JP2008169692A - Measuring device for sediment flow in chamber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a measuring device capable of responding to a sudden change in properties of excavated ground. <P>SOLUTION: An excavator 12 has a measuring device 10a for finding a flowing direction and a size of a mixture in a chamber 20. The measuring device 10a has a measuring rod 50 installed retractably to the chamber 20; and the flowing direction and the size of the mixture can be estimated from an amount of deformation of the measuring rod 50. On the other hand, a machine model of the chamber is set in advance, and a plurality of results of fluid analysis with visualized size, direction and distribution of the velocity in the chamber 20 are predetermined based on the viscosity of the mixture. Further, good correlations between the estimate obtained by the measuring device 10a and the results of the fluid analysis are selected; and the results of fluid analysis selected are considered as a state of flow at a time when the estimate is obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a measurement device for sediment flow in a chamber, and more particularly to a measurement device for sediment flow in a chamber of a mud pressure shield machine.

The excavation of the ground earth and sand by the mud pressure type shield machine used for the construction work of the shield tunnel is, for example, as disclosed in Non-Patent Document 1, the earth and sand excavated by the cutter head is taken into the chamber and filled, The soil is discharged by the screw conveyor while stabilizing the face by the earth pressure in the chamber.

In this case, in the construction work, the rotation speed of the screw conveyor and the excavation speed are adjusted so that the earth pressure in the chamber can be discharged in accordance with the propulsion amount while the shield thrust is applied to the extent necessary for the stability of the face.

In the mud pressure shield method that discharges soil in such a manner, the fluidity and water blocking properties of the excavated soil greatly affect the earth pressure in the chamber, and thus are particularly important management items. However, such conventional mud pressure shield machine has the following technical problems.
"Encyclopedia of Civil Engineering Law Revised V" September 2001, 639-640pp

That is, in the conventional mud pressure type shield machine, the earth pressure gauge is installed in the chamber to control the earth pressure in the chamber, but the state of the excavated sediment in the chamber is not known. When the properties of the excavated ground suddenly changed, it caused spoilage and inability to remove the soil, and it took a lot of time and labor to recover.

In addition, in the conventional construction of shield tunnels, the evaluation of fluidity of excavated soil depends largely on the properties of the soil removed and machine data (cutter torque and magnitude of thrust), such as gravel ground and alternate ground. In this case, it was difficult to select an appropriate additive and to set the injection rate.

The present invention has been made in view of such conventional problems, and the object of the present invention is to respond to sudden changes in the properties of excavated ground by grasping the direction of sediment flow in the chamber. An object of the present invention is to provide an apparatus for measuring the flow in a chamber, which is capable of setting the selection of an appropriate additive and the injection rate.

In order to achieve the above object, the present invention provides a fluidity measuring device for the mixture in a chamber of a mud pressure shield machine that contains a stirring mixture of excavated earth and mud, and the measuring device comprises: A measuring rod that penetrates a partition wall that separates the chamber and is installed so as to be able to appear and retract in the chamber is provided. From the deformation amount of the measuring rod when the mixture flows, the flow direction and the size of the mixture And a visualization of the magnitude, direction, and distribution of the flow velocity of the mixture in the chamber based on a preset mechanical model of the chamber and a clay equation of the mixture in the chamber. A plurality of flow analysis results obtained are obtained, and the flow analysis selected by selecting a good correlation between the estimated value obtained by the measurement device and the flow analysis result. The results were such that the flow state at the time of the estimated value is obtained.

According to the measuring device for sediment flow in the chamber configured as described above, the measuring rod is provided so as to pass through the partition walls separating the chamber and be installed in the chamber so as to be able to appear and retract. Since the flow direction and size of the mixture are estimated from the amount of deformation, the flow direction of the mixture in the chamber can be grasped, and it is possible to cope with sudden changes in the properties of the excavated ground, and selection of appropriate additives And the injection rate can be set.

  In this case, according to the measuring apparatus of the present invention, based on a mechanical model of the chamber set in advance and the clay equation of the mixture in the chamber, a plurality of flow velocity magnitudes, directions, and distributions visualized are visualized. Obtain the flow analysis result, select the one with a good correlation between the estimated value obtained by the measuring device and the flow analysis result, and select the flow analysis result at the time when the estimated value was obtained. Therefore, it is possible to visualize the flow distribution in the entire area of the chamber, to easily cope with sudden changes in the properties of the excavation ground at the construction site, and to set the appropriate additive selection and injection rate. It is easy to do.

The measuring rod includes a plurality of strain gauges provided on the proximal end side, and the deformation amount can be obtained from detection signals of the strain gauges.

A plurality of the apparatus for measuring the sediment flow in the chamber may be arranged on the same circumference with a predetermined interval along the circumferential direction with respect to the chamber.

The measuring device may be provided with a shutter device that closes the partition wall opening when the rotating plate is retracted from the chamber.

According to the measurement device for sediment flow in the chamber according to the present invention, it is possible to cope with a sudden change in the properties of the excavated ground by grasping the direction and size of the sediment flow in the chamber, and appropriate addition. Material selection and injection rate can be set.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

FIG. 1 to FIG. 5 show Embodiment 1 of an apparatus for measuring sediment flow in a chamber according to the present invention. FIG. 1 shows a mud type shield machine 12 equipped with a measuring device 10 of the present invention.

The shield machine 12 shown in the figure includes a cylindrical skin plate 14, and a cutter 16 is disposed at the front end of the skin plate 14. 2, the cutter 16 includes a spoke-like cutter face 16a extending radially outward from the center and a number of cutter bits provided on the front face of the cutter face 16a. 16b and a center axis 16c fixed to the center of the back surface of the cutter face 16a.

On the front end side of the skin plate 14, a disk-shaped partition wall 18 having an outer peripheral edge fixed to the inner surface of the skin plate 14 is provided, and the cutter 16 rotates so that the central axis 16c passes through the partition wall 18. By arranging the cutter 16 in this manner, the chamber 20 is provided that is separated in a substantially disk shape by the back surface of the cutter face 16a and the partition wall 18.

A plurality of stirring blades 16d projecting into the chamber 20 are provided on the back side of the cutter face 16a, and a plurality of support stays 16e that abut against the partition wall 18 are provided on the back surface of the cutter face 16a. .

An agitator 16f installed in the chamber 20 is provided on the side surface of the central shaft 16c, and this agitator 16f is independent of the cutter face 16a by a drive motor 16g installed outside the partition wall 18. It is rotationally driven together with 16c.

One end of the support stay 16e penetrates the partition wall 18 and protrudes to the outside. A ring gear 16h is provided at the protruding portion, and a cutter drive motor 16i is connected to the ring gear 16h. When 16i is driven, the cutter face 16a is rotationally driven via the ring gear 16h, and excavation of the ground is performed by the cutter bit 16b.

The excavated earth and sand excavated by the cutter bit 16b is taken into the chamber 20 through the opening of the cutter face 16a. At this time, clay, bentonite, a highly water-absorbing resin, a thickening material such as a thickener is added to the excavated soil, and the excavated sediment and the mud material are agitated in the chamber 20 by the stirring blade 16d and the agitator 16f. By being mixed, it is made into a mixture having fluidity and is filled in the chamber 20 to counter the face.

And such a mixture is discharged | emitted outside through the earth removal mechanism (screw conveyor) 22 provided so that the partition 18 might be penetrated, ensuring the stability of a face. In addition, the member shown with the code | symbol 24 in FIG. 1 is a shield jack which takes the reaction force to the segment 26 assembled in the rear part side of the shield machine 12 and propels the machine 12 forward.

The basic configuration of the mud shield shield machine 12 as described above is the same as that of the conventional machine of this type, but the drill machine 12 of the present embodiment has remarkable features in the following points.

That is, the shield machine 12 of the present embodiment is a measuring device that grasps the flow direction and flow rate of the mixture in the chamber 20 of the mud pressure shield machine 12 in which the agitated mixture of excavated earth and mud is accommodated. 10a is installed.

FIG. 3 shows details of the measuring apparatus 10a. The measuring apparatus 10a shown in the figure is applied to a mud type shield excavator, and the measuring apparatus 10a is installed so as to be able to appear in the chamber 20 through the partition wall 18 separating the chamber 20. The measurement rod 50 is provided, and the flow direction and the size of the mixture are estimated from the deformation amount of the measurement rod 50 when the mixture flows.

In the case of the present embodiment, as shown in FIG. 2, four measuring devices 10a having the same configuration are arranged on the same circumference with respect to the chamber 20, and are arranged at predetermined intervals in the circumferential direction. Has been. These measuring devices 10a are arranged at positions where mutual interference with the stirring blade 16d and the agitator 16f is avoided when the rotating plate 28 is protruded into the chamber 20.

The measuring rod 50 is a hollow tube supported by a slider 38a installed in the guide tube 36a and closed at the tip, and includes a plurality of strain gauges 52 provided on the inner surface on the base end side. . A plurality of strain gauges 52 are arranged at equiangular intervals in the circumferential direction, and a plurality of strain gauges 52 are also arranged in the radial direction.

The slider 38a slides along the guide cylinder 36a along with the expansion and contraction operation of the cylinder 40a. The guide cylinder 36 a is closed by the shutter device 42 when the measuring rod 50 is retracted from the chamber 20. In the case of the present embodiment, the deformation amount generated in the measuring rod 50 is obtained from the detection signal of the strain gauge 52 installed on the measuring rod 50.

The shutter device 42 is installed below the measuring device 10 and includes a shutter plate 42a that can move up and down to close the guide cylinder 36, and a drive cylinder 42b of the shutter plate 42a.

In the measuring apparatus 10 configured as described above, when the sediment flow in the chamber 20 is not measured, the measuring rod 50 is positioned on the rear side of the guide cylinder 36a, and the guide cylinder 36a is a shutter device. 42 is occluded.

When measuring the sediment flow in the chamber 20, the closed state of the guide cylinder 36 a of the shutter device 42 is opened, the cylinder 40 a is driven, and the measuring rod 50 is projected to a predetermined position in the chamber 20.

The deformation amount generated in the measuring rod 50 at this time is generated by the collision of the mixture of mud with the excavated earth and sand flowing in the chamber 20, and the magnitude of the deformation amount corresponds to the flow direction. Is the direction of flow of the mixture, and the variation at that point is estimated as the size of the flow direction.

According to the chamber earth and sand flow measuring device configured as described above, the measuring rod 50 that penetrates the partition wall 18 separating the chamber 20 and is installed in the chamber 20 so as to be able to appear and retract is provided, and the mixture flows. Since the flow direction and size of the mixture are estimated from the deformation amount of the measuring rod 50 at the time, the flow direction of the mixture in the chamber 20 is grasped, and it is possible to cope with a sudden change in the properties of the excavated ground, and It is possible to select an appropriate additive and set an injection rate.

Further, the measurement apparatus of the present embodiment employs a flow analysis technique. 4 and 5 show an example of flow analysis employed in this embodiment. These figures are shown in, for example, Non-Patent Documents 2 and 3 (Non-Patent Document 2, “Analysis of Mud and Mud Flow in a Shield Chamber” August 1994 “Tunnel and Underground” 35-39pp, Non-Patent Document 3, “ Example of applying the analysis result based on the flow analysis in the shield chamber disclosed in "Obayashi Institute of Technology Research Report, No. 48, 1994) to the actual shield machine" Show.

As disclosed in Non-Patent Documents 2 and 3 above, the flow analysis of the mixture of excavated earth and mud in the chamber of the shield machine is performed using the mechanical model of the chamber of the shield machine and the clay equation ( (μ = C1 + C2 / γ) is given, it is known that detailed analysis results such as the magnitude, direction, and distribution of the flow velocity in the chamber can be obtained.

Here, μ: Viscosity for mixed fluid of earth and sand and mud material (bubbles) γ: Strain rate C ₁ , C ₂ : (Material) constant depending on earth and α α: Earth and sand and mud material (bubbles) Volume occupancy of mud in mixed fluid (0 ≦ α ≦ 1)
The constants C ₁ and C ₂ in the upper viscosity formula are determined by a flow analysis corresponding to a fluid measurement experiment as a function of the inclusion ratio (volume occupation ratio) α of the mud material for each kind of earth and sand.

However, such an analysis is only a simulation, and it has not been confirmed how it is actually performed by a shield machine. Therefore, in this embodiment, a machine model related to the chamber 20 of the shield machine shown in FIG. 1 is set as shown in FIG. 4, and the clay formula of the mixture is changed to various geological features such as on-site excavated soil, sand ground, clay ground. Accordingly, flow analysis is performed in advance, and a plurality of visualized flow analysis results as shown in FIG. 5 are obtained.

Then, the measuring device 10a described above estimates the flow direction and size of the mixture by the above-described means, collates this with the result of the flow analysis, and installs the measuring device 10a (circled in FIG. 5). In the parts A to D), the one having the best correlation is selected, and the flow analysis result is set as the flow state at the time of measurement by the measuring apparatus 10a.

When the flow analysis result is used in this way, the flow distribution and the like in the entire region within the chamber 20 is visualized, so that it is possible to easily cope with a sudden change in the properties of the excavated ground at the construction site, and an appropriate The selection of the additive and the injection rate can also be easily set.

When the apparatus for measuring the sediment flow in the chamber according to the present invention is applied to a mud type shield excavator, it can be effectively used to ensure the safety and economics of construction.

It is sectional drawing of the shield machine which the measuring apparatus of the sediment movement in a chamber concerning this invention is applied. It is a front view of FIG. It is a side view which shows an example of the measuring apparatus of the earth sand sand flow concerning this invention. It is explanatory drawing of the mechanical model of the analysis used for the measuring apparatus of the sediment flow in the chamber concerning this invention. It is explanatory drawing of the flow-analysis result used for the measuring apparatus of the earth-sand flow in a chamber concerning this invention.

Explanation of symbols

10a Measuring device 12 Shield machine 20 Chamber 50 Measuring rod

Claims (4)

In the apparatus for measuring the fluidity of the mixture in a chamber of a mud pressure shield machine that contains a stirring mixture of excavated earth and mud,
The measuring device includes a measuring rod that is installed so as to be able to appear and retract in the chamber through a partition wall that separates the chamber.
From the amount of deformation of the measuring rod when the mixture flows, a measuring device for estimating the flow direction and the size of the mixture,
Based on a mechanical model of the chamber set in advance and a clay equation of the mixture in the chamber, a plurality of flow analysis results in which the magnitude, direction, and distribution of the flow velocity of the mixture in the chamber are visualized are obtained. Every
Selecting an estimated value obtained by the measuring device and a good correlation between the flow analysis result and setting the selected flow analysis result to a flow state at the time when the estimated value is obtained. Measuring device for sediment flow in the chamber. The measuring rod includes a plurality of strain gauges provided on the proximal end side,
The apparatus for measuring sediment flow in a chamber according to claim 1, wherein the deformation amount is obtained from a detection signal of the strain gauge. The apparatus for measuring the sediment flow in a chamber according to claim 1 is characterized in that a plurality of the sediment flows in the chamber are arranged on the same circumference at predetermined intervals along the circumferential direction. measuring device. The said measuring apparatus has a shutter apparatus which obstruct | occludes a partition opening part, when the said rotary plate retracts | saves from the inside of the said chamber, The sediment movement of the chamber internal sand of Claim 1 characterized by the above-mentioned. measuring device.

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