JP6000840B2 - Non-contact measuring method and apparatus for dynamic deflection of PC girder - Google Patents

Description

  The present invention relates to a noncontact measurement method and apparatus for dynamic deflection of PC (prestressed concrete) girders.

  Conventionally, deflection measurement of a girder is generally performed by attaching a piano wire to the girder and attaching it to a ring displacement meter installed on the ground. However, this method is difficult to measure when the digit is road or river.

  Under such circumstances, a non-contact measurement method using a laser Doppler velocimeter (LDV) or the like has recently been used.

  Therefore, the inventors of the present application have also proposed a measurement method using a non-contact sensor such as LDV (see Patent Documents 1 and 2 below).

  Also, a marking ball launching device suitable for carrying has been proposed (see Patent Document 3 below).

  Such a measurement method using a non-contact sensor such as an LDV has an advantage that the measurement can be performed more efficiently and safely than the conventional method.

JP 2004-184377 A JP 2008-281422 A JP 2006-038445 A

Hiroyuki Nishiyama, Isao Nakanishi, Tatsuhiko Hatanaka, Fumiaki Kamihan, “Correction Method when Measuring PC Girder Deflection Using“ U Doppler ””, 67th Annual Conference of Japan Society of Civil Engineers, September 2012

  However, when measuring the deflection of a digit with a large horizontal displacement using a sensor that can measure only the uniaxial speed and displacement like the conventional LDV, the measurement direction of the sensor and the vibration direction of the measurement object do not match. In the measurement by the sensor, an error becomes large, and there is a problem that an accurate deflection cannot be measured (see the above-mentioned Non-Patent Document 1).

  In view of such circumstances, the present invention provides a non-contact measuring method for dynamic deflection of a PC girder that can measure dynamic deflection of a PC girder using one or a plurality of sensors that can be easily and accurately measured. An object is to provide such a device.

In order to achieve the above object, the present invention provides
[1] In the non-contact measuring method of the dynamic deflection of the PC girders, when correcting the vertical deflection error of the PC girders with horizontal displacement, the horizontal displacement of the PC girders is measured by the movable support portion, A non-contact measuring method for dynamic deflection of a PC digit, wherein the deflection of the PC digit is performed using a non-contact sensor, and the deflection is corrected using an error table for correcting the measurement result and error. The table is a nomogram, and is characterized in that it is a graph summarizing the relationship between the measurement angle between the actual vertical deflection dy direction and the displacement u direction measured by the non-contact sensor and the error due to the horizontal displacement .

  [2] In the non-contact measurement method for dynamic deflection of a PC girder described in [1] above, the non-contact sensor is an LDV.

[ 3 ] In the non-contact measurement method for dynamic deflection of a PC girder described in [ 1 ] above, when the two non-contact sensors are used for measurement, the nomogram is measured from the fixed support portion side with respect to the center. The case of measuring from the movable support side is shown.

[4 ] Two non-contact sensors, a data acquisition device connected to the two non-contact sensors, and a data recording / analysis device connected to the data acquisition device. When correcting the deflection error in the vertical direction, the horizontal displacement of the PC girder is measured by the movable support portion, the deflection of the PC girder is measured, and the measurement result and an error table used for correcting the error are provided. A non-contact measuring apparatus for dynamic deflection of a PC girder, wherein the error table is a nomogram, and an error caused by a measurement angle and a horizontal displacement between an actual vertical deflection dy direction and a displacement u direction measured by a non-contact sensor. It is a graph that summarizes the relationship between

[ 5 ] The non-contact measuring apparatus for dynamic deflection of a PC girder according to [ 4 ] above, wherein the non-contact sensor is an LDV.

[ 6 ] In the non-contact measuring apparatus for dynamic deflection of a PC girder described in [ 4 ] above, when the two non-contact sensors are used for measurement, the nomogram is measured from the fixed support portion side with respect to the center. The case of measuring from the movable support side is shown.

  According to the present invention, even when measuring the deflection of a PC girder with a large horizontal displacement, it is possible to accurately and easily measure the deflection from the bottom of the PC girder using a non-contact sensor such as an LDV.

It is explanatory drawing of the horizontal displacement of the PC girder concerning this invention. It is explanatory drawing of an actual horizontal displacement and an actual vertical deflection. It is a measurement flowchart which shows the Example of this invention. It is a figure which shows the nomograph which concerns on this invention. It is a figure which shows the apparatus which correct | amends the bending of the PC girder which shows the Example of this invention. It is a figure which shows the measurement by two sensors which show the Example of this invention.

In the non-contact measuring method for dynamic deflection of a PC girder according to the present invention, when correcting an error in deflection in a vertical direction of a PC girder having a horizontal displacement, the horizontal displacement of the PC girder is measured by a movable bearing, A non-contact measuring method for dynamic deflection of a PC digit, wherein the deflection of the PC digit is performed using a non-contact sensor, and the deflection is corrected using an error table for correcting the measurement result and error. The table is a nomogram, and is a graph summarizing the relationship between the measurement angle between the actual vertical deflection dy direction and the displacement u direction measured by the non-contact sensor and the error due to the horizontal displacement .

  Hereinafter, embodiments of the present invention will be described in detail.

  The present invention calculates an accurate deflection of a digit by proposing a method for correcting an error of deflection in a vertical direction of a PC digit having a horizontal displacement in measurement using a non-contact sensor such as an LDV.

  FIG. 1 is an explanatory diagram of horizontal displacement of a PC girder according to the present invention.

  In this figure, 1 is a PC girder (bridge) with an upward sled (camber), 2 is a fixed bearing part of the PC girder 3, 3 is a movable bearing part of the PC girder 4, and 4 is a train load.

  As shown in FIG. 1, the horizontal displacement of the PC girder 1 is generated when the PC girder 1 has an upward warp (camber), and is deformed when a train load 4 is applied. A horizontal displacement occurs in the part 3. Therefore, the fluctuation in the vertical direction and the horizontal displacement are in phase, and the horizontal displacement at the central portion of the PC girder 1 is half (1/2) dx of the horizontal displacement in the movable support portion 3.

  (1) Basically, the horizontal displacement of the PC girder 1 is measured with a dial gauge or other sensor of the movable support 3 and the deflection of the PC girder 1 is performed with a non-contact sensor such as an LDV. Then, the deflection is corrected using the nomogram for correcting the measurement result and the error. The nomogram summarizes the relationship between the measurement angle and the error due to the horizontal displacement, and is created by the following calculation.

u = dy′cos θ
u = dycos θ + dxsin θ
dycos θ = dy′cos θ−dxsin θ
dy / dy ′ = 1− (dx / dy ′) tan θ
Where dx: actual horizontal displacement, dy: actual vertical deflection, u: displacement measured by a non-contact sensor, dy ′: vertical deflection after correction of the measurement angle when there is no horizontal displacement, θ: measurement angle Yes (see FIG. 2).

  FIG. 3 is a measurement flowchart showing an embodiment of the present invention.

  FIG. 4 is a diagram showing a nomograph according to the present invention, wherein the horizontal axis represents the measurement angle θ (°), the vertical axis represents normalized deflection,% represents (horizontal displacement / vertical deflection) × 100%, and the arrow A represents the fixed support side. Measured from B, arrow B shows the case measured from the movable support side.

  Here, the PC girder is a measurement target and there is a displacement in the horizontal direction.

[A] First, when using one sensor,
(1) A measurement method for horizontal vibration of a PC digit is selected (step S1).
(2) First, horizontal vibration of a support portion of a PC girder or the like is measured by a dial gauge or the like (step S2).
(3) The deflection of the PC digit is measured (step S3).
(4) Secondly, horizontal vibration is measured by a non-contact sensor (when the vehicle load and speed are constant) (step S4).
(5) The PC digit deflection is measured (step S5).
(6) The presence or absence of a correction device is checked (step S6).
(7) If there is no correction device, only correction by nomogram is performed (step S7).
(8) If there is a correction device, correction by the correction device is performed (step 8).
(9) Next, the PC digit deflection limit value is collated and evaluated (step S9).

[B] Next, when using two sensors,
(1) It is checked whether measurement from both the fixed support part side and the movable support part side is possible (step S11).
(2) In the case of NO at step S11, one unit measures the deflection of the PC girder, and the other unit measures horizontal vibration of the movable support portion (step S12).
(3) Next, the presence / absence of a correction device is checked (step S13).
(4) If there is no correction device in step S13, only correction by nomogram is performed (step S7).
(5) If YES in step S11, the sensors are installed on the fixed support portion side and the movable support portion side to measure the deflection (step S14).
(6) Next, the presence or absence of a correction device is checked (step S15).
(7) If YES in step S15, correction by the correction device is performed (step 8).
(8) Next, evaluation is performed by collating with the deflection limit value (step S9).
(9) If there is no correction device in step S15, the average is obtained and corrected (step S16).
(10) Next, evaluation is performed by collating with the deflection limit value (step S9).

  Thus, the measurement is performed according to the flowchart shown in FIG. When there is one sensor (steps S1 to S9), horizontal vibration is also measured by a dial gauge or the like simultaneously with the deflection measurement. After that, the percentage of the vertical deflection measured by the sensor is calculated as the percentage of the vertical deflection measured, the normalized deflection is obtained from the nomogram of FIG. 4, and the actual deflection is obtained by multiplying the value by the deflection measured by the sensor. . If it is difficult to measure horizontal vibration using a dial gauge, etc., and the load and speed of the passing train are almost constant, the horizontal vibration measurement is also corrected for the different trains using the same sensor. Correction in this case is also performed using a nomogram or an apparatus as shown in FIG.

  FIG. 5 is a schematic diagram showing an apparatus for correcting deflection according to an embodiment of the present invention, and FIG. 6 is a diagram showing an example of measurement by two sensors showing the embodiment of the present invention.

  In FIG. 5, 11 is a first sensor, 12 is a second sensor, 13 is a data acquisition device, and 14 is a data recording / analysis device.

  In FIG. 6, 31 and 51 are first sensors, 32 and 52 are second sensors, 21 and 41 are PC girders (bridges), 22 and 42 are fixed support portions of PC girders, and 23 and 43 are PC girders. It is a movable bearing part.

  (2) When two sensors are used, measurement is performed at the same measurement angle from the fixed support part side and the movable support part side of the PC girder, and the horizontal component is removed from the deflection displacement. When the measurement is performed on the fixed support portion side and the movable support portion side of the PC girder, since the error has the same absolute value and the sign is reversed, the horizontal component can be removed by averaging both. The averaging can be performed by the apparatus, and the averaging is automatically performed by connecting two sensors to the apparatus during the measurement.

  (3) If it is difficult to install the sensor so that the measurement angle is equal on the fixed support part side and the movable support part side of the PC girder, use one of the two sensors to center the PC girder. The displacement of the part is measured, and the horizontal displacement of the movable support part of the PC girder is measured with the other unit. When measuring, two sensors and a device for correcting the error are connected, and the correction result is shown. The device performs the same calculation as when creating the nomogram and corrects the deflection. Note that the bearing portion also has vertical vibrations, and errors are included in the horizontal vibration measurement results. However, the vertical vibration of the bearing is due to the sinking of the pier and is considered to be smaller than the horizontal vibration, and the error can be reduced by reducing the angle of the sensor at the time of measurement.

  (4) When there is almost no change in the speed and load of the train crossing the bridge, as in the Tokaido Shinkansen, the deflection of the central part of the PC girder when passing through the train and the horizontal vibration of the movable bearing part due to a different train are 1 It is also possible to perform error correction by measuring with a sensor on the table. The apparatus records the horizontal displacement and deflection, and the deflection is corrected from the recorded data in the same manner as in (3) above.

  When two sensors can be used, measurement is performed so that the measurement angles on the fixed support portion 22 side and the movable support portion 23 side are the same as shown in FIG. Two sensors 31, 32 are connected to the apparatus, and the horizontal component is removed by averaging the measured values with the apparatus. If the sensors 31 and 32 cannot be installed in the direction of the bridge axis, the displacement in the direction perpendicular to the bridge axis is removed by installing as shown in FIG. When two sensors can be used but it is difficult to install them at the same measurement angle, the one sensor 51 bends and the other sensor 52 measures horizontal vibration as shown in FIG. Measurement is performed by connecting two sensors 51 and 52 to the apparatus, and deflection is corrected. When there is no device for correcting deflection, the two sensors 51 and 52 are corrected by using nomograms from the respective results.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The non-contact measuring method and apparatus for dynamic deflection of a PC girder according to the present invention is a PC girder capable of measuring the dynamic deflection of a PC girder using one or more sensors capable of easy and accurate measurement. It can be used as a non-contact measurement method and apparatus for dynamic deflection.

1, 21, 41 PC girder (bridge) with upward sled (camber)
2, 22, 42 PC girder fixed support part 3, 23, 43 PC girder movable support part 4 Train load 11, 31, 51 First sensor 12, 32, 52 Second sensor 13 Data acquisition device 14 Data recording・ Analysis equipment

Claims (6)

When correcting the vertical deflection error of a PC girder with horizontal displacement, the horizontal displacement of the PC girder is measured by a movable bearing, and the deflection of the PC girder is performed using a non-contact sensor. A non-contact measuring method of dynamic deflection of a PC girder for correcting the deflection using an error table for correcting an error, wherein the error table is a nomogram, and an actual vertical deflection dy direction and a non-contact sensor A non-contact measurement method for dynamic deflection of a PC girder, characterized in that the graph is a graph summarizing the relationship between the measurement angle formed by the displacement u direction measured in step 1 and the error due to horizontal displacement .   2. The non-contact measuring method for dynamic deflection of a PC girder according to claim 1, wherein the non-contact sensor is an LDV. 2. The non-contact measuring method for dynamic deflection of a PC girder according to claim 1 , wherein when the two non-contact sensors are used for measurement, the nomogram is measured from the fixed support portion side with respect to the center, and the movable support portion. A non-contact measuring method for dynamic deflection of a PC girder, characterized by showing a case of measurement from the side. Two non-contact sensors, a data acquisition device connected to the two non-contact sensors, and a data recording / analysis device connected to the data acquisition device When correcting the deflection error, the horizontal displacement of the PC girder is measured by the movable bearing, the deflection of the PC girder is measured, and the measurement result and the PC girder having an error table used for correcting the error are measured . This is a non-contact measuring device for dynamic deflection, wherein the error table is a nomogram, and shows the relationship between the measurement angle formed by the actual vertical deflection dy direction and the displacement u direction measured by the non-contact sensor and the error due to horizontal displacement. A non-contact measuring device for dynamic deflection of PC girders, characterized in that it is a summarized graph . 5. The non-contact measuring apparatus for dynamic deflection of a PC girder according to claim 4 , wherein the non-contact sensor is an LDV. 5. The non-contact measuring apparatus for dynamic deflection of a PC girder according to claim 4 , wherein when the two non-contact sensors are used for measurement, the nomogram is measured from the fixed support part side with respect to the center, and the movable support part. A non-contact measuring device for dynamic deflection of a PC girder, characterized in that it shows a case of measurement from the side.

Images