KR101589977B1 - Measuring Method and Apparatus of Train Running-Stopping Load regarding Girder of Bridge - Google Patents

Abstract

The present invention relates to a method and a device for economically and conveniently measuring a starting and stopping load of a train, which is applied to a railway bridge, with high reliability by using a device of measuring change in length without attaching a strain gauge to a bridge pier. The method for measuring a starting and stopping load of a train includes: a step of applying a test tension (ST) to the bridge pier (2) by a tension cable (100) and calculating a correlation coefficient (Δ) between the test tension (ST) and a sum of diagonal displacement by repeatedly performing a step of calculating the sum of the diagonal displacement generated in the bridge pier (2); a step of measuring an absolute value of the diagonal displacement generated in the each bridge pier (2) when the starting and stopping load is applied to the railway bridge since a train drives on the railway bridge, to calculate the sum of the diagonal displacement; and a step of calculating the starting and stopping load of the train by using the correlation coefficient calculated in advance and the calculated sum of the diagonal displacement.

Description

Technical Field [0001] The present invention relates to a method and a device for measuring a time-varying load of a train acting on a railroad bridge,

The present invention relates to a method and an apparatus for measuring a load acting on a girder of a railway bridge in the longitudinal direction (direction of travel of a train), that is, "the momentary load of a train" when the train is braked to start or stop Specifically, by using a device for measuring a change in length without attaching a strain gauge to a bridge pier, it is possible to economically, easily, and reliably provide a tentative load of a train acting on a girder of a railway bridge And more particularly to a method and an apparatus that can be measured.

When trains start or stop, the load on the girders of the railway bridge (the momentary load of the train) acts on the girder. The momentary load of such a train is called the "major load" "Thus, for the economic design and construction of railway bridges, the tidal load of these trains need not only be measured accurately but also should be measured in a more convenient way.

Figs. 8 and 9 are schematic side views schematically showing a state in which a momentary load of a train acts on a girder and a bridge in a railroad bridge, and Fig. 8 is a schematic side view in which the bridge is not yet deformed And Fig. 9 is a schematic lateral side view showing a state in which the bridge pier is deformed by the momentary load of the train. Fig. 8 and 9, reference numeral 81 denotes a base 81 of the movable stage and reference numeral 82 denotes a base 82 of the fixed stage. 8, the moment load of the train applied to the girder 1 is applied to the bridge bridge 2 through the support 82 of the bridge bridge as shear force S, 9 as shown in Fig.

The shear force S applied to the bridge pier 2 can be calculated theoretically by the following equation (1) if the shear strain y and the shear modulus G of the bridge pier 2 are known.

In the above equation (1), A is the area when the bridge pier 2 is viewed from the lateral direction, that is, the area of the lateral side.

However, since the accurate shear modulus G of the bridge pier 2 made of a concrete member can not be known, the shear modulus G of the bridge pier 2 is inevitably "estimated ", and in this case, The calculated value of the shearing force S applied to the bridge pier 2 has a problem that reliability becomes extremely low.

Particularly, when a strain gauge is used to measure the shear strain? Of the pier 2, as disclosed in Korean Patent Laid-Open Publication No. 10-2011-0108484, a structure to which a strain sensor is to be attached, It is necessary to arrange the surface of the strain sensor 2 so as to be free of foreign substances and to install the strain sensor integrally and integrally using an adhesive or the like and wait until the adhesive hardens, There is a problem that the inability to operate easily occurs and in this case, the inaccuracy of the measurement result becomes very large.

In particular, when the strain sensor is used, only the shear strain at the position where the strain sensor is attached is known, and the shear force acting on the entire pier 2 by using only the measurement results at the local and local positions, There are inherent limitations in estimating prototype loads that many uncertainties can not be avoided.

Korean Patent Publication No. 10-2011-0108484 (published on October 10, 2011).

The present invention has been developed in order to overcome the limitations and problems of the prior art as described above, and it is an object of the present invention to provide a strain gauge capable of preventing a strain gauge from acting on a railway bridge, And to provide a method for economically and simply measuring the tibial dynamic load of a train.

Particularly, the present invention is based on the measurement of the transient load of a train on the basis of the reaction at the bridge pier due to the transient load of the train, and based on the reaction of the whole pier rather than the local and local reaction, And to provide a method for measuring the tidal load of a train.

According to an aspect of the present invention, there is provided a method of measuring a transient moment load acting on a railway bridge, the method comprising: installing a tension cable between neighboring piers; Tensioning the tension cable to load the test tension on the pier; Measuring an absolute value of a diagonal displacement amount generated in the bridge pier to which the test tensions are applied, and calculating a diagonal displacement sum; Repeatedly performing the load, diagonal displacement amount absolute value measurement, and diagonal displacement sum calculation process of the test tension force described above while varying the magnitude of the test tension force to be loaded; Calculating a correlation coefficient between the sum of the test tensile force and the diagonal displacement amount collected as a result of the repetition; Installing a railway bridge by installing a girder on the bridge pier, and running a train on the constructed railway bridge to load the train prototype load on the railway bridge; Measuring the absolute value of the diagonal displacement generated at each pier due to the loading of the train prototype load, and calculating the diagonal displacement sum; And a step of calculating a train momentum load using the measured diaphragm displacement sum and a previously calculated correlation coefficient.

In the above measuring method of the present invention, the load of the test tension force, the absolute value of the diagonal displacement amount, and the diagonal displacement sum calculation process are repeated while varying the magnitude of the test tensile force, A linear regression analysis is performed to calculate the one-dimensional proportional constant, so that the correlation coefficient between the test tension force and the diagonal displacement sum can be calculated.

Particularly, in the measuring method of the present invention as described above, an arithmetic operation of multiplying the measured and calculated diagonal displacement sum by a previously calculated correlation coefficient is performed, and the calculated result value is regarded as a train momentum load.

Further, in the present invention, a first diagonal displacement meter and a second diagonal displacement meter capable of measuring the diagonal length change in the first diagonal direction and the second diagonal direction are provided on the lateral sides of the pier, and the first diagonal displacement meter and the second diagonal displacement meter, The absolute value of the diagonal displacement amount generated in the bridge pier can be measured by the second diagonal displacement meter.

In addition, in the present invention, a tension cable is installed between piers adjacent to each other in the longitudinal direction, and a tensioning force is applied to the pier by tensioning the tension cable. In this case, One end of the tension cable is fixed to the outer surface of the one pier using an anchorage port, and the other end of the tension cable is connected to the hydraulic jack at the outer surface of the other pier to stretch the tension cable to tighten the tension cable , The test tensions may be applied to each pier to approach each other from the two piers.

In the present invention, the first diagonal displacement gauge and the second diagonal displacement gauge may be composed of an optical fiber sensor (for example, FBG optical fiber sensor).

According to the present invention, since the absolute value of the diagonal length change (diagonal displacement amount) of the pier is measured without using a strain sensor directly attached to the outer surface of the pier, and the result is used to measure the prototype dynamic load of the train, It is possible to measure the prototype dynamic load of a train with a low measurement error with a simple, quick, and inexpensive cost, without problems such as a decrease in working efficiency, an increase in cost, and a possibility of error due to damage of a strain sensor .

Particularly, in the present invention, since the transient moment load is measured using the diagonal displacement amount caused by the deformation of the entire pier, the measured value of the transient moment load measured by the present invention is based on the reaction of the entire pier There is an advantage that the reliability is higher than that of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic lateral side view of a bridge pier to illustrate the relationship between shear forces acting on bridge piers and their corresponding deformation;
2 is a schematic flow chart of the measuring method of the present invention.
3 is a block diagram schematically illustrating a configuration of a measuring apparatus according to the present invention.
4 is a schematic lateral side view showing a tension cable installed between neighboring piers of a railway bridge in order to carry out the measuring method of the present invention.
5 is a schematic lateral side view showing a state in which a pier is deformed by a test tensional force according to tension of a tension cable after a pier construction.
6 is a schematic lateral side view showing a state in which a girder is installed on a pier.
7 is a schematic lateral side view showing a state in which a bridge is deformed due to the application of a train momentum load to a girder as the train travels.
8 is a schematic lateral side view of a railway bridge.
Fig. 9 is a schematic lateral side view showing a state in which a pier is deformed by a momentary load of a train in a railroad bridge. Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Although the present invention has been described with reference to the embodiments shown in the drawings, it is to be understood that the technical idea of the present invention and its essential structure and operation are not limited thereby.

Fig. 1 shows a schematic lateral side view for explaining the relation between the shear force S acting on the bridge pier 2 and the corresponding deformation, in order to measure the prototype dynamic load of a train according to the present invention. Fig. 1 (a) is for a bridge bridge 2 in a state before shearing force is applied, and Fig. 1 (b) is for a state after a shear force S is applied and bridge bridge 2 is deformed.

1 (b), when the shear force S is applied to the pier 2, the pier 2 is deformed into a parallelogram shape. As described above, the shear force S acting on the pier 2, Has theoretically a mathematical relationship expressed by Equation (1) and the shear modulus (G) of the shear strain (?) And the pierce angle (2).

On the other hand, when the bridge pier 2 is deformed by the shear force S, the lengths of the two diagonals, that is, the "first diagonal line" and the "second diagonal line" existing on the lateral sides of the bridge pier 2, are changed accordingly. That is, when the shearing force S acts from left to right in the drawing, the length of the first diagonal line shown in the drawing is reduced after the shearing force S acts, and the length of the second diagonal line is increased after the shearing force S acts do.

Thus the piers (2) applying a shear force (S) acts by a first diagonal of the change in the absolute value as, and displays this, δ ₁ la "first diagonal displacement magnitude" of the absolute change in length of a second diagonal " second diagonal displacement absolute value "if it, and displays the information as δ _2, shear strain (γ) when the pier (2) shear force (S) this function can be calculated by equation 2 below.

In Equation (2), a is the transverse length of the transverse side of the bridge pier (2), and b is the transverse length of the transverse side of the bridge pier (2).

)은 교각(2)의 횡측면에서의 제1대각선 변위량 절대값(δ₁)과 제2대각선 변위량 절대값(δ₂)의 합(

)(이하, "대각선 변위량 합"이라고 한다)에 비례하게 된다. 또한 앞서 살펴본 수학식 1에서 알 수 있듯이 횡측면이 사각형을 이루고 있는 교각(2)에서 전단변형률(

)은 전단력(S)에 비례하는 관계를 가진다. That is, as can be seen from Equation (2), when a shear force (S) acts on a pier (2) having a rectangular cross-section, the shear strain

Is the sum of the absolute value of the first diagonal displacement amount? ₁ and the absolute value of the second diagonal displacement amount? ₂ at the lateral side of the bridge pier 2

) (Hereinafter referred to as "diagonal displacement amount sum"). In addition, as can be seen from the above-mentioned equation (1), the shear strain at the pier (2)

) Is proportional to the shear force (S).

In the present invention, based on this theory, when the moment load of a train acts on a railway bridge, the amount of diagonal displacement of the railway bridge at the pier is measured, and the shear force (S) To measure the tidal load (P) of the train.

FIG. 2 is a schematic flow chart of a method for measuring a timepiece load of a train according to the present invention (hereinafter abbreviated as "method of measurement"). FIG. 3 is a schematic diagram of a train timepiece load measuring apparatus (Abbreviated as "measurement device") is schematically shown. 4, in order to carry out the measurement method of the present invention, the bridge pier of the railway bridge is completed but the upper structure such as the girder has not yet been installed, and the tension cable 100 is installed between adjacent piers A schematic lateral side view is shown.

3, the measuring apparatus according to the present invention comprises a tension cable 100 installed between vertically adjacent piers 2 and a tension cable 100 for placing the test tension ST in the piers 2. [ A cable diagonal device installed on the lateral side of the bridge pier 2 for measuring the diagonal length variation in the first diagonal direction and the second diagonal direction, A linear regression analysis performing unit 150 for calculating a one-dimensional calibration factor by performing a linear regression analysis on the values of the test tensile force ST and the sum of the diagonal displacement amounts, and a second diagonal displacement gauge 12, And a train momentum load calculation unit 160 for calculating a train momentum load. The linear regression analysis execution unit 150 and the train momentum load calculation unit 160 may be implemented in the form of a program running on a computer.

Hereinafter, the present invention will be described in more detail.

First, as shown in Fig. 4, a bridge pier 2 having a rectangular lateral side when viewed from the lateral direction is constructed (step 1). When the construction of the bridge pier 2 is completed, the tension cable 100 is installed between the two bridge piers 2 arranged adjacent to each other in the direction of the throttle axis (longitudinal direction) (step 2). A longitudinal through hole 20 is formed in the upper end of the pier 2 when the pier 2 is installed. For example, when the pier 2 is installed, And the sheath tube is buried. One end of the tension cable 100 is connected to the outer surface of the one pier bridge 2 by using the fixing port 110 after passing the tension cable 100 through the two through holes 20 in the two neighboring pier 2 And the hydraulic jack 120 is coupled to the other end of the tension cable 100 at the outer surface of the other pier 2. The hydraulic jack 120 corresponds to a cable tension device.

After the installation of the tension cables 100 is completed, the hydraulic jacks 120 are stretched to tense the tension cables 100 so that the test tensile forces ST () are applied to the respective bridge columns 2 so as to approach the two bridge columns 2 toward each other. (Step 3). 5 shows a schematic lateral side view showing a state in which the bridge pier 2 is deformed by applying a test tension ST to the bridge bridge 2 by the tension of the tension cable 100 in the state where the bridge bridge is installed.

)을 산출한다(단계 4). The first diagonal displacement amount absolute value δ ₁ and the second diagonal displacement amount absolute value δ ₂ are measured with respect to each pier 2 in a state in which the test tensional force ST is applied and the diagonal displacement amount sum

(Step 4).

The absolute values of the first and second diagonal displacement amounts can be measured in various ways. It is most preferable to measure the absolute values of the first and second diagonal displacement amounts by installing a diagonal displacement meter for improving the accuracy of measurement and for convenience. For this purpose, it is preferable that a device capable of measuring the absolute value of the diagonal displacement amount, that is, a "diagonal displacement meter" is installed on the lateral side of the bridge pier 2 in advance on the lateral side of the bridge pier 2 (Step 2-1). That is, in the first diagonal direction in which the length is reduced when the test tensile force ST acts on the lateral sides (transverse sides) of the bridge piers 2, a first diagonal displacement meter A second diagonal displacement gauge 12 is provided which is capable of measuring the absolute value of the second diagonal displacement amount in the second diagonal direction in which the length of the second diagonal displacement amount 11 is increased when the test tensional force ST acts. For example, an optical fiber sensor may be used as the first and second diagonal displacement meters 11 and 12. The optical fiber sensor may be configured such that both ends of the optical fiber sensor are fixed to both ends of the first diagonal direction, The first and second diagonal displacement gauges 11 and 12 can be installed in such a manner that the first and second diagonal displacement gauges 11 and 12 are fixed to both end edges in the diagonal direction. However, the first and second diagonal displacement gauges 11 and 12 are not limited to the above-described optical fiber sensors, and various other configurations may be used as long as they can measure the diagonal length change. Furthermore, if necessary, the operator may directly measure the diagonal length change using a ruler instead of the first and second diagonal displacement meters 11 and 12.

)을 산출하는 과정 즉, 시험긴장력 재하단계 및 대각선 변위량 측정단계를, 시험긴장력의 크기를 변화시켜가면서 복수회 반복 수행한다(단계 5). In the present invention, the test tensions are applied as described above, and the first diagonal displacement amount absolute value (δ ₁ ) and the second diagonal displacement amount absolute value (δ ₂ ) are measured to calculate the diagonal displacement amount sum

), That is, the step of loading the test tension force and the step of measuring the diagonal displacement amount are repeated a plurality of times while varying the magnitude of the test tension force (step 5).

)의 결과에 대해 선형회귀분석을 수행하여, 시험긴장력(ST)과 대각선 변위량 합(

) 사이의 1차원 비례 상수(calibration factor)를 산출한다. 즉, 아래의 수학식 3에서 시험긴장력(ST)과 대각선 변위량 합(

)간의 상관관계 계수 Δ를 산출하는 것이다(단계 6). 이러한 상관관계 계수 Δ의 산출은, 컴퓨터 프로그램으로 구현된 선형회귀분석 수행 연산부(150)를 통해서 자동적으로 수행되도록 할 수 있다.
Each of the test tensions (ST) and diagonal displacement amounts

), And the results of the test stress (ST) and diagonal displacement sum (

) Of the calibration factor. That is, in Equation (3) below, the test tensile force (ST) and the diagonal displacement amount sum

) (Step 6). The calculation of the correlation coefficient? Can be performed automatically through the linear regression analysis execution unit 150 implemented by a computer program.

When the calculation of the correlation coefficient? Through the loading of the test tension ST is completed, the girder 1 is installed on the bridge pier 2 to complete the construction of the railway bridge (Step 7). Fig. 6 shows a schematic lateral side view showing a state in which the girder 1 is installed on the bridge pier 2. Fig. After the railway bridge is completed, the tension cable 100 no longer needs to be present.

(Step 8), the first and second diagonal displacement meters 11 and 12 installed on the lateral side of the bridge pier 2 are subjected to the train momentum load P while the train is running on the completed railway bridge, , The absolute value of the first diagonal displacement and the absolute value of the second diagonal displacement are measured, and the resulting sum of the diagonal displacement is calculated (Step 9 - Actual Timing Load Diagonal displacement sum measurement step). 7 is a schematic lateral side view showing a state in which a bridge 300 is running on a railway bridge and a girder 1 is subjected to a train momentum load P so that the pier 2 is deformed.

The correlation coefficient Δ previously calculated through the sum of the diagonal displacement amount calculated by the measurement in the traction load state of the train and the load of the test tensile force ST is substituted into the right side of the above Equation 3 The value of the left side is calculated, and the calculated value is taken as the measured value of the train momentum load (P). That is, the value calculated by multiplying the sum of the absolute value of the first diagonal displacement amount and the absolute value of the second diagonal displacement amount by the correlation coefficient DELTA is applied to the longitudinal load acting on the bridge bridge 2 by the actual train momentum, Is considered as a measured value of the train prototype load (P) (Step 10). The computation of the train momentum load at step 10 can be automatically performed through the train momentum load calculation unit 160 implemented by a computer program.

As described above, in the measuring method according to the present invention, the strain sensor is not directly attached to the outer surface of the pier, but a diagonal length of the pier is changed by using a sensor such as an optical fiber sensor, (Diagonal displacement amount) is measured and the result is used to measure the moment load of the train.

As mentioned earlier, when using the strain sensor, the surface of the bridge pier is cleaned, and the pier surface is organized to make it flat and easy to attach, and the work of attaching and hardening the strain sensor by using an adhesive such as epoxy is troublesome The strain sensor is expensive, and it is easily damaged by an external force such as a shock, and thus there is a disadvantage that an error occurs in the measurement result.

However, since the present invention uses the result of measuring the diagonal length change as described above, there is no need to provide a strain sensor. Accordingly, it is possible to solve the above-mentioned problem of the prior art using a strain sensor, It is possible not only to perform the operation much more simply and quickly but also to reduce the cost for the measurement operation and to reduce the possibility of measurement error due to impact or the like.

In particular, in the case of the prior art using a strain sensor, the measured result is based on a local and local reaction of the pier, so that the reliability is determined based on the reliability Was low. However, in the present invention, since the transient moment load of the train is measured using the diagonal displacement amount caused by the deformation of the entire pier, the measured value of the transient moment load measured by the present invention is based on the reaction of the whole pier, There is an advantage that the reliability is higher than that by the technology.

1: girder
2: Pier
11: 1st diagonal displacement meter
12: Second diagonal displacement meter

Claims (7)

As a method for measuring the transient moment load acting on a railway bridge,
Providing a tension cable (100) between longitudinally adjacent piers (2);
Tensioning the tension cable (100) to load the test tension (ST) on the bridge pier (2);
Measuring an absolute value of the diagonal displacement amount generated in the bridge bridge (2) to which the test tensile force (ST) is applied, and calculating a diagonal displacement sum;
Repeating the steps of measuring the absolute value of the load, the diagonal displacement amount of the test tensile force (ST) and calculating the diagonal displacement sum sum while changing the magnitude of the test tensile force (ST) to be loaded;
Calculating a correlation coefficient (?) Between the sum of diagonal displacement amounts and the test tensile force (ST) collected as a result of the repetition;
Installing a girder (1) on the bridge pier (2), constructing a railway bridge, and running a train on the constructed railway bridge to load the train prototype load on the railway bridge;
Measuring the absolute value of the diagonal displacement at each bridge pier (2) due to the loading of the train prototype load, and calculating the diagonal displacement sum; And
And calculating a train momentum load using the measured diaphragm displacement sum and a correlation coefficient calculated in advance.
The method according to claim 1,
In the step of calculating the correlation coefficient (?) Between the test tensile force (ST) and the diagonal displacement amount sum,
The measured values of the test tension (ST) and the diagonal displacement sum of the test tensile force (ST) were measured by repeating the loading, the measurement of the absolute value of the diagonal displacement and the calculation of the diagonal displacement. And performing a linear regression analysis to calculate a one-dimensional calibration factor.
3. The method according to claim 1 or 2,
In the step of calculating the train momentum load using the measured dioptric displacement amount sum and the previously calculated correlation coefficient,
Wherein the calculated sum of the diagonal displacement amounts is multiplied by a correlation coefficient calculated in advance, and the calculated result is regarded as a train momentum load.
3. The method according to claim 1 or 2,
To measure the absolute value of the diagonal displacement amount generated in the bridge pier 2,
A first diagonal displacement meter 11 and a second diagonal displacement meter 12 are provided on the lateral side of the bridge pier 2 so as to measure a change in the diagonal line length in the first diagonal direction and the second diagonal direction respectively,
Is performed by the first diagonal displacement gauge (11) and the second diagonal displacement gauge (12).
3. The method according to claim 1 or 2,
The tensioning cable 100 is installed between the vertically adjacent bridge piers 2 and the tensioning force ST is applied to the bridge pier 2 by tensioning the tension cable 100,
A through hole 20 is formed in the longitudinal direction at the upper end portion of the bridge pier 2 at the time of construction of the bridge pier 2 so that the tension cable 100 is passed through the respective through holes 20, One end of the tension cable 100 is fixed to the outer surface of the one pier bridge 2 by using the fixing port 110 and the hydraulic jack 120 is coupled to the other end of the other pier bridge 2 at the other end thereof, So that the test tensions (ST) are applied to the respective piers (2) so as to approach the two piers (2) toward each other.
5. The method of claim 4,
Wherein the first diagonal displacement meter (11) and the second diagonal displacement meter (12) comprise optical fiber sensors.
An apparatus for measuring a transient moment load acting on a railroad bridge,
A tension cable (100) installed between vertically adjacent piers (2);
A cable tensioner installed to strain the tension cable 100 to load the test tension ST in the bridge pier 2;
A first diagonal displacement gauge 11 and a second diagonal displacement gauge 12 installed on the lateral side of the bridge pier 2 and capable of measuring a diagonal length change in the first diagonal direction and the second diagonal direction, respectively;
A linear regression analysis performing unit 150 for calculating a one-dimensional calibration factor by performing a linear regression analysis on the value of the test tensile force ST and the diagonal displacement sum; And
And a train momentum load calculating unit (160) for calculating a train momentum load.

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