JP6886376B2 - Sentry for lining concrete placement and its installation and usage - Google Patents

Description

The present invention relates to a lining concrete casting center (formwork device) used for tunnel construction and a method for installing (and using) the center.

The lining concrete placing center is a formwork (panel foam) that forms a space for placing lining concrete between the inner peripheral surface of the tunnel and a formwork that supports the formwork and determines the installation position. It is configured to include a support device (running stand and jack).
Then, the lining concrete placing center is removed from the mold after the lining concrete is placed, moved in the direction of the tunnel axis, and installed at the next placement location.

Here, a wrap portion is provided at one end of the formwork in the tunnel axial direction, and the outer peripheral surface of the wrap portion is pressed against the inner peripheral surface of the cast lining concrete.

However, when the centre is installed at the next casting location, the wrapping portion may be locally excessively pressed against the cast lining concrete, and the cast lining concrete may crack. Such cracks cause the block to come off, leading to an accident.

Therefore, in Patent Document 1, a pressure sensor (pressure sensor such as a load cell or strain gauge foil) is installed at an appropriate position in the wrap portion of the center, and when the detection result exceeds the upper limit value, an alarm is issued or a pressing operation is performed. It has been proposed to stop.

Japanese Patent No. 3535464

However, in the technique described in Patent Document 1, since the detection of local excessive pressing of the center depends on the arrangement position and number of pressure sensors, it cannot always be detected accurately and may be overlooked. There was also.
Moreover, since the comparison result with the upper limit value is only shown for the detection result at each sensor position, it is not intuitively understood how to operate the formwork from the detection result, and from the viewpoint of operability. But there is room for improvement.

The present invention has been made in view of such an actual situation, and has a configuration in which it is possible to detect the local excessive pressing of the center without overlooking, and it is possible to intuitively recognize the biased state of the formwork. The task is to do.

The lining concrete casting center according to the present invention is a formwork that forms a space for placing lining concrete between the inner wall surface of the tunnel and a formwork that supports the formwork and determines the installation position. The formwork is provided with a support device, and the formwork is pressed against the inner peripheral surface of the cast lining concrete at the outer peripheral surface of the wrap portion provided at one end in the tunnel axial direction.
Then, among the outer peripheral surfaces of the lap portion, at least the outer peripheral surface of the top end portion includes a sheet-shaped pressure sensor that is continuous in the tunnel circumferential direction, and the pressure sensor is the lap portion and the driven portion. It is possible to measure the pressure distribution in the circumferential direction of the tunnel with the lining concrete.
Further, it is preferable to further include a color image display device that displays the pressure distribution in the tunnel circumferential direction detected by the pressure sensor with a multicolor gradation.
Further, the pressure sensor has an extension portion extending from the wrap portion into the casting space of the lining concrete, and the extension portion can detect the concrete filling pressure at the time of placing the lining concrete.

According to the present invention, since the pressure distribution in the tunnel circumferential direction is measured by using the sheet-shaped pressure sensor continuous in the tunnel circumferential direction, the mold is not overlooked such as local excessive pressing of the centre. It becomes possible to easily recognize the biased state of the body.
In particular, by displaying the pressure distribution in a multicolor gradation, it is possible to intuitively recognize the biased state and perform an intuitive operation.
In addition, the extension of the pressure sensor makes it possible to easily detect the filling of concrete into the lining concrete placing space, and the pressure sensor can be effectively used not only when the centre is installed but also when the concrete is filled.

Cross-sectional view of a tunnel in a center-installed state showing an embodiment of the present invention. Cross-sectional view of the center wrap along the tunnel axis direction Schematic cross-sectional view showing the laminated structure of pressure sensors Schematic plan and circuit diagram of pressure sensor A cross-sectional view of a center wrap portion along the tunnel axial direction showing another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a cross-sectional view of a tunnel in a center-installed state showing an embodiment of the present invention.
The lining of the present embodiment is a secondary lining. Therefore, in the tunnel 1 to be lining, immediately after excavation, the inner peripheral surface (excavation surface) of the tunnel 1 is first lining with sprayed concrete 2, and a waterproof sheet (not shown) is attached to the surface thereof. ing.
Further, on the bottom surface (roadbed) 3 of the tunnel 1 to be lining, a rail 4 is laid for moving the lining concrete placing center in the direction of the tunnel axis.

The lining concrete placing center (movable formwork device) 5 moves in the direction of the tunnel axis by a predetermined length (for example, 5 to 6 m) of the placing unit, and sets the formwork at each moving position. And then cast, then demold and move to the next casting position.

The center 5 will be described in more detail.
The center 5 includes a gantry (trolley) 6, a plurality of jacks 7 attached to the gantry 6, and a formwork (panel foam) 8 supported by the tip of the jacks 7.
Here, the gantry 6 and the jack 7 form a formwork support device that supports the formwork 8 and determines the installation position.

The gantry 6 can be moved in the direction of the tunnel axis along the rail 4 laid on the bottom surface 3 of the tunnel 1, and can be positioned and fixed at an arbitrary moving position.

The formwork body 8 forms a lining concrete placing space 9 with the inner wall surface (inner wall surface after the primary lining) of the tunnel 1.
The formwork body 8 is configured such that a plurality of formwork members (panel foam members) 8a to 8c are hinged in the tunnel circumferential direction to form an arch shape as a whole.

In the present embodiment, the formwork body 8 includes one top panel foam member 8a, two side panel foam members 8b and 8b on the left and right sides thereof, and two leg panel foam members on each lower side thereof. It has a five-divided structure with 8c and 8c.

Here, the top panel foam member 8a is supported by a pair of left and right jacks 7a and 7a that can be expanded and contracted in the vertical direction.
Each side panel foam member 8b is supported by a pair of upper and lower jacks 7b, 7b that can be expanded and contracted sideways.
Each leg panel foam member 8c is arranged obliquely downward and supported by a stretchable jack 7c.
Therefore, the diameter of the formwork 8 can be increased or decreased by operating these jacks 7 (7a to 7c).

FIG. 2 is a cross-sectional view of the center wrap portion along the tunnel axial direction.
Wrap around one end of the formwork 8 of the center 5 in the tunnel axial direction (the rear end in the direction of tunnel lining; the end on the wellhead side when tunnel lining is advanced in the tunnel excavation direction). Part 10 is set.

The wrap portion 10 closes one end side of the lining concrete placing space 9 by being pressed against the inner peripheral surface of the lining concrete (existing concrete) 11 that has already been placed on the outer peripheral surface thereof.

It should be noted that joints of the lining concrete in the tunnel axial direction are provided with joints in advance so as to have corners in order to prevent corner chipping. Therefore, as shown in FIG. 2, a rubber face wood (joint material) 12 having a triangular cross section is formed between the already placed lining concrete 11 on the wrap portion 10 side and the lining concrete placing space 9. Have been placed.
Further, the other end side of the lining concrete placing space 9 is closed by a wife form (not shown).

Here, a flexible sheet-shaped pressure sensor 13 is arranged on the outer peripheral surface of the wrap portion 10 of the formwork 8 of the center 5, and when the formwork 8 is installed, the sheet-shaped pressure sensor 13 is placed. , It is interposed between the outer peripheral surface of the wrap portion 10 of the formwork 8 and the inner peripheral surface of the lining concrete 11 that has already been cast.
The pressure sensor 13 measures the pressure distribution in the tunnel circumferential direction between the wrap portion 10 and the cast lining concrete 11, and may be provided over the entire circumference of the wrap portion 10, but the wrap portion 10 may be provided. Of the outer peripheral surfaces of the above, at least the outer peripheral surface of the top end portion (for example, in the angle range of 10 o'clock to 2 o'clock of the clock) may be provided so as to be continuous in the tunnel circumferential direction. This is because even if the block is peeled off due to a chipped corner or the like on the side of the tunnel, there is little damage and repair is easy.

The specific configuration of the pressure sensor 13 will be described with reference to FIGS. 3 and 4.
FIG. 3 is a schematic cross-sectional view showing a laminated structure of pressure sensors, and FIG. 4 is a schematic plan view and a circuit diagram of pressure sensors.

The sheet-shaped pressure sensor 13 is of an electromagnetic induction method, and as shown in FIG. 3, a drive coil layer 21 in which a plurality of drive coils 31c are arranged in a matrix from the bottom to the top, and the plurality of drive coils. A detection coil layer 22 in which a plurality of detection coils 32c are arranged in a matrix so as to form a pair with 31c, an elastic body layer 23 made of an insulating elastic body (cushion material), and a conductor (for example, aluminum or the like). The conductor layer 24 made of the above metal sheet) is laminated. In the plan view of FIG. 4, only the drive coil layer 21 (dotted line) and the detection coil layer 22 (solid line) are shown, and the elastic layer 23 and the conductor layer 24 are not shown.

The drive coil layer 21 is provided with a plurality of loop electrode wires 31 extending in the X-axis direction and folded back on the flexible substrate, and is a flat surface such as a polygon or a circle on each loop electrode wire 31 at predetermined intervals. A coil is formed to form a drive coil 31c.
The detection coil layer 22 is provided with a plurality of loop electrode lines 32 extending in the Y-axis direction and folded back on the flexible substrate, and is a flat surface such as a polygon or a circle on each loop electrode line 32 at predetermined intervals. A coil is formed to form a detection coil 32c.
Here, the drive coil 31c and the detection coil 32c are arranged in a matrix and overlap each other in the vertical direction to form a pair.

The elastic body layer 23 may be an elastic member (cushion material) having an insulating property and whose thickness changes depending on an external force (surface pressure), but a silicon sponge sheet or the like can be preferably used.
As the conductor layer 24, various materials such as aluminum foil and copper foil can be used as long as they have conductivity.
Here, the elastic body layer 23 and the conductor layer 24 on the surface side thereof are layers whose thickness is changed by an external force to change the degree of electromagnetic coupling of each pair of the drive coil 31c and the detection coil 32c.

Here, in a state where the drive coil 31c is driven at a high frequency, the elastic body layer 23 is compressed into the pair of the drive coil 31c and the detection coil 32c that are electromagnetically coupled, and when the conductor layer 24 approaches, the electromagnetic coupling is performed. The degree becomes weaker, and the induced current or induced voltage measured from the detection coil 32c becomes smaller. By utilizing this phenomenon, it is possible to measure the change in the thickness of the elastic body layer 23, which changes according to the pressure applied to the position of each pair of the drive coil 31c and the detection coil 32c, from the degree of electromagnetic coupling.

When a magnetic material layer made of a magnetic material is used instead of the conductor layer 24, when the magnetic material approaches the pair of the driving coil 31c and the detection coil 32c that are electromagnetically coupled, the degree of electromagnetic coupling becomes stronger and the detection is performed. The induced current or induced voltage measured from the coil 32c becomes large. Therefore, this phenomenon can also be used.

Further, regarding the conductor layer 24, instead of providing the conductive substance on the entire surface in the form of a sheet, a plurality of independent conductive substances are arranged in the form of a matrix corresponding to the drive coil and the detection coil arranged in the form of a matrix. You may try to do so.
In this case, when the conductive substance approaches each pair of the drive coil and the detection coil, an eddy current flows through the conductive substance and a magnetic field is generated in the vertical direction, so that the degree of electromagnetic coupling becomes stronger. Therefore, this phenomenon is used.

Further, between the drive coil layer 21 in which a plurality of drive coils are arranged in a matrix and the detection coil layer 22 in which a plurality of detection coils are arranged in a matrix so as to form a pair with the plurality of drive coils. It is also possible to provide an elastic layer made of an elastic body (cushion material) having an insulating property, and to change the degree of electromagnetic coupling of each pair by changing the distance between the drive coil and the detection coil.

Next, the circuit configuration for measuring the pressure distribution will be described with reference to FIG.
The drive circuit 41 is composed of an oscillator 42 and a current driver 43, and is sequentially connected to one end of the loop electrode line 31 on the drive coil 31c side by a changeover switch 44 composed of a multiplexer or the like, and the drive coil is connected to each loop electrode line 31. Drive 31c. The other end of the loop electrode wire 31 is grounded.

The detection circuit 45 includes a current amplifier 46, a synchronous detection unit 47, and an AD conversion unit 48, and is sequentially connected to one end of the loop electrode wire 32 on the detection coil 32c side by a changeover switch 49 composed of a multiplexer or the like to form a loop. For each electrode line 32, the signal of the detection coil 32c paired with the driving coil 31c being driven is detected. The other end of the loop electrode wire 32 is grounded.

Here, the current amplified by the current amplifier 46 is input to the synchronous detection unit 47, and the output from the oscillator 42 is also connected to the synchronous detection unit 47. Therefore, the synchronous detection unit 47 synchronizes the output from the oscillator 42 with the signal by electromagnetic coupling, and the AD conversion unit 48 converts the signal into a digital signal.

The arithmetic processing unit (MPU) 50 controls the changeover switches 44 and 49, while reading a digital signal from the AD conversion unit 48 to perform processing necessary for pressure distribution detection. That is, while driving the loop electrode wire 31 on the drive coil 31c side at one position in the X direction selected by the changeover switch 44, the changeover switch 49 is switched one after another in the Y direction to drive on the loop electrode wire 31. The degree of electromagnetic coupling between the coil 31c and the detection coil 32c is read. Next, the selection position of the changeover switch 44 is changed in the X direction, and in this state, the changeover switch 49 is changed one after another in the Y direction, and the same operation is repeated. As a result, it is possible to read all the degrees of electromagnetic coupling between the drive coil 31c and the detection coil 32c arranged in a matrix, thereby detecting the pressure distribution.

The color image display device 51 displays the pressure distribution detected by the pressure sensor 13 (the calculation processing unit 50 thereof) with a multicolor gradation. Specifically, the zero pressure portion is displayed in dark blue, the maximum pressure portion is displayed in dark red, and the middle is displayed in shades.

Next, the pressure distribution measurement and the centre installation method in the centre wrap portion using the pressure sensor 13 (and the color image display device 51) will be described.

When the above pressure sensor 13 is applied to the center wrap portion, either the X-axis direction or the Y-axis direction (Y-axis direction in FIG. 4) is lengthened so as to correspond to the tunnel circumferential direction, and the other (FIG. 4). In 4, the X-axis direction) is shortened so as to correspond to the width direction (tunnel axis direction) of the lap portion. This makes it possible to measure the pressure distribution in the tunnel circumferential direction (Y-axis direction in FIG. 4).
Although it is possible to measure the pressure distribution in the width direction (tunnel axis direction) of the lap portion, the pressure distribution in the width direction (tunnel axis direction) of the wrap portion can be regarded as constant, so the X axis. The output change in the direction may be ignored, or an averaging process may be performed.

From this, the arithmetic processing unit 50 can measure the pressure distribution in the circumferential direction of the lap unit 10, and the color image display device 51 can measure the pressure distribution in the circumferential direction of the tunnel detected by the pressure sensor 13 (the arithmetic processing unit 50). The pressure distribution can be displayed by multicolor gradation.

As described above, a sheet-shaped pressure sensor 13 continuous in the tunnel circumferential direction is arranged on the wrap portion 10 between the formwork 8 of the center 5 and the cast lining concrete 11 to obtain pressure in the tunnel circumferential direction. Since the distribution is measured, the local excessive pressing of the center 5 and the like are not overlooked, and the biased state of the mold 8 can be easily recognized. Therefore, based on the measurement result of the pressure distribution, the balance can be adjusted by the left and right jacks 7a and 7b, and the center 5 can be installed so that the unbalanced pressure does not occur.

In particular, by displaying the pressure distribution in a multicolor gradation using the color image display device 51, it is possible to intuitively recognize the biased state and perform an intuitive operation.

In this way, when installing the Centre 5, it is possible to manage the existing concrete so that unbalanced pressure does not occur by monitoring not at points but at surfaces, so that the existing concrete is cracked or chipped. It will almost never occur, and repair work and repair costs can be reduced. In addition, if cracks or corner chips occur and cannot be found during construction, the part may fall after operation and cause damage to a third party. It is possible to prevent personal damage.

As the pressure sensor, in addition to the electromagnetic induction method used in the above embodiment, there are a pressure sensitive resistance method, a capacitance method, etc., but it is said that the electromagnetic induction method is superior in terms of durability and price. be able to.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a cross-sectional view of the center wrap portion along the tunnel axial direction showing another embodiment of the present invention.

In the present embodiment, the width (length in the tunnel axis direction) of the sheet-shaped pressure sensor 13 is increased, and an extension portion 13a extending from the wrap portion 10 into the lining concrete casting space 9 is provided.
According to this, the extension portion 13a of the pressure sensor 13 can detect the concrete filling pressure at the time of placing the lining concrete.

Since the lining concrete placing space 9 is generally filled with concrete from the end formwork side, it is extremely important to determine whether or not the filling is correctly performed up to the vicinity of the wrap portion 10. Therefore, according to the present embodiment, it is possible to easily detect the filling of concrete into the lining concrete placing space 9, and the pressure sensor 13 can be effectively used not only when the centre is installed but also when the concrete is filled. it can.

In this case, since the surface side of the pressure sensor 13 comes into contact with the concrete to be cast, if the surface side of the pressure sensor 13 is covered with a protective film that can be easily peeled off, the pressure sensor 13 can be reused at the next casting position. Is certain.

It should be noted that the illustrated embodiments merely illustrate the present invention, and the present invention includes various improvements and improvements made by those skilled in the art within the scope of claims, in addition to those directly shown by the described embodiments. It goes without saying that it involves changes.

1 Tunnel 2 Sprayed concrete 3 Tunnel bottom surface 4 Rail 5 Center 6 Stand 7 Jack 8 Form frame 9 Ladening concrete Placement space 10 Wrap part 11 Placed lining concrete 12 Rubber surface wood 13 Pressure sensor 21 Drive coil layer 22 Detection coil layer 23 Elastic layer 24 Conductor layer 31 Loop electrode wire on the drive coil 31c side 32 Loop electrode wire on the detection coil 32c side 41 Drive circuit 42 Oscillator 43 Current driver 44 Changeover switch 45 Detection circuit 46 Current amplifier 47 Synchronous detector 48 AD conversion unit 49 selector switch 50 arithmetic processing unit (MPU)
51 color image display device

Claims (2)

A formwork body that forms a space for placing lining concrete between the inner wall surface of the tunnel and
A formwork support device that supports the formwork and determines the installation position is provided.
The formwork is a lining concrete placing center that is pressed against the inner peripheral surface of the lining concrete that has already been placed on the outer peripheral surface of the wrap portion provided at one end in the tunnel axial direction.
Of the outer peripheral surface of the lap portion comprises a sheet-like pressure sensor that is disposed on the outer peripheral surface of at least top end portion,
The pressure sensor can measure the pressure distribution in the tunnel circumferential direction between the lap portion and the cast lining concrete .
The pressure sensor is characterized in that it has an extension portion extending from the wrap portion into the casting space of the lining concrete, and the extension portion can detect the concrete filling pressure at the time of placing the lining concrete. A center for lining concrete placement. A formwork that forms a space for placing lining concrete between the inner wall surface of the tunnel and the outer peripheral surface of the wrap portion provided at one end of the formwork in the tunnel axial direction has been placed. When pressing against the inner peripheral surface of lining concrete and installing
Of the outer peripheral surface of the wrap portion, a sheet-shaped pressure sensor arranged between at least the outer peripheral surface of the top end portion and the cast lining concrete and capable of measuring the pressure distribution is used.
Adjusting the installation position of the formwork based on the measurement result of the pressure distribution, and
The pressure sensor has an extension portion extending from the wrap portion into the casting space of the lining concrete, and the extension portion detects the concrete filling pressure at the time of placing the lining concrete . How to install and use the lining concrete placing center.

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