JP6638894B2 - Evaluation method of plastic fluidity of excavated soil in chamber in earth pressure shield method and earth pressure shield excavator - Google Patents

Description

  The present invention relates to a method for evaluating the plastic flowability of excavated soil in a chamber in an earth pressure shield construction method and an earth pressure shield excavator.

  BACKGROUND ART Conventionally, an earth pressure type shield construction method applied to shield tunnel construction is known. This method uses an earth-pressure shield excavator equipped with a chamber for taking in excavated soil behind the cutter device. The excavated soil taken in the chamber is exposed to chemicals such as hydrobentonite and polymer materials or bubbles. Is added to the excavated soil and agitated by an agitating blade, whereby the excavated soil has a predetermined plastic fluidity, and the earth pressure is applied to the face to excavate while maintaining the face stably.

  In this earth pressure shield method, it is important that the earth pressure from the excavated soil acts uniformly and stably on the entire face of the face, so that the plastic fluidity of the excavated soil in the chamber is appropriately set and stabilized. Need to be maintained. For that purpose, it is necessary to sequentially confirm whether or not the excavated soil is uniformly plastically fluidized in the entire chamber during excavation. In particular, in recent years, with the enlargement of the earth pressure shield method, the need to evaluate the plastic fluidity of excavated soil in a chamber is increasing. As a conventional method for evaluating the plastic fluidity of excavated soil, for example, those disclosed in Patent Documents 1 to 3 are known.

  The methods disclosed in Patent Literatures 1 and 2 directly evaluate the plastic fluidity of excavated soil at an installation location by installing a rotary torque measuring instrument in a chamber and measuring a rotating torque. is there. This method has a problem that the torque measuring instrument is exposed in the chamber, so that the torque measuring instrument is likely to fail.

  The method disclosed in Patent Literature 3 indirectly evaluates the plastic fluidity of the excavated soil by evaluating the fluctuation of the earth pressure of the excavated soil in the chamber. However, this method does not directly evaluate the shear resistance (plastic flowability) of excavated soil.

Japanese Patent No. 4024504 Japanese Patent No. 4770472 JP 2014-9545 A

  Meanwhile, a shield machine 1 of a general earth pressure type shield excavator as shown in FIG. 5 is provided with a stirring blade 5 on the cutter spoke 4 side in order to enhance the stirring effect of the excavated soil 3 in the chamber 2. The fixed wing 7 is installed on the partition (bulk head) 6 side separated by. The fixed wing 7 is usually made of a cylindrical steel material, and is attached to a plurality of locations on the partition wall 6 side.

  When an apparatus for evaluating plastic fluidity is to be installed in the chamber 2, it is difficult to install a new apparatus because various apparatuses are already installed on the cutter spoke 4 side. However, the portion of the fixed wing 7 is a simple columnar steel material with a hollow inside, and is a place where there is room for mounting some device, and the device can be modified from inside the shield machine 1 (underground). It is also a place where you can respond even if a failure occurs.

  Therefore, the present inventor has paid attention to the fixed wing portion, and has invented a technique capable of directly and continuously accurately evaluating the plastic fluidity of the excavated soil in the chamber.

  The present invention has been made in view of the above, and it is possible to directly and continuously accurately evaluate the plastic fluidity of excavated soil in a chamber. It is an object of the present invention to provide a method for evaluating the performance and an earth pressure shield excavator.

  In order to solve the above-mentioned problems and achieve the object, a method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure shield method according to the present invention includes a stirring blade installed on a cutter spoke side and a chamber. With the cylindrical fixed wings installed on the partition wall side, the excavated soil in the chamber is agitated to impart plastic fluidity to the excavated soil, and the earth pressure of the excavated soil acts on the face to stabilize the face. Applied to the earth pressure shield construction method to excavate while becoming, is an evaluation method for evaluating the plastic fluidity of the excavated soil in the chamber, provided coaxially a cylindrical rotating body inside the fixed wing, The torque is measured while giving a predetermined number of rotations to the rotating body, a shear rate applied to the excavated soil is obtained based on the number of rotations, and a work is performed on the excavated soil based on the measured torque. To the shear stress determined that, based on the relationship shear rate and shear stress was determined, and evaluating the plastic flow properties of the excavated soil in the chamber.

  Further, the plastic fluidity evaluation method of the excavated soil in the chamber in another earth pressure shield method according to the present invention, in the above-described invention, assuming that the excavated soil is a viscous fluid, by a yield value and a plastic viscosity as a viscous fluid. The plastic fluidity of the excavated soil is evaluated.

  In addition, in another earth pressure type shield method according to the present invention, the method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure type shield method according to the above-described invention, further comprising: It is characterized by having.

  According to another aspect of the present invention, there is provided a method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure shield method, wherein the rotating body is configured to be movable in an axial direction in the above-described invention.

  Further, the plastic fluidity evaluation method of the excavated soil in the chamber in another earth pressure type shield method according to the present invention, in the above-described invention, when the torque is not measured by the rotating body is stored in the fixed wing, When the torque is measured by the rotating body, the rotating body is moved in the axial direction and is pushed out of the fixed wing.

  According to another aspect of the present invention, there is provided a method for evaluating plasticity and fluidity of excavated soil in a chamber in an earth pressure shield method according to the present invention, wherein the fixed wing is provided at a plurality of locations on the partition wall side in the above-described invention.

  In addition, in the above-described invention, the plastic fluidity of the excavated soil is evaluated while rotating the cutter in the above-described invention. Information indicating plastic fluidity is visualized and displayed on a display unit.

  Further, the earth pressure shield excavator according to the present invention, in the above-described invention, the stirring blade installed on the cutter spoke side, the cylindrical fixed blade installed on the partition wall side separating the chamber, the inside of the chamber. An earth-pressure shield excavator that agitates excavated soil to impart plastic fluidity to the excavated soil, applies excavated soil pressure to the face to stabilize the face, and excavates while excavating. A cylindrical rotating body is provided coaxially inside, and a torque is measured while giving a predetermined number of rotations to the rotating body, and a shear rate given to the excavated soil is determined based on the number of rotations. Determine the shear stress acting on the excavated soil based on, based on the relationship between the determined shear rate and shear stress, evaluate the plastic fluidity of the excavated soil in the chamber, evaluation Characterized in that it comprises a management means for displaying visible plastic flowability.

  According to the plastic fluidity evaluation method of the excavated soil in the chamber in the earth pressure shield method according to the present invention, a stirring blade installed on the cutter spoke side, a cylindrical fixed blade installed on the partition wall side separated the chamber Thereby, the excavated soil in the chamber is agitated to impart plastic fluidity to the excavated soil, and the earth pressure of the excavated soil is applied to the face to stabilize the face by applying the earth pressure type shield method for excavation while stabilizing the face. An evaluation method for evaluating the plastic fluidity of the excavated soil in the chamber, wherein a cylindrical rotating body is provided coaxially inside the fixed wing, and a torque is given while giving a predetermined number of rotations to the rotating body. Measure and determine the shear rate applied to the excavated soil based on the number of rotations, and determine the shear stress acting on the excavated soil based on the measured torque to determine the shear stress. Since the plastic fluidity of the excavated soil in the chamber is evaluated based on the relationship between the speed and the shear stress, the plastic fluidity (viscosity, yield value) of the excavated soil in the chamber is evaluated by the rotating body inside the fixed wing. There is an effect that direct and continuous evaluation can be performed with high accuracy.

  According to another method for evaluating plastic fluidity of excavated soil in a chamber in another earth pressure shield method according to the present invention, the excavated soil is assumed to be a viscous fluid, and the excavated soil is determined by a yield value and a plastic viscosity as a viscous fluid. Since the plastic fluidity is evaluated, it is based on the conventional viscosity evaluation test method, and thus the reliability of the evaluation result is high. For this reason, there is an effect that the plastic fluidity of the excavated soil in the chamber can be accurately evaluated.

  According to the plastic fluidity evaluation method of the excavated soil in the chamber in another earth pressure shield method according to the present invention, since the frictional force improving portion for improving the frictional force is provided on the outer peripheral surface of the rotating body, Slip at the boundary surface between the outer peripheral surface of the rotating body and the excavated soil is suppressed, and more accurate torque measurement becomes possible. For this reason, there is an effect that the plastic fluidity of the excavated soil in the chamber can be accurately evaluated.

  Further, according to the method for evaluating the plastic flowability of excavated soil in a chamber in another earth pressure type shield method according to the present invention, the rotating body is configured to be movable in the axial direction, so that the rotating body is moved in the axial direction. This has the effect that the excavated soil inside the fixed wing can be replaced with the outside.

  Further, according to the method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure type shield method according to the present invention, when the torque is not measured by the rotating body, the rotating body is housed inside the fixed wing, When the torque is measured, the rotating body is moved in the axial direction and pushed out of the fixed wing, so that the rotating body as the torque measuring device can be protected when not measuring.

  According to the method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure shield method according to the present invention, since the fixed wings are provided at a plurality of locations on the partition wall side, excavated soil over a wide area in the entire chamber. This has the effect that the plastic fluidity can be evaluated.

  According to another method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure type shield method according to the present invention, the plastic fluidity of the excavated soil is evaluated while rotating the cutter, and the evaluated plastic fluidity is evaluated. Is displayed on the display so that the plastic flow of the whole chamber can be accurately and continuously grasped in real time with high accuracy by looking at the display, and the plastic flow can be managed with high accuracy. It has the effect of becoming.

  Further, according to the earth pressure type shield excavator according to the present invention, the excavated soil in the chamber is stirred by the stirring blade installed on the cutter spoke side and the cylindrical fixed blade installed on the partition wall separating the chamber. An earth-pressure shield excavator that stirs and excavates while imparting plastic fluidity to the excavated soil by stirring and exerting the earth pressure of the excavated soil on the face. A cylindrical rotating body is provided coaxially, a torque is measured while giving a predetermined number of rotations to the rotating body, and a shear rate given to the excavated soil is determined based on the number of rotations, and the shearing rate is determined based on the measured torque. Determine the shear stress acting on the excavated soil, based on the relationship between the determined shear rate and the shear stress, evaluate the plastic fluidity of the excavated soil in the chamber, and evaluate the evaluated plastic fluidity. Since the control means for visualizing and displaying is provided, it is possible to directly and continuously accurately evaluate the plastic fluidity (viscosity and yield value) of the excavated soil in the chamber by the rotating body inside the fixed wing. To play.

FIG. 1 is an enlarged side view of a main part showing Embodiment 1 of a method for evaluating the plastic flowability of excavated soil in a chamber and an earth pressure shield excavator in an earth pressure shield method according to the present invention, wherein (1) is a front cross section FIG. 2B is a side sectional view. FIG. 2 is an explanatory diagram of Embodiment 1 of the method for evaluating the plasticity and fluidity of excavated soil in a chamber in the earth pressure shield method according to the present invention, and is a diagram illustrating a relationship between a shear rate and a shear stress. FIG. 3 is a diagram illustrating an example of a visualization display by the management unit in the first embodiment of the earth pressure type shield excavator in the earth pressure type shield excavator according to the present invention. FIG. 4 is an enlarged side view of a main part showing a second embodiment of the method for evaluating the plastic flowability of excavated soil in a chamber and an earth pressure shield excavator in the earth pressure shield method according to the present invention, wherein (1) is a front cross section. FIG. 2B is a side sectional view. FIG. 5 is a diagram showing a chamber of a shield machine of a conventional earth pressure type shield excavator, (1) is a schematic rear view of a cutter face, and (2) is a schematic side sectional view of the chamber.

  Hereinafter, an embodiment of a method for evaluating the plastic flowability of excavated soil in a chamber and an earth pressure shield excavator in an earth pressure shield method according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

[Evaluation method of plastic fluidity of excavated soil in chamber in earth pressure shield method]
First, a method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure shield method according to the present invention will be described.

(Embodiment 1)
First, Embodiment 1 will be described.
The method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure shield method according to the first embodiment includes a stirring blade installed on a cutter spoke side and a cylinder installed on a bulkhead (bulkhead) side separating the chamber. With the fixed wings, the excavated soil in the chamber is agitated to impart plastic fluidity to the excavated soil, and the earth pressure of the excavated soil is applied to the face to stabilize the face and excavate while excavating. This evaluation method is applied to the shield method and evaluates the plastic fluidity of excavated soil in a chamber.

  1 is an enlarged view of a main part of a fixed wing installed on a partition wall behind a chamber of an earth pressure shield excavator, (1) is a front sectional view, and (2) is a side sectional view. As shown in this figure, a partition wall 12 behind a general chamber 10 is equipped with fixed wings 14 projecting into the chamber 10 as is well known. Therefore, in the present embodiment, a columnar rotating body 16 which is slightly smaller than the fixed wing 14 is provided coaxially.

  The fixed wing 14 includes a cylindrical portion 14a having an open end face and forming an outer wall. The rotation axis Z of the rotating body 16 is coaxial with the axis of the cylindrical portion 14a, and is connected coaxially to one end 18a of the rotating shaft 18 at the end face on the partition 12 side. The rotating shaft 18 is arranged to penetrate the partition 12, and the other end 18 b is connected to a rotation driving device (not shown) outside the partition 12. This rotation driving device includes a motor device that reversibly rotates the rotating body 16 and that can adjust the number of rotations (rotation speed). Therefore, the rotating body 16 is rotatable via the rotating shaft 18 under the control of the rotation driving device. On the outer peripheral surface of the rotating body 16, four low-height wing members 20 diametrically extending in a plate shape are provided at equal intervals in a circumferential direction as frictional force improving portions for improving frictional force.

In the present embodiment, the rotating body 16 is rotated inside the fixed wing 14 while giving a predetermined rotating speed (angular velocity ω) to the rotating body 16, the torque T at that time is measured, and excavation is performed based on the rotating speed ω. Find the shear rate given to the soil. On the other hand, the shear stress acting on the excavated soil is determined based on the measured torque T. The plastic fluidity of the excavated soil in the chamber 10 is evaluated based on the obtained relationship between the shear rate and the shear stress. By doing so, the plastic fluidity (viscosity, yield value) of the excavated soil in the chamber 10 can be directly and continuously accurately evaluated by the rotating body 16 inside the fixed blade 14. This is the same format as the measurement method of the coaxial double cylinder type when measuring the viscosity of the fluid (for example, see Reference 1 below).
[Reference 1] "Primix Co., Ltd. Homepage Rheology Understandable in Literature", [online], [Search on February 4, 2015], Internet <URL: http://www.primix.jp/mixer_lecture/vol2/05 .html>

Next, a method of calculating plastic fluidity (viscosity, yield value) according to the present embodiment will be described. Here, the inner radius of the cylindrical portion 14a measured from the rotation axis Z is R _o , the radius of the cylinder of the rotating body 16 is R _i , the height (length in the axial direction) of the cylinder of the rotating body 16 is h, and the circumference is Let the rate be π.

  The shear rate given to the excavated soil can be calculated by the following equation (1).

  The shear stress acting on the excavated soil can be calculated by the following equation (2).

  By changing the rotation speed (angular speed ω), the shear speed γ (gamma dot) changes, and the shear stress τ is calculated from the torque T changing accordingly. Therefore, as shown in FIG. 2, a plurality of measured values of the shear rate γ and the shear stress τ are plotted, and a relationship obtained by linearly approximating these plots is obtained.

Assuming that the excavated soil in the chamber 10 is a viscous fluid, characteristic values (yield value τ _y , plastic viscosity μ) as the viscous fluid can be obtained from the relationship between the shear rate and the shear stress as shown in FIG. Intercept of the approximate straight line of the figure in the yield value tau _y, the inclination corresponds to a plastic viscosity mu. In the present embodiment, the yield value and the plastic viscosity thus obtained are treated as evaluation values representing the plastic fluidity of the excavated soil in the chamber 10.

  Then, while rotating the cutter or while the cutter is stopped, the plastic fluidity (yield value and plastic viscosity) of the excavated soil is evaluated, and the evaluation result (information) is displayed on a computer display (display unit) (not shown). Visualize and display. FIG. 3 shows a display example on this display. The example of the figure shows a case where the fixed wings 14 are provided at six locations at equal intervals in the circumferential direction and the plastic fluidity of the excavated soil is evaluated over a wide range in the entire chamber 10. The degree of hardness and softness obtained based on the value and the plastic viscosity is displayed as a spatial distribution diagram of the entire chamber 10. The degree of hardness and softness can be represented by, for example, a difference in color or shade.

  By monitoring the contents displayed on the display when the cutter is rotating or stopped, the plastic fluidity of the excavated soil in the chamber 10 can be accurately and continuously grasped in real time with high accuracy. It is possible to do. For this reason, management of plastic fluidity can be performed with high accuracy. In addition, by providing the fixed wings 14 at a plurality of locations on the partition 12 side, the plastic fluidity of the excavated soil can be evaluated over a wide range in the entire chamber 10.

  Further, according to the present embodiment, the excavated soil is assumed to be a viscous fluid, and the plastic fluidity of the excavated soil is evaluated based on the yield value and the plastic viscosity as the viscous fluid. This is based on the conventional viscosity evaluation test method, and the reliability of the evaluation result is high. For this reason, according to the present embodiment, the plastic fluidity of the excavated soil in the chamber 10 can be accurately evaluated.

  Further, according to the present embodiment, the wing member 20 is provided as a frictional force improving portion for improving the frictional force on the outer peripheral surface of the rotating body 16, so that the boundary surface between the outer peripheral surface of the rotating body 16 and the excavated soil is provided. The slip at the point is suppressed, and more accurate torque measurement can be performed. Therefore, the plastic fluidity of the excavated soil in the chamber 10 can be accurately evaluated.

  In the above embodiment, since it is necessary to replace the excavated soil inside the fixed wing 14, it is preferable that the rotating body 16 disposed inside the cylindrical portion 14a is configured to be movable in the axial direction. In this way, it is possible to replace the excavated soil inside the fixed wing 14 with the excavated soil outside. For example, in a case where the rotating body 16 has a movable structure such as a piston, when the rotating body 16 moves in a direction away from the partition wall 12, the rotating body 16 removes excavated soil adjacent to the end face far from the partition wall 12 into the cylindrical portion 14a. And push it out through the opening. Conversely, when the rotating body 16 moves in the direction approaching the partition wall 12, the rotating body 16 pulls in external excavated soil into the inside of the cylindrical portion 14a from the opening of the cylindrical portion 14a, and at the same time, closes the end face near the partition wall 12 and the partition wall. 12 is extruded toward the opening of the cylindrical portion 14a. By doing so, the excavated soil inside the fixed wing 14 can be replaced with the excavated soil outside.

  In addition, since the device described in Patent Document 2 is installed in a bare state in the chamber, there is a high possibility that the device will be damaged when boulders collide or the like. However, according to the evaluation method of the present embodiment, there is a merit that the cylindrical portion 14a forming the outer wall (the wall of the conventional fixed wing) exerts an effect of protecting the rotating body 16 serving as the measuring portion during torque measurement. can get.

(Embodiment 2)
Next, a second embodiment will be described.
Conventionally, a rotational viscometer for examining the fluidity of fresh concrete is known. According to previous studies, for materials with low plastic viscosity and high yield value, such as fresh concrete, measuring the torque with the double cylinder type as described in the first embodiment above, the outer peripheral surface of the rotating body and the material It has been pointed out that slippage is likely to occur at the boundary surface of the sample, making accurate measurement difficult. In order to suppress the slip, for example, as shown in FIG. 1, a device for improving the frictional force by attaching a low-profile plate-like wing member 20 to the rotating body 16 or by providing a thin groove. Have been.

  However, it is assumed that a problem such as rotation failure may occur due to bites of gravel or the like. Therefore, a rotary blade type viscometer as shown in Reference 2 below has been proposed.

  [Reference Document 2] Experimental study on compounding design method of high fluidity concrete, Toru Kawai, Doctoral dissertation, Tokyo Institute of Technology, 1996

  That is, in the above-described first embodiment, it is assumed that a problem such as rotation failure may occur due to the gravel or the like biting into the gap between the cylindrical portion 14a of the fixed wing 14 and the rotating body 16 therein. You. For this reason, the method of evaluating the plastic fluidity of the excavated soil in the chamber in the earth pressure shield method according to the second embodiment is an example in which the above-described principle of the rotary-wing viscometer is applied to solve such a problem. Is presented.

  FIG. 4 is an enlarged view of a main part of a fixed wing installed on a partition wall behind a chamber of an earth pressure shield excavator, (1) is a front sectional view, and (2) is a side sectional view. As shown in this figure, a fixed wing 22 protruding into the chamber 10 is provided on the partition wall 12 behind the chamber 10. In the present embodiment, a cylindrical rod-shaped rotating body 24 that is slightly smaller is provided coaxially inside the fixed wing 22. The diameter of the rotating body 24 is considerably smaller than the diameter of the rotating body 16 of the first embodiment.

  The fixed wing 22 includes a cylindrical portion 22a having an open end face and forming an outer wall. The rotating body 24 has its rotation axis Z coaxial with the axis of the cylindrical portion 22a, and is arranged so as to penetrate the partition wall 12. On the outer peripheral surface of the one end 24a of the rotating body 24, wing members 26 are arranged at equal intervals in the axial direction as a frictional force improving portion for improving the frictional force, and are respectively shifted by 90 degrees around the axis Z. Are provided at a total of four locations. Each of the wing members 26 has a substantially trapezoidal plate shape having a shorter side near the axis Z and a longer side farther from the axis Z. The wing members 26 are obliquely attached to the outer peripheral surface of the rotating body 24 in such a manner that the wing members 26 move in the circumferential direction as they move in the axial direction. The radial height of the wing member 26 from the outer peripheral surface of the rotating body 24 is larger than the diameter of the rotating body 24.

  The other end 24 b of the rotating body 24 is connected to a rotation drive device (not shown) outside the partition 12. This rotation drive device includes a motor device that reversibly rotates the rotating body 24 and that can adjust the number of rotations (rotation speed). Therefore, the rotating body 24 is rotatable under the control of the rotation driving device.

  Also in the present embodiment, the torque T is measured while applying a predetermined rotation speed (angular velocity ω) to the rotating body 24, and applied to the excavated soil based on the rotation speed ω in the same manner as in the first embodiment. Find the shear rate. On the other hand, the shear stress acting on the excavated soil is determined based on the measured torque T. The plastic fluidity of the excavated soil in the chamber 10 is evaluated based on the obtained relationship between the shear rate and the shear stress. By doing so, the plastic fluidity (viscosity, yield value) of the excavated soil in the chamber 10 can be directly and continuously accurately evaluated by the rotating body 24 inside the fixed blade 22. Note that, in the present embodiment, unlike the above-described first embodiment, a correction for calculating an index (viscosity, yield value) of plastic fluidity is separately required.

  Note that, in the present embodiment, unlike the case of the above-described first embodiment, the cylindrical portion 22a forming the outer wall is not indispensable at the time of measuring the torque. When the torque is measured, it is desirable to measure the torque while the rotating body 24 is moved in the axial direction and pushed out of the fixed wing 22. As described above, when not used for torque measurement, the rotating body 24 as a torque measuring device can be protected by storing it in the fixed wing 22 and pushing it out only at the time of torque measurement. Note that, similarly to the above-described first embodiment, the configuration may be such that the rotating body 24 is rotated within the fixed wing 22 to measure the torque. In this case, the rotating body 24 may be configured to be movable in the axial direction, and the excavated soil inside the fixed wing 22 may be replaced with external excavated soil.

  In addition, since the device described in Patent Document 2 is installed in a bare state in the chamber, there is a high possibility that the device will be damaged when boulders collide or the like. However, according to the evaluation method of the present embodiment, there is an advantage that the cylindrical portion 22a (wall of the conventional fixed wing) forming the outer wall exerts an effect of protecting the rotating body 24 serving as the measuring unit.

[Earth pressure shield excavator]
Next, an earth pressure shield excavator according to the present invention will be described.

  The earth pressure type shield excavator according to the present invention includes a stirring blade provided on the cutter spoke side and a cylindrical fixed blade 14 (or 22) provided on the partition 12 side of the chamber 10. This is an earth-pressure shield excavator that stirs excavated soil in the excavated soil 10 to impart plastic fluidity to the excavated soil and applies the earth pressure of the excavated soil to the face to stabilize the face and excavate.

  As shown in FIG. 1 (or FIG. 4), in this earth pressure shield excavator, a columnar rotating body 16 (24), which is slightly smaller, is provided coaxially inside a fixed wing 14 (22), and the rotating body 16 ( 24) The torque is measured while giving a predetermined number of rotations, the shear rate applied to the excavated soil is determined based on the number of rotations, and the shear stress acting on the excavated soil is determined based on the measured torque. An unillustrated management means for evaluating the plastic fluidity of the excavated soil in the chamber 10 based on the relationship between the shear rate and the shear stress, and visualizing and displaying the evaluated plastic fluidity is provided.

  This management means can be constituted by a computer having a CPU for evaluating the plastic fluidity of the excavated soil, a display for visualizing and displaying the plastic fluidity evaluated by the computer, and the like. A display example on a display or the like is as shown in FIG. By monitoring the contents displayed on the display or the like when the cutter rotates, the plastic fluidity of the excavated soil in the chamber 10 can be accurately grasped in real time, and excavation can be performed while performing appropriate construction management based on the flow. It is possible. For this reason, management of plastic fluidity can be performed with high accuracy.

  Thus, according to the earth pressure type shield excavator according to the present embodiment, the plastic fluidity (viscosity, yield value) of the excavated soil in the chamber 10 is controlled by the rotating body 16 (24) inside the fixed wing 14 (22). ) Can be evaluated directly and continuously with high accuracy and can be managed.

  As described above, according to the method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure shield method according to the present invention, the stirring blades installed on the cutter spoke side and the stirring blades installed on the partition wall side separating the chamber are provided. With the cylindrical fixed wings, the excavated soil in the chamber is agitated to impart plastic fluidity to the excavated soil, and the earth pressure of the excavated soil is applied to the face to stabilize the face while excavating. Applied to the pressure shield construction method, is an evaluation method for evaluating the plastic fluidity of the excavated soil in the chamber, wherein a cylindrical rotating body is provided coaxially inside the fixed wing, a predetermined rotation of the rotating body The torque is measured while giving the number, the shear rate given to the excavated soil is determined based on the rotation speed, and the shear response acting on the excavated soil is determined based on the measured torque. And the plastic fluidity of the excavated soil in the chamber is evaluated based on the obtained relationship between the shear rate and the shear stress. Therefore, the plastic fluidity of the excavated soil in the chamber by the rotating body inside the fixed wing ( (Viscosity, yield value) can be directly and continuously evaluated with high accuracy.

  According to another method for evaluating plastic fluidity of excavated soil in a chamber in another earth pressure shield method according to the present invention, the excavated soil is assumed to be a viscous fluid, and the excavated soil is determined by a yield value and a plastic viscosity as a viscous fluid. Since the plastic fluidity is evaluated, it is based on the conventional viscosity evaluation test method, and thus the reliability of the evaluation result is high. Therefore, the plastic fluidity of the excavated soil in the chamber can be accurately evaluated.

  According to the plastic fluidity evaluation method of the excavated soil in the chamber in another earth pressure shield method according to the present invention, since the frictional force improving portion for improving the frictional force is provided on the outer peripheral surface of the rotating body, Slip at the boundary surface between the outer peripheral surface of the rotating body and the excavated soil is suppressed, and more accurate torque measurement becomes possible. Therefore, the plastic fluidity of the excavated soil in the chamber can be accurately evaluated.

  Further, according to the method for evaluating the plastic flowability of excavated soil in a chamber in another earth pressure type shield method according to the present invention, the rotating body is configured to be movable in the axial direction, so that the rotating body is moved in the axial direction. As a result, the excavated soil inside the fixed wing can be replaced with the outside.

  Further, according to the method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure type shield method according to the present invention, when the torque is not measured by the rotating body, the rotating body is housed inside the fixed wing, When the torque is measured, the rotating body is moved in the axial direction and is pushed out of the fixed wing, so that the rotating body as the torque measuring device can be protected during non-measurement.

  According to the method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure shield method according to the present invention, since the fixed wings are provided at a plurality of locations on the partition wall side, excavated soil over a wide area in the entire chamber. Plastic fluidity can be evaluated.

  According to another method for evaluating the plastic fluidity of excavated soil in a chamber in another earth pressure type shield method according to the present invention, the plastic fluidity of the excavated soil is evaluated while rotating the cutter, and the evaluated plastic fluidity is evaluated. Is displayed on the display so that the plastic flow of the whole chamber can be accurately and continuously grasped in real time with high accuracy by looking at the display, and the plastic flow can be managed with high accuracy. Become.

  Further, according to the earth pressure type shield excavator according to the present invention, the excavated soil in the chamber is stirred by the stirring blade installed on the cutter spoke side and the cylindrical fixed blade installed on the partition wall separating the chamber. An earth-pressure shield excavator that stirs and excavates while imparting plastic fluidity to the excavated soil by stirring and exerting the earth pressure of the excavated soil on the face. A cylindrical rotating body is provided coaxially, a torque is measured while giving a predetermined number of rotations to the rotating body, and a shear rate given to the excavated soil is determined based on the number of rotations, and the shearing rate is determined based on the measured torque. Determine the shear stress acting on the excavated soil, based on the relationship between the determined shear rate and the shear stress, evaluate the plastic fluidity of the excavated soil in the chamber, and evaluate the evaluated plastic fluidity. Since a management means for visualization display, plastic flow properties (viscosity, yield value) of the excavated soil in the chamber by an internal rotating body fixed wing directly, and it can be continuously and accurately assessed.

  As described above, the plastic flow evaluation method and the earth pressure type shield excavator of the excavated soil in the chamber in the earth pressure type shield method according to the present invention are useful for the earth pressure type shield method applied to shield tunnel construction, It is suitable for directly and continuously accurately evaluating the plastic fluidity of excavated soil in a chamber.

DESCRIPTION OF SYMBOLS 10 Chamber 12 Partition wall 14, 22 Fixed wing 14a, 22a Cylindrical part 16, 24 Rotating body 18 Rotation shaft part 18a, 24a One end part 18b, 24b Other end part 20, 26 Wing member Z Rotation axis

Claims (6)

The excavated soil in the chamber is agitated by stirring blades installed on the cutter spoke side and cylindrical fixed blades installed on the partition wall side separating the chamber and protruding into the chamber. Is applied to the earth pressure type shield method in which the excavated soil is excavated while stabilizing the face by applying the earth pressure of the excavated soil to the face, and evaluates the plastic fluidity of the excavated soil in the chamber. Evaluation method,
The inside is provided a cylindrical rotary body coaxially Rutotomoni fixed wing, and movable in the rotating body in the axial direction with respect to the fixed wing, wherein in that the rotating body is moved in the axial direction While the excavated soil inside the fixed wing can be replaced with the excavated soil outside the fixed wing, torque is measured while giving a predetermined rotation speed to the rotating body inside the fixed wing, and the rotation speed is measured. Along with determining the shear rate given to the excavated soil based on, based on the measured torque to determine the shear stress acting on the excavated soil, based on the relationship between the determined shear rate and shear stress, in the chamber A method for evaluating the plastic fluidity of excavated soil in a chamber in the earth pressure shield method, wherein the plastic fluidity of the excavated soil is evaluated.   The excavated soil in a chamber in the earth pressure shield method according to claim 1, wherein the excavated soil is assumed to be a viscous fluid, and a plastic fluidity of the excavated soil is evaluated based on a yield value and a plastic viscosity as a viscous fluid. Plastic fluidity evaluation method.   The method according to claim 1 or 2, further comprising a frictional force improving portion provided on an outer peripheral surface of the rotating body for improving a frictional force. The method according to any one of claims 1 to 3 , wherein the fixed wing is provided at a plurality of locations on the partition wall side. The plastic fluidity of the excavated soil is evaluated while rotating the cutter, and information indicating the evaluated plastic fluidity is visualized and displayed on a display unit. The method according to any one of claims 1 to 4 , wherein Of plastic fluidity of excavated soil in chamber in earth pressure shield method in Japan. The excavated soil in the chamber is agitated by stirring blades installed on the cutter spoke side and cylindrical fixed blades installed on the partition wall side separating the chamber and protruding into the chamber. An earth-pressure shield excavator that imparts plastic fluidity to the excavated soil and applies excavation soil pressure to the face to stabilize the face while excavating.
The inside is provided a cylindrical rotary body coaxially Rutotomoni fixed wing, and movable in the rotating body in the axial direction with respect to the fixed wing, wherein in that the rotating body is moved in the axial direction While the excavated soil inside the fixed wing can be replaced with the excavated soil outside the fixed wing, torque is measured while giving a predetermined rotation speed to the rotating body inside the fixed wing, and the rotation speed is measured. Along with determining the shear rate given to the excavated soil based on, based on the measured torque to determine the shear stress acting on the excavated soil, based on the relationship between the determined shear rate and shear stress, in the chamber An earth pressure shield excavator, comprising: management means for evaluating the plastic fluidity of the excavated soil and visualizing and displaying the evaluated plastic fluidity.

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