a direction perpendicular to the erection direction of the mounting erection portion 46 along the cutout surface of the cutout cross-sectional shape portion 46b, the X direction faces the erection direction of the mounting erection portion 46 along the cutout surface of the cutout cross-sectional shape portion 46b, and the Y direction faces a direction perpendicular to the cutout surface of the cutout cross-sectional shape portion 46b.

[0046] In addition, in this embodiment, the four bolt insertion holes 45a formed in the outer peripheral region surrounding the fitting hole 45b in the central part of the base portion 45 and the standing base end portion 46a of the mounting stand portion 46 fitted thereto are, as shown in Figure 5(b), one pair of bolt insertion holes 45a are formed on both sides of the fitting hole 45a and the standing base end portion 46a of the mounting stand portion 46 in a direction parallel to the cutout surface of the cutout cross-sectional shape portion 46b, and the other pair of bolt insertion holes 45a are formed on both sides of the fitting hole 45b and the standing base end portion 46a of the mounting stand portion 46 in a direction perpendicular to the cutout surface of the cutout cross-sectional shape portion 46b.

[0047] On the other hand, at the mounting position of the acceleration detection bits 41, 42 on the front panel 43a of the cutter spoke 43, four bolt fastening holes 43c are formed in the outer peripheral region of the mounting fixing hole 43b into which the mounting erection portion 46 of the detection jig 44 is inserted and fixed.One pair of bolt fastening holes 43c are formed on both sides of the mounting fixing hole 43b in a direction perpendicular to the longitudinal direction L of the acceleration detection bits 41, 42, and the other pair of bolt fastening holes 43c are formed on both sides of the mounting fixing hole 43b in a direction parallel to the longitudinal direction L of the acceleration detection bits 41, 42.

[0048] As a result, according to this embodiment, when the leading bit 16b including the acceleration detection bits 41, 42 is attached to the cutter spokes 43 that constitute the cutter head 13, and the front plate 43a at the attachment position of the acceleration detection bits 41, 42 has an attachment fixing hole 43b and a bolt fastening hole 43c formed therein, the above-mentioned detection jig 44, in which the acceleration sensor 14 is housed in the inner tip portion of the attachment standing portion 46, is inserted and attached to the attachment fixing hole 43b to a depth reaching the bite holes 41d, 42d, and the attachment standing portion 46 is fastened and fixed to the front plate 43a of the cutter spoke 43 from the back side using the fastening bolt 47, this can be easily and smoothly performed by an operator in the hollow interior 43d of the cutter spoke 43, which is preferably large enough for the operator to enter. This also makes it possible to easily and smoothly attach and fix the acceleration sensor 14 as a single unit to each of the acceleration detection bits 41, 42, preferably with the Z direction as the first detection direction, aligned along the longitudinal direction L of the acceleration detection bits 41, 42, which is the rotation direction of the cutter head 13, and preferably with the X direction as the second detection direction, aligned along the protruding direction of the acceleration detection bits 41, 42, which is perpendicular to the front panel 43a of the cutter spokes 43 that constitute the head surface of the cutter head 13, which is the excavation direction of the cutter head 13.

[0049] In this embodiment, the mounting portion 46 of the detection jig 44 is inserted into the mounting hole, preferably with its entire outer periphery coated or filled with adhesive. This allows the acceleration sensor 14 to be accurately positioned on the acceleration detection bits 41, 42 in a more stable state, preferably with the Z direction aligned with the longitudinal direction L of the acceleration detection bits 41, 42, which is the rotation direction of the cutter head 13, and firmly fixed as a single unit.

[0050] If it is difficult to ensure sufficient space for an operator to enter the hollow interior 43d of the cutter spoke 43, for example, an openable access window (not shown) can be provided in the rear plate 43e (see FIG. 3) of the cutter spoke 43, preferably in an area corresponding to the portion where the acceleration detection bits 41 and 42 are attached, of the rear plate 43e. With the leading bit 16b including the acceleration detection bits 41 and 42 attached to the cutter head 13 and the attachment holes 43b and bolt fastening holes 43c formed at the attachment positions of the acceleration detection bits 41 and 42, the above-mentioned detection jig 44, with the acceleration sensor 14 housed in the inner tip of the attachment portion 46, can be smoothly inserted and attached through the openable access window to the attachment holes 43b to a depth reaching the bite holes 41d and 42d, and then fastened to the front plate 43a of the cutter spoke 43 from the back side using fastening bolts 47.

[0051] In addition, in this embodiment, the acceleration sensor 14 is preferably arranged in the longitudinal direction L of the acceleration detection bits 41, 42, which is a direction along the circumferential direction of rotation of the cutter head 13, with the Z direction as the first detection direction, and the X direction as the second detection direction, which is a direction along the excavation direction perpendicular to the head surface of the cutter head 13.This makes it possible to efficiently measure the ground response acceleration in the circumferential direction of rotation using the first detection direction Z, and the ground response acceleration in the excavation direction using the second detection direction X, and it becomes possible to obtain even more accurate concentric circular cutting vibration distributions 23a, 23b (see Figure 7) from the response acceleration detected by these outer peripheral acceleration detection bit 41 and middle acceleration detection bit 42.

[0052] In this embodiment, as shown in FIG. 1, auxiliary acceleration sensor 18 is attached to the back surface of partition wall 17, which separates compartment 19, as the inner wall surface of shield body 15. Like acceleration sensor 14, auxiliary acceleration sensor 18 is a three-axis piezoelectric acceleration detector, and is preferably attached to the back surface of partition wall 17 with its first detection direction aligned with the circumferential direction of rotation of cutter head 13 and its second detection direction aligned with the excavation direction of shield machine 11. This makes it possible to efficiently and accurately measure and obtain specific vibration data caused by vibration of shield body 15 during operation of shield machine 11. Auxiliary acceleration sensor 18 is also connected to acceleration sensor amplifier 25b via a connection cable. The main body vibration data from the auxiliary acceleration sensor 18 is sent to the computer 20 via the acceleration sensor amplifier 25b and the transmission system 29, and the vibration data display unit 22 is able to display the cutting vibration data for each rotation angle sent from the acceleration sensor 14 as multiple concentric ring-shaped cutting vibration distributions 23a, 23b, with noise and mechanical vibrations removed.

[0053] Furthermore, in this embodiment, a tachometer (not shown) consisting of, for example, a rotary encoder is attached to the center shaft 13a of the cutter head 13. The rotation angle measured by this tachometer is sent to the computer 20 via the transmission system 29, and cutting vibration data measured by the acceleration sensor 14 when cutting the working face 12 can be stored in the vibration data storage unit 21 for each predetermined rotation angle.

[0054] According to this embodiment, the frequency Δθ of circumferential measurements by acceleration sensor 14 is determined by the formula Δθ = r / 60 × Δt × 360°, using the data collection time interval Δt and the rotational speed r (ppm) of cutter head 13. For example, if shield machine 11 is a small-diameter machine with an excavation outer diameter of approximately 2360 mm and has a fast rotational speed r = 2.3 (ppm), the measurement frequency Δθ when the measurement time interval Δt is set to 0.1 seconds is Δθ = 2.3 / 60 × 0.1 × 360°, which is 1.38°. Therefore, acceleration sensor 14 will take a measurement every 1.38°.

[0055] In addition, in this embodiment, in order to grasp the circumferential position θ° of the acceleration sensor 14 in the cutter head 13, a contact switch (not shown) is installed on the center shaft 13a of the cutter head 13, and for example, the top of the shield tunneling machine 11 can be set as the zero point, and a reset process can be performed every time this zero point is passed.

[0056] In this embodiment, the cutting vibration data measured by the acceleration sensor 14 at each predetermined rotation angle is output via dedicated acceleration sensor amplifiers 25a, 25b, together with the main body vibration data measured by the auxiliary acceleration sensor 18, preferably at the same timing as the measurement by the acceleration sensor 14, and the output signal passes through the control panel 26 and sequencer panel 27 and is sent to the operation control room 30 via the same transmission system 29 as other excavation management data.

[0057] In this embodiment, the computer 20 is configured to include the vibration data storage unit 21 and the vibration data display unit 22, as described above. The vibration data storage unit 21 stores cutting vibration data, which is transmitted from the acceleration sensor 14 to the computer 20 via the acceleration sensor amplifier 25a and the transmission system 29 when the cutting face 12 is cut by the cutter bit 16, for each predetermined rotation angle of the cutter head 13. The vibration data storage unit 21 also stores main body vibration data, which is transmitted from the auxiliary acceleration sensor 18 to the computer 20 via the acceleration sensor amplifier 25b and the transmission system 29 when the cutting face 12 is cut by the cutter bit 16 and is caused by the shield main body 15 itself vibrating due to drive of the rotation drive motor or the like, for each predetermined rotation angle of the cutter head 13. The cutting vibration data and main body vibration data are integrated in chronological order with measurement values collected from various measuring instruments used in the shield tunneling method in a known shield tunneling management system incorporated in the computer 20, and can be stored as data preferably linked to the ring number of each ring assembled using segments.

[0058] The vibration data display unit 22 displays the cutting vibration data for each rotation angle stored in the vibration data storage unit 21 as a plurality of concentric ring-shaped cutting vibration distributions 23a, 23b distributed in the circumferential direction of a circle that imitates the cutting face cross section. That is, as shown in Fig. 7, the vibration data display unit 22 is capable of displaying, as cutting vibration data for each rotation angle, preferably a distribution of magnitude of vibration acceleration (ground response acceleration during cutting) for each rotation angle, as a plurality of concentric ring-shaped cutting vibration distributions 23a, 23b on, for example, a display 20a connected to the computer 20, with noise and mechanical vibrations removed using main body vibration data sent from the auxiliary acceleration sensor 18.

[0059] The computer 20 also includes a boundary line display unit 31 (see FIG. 1) that enables the boundary portions of different soil types in the ground 12a, 12b, 12c of the working face 12 to be identified from the fluctuation points 24a, 24b of the distribution wave state in the circumferential cutting vibration distributions 23a, 23b displayed by the vibration data display unit 22. The boundary line display unit 31 is preferably configured to display, as shown in FIG. 7, a polygonal connecting line 50 that sequentially connects the fluctuation points 24a, 24b, 24b, 24a of the wave state of each adjacent pair of distributions in the multiple concentric annular cutting vibration distributions 23a, 23b displayed by the vibration data display unit 22, as the boundary portions of different soil types in the ground of the working face. The boundary line display unit 31 can also display a straight connecting line 51 connecting the midpoints of each pair of adjacent fluctuation points 24a, 24b on both sides in the multiple concentric circular cutting vibration distributions 23a, 23b displayed by the vibration data display unit 22 as the boundary between different soil types in the ground at the cutting face.

[0060] 7 are displayed on the display 20a after removing noise and mechanical vibrations from the main body vibration data in the first detection direction, preferably the circumferential direction of the cutter head 13, detected by the auxiliary acceleration sensor 18. This makes it possible to display the cutting vibration distributions 23a and 23b, which more accurately reflect the condition of the ground 12a, 12b, and 12c on the working face 12 being cut by the cutter head 13.

[0061] Furthermore, the cutting vibration data of the cutting vibration distributions 23a and 23b shown in Figure 7 is based on the data obtained as the average of the measurement values for each ring of segments that make up the shield tunnel, with measurement starting when the jack stroke of the shield jack or the propulsion jack has advanced 100 mm from the start of excavation of the excavation span for that ring, for example, and continuing to measure the cutting vibration data while the cutter head 13 rotates five times.

[0062] 7 are obtained by the outer periphery acceleration detection bit 41 and the middle acceleration detection bit 42 attached to one of two selected cutter spokes 43, each of which is provided with an outer periphery acceleration detection bit 41 and a middle acceleration detection bit 42. The accuracy of the cutting vibration distributions 23a and 23b can be confirmed by obtaining similar cutting vibration distributions 23a and 23b based on the cutting vibration data from the outer periphery acceleration detection bit 41 and the middle acceleration detection bit 42 attached to the other cutter spoke 43. Preferably, similar cutting vibration distributions 23a and 23b can also be obtained from the average value of the cutting vibration data from the outer periphery acceleration detection bit 41 and the middle acceleration detection bit 42 of each of the two cutter spokes 43.

[0063] The system for determining soil type distribution at the tunnel face using a shield machine according to this embodiment makes it possible to easily identify the boundary between different soil types in the ground 12a, 12b, and 12c at the tunnel face 12 from the multiple concentric circular cutting vibration distributions 23a and 23b shown in Figure 7 displayed by the vibration data display unit 22. In other words, in this embodiment, by observing the multiple concentric circumferential cutting vibration distributions 23a and 23b displayed, vibration fluctuation points 24a and 24b, where the vibration distribution trend clearly changes, can be easily identified. In the cutting vibration distributions 23a and 23b in Figure 7, vibration fluctuation points 24a and 24b can be identified, one on each side. Furthermore, by drawing the broken line connecting line 50 or the straight line connecting line 51 using the above-mentioned method based on the fluctuation points 24a, 24b on both the left and right sides, the layer structure of the ground 12a, 12b, 12c on the working face 12 can be determined, and preferably by referring to a columnar diagram of the surrounding ground, it becomes possible to easily determine the soil quality of each layer of the determined layer structure.

[0064] Furthermore, according to this embodiment, a boundary line display unit 31 is provided which displays the connection lines 50, 51 connecting each pair of vibration fluctuation points 24a, 24b on both the left and right sides as the boundary portions of different soil types in the ground 12a, 12b, 12c of the working face 12. Therefore, by displaying the connection lines 50, 51 using this boundary line display unit 31, it becomes possible to more easily grasp the boundary portions of different soil types in the working face 12 and the layer structure of the ground 12a, 12b, 12c.

[0065] As a result, the system 10 for determining face soil distribution using a shield tunneling machine of this embodiment makes it possible, when constructing a shield tunnel, to grasp the condition of the ground 12a, 12b, 12c on the face 12 being cut by the cutter head 13 in real time and in a more accurate and detailed manner, allowing for more stable excavation management of the shield tunneling machine 11 and, by making it possible to avoid, for example, running over or sliding on hard ground 12a, it becomes possible to accurately maintain the longitudinal and horizontal alignment of the shield tunnel being constructed.

[0066] Furthermore, the discrimination system 10 of this embodiment can predict the soil distribution of the ground ahead of the excavation face 12 in the excavation direction and determine the soil distribution of the ground on the outer periphery of the shield tunnel based on multiple concentric ring-shaped cutting vibration distributions 23a, 23b for the ground 12a, 12b, 12c on the face 12 in multiple excavation spans, which are obtained during the excavation process by the shield machine 11. That is, for example, in multiple excavation spans at the leading end of the excavation direction, by calculating the tendency of vibration fluctuation points 24a, 24b in the multiple concentric ring-shaped cutting vibration distributions 23a, 23b to move in the excavation direction, the calculated displacement tendency of vibration fluctuation points 24a, 24b can be used to predict the ground fluctuation points 24a, 24b, for example, 10 m ahead of the face, making it possible to more precisely and easily determine the soil distribution of the ground ahead in the excavation direction in advance.

[0067] The present invention is not limited to the above embodiment and various modifications are possible. For example, the cutting vibration data stored by the vibration data storage unit does not necessarily have to be vibration acceleration for each rotation angle, but may be vibration frequency, vibration amplitude, etc. The circumferential cutting vibration distribution displayed by the vibration data display unit does not necessarily have to be a distribution of vibration acceleration for each rotation angle, but may be a cutting vibration distribution based on cutting vibration data such as vibration frequency and vibration amplitude. Even with such cutting vibration distribution based on cutting vibration data, it is possible to easily identify the boundary between different soil types in the ground at the working face from the location of vibration fluctuations.

[0068] The auxiliary acceleration sensor can also be attached to the inside wall of the shield body other than the back part of the partition. The auxiliary acceleration sensor is not necessarily required, and the cutting vibration distribution of the cutting vibration data does not necessarily need to be displayed in a state where noise and mechanical vibrations are removed using the main body vibration data. Furthermore, the boundary line display unit is not necessarily required, and the shield tunneling machine may be various other sealed types other than the mud pressure type, such as a mud water type.

[0069] In this embodiment, the cutter head is described as being of the spoke type, but the present invention can also be applied to cutter heads of the face plate type. When the cutter head is of the face plate type, the cutter spokes correspond to the main frame of the cutter face plate. Furthermore, if it becomes necessary to replace the bit during excavation work, as in the above embodiment, the bit can be first attached to the front plate of the cutter spoke by welding or the like, and then the mounting stand of the detection jig containing the acceleration sensor can be attached to the mounting fixing hole in the front plate and the base part can be fixed to the front plate with a fixing bolt, thereby attaching the acceleration sensor. [Explanation of symbols]

[0070] 10. System for determining soil distribution at tunnel face using a shield machine 11 Shield tunneling machine 12 Face 12a, 12b, 12c Ground at the face 13 Cutter head 13a Center shaft 13b Center Drum 13c fishtail bit 13d Periphery support ring 13e Opening for sediment intake 14 Accelerometer 15 Shield body 16-bit 16a Copy cutter 16b leading bit 17 Bulkhead 18 Auxiliary Accelerometer 19 compartment 20 Computer 21 Vibration data storage unit 22 Vibration data display 23a, 23b Circumferential cutting vibration distribution 24a, 24b Locations where the distribution wave state changes 29 Transmission Systems 30 Operation Control Room 31 Boundary line display area 40 Acceleration sensor mounting structure 41 Periphery acceleration detection bit 42 Intermediate acceleration detection bit 41a, 42a Fixation base 41d,42d Biting hole 43 Cutter Spoke 43a Front plate 43b Mounting and fixing hole 43c Bolt fastening hole 43d hollow interior 43e back plate 44 Detection jig 45 Base 45a Bolt insertion hole 45b Fitting hole 46 Mounting section 46a Standing base end part 46b Tip side notch cross-sectional shape part 46c Connector connection hole 46d. Link material 46e Wiring insertion hole 46f Wiring groove 46g Sensor mounting part 46h screw hole 46i Lid Plate 46j fixing screw 47 Fastening bolt 48 Cable 49 Connectors 50 Broken Line 51 Straight bond lines

Claims

1. A system for determining soil type distribution at a shield tunneling face using a shield tunneling machine, which is provided on an enclosed shield tunneling machine that has a rotating cutter head at the tip of the shield body and excavates while cutting the tunnel face using multiple bits attached to the cutter head, and which is capable of determining the soil type distribution of the ground at the tunnel face, The cutter head includes two or more acceleration detection bits selected from a plurality of bits, each of which is fixed to a front plate of a cutter spoke constituting the cutter head in a state of protruding forward from the front plate, and an acceleration sensor integrally attached to each of the acceleration detection bits, and a computer connected to the acceleration sensors. The two or more acceleration detection bits include a peripheral acceleration detection bit disposed on the peripheral portion of the cutter head, and a middle acceleration detection bit disposed in a middle region between the center portion and the peripheral portion of the cutter head, The computer is equipped with a vibration data storage unit that stores cutting vibration data sent from the acceleration sensors attached to the outer peripheral acceleration detection bit and the intermediate acceleration detection bit when cutting the face with these acceleration detection bits for each predetermined rotation angle of the cutter head, and a vibration data display unit that displays the cutting vibration data for each rotation angle stored by the outer peripheral acceleration detection bit and the intermediate acceleration detection bit in the vibration data storage unit as a plurality of concentric annular cutting vibration distributions distributed in the circumferential direction of a circle that imitates the face cross section, A system for determining the soil quality distribution at the face using a shield tunneling machine, which makes it possible to determine the boundary areas between different soil types in the ground at the face from the points where the wave state of the distribution changes in the multiple concentric ring-shaped cutting vibration distribution displayed by the vibration data display unit.

2. 2. A system for determining face soil distribution using a shield machine as described in claim 1, wherein the vibration data display unit displays the distribution of vibration acceleration for each rotation angle as the cutting vibration distribution in multiple concentric rings.

3. A system for determining face soil distribution using a shield tunneling machine as described in claim 1 or 2, wherein an auxiliary acceleration sensor connected to the computer is attached to the inner wall surface of the shield body, and the vibration data display unit displays the cutting vibration data for each rotation angle as a plurality of concentric rings of the cutting vibration distribution, with noise and mechanical vibrations removed using the main body vibration data sent from the auxiliary acceleration sensor.

4. The acceleration sensor is capable of detecting cutting vibration data in at least two directions perpendicular to each other, and is attached to the outer acceleration detection bit and the intermediate acceleration detection bit with a first detection direction aligned with the circumferential direction of rotation of the cutter head and a second detection direction aligned with a direction perpendicular to the head surface of the cutter head at the portion where the acceleration sensor is attached.A system for determining face soil distribution using a shield tunneling machine as described in claim 1 or 2.

5. A system for determining the soil distribution at the face using a shield tunneling machine as described in claim 1 or 2, wherein the intermediate acceleration detection bit to which the acceleration sensor is attached is attached at one location in the intermediate region between the center and the outer periphery of the cutter head, or at two locations spaced at different radial distances from the center.

6. 3. A system for determining face soil distribution using a shield machine according to claim 1 or 2, wherein the outer peripheral acceleration detection bit and the intermediate acceleration detection bit are arranged and attached to the same cutter spoke.

7. The computer is equipped with a boundary line display unit, which displays a polygonal connecting line connecting the points of change in the wave state of each pair of adjacent distributions in the multiple concentric ring-shaped cutting vibration distributions displayed by the vibration data display unit as the boundary between different soil types in the ground at the face of the shield tunneling machine as described in claim 1 or 2.

Images