JP5914430B2 - Elevation measurement method for bridges without live load - Google Patents

Description

  The present invention mainly applies to a long flexible bridge including a suspension bridge, a cable-stayed bridge, an arch bridge, a truss bridge and the like, with a live load loaded state (service state) in a short time and a live load unloaded state with high accuracy. The present invention relates to an altitude measurement method for obtaining altitude (shape) at a point.

  As a method of judging the soundness of bridge girders such as suspension bridges that are flexible, the overall shape measurement (elevation measurement) is performed to obtain the shape when there is no live load, and the shape change is within the allowable value. In addition, a method of confirming that the amount of change is not large even when compared with the shape of the previous year is adopted.

  Until now, leveling using the road surface has been adopted while traffic is restricted at midnight when the amount of vehicle traffic is low and the temperature is stable. However, leveling requires traffic regulation on the road surface over the entire length, and since the measurement work takes several hours, temperature changes are inevitable depending on the time zone even at midnight, Stable measurement values are not obtained from the characteristics of leveling work that requires the measurement to be repeated continuously, and that there is no traffic, including large vehicles, and that the effects of such deflection are included. It was.

  So, in the following patent document 1, it is a measuring method for obtaining the shape of the bridge structure in service under the active load under active load without loading, and installing a light wave rangefinder at a fixed point outside the bridge, The target is installed at the altitude measurement target position of the bridge, and the actual altitude of this target is continuously measured at a minute time interval for a predetermined time by the light wave range finder, and the average actual altitude value within the predetermined measurement time And obtaining an average deflection value Δh by the vehicle group passing through the bridge within the predetermined measurement time, and correcting the average actual elevation value by the light wave rangefinder with the average deflection value Δh by the passing vehicle group. There has been proposed a method for measuring the shape at the time of no loading of a live load in a bridge structure for obtaining the altitude at the time when the altitude measurement target position is not loaded. This measurement method is a method that converts the amount of deflection due to the load of a large vehicle passing through the bridge during the measurement time to an altitude of no load by removing it from the measured value (hereinafter referred to as the large vehicle impact assessment method). It is said.)

  However, in order to apply this large vehicle impact assessment method, the number of large vehicles that pass within the measurement time, the lane position, the speed, and the vehicle weight are required. Since a strain gauge is attached to calculate the weight from the strain or to shoot with a video camera, it takes a lot of time for measurement and the data organization after measurement becomes enormous, resulting in an increase in work costs. There were issues such as.

  Therefore, the present applicants, etc., in a live load loaded state (in-service state), with no relation to the number of large vehicles, travel lane position, speed, vehicle weight, etc., and with no live load loaded in a short time with high accuracy. In order to obtain the altitude (shape) at the above, in Patent Document 2 below, the height of the active load unloaded state at a number of altitude measurement points set at predetermined intervals in the route direction is obtained in a state where the live load is applied to the bridge. Each time a vehicle equipped with an omnidirectional prism as a collimation target (hereinafter referred to as a MAT vehicle (Movable-Auto-Tracking)) is driven and stopped at each elevation measurement point. The omnidirectional prism located at the altitude measurement point is continuously measured at a small time interval for a predetermined time by a total station with automatic tracking function installed outside, and the maximum altitude value Hmax and minimum altitude value within the measurement time Hmin Either or both and the average elevation value Have are measured, and these measurement values are obtained based on the deflection influence line, and one or both of the maximum elevation value Hmax and the minimum elevation value Hmin, the average elevation value Have and the constant k (k1). ~ 3) was substituted into the calculation formula for calculating the height H0 in the no-load state of the live load, and a method for measuring the altitude in the no-load state of the active load in the bridge was proposed.

Japanese Patent No. 3340393 JP 2011-257256 A

  However, in the case of the altitude measurement method according to Patent Document 2, when the number of measurement ratings is large, there is a problem that it takes a very long time for the entire measurement. For example, in order to obtain a stable measured value of unloaded state elevation, it is necessary to have a stop time of at least about 3 minutes per rating point. It will be necessary. As a result, the total measurement time required for a bridge having a measurement rating of 150 points will be as long as 5 minutes × 150 points = 750 minutes <about 13 hours>.

  In particular, in the case of suspension bridges and cable-stayed bridges, etc., where cable is a component, the influence of cable temperature on the bridge elevation is significant. There was a problem that there were signs that gradually changed. In the case of the altitude measurement method according to Patent Document 2, although the maximum altitude value Hmax, the minimum altitude value Hmin, and the average altitude value Have in the equation are indirectly considered, the influence on the altitude due to the cable temperature change is considered. As the measurement time becomes longer, there is a problem that the unloaded state altitude, which does not change originally, is calculated as a result with time, and the measurement result does not become a stable value.

  Therefore, the main problem of the present invention is that a MAT vehicle is measured in a lively loaded state (in service state) in a long flexible bridge such as a suspension bridge, a cable stayed bridge, an arch bridge, a truss bridge and the like. It is intended to provide an altitude measuring method for obtaining altitude (shape) in a live load no-loading state with higher accuracy and in a very short time compared with the conventional method while maintaining the moving state without stopping.

In order to solve the above-mentioned problem, the present invention according to claim 1 is a measurement method for obtaining an elevation shape line in a state where a live load is not loaded along a route direction in a state where a live load is loaded on a bridge. ,
While moving a moving object equipped with an omnidirectional prism as a collimation target in the route direction, the moving object is continuously measured at small time intervals by a total station with an automatic tracking function in which the omnidirectional prism is installed outside the bridge. A first procedure for obtaining altitude measurement values (Hj) at consecutive multiple points of the omnidirectional prism attached to
A second procedure for drawing an approximated polynomial curve based on the measured elevation values (Hj) at the multiple points and obtaining an approximated elevation value (Hm) at an arbitrary point;
At a number of arbitrary points set as elevation measurement points in a live load-unloaded state, the elevation measurement value (Hj) and the elevation approximation value (Hm) are compared,
If the measured altitude (Hj) ≥ approximate altitude (Hm), calculate the calculated altitude (Ho1) in the no-load state with the following formula (1)

If the measured altitude (Hj) <approximate altitude (Hm), calculate the calculated altitude (Ho3) without a live load using the following formula (2):

  A bridge characterized by comprising a third procedure for obtaining a polynomial approximation curve (elevation shape line) of the whole live load no-load state from the calculated height (Ho1) and the calculated altitude (Ho3) in the no-load state. The altitude measurement method in the state of no live load is provided.

  The invention described in claim 1 is a measuring method for obtaining an altitude shape line in a state in which a live load is not loaded along a route direction in a state where a live load is loaded on a bridge. In the measurement method proposed by the present applicant in Japanese Patent Laid-Open No. 2011-257256 (Patent Document 2), a vehicle equipped with an omnidirectional prism is stopped for each measurement rating point, and the stopped omnidirectional prism is stopped at a total station for a predetermined time. While the invention of the present application applies the basic measurement principle of Patent Document 2 above, the altitude measurement is performed while the moving body is moved without being stopped. The present invention provides an altitude measuring method for obtaining altitude (shape) in a state where no live load is loaded accurately and in a short time.

  First, while moving the movable body attached with the omnidirectional prism as a collimation target in the route direction, the omnidirectional prism is continuously measured at small time intervals by a total station with an automatic tracking function installed outside the bridge. Elevated measurement values (Hj) at consecutive multiple points of the omnidirectional prism attached to the moving body are obtained. The moving body is kept at a low speed along the bridge direction without stopping, and the altitude measurement value (Hj) is obtained by a total station in which the omnidirectional prism provided on the moving body is installed outside the bridge. To.

  Next, a polynomial approximation curve is drawn based on the measured elevation values (Hj) at the multiple points, and an elevation approximation value (Hm) can be obtained at an arbitrary point.

Then, at a number of arbitrary points set as elevation measurement points in a live load-unloaded state, the elevation measurement value (Hj) and the elevation approximation value (Hm) are compared,
If the measured altitude (Hj) ≥ approximate altitude (Hm), calculate the calculated altitude (Ho1) in the no-load state with the following formula (1)

If the measured altitude (Hj) <approximate altitude (Hm), calculate the calculated altitude (Ho3) without a live load using the following formula (2):

  A polynomial approximation curve (elevation shape line) of the whole live load unloaded state is obtained from the calculated altitude (Ho1) and the calculated altitude (Ho3) of the live load unloaded state.

  In the invention described in Patent Document 2, when it is considered that an arbitrary moving load (traveling vehicle) travels under a deflection influence line at an arbitrary point of the bridge, the maximum value Ymax and the minimum value of the deflection generated by this load are considered. Since the cause (load) of the deflection is common to the value Ymin, it is noted that there is some correlation (a constant ratio), and the concept of the average elevation value Have (average value of the measured value) is shown in this deflection influence line. Can be used to derive a formula to calculate the altitude H0 without a live load using either or both of the maximum altitude value Hmax and minimum altitude value Hmin, altitude value Have and constant k (basic measurement principle) .

  The deflection influence line is a curve drawn for each arbitrary point. However, when the basic measurement principle is developed in the direction of the bridge axis, it is considered as a “bundle” of the basic measurement principle, so the relationship is maintained. Can be considered. Therefore, it can be considered that the basic measurement principle can be similarly applied to altitude measurement values (Hj) at continuous multipoints of the omnidirectional prism attached to the moving body.

  However, when the above basic measurement principle is developed in the direction of the bridge axis, each elevation measurement point of the bridge cannot have both the “maximum value Ymax” and “minimum value Ymin” values due to the moving load. Since there is only one elevation measurement value (Hj), the basic measurement principle cannot be applied as it is.

  Therefore, in the present invention, paying attention to the fact that the raw data of the elevation measurement values (Hj) at multiple points is drawn in a zigzag shape so as to cross the basic line, with the basic shape line of the bridge as the basic line, Based on the altitude measurement value (Hj), for example, if a polynomial approximate curve is drawn by the least square method and the altitude approximation value (Hm) can be obtained at an arbitrary point, the altitude measurement value (Hj) and the above Using the altitude approximate value (Hm) and the constant k as parameters, a calculation formula for obtaining the altitude (H01, H03) in a state where there is no live load can be derived.

  Since the calculated altitude (H01, H03) is a collection of points, if a polynomial approximation curve of the whole live load unloaded state is obtained from these calculated altitude (Ho1) and calculated altitude (Ho3), The curve is the elevation shape line of the bridge with no live load.

  In the case of the altitude measurement method according to the present invention, the measurement can be completed in a time required for the mobile vehicle to pass through the bridge. It is possible to obtain the altitude (shape). For example, in the case of a bridge length of 1000 m, if it is assumed that the moving vehicle travels at a speed of 10 km per hour, the altitude measurement can be completed in 6 minutes.

  According to a second aspect of the present invention, the moving body is an inspection vehicle that is permanently installed on the bridge, a traveling vehicle that travels on the bridge surface at a low speed, a cart, or a bicycle. An altitude measurement method in a no-load state is provided.

  The invention according to claim 2 lists specific examples that can be used as the moving body. Specifically, in the case of a long bridge, an inspection vehicle that is movable along a rail provided on the bridge girder is permanently installed, and this inspection vehicle can be used. In addition, a traveling vehicle, a cart, or a bicycle that travels on the bridge surface at a low speed can be used.

  As described above in detail, according to the present invention, the MAT vehicle is mounted in a lively loaded state (in service state) in an easily flexible long bridge mainly including a suspension bridge, a cable-stayed bridge, an arch bridge, a truss bridge, and the like. It is possible to obtain an altitude (shape) in a state without a live load with high accuracy in a very short time as compared with the conventional method while maintaining the moving state without stopping at the measurement rating point.

It is an example of the side view of the long suspension bridge made into the measurement object. It is the example (the 1) of the measurement conceptual diagram by the total station. It is the example (the 2) of the measurement conceptual diagram by the total station. It is an example of the time history altitude change figure of the stiffening girder in the live load loading state actually measured by Lc / 2 point. It is an example of the deflection influence line in Lc / 2 point. It is a measurement elevation map of 134 rating points (Lc / 2 points) used for elevation measurement by the zero point elevation evaluation correction method in Example 1. It is the measurement altitude map (the 1) of 134 rating points (Lc / 2 points) used for the altitude measurement by the approximate zero point altitude evaluation correction method in Example 1. It is the measurement altitude map (the 2) of 134 rating points (Lc / 2 points) used for the altitude measurement by the approximate zero point altitude evaluation correction method in Example 1. In Example 1, it is the elevation figure of the no-load state of 134 rating points (Lc / 2 points) by the zero point elevation evaluation correction method and the approximate zero point elevation evaluation correction method. In Example 2, it is the altitude map of the unloaded state of 117 rating points (Lc / 4 points) by the zero point altitude evaluation correction method and the approximate zero point altitude evaluation correction method. It is a figure which shows the deflection data of a live load in Example 2. FIG. It is a figure which shows the virtual MAT-J elevation data used in Example 2. In Example 2, it is an elevation figure (part) of the no-load state by the approximate zero point elevation evaluation correction method. It is a figure which shows the approximation formula for the constants k1 and k3 used in Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view of a long suspension bridge to be measured in this embodiment. The suspension bridge 1 has main towers 2 and 3 on both left and right sides in a side view, and has anchorages 4 and 5 at positions further away from the main towers 2 and 3, respectively. Both ends of the cable 6 spanned between cable saddles (not shown) installed in the cable are fixed to the anchorages 4 and 5, and a predetermined distance is provided along the longitudinal direction of the cable 6. The hanger ropes 7, 7... Are suspended from the anchorage 4 and 5, and the stiffening girder 8 is suspended between the two anchorages 4 and 5, and is a bridge structure particularly applied to a long span bridge.

  Hereinafter, according to the method of the present invention with the long suspension bridge 1 as a target, the MAT vehicle 9 is maintained in a moving state without stopping at the measurement rating while being in a live load state (in-service state), compared to the conventional method. An altitude measurement method for obtaining altitude (shape) in a state where no live load is loaded with high accuracy in an extremely short time will be described.

(Device configuration)
As shown in FIGS. 2 and 3, a total station 10 with an automatic tracking function (hereinafter simply referred to as a total station) that automatically corrects the collimation of the target is installed on the ground portion outside the suspension bridge 1. A moving body (MAT car) 9 to which a target omnidirectional prism 11 is attached is collimated while tracking the omnidirectional prism 11 by the total station 10, and a distance L, a vertical angle α, and a horizontal angle β are set at small time intervals. Measure continuously. The total station 10 is capable of reading data 2.5 times per second (in the embodiment described later, measurement is performed twice per second), and the read data is stored in the computer 12 connected to the total station 10. It is like that. The installation coordinates of the total station 10 are known in advance.

(Measurement procedure)
The altitude measurement method in the state of no loading of live load in the bridge according to the present invention is based on the following procedures (1) to (3).

(1) While moving the moving body (MAT car) in the direction of the route, the omnidirectional prism 11 is continuously measured at a small time interval by the total station 10 with an automatic tracking function installed outside the bridge. A first procedure for obtaining altitude measurement values (Hj) at consecutive multiple points of the attached omnidirectional prism 11.

  As the movable body 9, in the case of a long bridge, an inspection vehicle that is movable along a rail provided on the bridge girder is provided permanently, and this inspection vehicle can be used. Also, as shown in FIG. 3, a traveling vehicle that travels on a bridge surface at a low speed, a cart, a bicycle, or the like can be used.

(2) A second procedure in which a polynomial approximation curve is drawn based on the elevation measurement values (Hj) at the multiple points, and an elevation approximation value (Hm) can be obtained at an arbitrary point.

  The mathematical meaning of representing the polynomial approximation curve is that the curve is relatively in line with the trend of the original data and the square of the difference from the original data is minimized. It is. The elevation measurement values (Hj) at the multipoints are drawn in a zigzag shape with the basic shape line of the bridge as a basic line and intersecting this basic line. Then, the altitude approximation (Hm) at an arbitrary point can be easily obtained by calculation. In addition, the polynomial approximate curve is a concept corresponding to a “deflection average value” to be described later, but the deflection average value varies depending on the passage of a large heavy vehicle. Has the advantage of stable values.

(3) At a number of arbitrary points set as elevation measurement points in a live load-unloaded state, the elevation measurement value (Hj) is compared with the elevation approximation value (Hm),
If the measured altitude (Hj) ≥ approximate altitude (Hm), calculate the calculated altitude (Ho1) in the no-load state with the following formula (1)

If the measured altitude (Hj) <approximate altitude (Hm), calculate the calculated altitude (Ho3) without a live load using the following formula (2):

  A third procedure for obtaining a polynomial approximation curve (elevation shape line) of the whole live load no load state from the calculated altitude (Ho1) and the calculated altitude (Ho3) in the no live load state.

(Measurement principle)
[Basic measurement principle]
First, since the measurement principle of the present invention is developed in the bridge axis direction based on the measurement principle of the invention described in Patent Document 2, the measurement principle of the invention of Patent Document 2 will be described first.

  In the invention according to Patent Document 2, the total station 10 continuously measures the collimation target 11 installed at the altitude measurement point at a small time interval for a predetermined time, and the maximum altitude value Hmax within the measurement time, the minimum One or both of the elevation values Hmin and the average elevation value Have are measured, and these measurement values are obtained based on the deflection influence line, and either or both of the maximum elevation value Hmax and the minimum elevation value Hmin, the average elevation value Have, and By substituting into the calculation formula for obtaining the altitude H0 in the no-load state with the constant k using the constant k, the altitude in the no-load state is obtained.

  FIG. 4 shows the time history elevation change of the stiffening girder in the live load loaded state actually measured at Lc / 2 point. As is apparent from FIG. 4, the altitude changes greatly with the passage of time, and it seems impossible to determine the altitude in the state without a live load from this graph.

  Since the “superposition principle” is established according to the linear deflection theory, the altitude in the loaded state is obtained by superimposing the deflection due to the loaded load on the unloaded elevation. That is, the no-load state altitude can be theoretically obtained by removing the amount corresponding to the deflection amount generated by all live loads (axial weight) from the altitude in the loaded state. However, the loading pattern of live loads exists infinitely, and the loading state changes from moment to moment, so the deflection of all the live loads loaded from the elevation of the live load loading state is removed by calculation for each vehicle. It is practically impossible to do.

  When changing the viewpoint of thinking and considering that an arbitrary moving load group (running vehicle group) travels under the deflection influence line, the maximum value Ymax and the minimum value Ymin of the deflection generated by this load group are Since the cause of deflection (load group) is common, it is considered that there is some correlation (constant ratio). Also, information that can be read from the elevation change graph of FIG. 4 is a maximum value Ymax of deflection, a minimum value Ymin, and an average elevation value Have (average value of measured values). The average altitude value Have is obtained by integrating the measured altitude over time and dividing by time, and is an average value of the altitude measurement values.

  Therefore, under the deflection influence line at Lc / 2 shown in FIG. 5 (assuming a 20 tf line load, the vertical axis is the deflection amount), the deflection average value Yave (in FIG. 5) If the concept of the average value of the measured values is introduced), one or both of the maximum deflection value Ymax and the minimum deflection value Ymin, the deflection average value Yave and the constant k are introduced. Can be used to derive a deflection relational expression for obtaining the deflection zero point Y0.

  From the deflection influence line in FIG. 5, the following three deflection relational expressions for obtaining the elevation of the deflection zero point Yo are established.

First equation: Deflection relational equation for calculating the deflection zero point Yo from the deflection maximum value Ymax and the deflection average value Yave
Yo = Yave + (Ymax-Yave) * k1 (1)
Second equation: Deflection relational equation for calculating deflection zero point Yo from deflection maximum value Ymax, deflection minimum value Ymin and deflection average value Yave
Yo = Yave + (Ymax-Ymin) * k2 (2)
Third equation: Deflection relational expression for calculating the deflection zero Yo from the deflection minimum value Ymin and deflection average value Yave
Yo = Yave + (Yave-Ymin) * k3 (3)
Here, Yave, Ymax, and Ymin theoretically have the following values assuming a 20 tf line load.

Yave (average deflection) = -0.0135m
Ymax (maximum deflection) = + 0.0059m
Ymin (minimum deflection) = -0.0678m
Further, k1, k2 and k3 (hereinafter referred to as k values) are constants determined by the deflection influence line of the structure at each elevation measurement point (that is, determined by the structure). These k values can be calculated from the amount of deflection generated by the following equations. That is, Yo is a deflection amount at a deflection zero point (a deflection amount in a no-load state), and Yo = 0, so that k1 can be obtained from a maximum deflection value and an average value in a deflection influence line, and k2 Can be obtained from the maximum value and the minimum value of the deflection in the deflection effect line, and k3 can be obtained from the minimum value and the average value in the deflection effect line.

k1 = (Yo−Yave) / (Ymax−Yave) = (0 + 0.0135) / (0.0059 + 0.0135) = 0.6959
k2 = (Yo−Yave) / (Ymax−Ymin) = (0 + 0.0135) / (0.0059 + 0.0678) = 0.1832
k3 = (Yo−Yave) / (Yave−Ymin) = (0 + 0.0135) / (− 0.0135 + 0.0678) = 0.2486
Since the deflection equation should be reproduced even at the actual bridge level, the maximum deflection value Ymax is the maximum elevation value Hmax, the minimum deflection value Ymin is the minimum elevation value Hmin, and the deflection average value is based on the corresponding relationship. When Yave is replaced with the average altitude value Have, the calculation formula for obtaining the altitude H0 in the state where there is no live load is as follows.

First formula H0 = Have + (Hmax-Have) * k1 (1) '
Second formula H0 = Have + (Hmax-Hmin) * k2 (2) '
Third formula H0 = Have + (Have-Hmin) * k3 (3) '

[Applied measurement principle]
Elevation measurement that can be measured at the measurement grade when the basic measurement principle is used in the direction of the bridge axis by making the measurement while maintaining the moving state without stopping the MAT car 9 at the measurement grade. The value (Hj) is only one numerical value, and cannot have both the “maximum value Ymax” and the “minimum value Ymin”. FIG. 4 is a graph obtained by continuously measuring for a predetermined time with the time history as the horizontal axis. In the present invention in which the MAT vehicle 9 is not stopped, the points to be measured are any of the graphs in FIG. That is a numerical value of one point.

  Therefore, in developing the basic measurement principle in the direction of the bridge axis, we will try to expand the measurement principle. That is, under the deflection influence line in FIG. 5, the above-mentioned first formula can be commonly applied in the zone region where the deflection influence line is higher than the deflection average value, and the deflection influence line is lower than the deflection average value. Assuming that the third equation can be commonly applied in the zone region, a calculation formula for obtaining the altitude in the state of no active load can be derived for the altitude measurement value (Hj) measured without stopping the MAT vehicle 9. it can.

Specifically, the raw elevation data (Hj) is drawn in a zigzag shape with the basic shape line of the bridge as the basic line and intersecting this basic line. Based on the measured value (Hj), a polynomial approximate curve is drawn by the least square method so that an altitude approximate value (Hm) can be obtained at an arbitrary point. The polynomial approximate curve is a concept corresponding to the “deflection average value” under the deflection influence line, but the elevation measurement value (Hj) is more than the polynomial approximation curve (altitude approximation value (Hm)). Is larger, the calculated altitude (Ho1) in the state of no live load is obtained by the following formula (1) corresponding to the first formula,

When the altitude measurement value (Hj) is smaller than the polynomial approximation curve (elevation approximation value (Hm)), the calculated altitude (Ho3) in the state of no active load is obtained by the following equation (2) corresponding to the third equation. To ask.

  Since the calculated altitude (H01, H03) is a set of points, a polynomial approximation curve of the whole live load unloaded state can be obtained from these calculated altitude (Ho1) and calculated altitude (Ho3). The curve becomes the elevation shape line of the bridge with no live load.

  In the present invention, while moving the moving body 9 in the route direction, the omnidirectional prism 11 is continuously measured at small time intervals by a total station with an automatic tracking function in which the omnidirectional prism 11 is installed outside the bridge, and is attached to the moving body 9. In this method, the altitude measurement values (Hj) at continuous multipoints of the omnidirectional prism 11 are obtained, and the altitude approximate value in the state of no active load is obtained by calculation from this data group. Although the error is expected to be slightly larger than that of the proposed measurement method, the extent of the error was verified.

  For convenience, the measurement method according to the present invention is referred to as “approximate zero point altitude correction method”, and the measurement method according to Patent Document 2 is referred to as “zero point altitude evaluation correction method”. Further, the measurement value data according to the present invention is referred to as “MAT-J” (J means slow travel), and the measurement value data according to Patent Document 2 is referred to as “MAT-S” (S means stop).

[Example 1] (Application to measurement values of arbitrary fixed points)
The approximate zero point elevation correction method can naturally be applied to the measurement value (MAT-S) of a fixed point. As an example of this, the no-load elevation is calculated based on the measured values of 134 grades (Lc / 2 points) and 117 grades (Lc / 4 points) of the existing suspension bridge. Compared with the no-load state altitude obtained in (1) above.

<Comparison at 134 grades (Lc / 2 points)>
(1) Zero point altitude evaluation correction method Figure 6 shows the measurement results between 1:09:00 and 1:19:00. The maximum value during this time is indicated by a thick broken line and the minimum value is indicated. The dotted line and the average value are indicated by a thin broken line. It can be seen that the maximum value at time 1:19:00 is 75.9240, the minimum value is 75.7787, and the average value is 75.8837. From these values, the no-load state altitude at time 1:19:00 can be calculated as follows.
(First formula) Ho1 = 75.8837 + (75.9240-75.8837) * 0.5079 = 75.9042m
(2nd formula) Ho2 = 75.8837 + (75.9240-75.7787) * 0.1188 = 75.9010m
(3rd formula) Ho1 = 75.8837 + (75.8837-75.7787) * 0.1551 = 75.9000m

(2) Approximate Zero Point Elevation Correction Method First, as shown in FIG. 7, a polynomial approximate straight line (Hm = 1.5828t + 78.8024) is obtained from all measured data (MAT-J). This approximate straight line is a straight line showing a tendency of rising to the right, and shows a change with time of the average value from the measurement start time. Although this approximate line changes with a value almost the same as the average value (dotted line) calculated by the zero point elevation evaluation correction method, the average value (dotted line) varies greatly due to the influence of the deflection of the bridge girder. On the other hand, it can be confirmed that it is stable.

Next, if the measured altitude (Hj) and the approximate altitude (Hm) are compared with each other and the measured altitude (Hj) ≥ approximate altitude (Hm), Calculate the calculated altitude (Ho1) of the loaded state (k1 = 0.5079), and if the measured altitude (Hj) <approximate altitude (Hm), then calculate the altitude (Ho3) with no live load using Equation (2) (K3 = 0.1551), and a polynomial approximation curve of the whole live load unloaded state (altitude shape line: H0 = 1.5747t + 75.8105) ). The calculation results are shown in Table 1 below and shown in FIG.

(3) Comparison of both Fig. 9 shows the no-load state altitude (no-load H1, no-load H2 and no-load H3) obtained from the first to third formulas in the zero-point elevation correction method, and approximate zero The no-load state elevation obtained by the point elevation correction method is shown. However, in the case of the approximate zero point elevation correction method, the value of 1:19:00, which is the last measurement time, was extracted as the no-load state elevation.

As shown in Table 2 below, the unloaded elevation values by the zero point elevation evaluation correction method are 75.904 (first formula), 75.901 (second formula) and 75.900 (third formula), respectively. According to the approximate zero point altitude correction method, it is 75.897 (thick solid line), and the value difference from the zero point altitude evaluation correction method is 7 mm at the maximum (difference from the first formula), and there is no big difference.

<Comparison at 117 rating (Lc / 4 points)>
Similarly, with respect to 117 rating points (Lc / 4 points), the result of calculating the no-load state altitude by the zero point altitude evaluation correction method and the approximate zero point altitude correction method is shown in FIG.

  From FIG. 10, the no-load state altitude value at the last measurement time (1:19:00) in the measurement from 1:09:00 to 1:19:00 is 75.039 (the first) according to the zero point altitude evaluation correction method. 1 set), 75.041 (2nd formula) and 75.0420 (3rd formula), but according to the approximate zero point elevation correction method, it is 75.040, and the difference from the zero point elevation evaluation correction method is 2 mm at maximum ( It is a difference from the third formula), which shows that the values are almost the same.

[Example 2] (Application to virtual MAT-J measurement value)
Next, as an example of verification of the approximate zero point elevation correction method, we attempt to obtain the no-load state elevation based on the virtual MAT-J measurement values. The target is an existing suspension bridge (center span: L = 712m) with a virtual planned height (UFL = -2.8425E-5x2 + 76.131), where the elevation value when a virtual live load deflection is generated Based on this, the no-load state altitude is obtained and compared with the initially set planned height. If the difference between the two is small, it means that “the unloaded elevation can be obtained by the approximate zero point elevation correction method”.

  The deflection added to the elevation value of the bridge girder occurred when the MAT car (actually the bridge inspection car) moves within the span shown in Fig. 11, and the x coordinate is the planned shape diagram of the bridge girder. To match.

  The result of generating the virtual deflection in the bridge girder is as shown in FIG. In this figure, the deflection of the live load shown in FIG. 11 is added to the planned height (UFL) of the secondary parabola bridge girder.

Based on the data of the virtual MAT-J elevation shown in FIG. 12, the altitude in the no-load state is calculated by the approximate zero point elevation correction method. The calculation results are shown in Table 3 below and shown in FIG. 13 (part). Note that the constants k1 and k3 used for the calculation were obtained by the approximate expression shown in FIG.

  In Example 2, the value obtained by adding a virtual live load deflection (L) to a bridge girder (UFL) having a secondary parabola shape is used as an altitude value obtained by MAT-J measurement. (Ho) was calculated by the “approximate zero point elevation correction method”. As a result, the no-load state elevation Ho is as shown in the AV column of Table 2, and the difference from the planned height (Ho-UFL) is extremely small at 0.00003m as shown in the AW column of Table 2. The unloaded elevation (Ho) obtained in step 1 is the same as the bridge girder shape (UFL) before loading the virtual live load deflection.

  As a result, it can be said that the approximate zero point elevation correction method can calculate the no-load state elevation based on the MAT-J measurement values.

[Other examples]
(1) In the above description of [Mode for Carrying Out the Invention], correction for temperature is not performed, but in order to obtain an altitude when there is no live load at a reference temperature (ex. 20 ° C.), the reference temperature It is only necessary to perform temperature correction by the difference temperature with respect to. Generally, since temperature and altitude can be expressed by a linear relationship, if the altitude correction amount per unit temperature is calculated in advance, the temperature can be easily corrected.

  DESCRIPTION OF SYMBOLS 1 ... Suspension bridge, 2.3 ... Main tower, 4.5 ... Anchorage, 6 ... Cable, 7 ... Hanger rope, 8 ... Stiffening girder, 9 ... Mobile (MAT car), 10 ... Total station, 11 ... All directions Prism, 12 ... computer

Claims (2)

In a state where a live load is loaded on a bridge, it is a measurement method for obtaining an elevation shape line in a state where there is no live load along the route direction,
While moving a moving object equipped with an omnidirectional prism as a collimation target in the route direction, the moving object is continuously measured at small time intervals by a total station with an automatic tracking function in which the omnidirectional prism is installed outside the bridge. A first procedure for obtaining altitude measurement values (Hj) at consecutive multiple points of the omnidirectional prism attached to
A second procedure for drawing an approximated polynomial curve based on the measured elevation values (Hj) at the multiple points and obtaining an approximated elevation value (Hm) at an arbitrary point;
At a number of arbitrary points set as elevation measurement points in a live load-unloaded state, the elevation measurement value (Hj) and the elevation approximation value (Hm) are compared,
If the measured altitude (Hj) ≥ approximate altitude (Hm), calculate the calculated altitude (Ho1) in the no-load state with the following formula (1)

If the measured altitude (Hj) <approximate altitude (Hm), calculate the calculated altitude (Ho3) without a live load using the following formula (2):

A bridge characterized by comprising a third procedure for obtaining a polynomial approximation curve (elevation shape line) of the whole live load no-load state from the calculated height (Ho1) and the calculated altitude (Ho3) in the no-load state. Altitude measurement method when no live load is applied.   The altitude measuring method in a state where no live load is applied to the bridge according to claim 1, wherein the moving body is an inspection vehicle permanently installed on the bridge, a traveling vehicle that travels on the bridge surface at a low speed, a cart, or a bicycle.

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