JP5261441B2 - Elevation measurement method for bridges without live load - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To find an altitude in a no-live-load state at an arbitrary point in a state in which a live load acts on a bridge. <P>SOLUTION: A total station 10 with an automatic tracking function which is installed outside a bridge measures a collimation target 11 installed at an altitude measurement point continuously for a predetermined time at small time intervals, measures any one of or both of a maximum altitude value Hmax and a minimum altitude value Hmin, and a mean altitude value Have in the measurement time, and substitutes those measured values in a calculation expression, for example, H0=Have+(Hmax-Have)*k, obtained based upon a flexure influence line, for finding an altitude H0 in the no-live-load state using any one of or both of the maximum altitude value Hmax and the minimum altitude value Hmin, the mean altitude value Have, and a constant (k), thereby finding the altitude in the no-live-load state. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

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 the measurement work takes several hours, so minute changes in temperature are unavoidable even at midnight. Including the traffic of the vehicles, including the influence of their deflection, and stable measurements were not obtained due to the characteristics of leveling work that required repeated measurements.

  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.

Japanese Patent No. 3340393

  The measurement method according to Patent Document 1 is a method of converting to an altitude in a no-load state by removing a deflection equivalent to the load of a large vehicle passing through a bridge during a measurement time from the measurement value (hereinafter, Large vehicle impact assessment method).

  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 main problem of the present invention is that, in the long flexible bridges including mainly suspension bridges, cable-stayed bridges, arch bridges, truss bridges, etc. It is an object to provide an altitude measurement method for obtaining altitude (shape) in a live load no-load state with high accuracy in a short period of time regardless of the travel lane position, speed, vehicle weight and the like.

In order to solve the above-mentioned problem, the present invention according to claim 1 is a measurement method for obtaining an altitude of an active load unloaded state at an arbitrary point in a state where a live load is applied to a bridge,
The collimation target installed at the altitude measurement point is continuously measured at a small time interval for a predetermined time by the total station with automatic tracking function installed outside the bridge, and the maximum altitude value Hmax and the minimum altitude value Hmin within the measurement time are measured. Either or both and the average altitude value Have are measured, and these measured values are obtained based on the deflection influence line, using either or both of the maximum altitude value Hmax and the minimum altitude value Hmin, the average altitude value Have, and the constant k. Thus, there is provided an altitude measuring method in a state where there is no live load in a bridge, which is obtained by substituting into a calculation formula for obtaining an altitude H0 in a state where there is no live load and by obtaining an elevation in a state where there is no live load.

  The invention described in claim 1 proposes a method for obtaining the altitude in a no-load state at an arbitrary point only by collimating the target by the total station (elevation measurement). That is, the total station continuously measures the collimation target at a small time interval for a predetermined time, and measures one or both of the maximum elevation value Hmax and the minimum elevation value Hmin and the average elevation value Have within the measurement time. Then, by simply substituting these measured values into a mathematical expression (calculation formula for obtaining the altitude H0 in the no-load state), the altitude in the no-load state is obtained by simple calculation.

  First, considering 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 Ymin of the deflection generated by this load are Focusing on the fact that there is some kind of correlation (a constant ratio) because the cause (load) is common, and introducing the concept of average elevation value Have (average value of measured values) to this deflection influence line, the maximum elevation value Using either or both of Hmax and the minimum altitude value Hmin, the average altitude value Have and the constant k, a calculation formula for obtaining the altitude H0 in the state of no active load can be derived. Accordingly, it is possible to easily obtain the altitude in a state where there is no live load by simply substituting one or both of the maximum altitude value Hmax and the minimum altitude value Hmin and the average altitude value Have measured by the total station.

  In the case of the above-described method of the present invention, it is possible to obtain the altitude (shape) in a live load-free state with high accuracy in a short time while irrelevant to the number of large vehicles, travel lane position, speed and vehicle weight. Become.

The present invention according to claim 2 is a measuring method for obtaining an altitude in a state in which no active load is loaded at a number of altitude measuring points set at predetermined intervals in a route direction in a state where a live load is applied to a bridge. ,
Each time a vehicle with an omnidirectional prism attached as a collimation target is run and stops at each altitude measurement point, the omnidirectional prism located at the altitude measurement point is set by a total station with an automatic tracking function installed outside the bridge. Measure continuously at a small time interval for a predetermined time, measure one or both of the maximum altitude value Hmax and minimum altitude value Hmin and the average altitude value Have within the measurement time, and use these measured values as the deflection influence line Substituting into the calculation formula for obtaining the altitude H0 in the no-load state using the maximum altitude value Hmax and / or the minimum altitude value Hmin, the average altitude value Have and the constant k, obtained based on There is provided an altitude measuring method in a state of no loading of a live load on a bridge, characterized by obtaining an altitude in a loaded state.

  The invention according to claim 2 is an application of the invention according to claim 1 in a state where a live load is not applied at a number of elevation measurement points set at predetermined intervals in the route direction in a state where a live load is applied. A measurement method (first method) for obtaining altitude is proposed.

  In other words, in the procedure of leveling, a work procedure in which pole-shaped collimating targets are sequentially installed using workers at each elevation measurement point requires a lot of time for measurement. Therefore, if a vehicle with an omnidirectional prism attached as a collimation target is devised, this vehicle is stopped at each elevation measurement point for a predetermined time, and this is collated at the total station to repeat the procedure of obtaining the elevation. It is possible to continuously measure a large number of measurement points in a short time. The measurement result is converted to the altitude value of the digit.

The present invention according to claim 3 is a measuring method for obtaining an altitude in a no-load state at a number of altitude measuring points set at predetermined intervals in the direction of the road in a state where a live load is applied to the bridge. ,
A total station with the first automatic tracking function and a total station with the second automatic tracking function are installed outside the bridge, and a fixed collimation target is provided at the altitude measurement point as the reference rating in the bridge. By collimating the collimating target with a function-equipped total station, the altitude in the no-load state of the reference rating point is determined in advance by the method according to claim 1, and the omnidirectional target becomes the collimating target Each time a vehicle equipped with a prism is run and stops at each altitude measurement point, the total station with the first automatic tracking function collimates the collimating target of the reference rating and obtains the altitude of the live load loaded state. , The total station with the second automatic tracking function collimates the omnidirectional prism of the vehicle and To obtain a high,
The difference between the height of the live load loaded state and the height of the live load unloaded state at the reference rating is obtained, and the difference is multiplied by the deflection vertical distance ratio between the reference rating and the elevation measuring point obtained from the deflection influence line. The bridge is characterized by calculating the correction amount at the altitude measurement point, and calculating the altitude of the altitude measurement point in the no-load state by adding or subtracting this correction amount to the altitude in the active load state at the altitude measurement point. The altitude measurement method in the state of no live load is provided.

  The invention according to claim 3 is an application of the invention according to claim 1 in a state where a live load is not applied at a number of elevation measurement points set at predetermined intervals in the route direction in a state where a live load is applied. A measurement method (second method) for obtaining altitude is proposed.

  This second method is applied to the fact that two points in the same bridge girder are deflected at a certain ratio due to the same loading load, and the unloaded state altitude is obtained in advance (or known). This is a method of obtaining an unloaded state altitude value of an arbitrary rating from an altitude of a loaded state in which an in-girder reference rating is measured at a certain time simultaneously with an altitude measurement of an arbitrary rating.

  As the present invention according to claim 4, the calculation formula for obtaining the altitude H0 in the no-load state of the live load is obtained by the following procedure, and the altitude measuring method in the no-load state of the live load in the bridge according to any one of claims 1 to 3 Is provided.

  Procedure 1: Based on the deflection influence line at the altitude measurement point, the deflection relational expression for obtaining the deflection zero point Y0 using one or both of the deflection maximum value Ymax and the deflection minimum value Ymin, the deflection average value Yave and the constant k. And calculating the constant k, which is an unknown, from one or both of the deflection maximum value Ymax and the deflection minimum value Ymin, which are known numbers, and the deflection average value Yave.

  Procedure 2: Under the assumption that the deflection relational expression is also reproduced 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, A second procedure for obtaining a calculation formula for obtaining an altitude H0 in a no-load state in which the deflection average value Yave is replaced with an average altitude value Have.

  As described above in detail, according to the present invention, in a large flexible bridge mainly including a suspension bridge, a cable-stayed bridge, an arch bridge, a truss bridge, etc. It is possible to obtain the altitude (shape) in a live load-free state with high accuracy in a short period of time, regardless of the number, travel lane position, speed, vehicle weight, etc.

It is an example of the side view of the long suspension bridge made into the measurement object. 2 is an example of a conceptual diagram of measurement by a total station 10. FIG. It is an example of the measurement procedure map by the total station. It is an example of the time history elevation 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 an example of the longitudinal profile which measured the altitude of the stiffening girder by the 3rd invention (2nd method). It is an example of the unloaded state elevation measurement result (standard temperature conversion value) of the stiffening girder after correction. It is a principle explanatory view of the two-point elevation evaluation correction method according to the second method. It is an example of the elevation change figure of the stiffening girder in Lc / 2 point when the vehicle group in Example 1 [Example-1] passes. It is an example of the theoretical deflection generation amount (deflection influence line) in Example 1 [Example-1]. It is an example of the elevation change figure of Lc / 2 point in Example 1 [Example-4]. It is an example of the altitude measurement result of the stiffening girder reference grade (Lc / 2 points) in Example 2 [Example-1]. It is an example of the altitude measurement result of the arbitrary rating points (Lc / 4 points) in Example 2 [Example-1].

  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.

[First invention]
Hereinafter, the active load at an arbitrary point in the state where the active load at an arbitrary point (the center position of the stiffening girder (hereinafter referred to as Lc / 2 point)) is applied to the long suspension bridge 1 according to the method of the present invention. A measurement method for obtaining the altitude in the unloaded state 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 with respect to the target is installed on the ground portion outside the suspension bridge 1, and the altitude measurement point A mirror 11 (hereinafter referred to as a target) is installed at the Lc / 2 point, and collimated while tracking the target 11 by the total station 10, and the distance L, vertical angle α, horizontal angle β for a predetermined time. Is continuously measured at small time intervals to determine the altitude (H) of the top 8 of the stiffening girder where the target 11 is placed. The total station is capable of reading data 2.5 times per second (actually set to measure every second), and the read data is stored in the computer 12 connected to the total station 10. It has become. The installation coordinates of the total station 10 are known in advance.

  In the first aspect of the invention, the total station 10 continuously measures the collimation target installed at the altitude measurement point at a small time interval for a predetermined time, and the maximum altitude value Hmax and the minimum altitude value Hmin within the measurement time. Either or both and the average altitude value Have are measured, and these measured values are obtained based on the deflection influence line, using either or both of the maximum altitude value Hmax and the minimum altitude value Hmin, the average altitude value Have, and the constant k. Thus, the altitude H0 in the state without a live load is obtained by substituting it into the calculation formula for obtaining the height H0 in the state without a live load.

(Measurement principle)
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 the live load exists infinitely and the loading state changes from moment to moment, so the deflection of all the live loads loaded from the altitude 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 value) are constants determined by the influence line of the structure (that is, determined by the structure). These k values can be calculated from the amount of deflection generated as follows. However, Yo is the deflection amount at the deflection zero point (the deflection amount when there is no load), and Yo = 0.

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) '
Theoretically, any of the first to third formulas may be used, but the error varies depending on how the error factors are generated. As shown in Example 1 described later, when the altitude measurement point is Lc / 2, the error in the first equation is the smallest. The reason why the fluctuation range of the error in the first equation is small is that the minimum deflection (positive) caused by the size of the load (weight) varies greatly, but the fluctuation range of the maximum deflection (negative) and the average deflection is small. This is probably because the result of the first equation derived from the difference between the maximum deflection and the average deflection is the most stable and the fluctuation of the error is small.

  Considering the measurement principle, the measurement time by the total station 10 needs at least the time (t) for the load (vehicle) to finish passing after entering the bridge. Preferably, it is desirable to set a time that is about three times (3 * t) or more in consideration of traffic jams, slow driving, uncertain error factors, accuracy improvement, and the like.

[Second invention]
As a core of the first aspect of the invention, this method is used to obtain an altitude in a state in which no live load is loaded at a number of altitude measurement points set at predetermined intervals in the route direction in a state where a live load is applied. (First method) will be described.

  In this first method, every time a vehicle equipped with an omnidirectional prism as a collimation target is run and stops at each elevation measurement point, it is located at an elevation measurement point by a total station with an automatic tracking function installed outside the bridge. The omnidirectional prism is continuously measured at a small time interval for a predetermined time, and the maximum altitude value Hmax and / or the minimum altitude value Hmin within the measurement time and the average altitude value Have are measured. Substitute into the calculation formula to find the altitude H0 in the no-load state using the maximum altitude value Hmax and / or the minimum altitude value Hmin, the average altitude value Have and the constant k obtained based on the deflection influence line. The altitude in a state where no live load is loaded is obtained.

  This measurement method is extremely advantageous in measuring the shape of a stiffening girder when there are many measurement points of stiffening girder, such as tens or more, or for confirming the vertical alignment of the road surface. It is possible to measure continuously in a shorter time than the measuring method or leveling. In addition, this method can be performed only by partial traffic restriction only in the vicinity of the work location.

  The omnidirectional prism is a prism that can be collimated from all directions within a substantially same plane, and is attached to the upper part of the vehicle.

  A vehicle equipped with an omnidirectional prism (hereinafter referred to as a MAT car “Movable-Auto-Tracking”) stops at each stiffening girder and stiffens like the Lc / 2 point. Measure the altitude of the digit.

[Third invention]
Utilizing the first invention, a measurement method for obtaining an altitude in a state in which no live load is loaded at a number of altitude measurement points set at predetermined intervals on a bridge in a state where a live load is applied (second method) (Method) will be described.

  In order to calculate the no-load state altitude for each rating point, it can be obtained by applying the above-mentioned first method, but this measurement method measures the altitude of the road surface. It is necessary to convert to altitude, and it takes time to measure because it is a condition that the MAT vehicle is stopped for a certain period of time at each measurement point.

Therefore, a total station with a first automatic tracking function and a second total station with a second automatic tracking function are installed outside the bridge, and a fixed collimation target is provided at an altitude measurement point as a reference rating point in the bridge. By collimating the collimating target with a total station with an automatic tracking function, the altitude of the reference rating position in a live load-unloaded state is previously known by the method according to claim 1 and becomes a collimating target. Each time a vehicle equipped with an omnidirectional prism is run and stops at each altitude measurement point, the total target with the first automatic tracking function is used to collimate the collimation target of the reference rating to obtain the altitude of the live load loaded state. At the same time, the total station with the second automatic tracking function collimates the omnidirectional prism of the vehicle and loads a live load. To obtain the elevation of the state,
The difference between the height of the live load loaded state (average elevation value Have) and the height of the live load unloaded state (average elevation value Have) at the reference grade is obtained, and the reference grade and elevation measurement obtained from the deflection influence line are obtained. Calculate the correction amount at the altitude measurement point by multiplying the above-mentioned difference by the deflection longitudinal distance ratio with the point, and add / subtract this correction amount to the altitude of the live load loading state at the altitude measurement point to eliminate the live load at the altitude measurement point. The altitude of the loaded state is obtained (hereinafter also referred to as “two-point altitude evaluation correction method”).

  This second method has an advantage that it is easy to avoid the possibility that the altitude of the arbitrary rating point becomes an abnormal value because the altitude of the unloaded live load of the arbitrary rating point is obtained by the relative difference from the deflection of the reference rating. .

  FIG. 6 shows a result obtained by collimating the omnidirectional prism of the vehicle by the above measurement method and obtaining an altitude in a live load state. In this measurement example, the stop time is longer (60 seconds) between the central diameters where the deflection caused by the vehicle is large, and the stop time is shortened (30 seconds) between the side diameters where the effect of deflection is small. Measurement is completed in 53 minutes. The whole measurement is performed in four divisions, and data obtained by abutment to main tower, main tower to Lc / 2 point, Lc / 2 point to main tower, and main tower to abutment is synthesized. Measurements are possible without dividing into four in this way, but this is because the collimation is temporarily interrupted by the main tower and the center stay of Lc / 2 points, and the data is reliably acquired and backed up. I took this technique.

  Each step that looks like a staircase should be a level originally, but when a large vehicle passes, the elevation of the stiffening girder changes greatly, so there are some parts that are uneven (the same The influence can be eliminated by the “two-point altitude evaluation correction method”. FIG. 7 shows the altitude measurement result (standard temperature conversion value) of the stiffening girder thus obtained in the unloaded state.

  This “two-point altitude evaluation correction method” is an application of the fact that two points in the same bridge girder are deflected at a certain ratio due to the same loading load. This is a method of obtaining an unloaded state altitude value of an arbitrary rating from an altitude of a loaded state in which a reference rating in the stiffening girder is measured at a certain time simultaneously with an altitude measurement of an arbitrary rating.

As shown in FIG. 8, it is assumed that only one vehicle has passed the main bridge. At this time, it is assumed that a deflection corresponding to the vehicle occurs at the point Lc / 2, and the average value of the deflection is _{ΔWL / 2} .

On the other hand, deflection occurs at the Lc / 4 point due to the same load, but if the ratio of the deflection average value at the Lc / 4 point to the deflection average value at the Lc / 2 point is g, the deflection occurs at the Lc / 4 point. The value of is g * Δ _{WL / 2} . This ratio g (vertical distance ratio) is a value specific to the structure and can be calculated from a deflection influence line.

  Therefore, the altitude Hj in an unloaded state at an arbitrary rating can be obtained by the following equation (4).

Hj = H0−g * Δave (4)
Where Hj: altitude (m) with no rating (j)
H0: Elevation without load of standard grade (0) (m)
g: Average deflection ratio of arbitrary rating to reference rating (vertical distance ratio)
Δave: Average deflection of the reference rating (difference)
This “two-point altitude evaluation correction method” is a method that is established when one large vehicle passes completely, as described in the principle explanatory diagram (FIG. 8). Therefore, if many vehicles pass continuously or if there are vehicles in the middle of passing, a correction error naturally occurs. In order to reduce the generated error, the measurement time for each rating may be set to about 3 minutes (180 sec) or more from [Example 2] [Example-2] described later. However, if a large vehicle is passing and if the large vehicle is completely included in the correction target for both two points (reference rating, optional rating), the error can be reduced even in a short time. .

[Example 1]
In the [first invention] column, a single line load of 20 tf was loaded. However, when multiple different loads are entrained, Ymax, Yymin and Yave in the above equation are different from the case of a single line load. Therefore, the k value is expected to take an arbitrary value unlike the above value. Therefore, when a plurality of vehicles were taken, a virtual simulation was performed to examine the measurement error and the k value variation.

[Example-1]
Example of calculating the no-load state altitude when 8 arbitrary vehicles (line loads) pass within the measurement time of 5 minutes on the stiffening girder where the no-load state altitude (Ho = 40.000m) is known. Indicates. The weight was 4 to 28 tf, and the time required to pass through the bridge was a low-speed vehicle (60 sec) and a super-low-speed vehicle (120 sec) (Table 1).

  The elevation change diagram of the stiffening girder at the point Lc / 2 when these vehicle groups pass is as shown in FIG. The elevation map shown in FIG. 9 is obtained by superimposing the deflection generated by each vehicle on a stiffening girder (Ho = 40.000 m) in an unloaded state. Although FIG. 9 shows that the no-load state altitude is set to 40.000 m, it is not clear from this figure how much the no-load state altitude is.

Therefore, by applying [First Invention], an attempt is made to calculate an unloaded state altitude that is originally unknown from only the measured values (Hmax, Have, and Hmin) obtained from FIG. Here, when the average value, the maximum value, and the minimum value are calculated from the deflection amount (deflection influence line) of FIG. 10 for all the vehicles, it is as shown in Table 2. From this value, the k value can be calculated as shown in Table 3.

The no-load state altitude is calculated based on these k values and the altitude measurement results shown in FIG. 9 (Table 4).

Calculation of the no-load state elevation by the first formula
Yo = 39.9732 + (40.0115-39.9732) * 0.7003 = Ho (= 40.000m)
Calculation of the no-load state elevation by the second equation
Yo = 39.9732 + (40.0115-39.9079) * 0.2586 = Ho (= 40.000m)
Calculation of the no-load state altitude using the third equation
Yo = 39.9732 + (39.9732-39.9079) * 0.4101 = Ho (= 40.000m)
As a result, it was proved that the unloaded state altitude was equal to Ho = 40.000m, which was initially set in the first to third formulas, and it was possible to estimate the unloaded state altitude.

[Example-2]
The example which calculated the no-load state altitude about the case where the magnitude | size of a load is changed arbitrarily in a previous example is shown. The vehicle weight is a total of 25 cases with 0 to 28tf (Table 5).

  If the k value calculated for each case in Table 5 is used, the unloaded altitude is 40.000m. However, for example, k1 changes from 0.55 to 0.80, and when the k value fluctuates in this way, it is not easy to formulate a general formula for calculating the no-load state altitude.

Therefore, k1 changing from 0.55 to 0.80 is changed to 0.70 (k1 = 0.6959 in the case of single-line load loading), and k2 changing from 0.10 to 0.29 is set to 0.18 (same k2 = 0.1832 rounded to the same value) and k3 changing from 0.12 to 0.48 was assumed to be 0.25 (same as the rounded value of k3 = 0.2486), and calculated using those values. It was confirmed how much the calculated value of unloaded state elevation was different from the initially assumed unloaded state elevation Ho = 40.000m (Table 6).

  As a result, even though it was assumed that k1 = 0.70 in the first formula, it was confirmed that it would be within ± 4mm, but in the second and third formulas (when k2 and k3 in the case of single-line load loading state) It was confirmed that an error of about 15mm was inevitable.

  The reason why the fluctuation range of the error is stable regardless of the loading condition of the estimation formula using the k1 value is that the minimum deflection (positive) caused by the load (weight) is large. Although it fluctuates, the fluctuation range of the maximum deflection (negative) and the average deflection is small, and as a result, the result of the first formula derived from the difference between the maximum deflection and the average deflection is the most stable, and the fluctuation of the error is small. (See FIG. 5).

  Fig. 5 shows the deflection effect line at Lc / 2 when 20tf load is loaded. Ymax, Yave and Ymin in this figure also represent the difference from 0tf (no load) (difference due to load 20tf). From this, it can be understood that the first equation estimated from the values of Ymax and Yave has a small fluctuation range and is stable.

  From this, it can be seen that the first formula (calculation formula obtained using the altitude average value and the altitude maximum value) is extremely effective as a method for calculating the no-load-state altitude from the altitude of the loaded state. Note that this is the case of Lc / 2 points, and since the shape of the deflection influence line differs at each measurement point, the first equation does not minimize the error in all cases.

[Example-3]
So far, all large vehicles have been handled as line loads. Therefore, here, the effect when a multi-axis vehicle passes is examined. Although the measurement time was fixed at 5 minutes, there should be no problem if the error is small even in a shorter time than this, and the influence of the measurement time was also examined.

  It is assumed that the vehicle weight is arbitrary and that there are three types: a high-speed vehicle (30 sec), a medium-speed vehicle (40 sec), and a low-speed vehicle (60 sec) with a very short transit time.

  Tables 7 and 8 show the results of the study. The altitude calculation value in the no-load state calculated with the assumed k value had the smallest error in the case of the first equation. Also, the difference in altitude value was as small as ± 2 mm, and the measurement time was almost the same whether it was as short as 30 sec (Table 7) or as long as 300 sec (Table 8). In the table, (none) indicates the no-load state elevation value, (flat) indicates the average elevation value, (large) indicates the maximum elevation value, and (small) indicates the minimum elevation value.

［例-4］
図１１は、実計測結果の無載荷状態標高からk値を算出したものである。Lc/2点の標高変化からもわかるように全く標高が変化していない無載荷状態標高が計測でも得られている（○部分）。この例の無載荷状態標高からk値を算出する（表９）。

The time setting of 30 seconds is set as the minimum time required for a high-speed vehicle to pass through the bridge. However, the measurement results in Table 7 show that the measurement time zone is midnight and one high-speed vehicle is Since it was a case of passing, it is predicted that such a result was obtained. Therefore, in consideration of traffic jams, slow speeds, uncertainties (disturbances), and accuracy improvements, it is desirable to set a time that is about three times (3 * t) or more.

[Example-4]
FIG. 11 shows the k value calculated from the no-load state altitude of the actual measurement result. As can be seen from the elevation change at the Lc / 2 point, the no-load elevation where no elevation has changed at all is also obtained from the measurement (circled portion). The k value is calculated from the no-load state altitude in this example (Table 9).

  When the k1 value for matching the unloaded state altitude with the altitude of 47.8278 m in the time zone in which the altitude in FIG. 11 hardly changes is obtained, k1 = 0.64.

  If k1 is calculated from the theoretical value of Motohashi's deflection influence line, it should be 0.70 as described above. However, this value is 0.64, which is slightly different. The reason for this can be considered as a result that the deflection influence line of the actual structure is not necessarily the theoretical value.

  The altitude calculated as k1 = 0.70 is 47.8290 m, and the difference from the above value (47.828 m) is 1 mm, which is not a problem value when evaluating the shape result.

[Example 2]
[Example-1]
In the present Example 2, the above-mentioned [3rd invention] calculated | required the unloaded state altitude of Lc / 4 point in the conditions which the super-large-sized vehicle loaded. The Lc / 2 point, which is the standard rating point within the stiffening girder, and the Lc / 4 point, which is an arbitrary rating point, are simultaneously measured, and the elevation value (obtained by the first invention) and loading of the Lc / 2 point are measured. Calculated using the deflection influence line due to live load.

  FIG. 12 shows the altitude measurement result of Lc / 2 point, which is the reference grade within the stiffening girder. Moreover, the altitude at the time of no loading calculated | required by 1st invention is shown in the same figure.

  The loaded state average elevation value and the unloaded state elevation at Lc / 2 points in the above time zone are as follows.

(Loaded state average altitude value) = 47.819m
(No load state altitude value) = 47.828m
From this, the influence value of the deflection due to the live load acting on this time zone can be calculated as follows.

(Influence value of deflection due to live load) = (No load state altitude value)-(Load state average altitude value)
= 47.828-47.819
= 0.009m
Next, from the elevation measurement result diagram of Lc / 4 point (FIG. 13), the elevation value in the same time zone as the measurement of Lc / 2 point is 46.249 m.

  On the other hand, the deflection average values at the Lc / 2 point and the Lc / 4 point are the following values from the respective deflection influence lines (theoretical values), and the deflection vertical distance ratio g is as follows.

(Lc / 2 point deflection average value) = 0.01350m
(Lc / 4 point deflection average value) = 0.00967m
(Lc / 4 point deflection length ratio) g = 0.716
From this, the corrected unloaded state elevation value at Lc / 4 point can be calculated by the following equation.
(Lc / 4 point corrected no-load state altitude value) = (average altitude value in the loaded state) + (deflection effect value due to load)
= 46.249 + 0.716 * 0.009
= 46.255m
The calculated corrected no-load state altitude value is shown in FIG. 13, and this value indicates that the large vehicle appearing between 0:28:42 and 0:29:00 in the figure is It was the same as the altitude value (46.2545-46.2548), confirming the correctness of this method.

[Example-2]
The “two-point elevation evaluation correction method” according to the “third invention” is a method that is established when one large vehicle passes completely as described in the principle explanatory diagram (FIG. 8). Therefore, if many vehicles pass continuously or if there are vehicles in the middle of passing, a correction error naturally occurs. Here, we examined the generation error and a method to reduce it.

In general, if the measurement time is lengthened, the error can be expected to be small. However, the longer the measurement time, the longer the overall work time becomes, and the influence of an unexpected temperature change is included.
Therefore, using the data of the entire measurement time (0:22:00 to 0:29:00), the total measurement time (7 minutes) was arbitrarily subdivided into 15 seconds to 420 seconds, and obtained by each calculation. An error was calculated by comparing the corrected unloaded elevation (H) with the unloaded elevation (Ho) obtained independently, and the optimum measurement time was studied.

The investigation was conducted based on the altitude measurement result at Lc / 4 point shown in FIG. 13, and the no-load state altitude (Ho) is 46.255 m. The results are shown in Table 10.

From Table 10, the examination results are as follows.
(1) The longer the measurement time, the smaller the error that can occur.
(2) About 3 minutes (180 sec) or more is required to reduce the amount of generated error to a few millimeters.
(3) In the measurement time of 3 minutes (180 sec) or less, the error may become extremely large.
(4) Especially when a large vehicle is passing, if the large vehicle is completely included in the correction target for both the two points (reference rating and arbitrary rating), the error can be reduced even in a short time. Is possible.
(5) Even if the measurement time is relatively long, the error may increase if a large vehicle is not completely included in the correction target.

[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 (bridge), 6 ... Cable, 7 ... Hanger rope, 8 ... Stiffening girder, 10 ... Total station, 11 ... Target, 12 ... Computer

Claims (4)

In a state where a live load is applied to a bridge, a measurement method for obtaining an altitude of a no-load state at any point,
The collimation target installed at the altitude measurement point is continuously measured at a small time interval for a predetermined time by the total station with automatic tracking function installed outside the bridge, and the maximum altitude value Hmax and the minimum altitude value Hmin within the measurement time are measured. Either or both and the average altitude value Have are measured, and these measured values are obtained based on the deflection influence line, using either or both of the maximum altitude value Hmax and the minimum altitude value Hmin, the average altitude value Have, and the constant k. A method for measuring an altitude when a bridge is not loaded with a live load, wherein the altitude H0 is calculated by calculating an altitude H0 of a load without a live load, and calculating an altitude when the load is not loaded with a live load. In a state where a live load is applied to a bridge, it is a measurement method for obtaining an altitude in a state where there is no live load at a number of altitude measurement points set at predetermined intervals in the route direction,
Each time a vehicle with an omnidirectional prism attached as a collimation target is run and stops at each altitude measurement point, the omnidirectional prism located at the altitude measurement point is set by a total station with an automatic tracking function installed outside the bridge. Measure continuously at a small time interval for a predetermined time, measure one or both of the maximum altitude value Hmax and minimum altitude value Hmin and the average altitude value Have within the measurement time, and use these measured values as the deflection influence line Substituting into the calculation formula for obtaining the altitude H0 in the no-load state using the maximum altitude value Hmax and / or the minimum altitude value Hmin, the average altitude value Have and the constant k, obtained based on An altitude measurement method for a bridge in a state where no live load is applied, characterized by obtaining an altitude in a loaded state. In a state where a live load is applied to a bridge, it is a measurement method for obtaining an altitude in a state where there is no live load at a number of altitude measurement points set at predetermined intervals in the route direction,
A total station with the first automatic tracking function and a total station with the second automatic tracking function are installed outside the bridge, and a fixed collimation target is provided at the altitude measurement point as the reference rating in the bridge. By collimating the collimating target with a function-equipped total station, the altitude in the no-load state of the reference rating point is determined in advance by the method according to claim 1, and the omnidirectional target becomes the collimating target Each time a vehicle equipped with a prism is run and stops at each altitude measurement point, the total station with the first automatic tracking function collimates the collimating target of the reference rating and obtains the altitude of the live load loaded state. , The total station with the second automatic tracking function collimates the omnidirectional prism of the vehicle and To obtain a high,
The difference between the height of the live load loaded state and the height of the live load unloaded state at the reference rating is obtained, and the difference is multiplied by the deflection vertical distance ratio between the reference rating and the elevation measuring point obtained from the deflection influence line. The bridge is characterized by calculating the correction amount at the altitude measurement point, and calculating the altitude of the altitude measurement point in the no-load state by adding or subtracting this correction amount to the altitude in the active load state at the altitude measurement point. Altitude measurement method when no live load is applied. The calculation formula for obtaining the altitude H0 in the no-load state of the live load is an altitude measuring method in a no-load state of a live load in the bridge according to any one of claims 1 to 3, which is obtained by the following procedure.
Procedure 1: Based on the deflection influence line at the altitude measurement point, the deflection relational expression for obtaining the deflection zero point Y0 is obtained by using one or both of the deflection maximum value Ymax and the deflection minimum value Ymin, the deflection average value Yave and the constant k. A procedure for calculating the constant k, which is an unknown, from the deflection maximum value Ymax, the deflection minimum value Ymin, or the deflection average value Yave, which is a known number.
Procedure 2: Under the assumption that the deflection relational expression is also reproduced 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, A second procedure for obtaining a calculation formula for obtaining an altitude H0 in a no-load state in which the deflection average value Yave is replaced with an average altitude value Have.

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