JP5501924B2 - Roadbed soundness judgment method, roadbed repair method - Google Patents

Description

  The present invention relates to a roadbed soundness determination method and a roadbed repair method for determining roadbed soundness due to a cavity or the like generated under a concrete roadbed.

  Conventionally, for concrete structures, in addition to defects and deterioration that can be found visually, it is necessary to find defects that exist inside, and to quantify such defects. Is required.

  As a method for diagnosing such a concrete structure, a weight is struck perpendicularly to the surface of the structure, the vibration generated by this struck is detected by a sensor or the like, and the change of the natural frequency by Fourier analysis is performed. There is a method for evaluating soundness (Patent Document 1).

JP 2007-51873 A

  However, since the method described in Patent Document 1 uses a weight, there is a problem that it is necessary to move and install the weight and the hitting device for each hitting site.

  On the other hand, even if there is no defect or the like in the structure of the roadbed such as a concrete roadbed, if a cavity is created between the ground below the roadbed and the roadbed, there is a risk of subsidence of the roadbed. There is. Such cavities are generated, for example, when the rocks and gravel layers under the roadbed are crushed and finely granulated due to the influence of repeated loads by the train, and this flows out under the influence of groundwater. Therefore, a reliable diagnostic method for such a sub-base cavity is desired. As a reliable diagnosis method, there is a method of directly drilling a roadbed concrete and visually confirming it. However, the method of confirming the roadbed concrete by directly drilling the core requires a lot of labor, and there are many time restrictions in the maintenance work.

  In addition, when trying to evaluate the soundness of the roadbed in a non-destructive manner, in addition to the influence of the cavity under the roadbed, factors on the track side are also included. For this reason, it is necessary to distinguish these factors. If it is a factor on the track side, it is necessary to repair the damage of the track slab and cement asphalt mortar under the track slab instead of filling the roadbed with concrete or the like. In other words, the repair method differs depending on the factor, and it is desired to determine whether the factor is on the roadbed side or on the track side.

  In addition, the repair method under the roadbed is to drill the roadbed and fill the injection material, but since only the injection volume to be filled is controlled, whether or not the injection material was actually filled in the cavity surely? Couldn't judge and couldn't know the effect of repair.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide a roadbed soundness determination method and the like that are easy to work and that can determine a roadside factor and a trackside factor. And

  In order to achieve the above-described object, the first invention is a method for determining the soundness of a roadbed comprising a track above and comprising roadbed concrete and a slab provided on the roadbed concrete. Install an exciter in the approximate center of the track, install an accelerometer at a position away from the exciter, obtain vibration information by the accelerometer by oscillating vibration from the exciter, Orbital displacement information for a predetermined period of the part is acquired, and each vibration information obtained in a plurality of reference target parts is Fourier transformed to calculate an area of a Fourier spectrum in a predetermined frequency range, and the orbital displacement information. From this, the displacement amount of the trajectory for a predetermined period in each reference target part is calculated, and the surface is calculated from the relationship between the obtained area and the displacement amount of each part. And obtaining the relational expression of the displacement amount in advance, obtaining the vibration information and the trajectory displacement information in the measurement target part, calculating the area and the displacement amount of the part, respectively, and comparing with the relational expression The roadbed soundness determination method is characterized in that the roadbed soundness level in the measurement target part and the roadbed side factors and the track side factors with respect to the soundness level are determined.

  A convex portion is formed on a part of the roadbed concrete, and the periphery of the convex portion is embedded by the slab so that the upper surface of the slab and the upper surface of the convex portion substantially coincide with each other. The vibrator may be installed on the upper surface of the convex portion, and the accelerometer may be installed on the roadbed concrete exposed to the side of the slab.

  The frequency range for calculating the area is 3 to 50 Hz, the displacement amount is a displacement amount in the vertical direction for 4 months with respect to the length of 10 m of the trajectory, and the relational expression is a plurality of the area and the displacement amount. It is desirable to calculate by the least square method from the relationship of

  According to the first invention, a Fourier spectrum is obtained from vibration information obtained by vibrating the roadbed, a spectrum area in a predetermined frequency range is obtained therefrom, and information on the amount of displacement in a predetermined period of the track at the same position, A relational expression between the area and the displacement amount is derived, and the roadside factor and the trackside factor can be discriminated from this relational expression.

  Moreover, accurate vibration information of the roadbed can be obtained by installing a vibrator on the upper surface of the convex portion of the roadbed. Moreover, the relational expression of an area and a displacement amount can be calculated | required accurately by calculating | requiring the spectrum area in a 3-50Hz frequency range. Note that 3 to 50 Hz substantially corresponds to the frequency band of vibration when the Shinkansen passes, for example, and corresponds to the frequency generated by the railway traveling on the track.

  According to the second invention, the roadbed soundness determination method according to the first invention discriminates the roadbed soundness in the measurement target part, the roadbed-side factors and the track-side factors with respect to the soundness, and the roadbed-side factors are sound. Drilling the roadbed of the part judged to be poor, filling the injection material under the roadbed, curing the injection material, recalculating the area and the displacement amount of the part, and data before filling the injection material It is a repair method of the roadbed characterized by confirming the repair effect by comparing with.

  According to the second invention, it is only necessary to drill the roadbed only when it is a roadbed factor, and since this effect can be confirmed after filling with the injection material, the roadbed can be reliably repaired.

  According to the present invention, it is possible to provide a roadbed soundness determination method and the like that are easy to work and that can distinguish a roadside factor and a trackside factor.

It is a figure which shows the judgment state of a roadbed soundness degree, (a) is an elevation view, (b) is a top view. The figure which shows the hardware constitutions of the diagnostic apparatus 17. The figure which shows the hardware constitutions of the analysis apparatus 13. The flowchart for obtaining the relational expression of an area and displacement. The conceptual diagram of the Fourier spectrum when the roadbed is healthy and when it is unhealthy. The figure which shows the relationship between an area and a displacement amount. The flowchart for determining a soundness degree. The conceptual diagram which shows the determination method of each factor in the relationship between an area and a displacement amount. The figure which shows the repair method of the cavity under a roadbed.

  Hereinafter, a method for diagnosing a cavity under a roadbed according to an embodiment of the present invention will be described. FIG. 1 is a diagram showing a state of determining the soundness of a roadbed. FIG. 1A is a cross-sectional view (cross-sectional view taken along the line S-S in FIG. 1B), and FIG. 1B is a plan view. . In the following description, the case where the cavity 11 is generated below the roadbed 1 will be described.

  The roadbed 1 includes a roadbed concrete 5 provided on the ground 2, a slab 6 provided on the roadbed concrete 5, and the like, and a track 3 is disposed on the slab 6. The concrete slab 6 is narrower than the width of the roadbed concrete 5 and can be disposed on the track 3. Accordingly, the roadbed concrete 5 and the slab 6 are arranged in a stepped manner, and the roadbed concrete 5 is exposed on both sides of the slab 6.

  A part of the roadbed concrete 5 is formed with a convex portion 8 protruding upward. Slab 6 is formed so that the circumference of convex part 8 may be covered. That is, the convex part 8 and the slab 6 are substantially the same height, and the upper surface of the slab 6 and the upper surface of the convex part 8 are substantially the same surface.

  The convex portion 8 is located at approximately the center of the track 3 and is exposed at approximately the center of the track 3. A vibrator 9 is installed on the upper surface of the convex portion 8. A plate or the like having a predetermined weight may be installed between the vibrator 9 and the upper surface of the convex portion 8. Moreover, when the upper surface of the convex part 8 is lower than the upper surface of the slab 6, a sand bag for height adjustment may be installed on the convex part 8, and a plate may be installed on the sand bag.

  As long as the vibrator 9 can vibrate vertically with respect to the installation surface (upper surface of the convex portion 8), a commonly used vibrator or vibrator can be used. For example, a combination of a permanent magnet and a moving coil can be used.

  A plurality of accelerometers 7 are installed at a site away from the site where the vibrator 9 is installed by a predetermined distance. The accelerometer 7 may be a general accelerometer as long as it can receive the vibration generated by the vibrator 9 and transmitted to the roadbed 1 (roadbed concrete 5). The accelerometer 7 is installed on the upper surface of the roadbed concrete 5 exposed to the side of the slab 6 in the direction perpendicular to the track 3 from the position of the convex portion 8 where the vibrator 9 is installed. .

  As shown in FIG. 1B, the plurality of accelerometers 7 are connected to the processing device 15 (in FIG. 1A, the processing device and the analysis device are not shown). The processing device 15 is further connected to the analysis device 13. The vibrator 9 is controlled by a control device (not shown) and connected to the analysis device 13.

  As shown in FIG. 1A, a cavity 11 is formed between the roadbed concrete 5 and the ground 2. The cavity 11 is formed by ground subsidence after installation of the roadbed 1 or the like, or vibration of a train or the like traveling on the track. Usually, when the cavity 11 does not exist, the roadbed concrete 5 is supported in close contact with the ground 2 from below. That is, for example, according to a beam theory on an elastic floor in which the ground 2 is replaced with a spring, the roadbed concrete 5 is supported by the ground 2 from below. On the other hand, when the cavity 11 is formed in a part below the roadbed concrete 5, this part is not supported from the ground, and is supported from the ground 2 at the peripheral edge of the cavity 11. Therefore, a large amplitude is generated at the site where the cavity 11 is formed.

  FIG. 2 is a hardware configuration diagram showing a diagnostic device 17 for diagnosing a cavity under a roadbed according to the present invention. The processing device 15 is a part that amplifies and digitizes the vibration received by the accelerometer 7. In addition, although the acceleration information obtained by the accelerometer may obtain the Fourier spectrum as the acceleration as it is, it may obtain the Fourier spectrum converted into velocity or displacement. The analysis device 13 is a part that performs various calculations based on the obtained information and performs information processing. In addition, the control apparatus which abbreviate | omitted illustration performs control of the vibrator 9, such as the setting of the vibration condition of the vibrator 9, and the start and stop of vibration.

  The vibration oscillated by the vibrator 9 is transmitted to the roadbed 1 (roadbed concrete 5 or the like). The vibration propagated through the roadbed 1 is received by the accelerometer 7. The vibration information received by the accelerometer 7 is amplified and digitized by the processing device. The processed vibration information (acceleration, velocity, displacement) is sent to the analysis device 13. On the other hand, the vibration information oscillated by the vibrator 9 is processed as necessary and sent to the analysis device 13 as digital information.

  The processing device 15 includes an amplifier, an A / D converter, and a communication interface. The measurement signal sent from the accelerometer 7 is amplified by the amplifier, digitized by the A / D converter, and converted into digital data. The measured data is sent to the data analysis device 13 via the communication interface.

  Next, the hardware configuration of the analysis device 13 will be described. FIG. 3 is a hardware configuration diagram of a computer that implements the analysis device 13. In the analysis device 13, a control unit 21, a storage unit 23, a media input / output unit 25, a communication control unit 27, an input unit 29, a display unit 31, a peripheral device I / F unit 33 and the like are connected via a bus 35. .

  The control unit 21 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU calls and executes a program stored in the storage unit 23, ROM, recording medium, or the like in a work memory area on the RAM, and drives and controls each device connected via the bus 35. The control unit 21 may control the vibration excitation force, displacement, speed, acceleration, frequency, and the like of the vibrator 9.

  The ROM is a non-volatile memory and permanently holds a computer boot program, a program such as BIOS, data, and the like. The RAM is a volatile memory, and temporarily stores programs, data, and the like loaded from the storage unit 23, ROM, recording medium, and the like, and includes a work area used by the control unit 21 for performing various processes.

  The storage unit 23 is an HDD (hard disk drive), and stores a program executed by the control unit 21, data necessary for program execution, an OS (operating system), and the like. As for the program, a control program corresponding to an OS (operating system) and an application program corresponding to processing described later are stored. Each of these program codes is read by the control unit 21 as necessary, transferred to the RAM, read by the CPU, and executed as various means.

  The media input / output unit 25 (drive device) inputs / outputs data, for example, floppy (registered trademark) disk drive, CD drive (-ROM, -R, RW, etc.), DVD drive (-ROM, -R, etc.). -RW etc.) and media input / output devices such as MO drives.

  The communication control unit 27 includes a communication control device, a communication port, and the like, and is a communication interface that mediates communication between the computer and the network, and performs communication control with the vibrator 9, the processing device 15, and the like.

  The input unit 29 inputs data and includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad. An operation instruction, an operation instruction, data input, and the like can be performed on the computer via the input unit 29.

  The display unit 31 includes a display device such as a CRT monitor and a liquid crystal panel, and a logic circuit (such as a video adapter) for realizing a video function of the computer in cooperation with the display device.

  The peripheral device I / F (interface) unit 33 is a port for connecting a peripheral device to the computer, and the computer transmits and receives data to and from the peripheral device via the peripheral device I / F unit 33. The peripheral device I / F unit 33 is configured by USB, IEEE 1394, RS-232C, or the like, and usually has a plurality of peripheral devices I / F. The connection form with the peripheral device may be wired or wireless.

  The bus 35 is a path that mediates transmission / reception of control signals, data signals, and the like between the devices. Note that the analysis device 13 is not limited to the one including all the above-described configurations.

  Next, a flow for obtaining a relational expression between the spectrum area and the orbital displacement amount in the present invention will be described. FIG. 4 is a flowchart showing a flow for obtaining a relational expression. Note that the following flow may be performed inside the diagnostic apparatus, or may be performed separately and stored in the storage unit. In addition, the following measurements and the like may be obtained in advance in the reference measurement unit, or may be aggregated into the actual measurement results on site.

  First, the conditions for exciting the vibrator 9 are set (step 101). The setting of the excitation condition may be performed by a control device (control unit) or the like, or the excitation condition set and stored in advance may be read and executed. Next, the vibrator 9 is driven according to the set vibration conditions, and vibration is oscillated (step 102).

  Next, vibration data (vibration information) of the object to be inspected is detected by the accelerometer 7 (step 103). Information about each of the plurality of accelerometers 7 is acquired separately.

  Next, the measurement data is processed by the processing device 15 (step 104). In the measurement data processing, the measurement data is amplified and digitally converted. The processed measurement data is transmitted to the analysis device 13.

  Next, the obtained vibration information is Fourier-transformed to obtain a Fourier spectrum (step 106). An area in a predetermined frequency range (for example, 3 to 50 Hz) is calculated from the obtained Fourier spectrum (step 107).

  FIG. 5 is a conceptual diagram of the obtained Fourier spectrum. Taking the frequency on the horizontal axis and the amplitude (intensity) on the vertical axis, the Fourier spectrum in an unhealthy state (for example, having a cavity) shows a high amplitude, particularly on the low frequency side. On the other hand, when the sound is healthy, the amplitude is small in the frequency range. For example, in the figure, when the area of each spectrum in the frequency range (the area surrounded by the horizontal axis and the spectrum curve from the lower frequency limit to the upper limit) is obtained, the area increases when it is unhealthy and is healthy. Smaller if there is.

  On the other hand, at the same site, the 10 m-string 4-month displacement (advance) amount of the track is measured (step 107). The 10 m-string 4-month displacement (advance) amount of the orbit is a string in the range of 10 m of the orbit, the distance from the string to the orbit is measured at the center (5 m) position, and the amount of change every 4 months. (Hereinafter simply referred to as “displacement amount”) is calculated for each measurement (step 108). That is, the amount of displacement of the trajectory within a predetermined period.

  The area and displacement of the subject obtained as described above are used as a set of data, and this data is acquired for a plurality of subjects and examination times, and the obtained relationship is, for example, a linear relationship by the least square method. Obtained as an expression (step 109). As described above, the relational expression in the present invention can be obtained. It should be noted that obvious abnormal data is appropriately excluded, and for example, it is desirable that the correlation coefficient is 0.6 or more.

  FIG. 6 is a conceptual diagram in which a plurality of obtained “area / displacement amount” data is plotted and a relational expression (straight line T in the figure) is obtained by the least square method. The relational expression may be approximated by a linear function with the horizontal axis representing the displacement (10 m-string 4-month progress) and the vertical axis representing the area corresponding to the measured displacement. The minus value of the displacement amount indicates the direction in which the track sinks, and the displacement amount may be an absolute value. If the absolute value of the displacement amount is taken on the horizontal axis, the relational expression T can be obtained as a straight line rising to the right. That is, there is a correlation between the amplitude of the roadbed and the displacement of the track, and the amplitude increases when the displacement of the track is large. This is because, for example, even when slab damage, which is a factor on the track side, or cement asphalt mortar under the slab is damaged, the amplitude on the low frequency side increases due to this effect in the vibration information of the roadbed, and factors other than the cavity This is because the spectrum area becomes large.

  Next, based on the obtained relational expression, the flow of determining the soundness level in the actual measurement target will be described. FIG. 7 is a flowchart showing a flow of determining the soundness level. Steps 201 to 208 are performed by installing a vibrator or the like in the measurement target portion. Steps 207 and 208 may be performed separately. In addition, steps 201 to 208 are the same steps as steps 101 to 108 for obtaining the relational expression, and thus a duplicate description is omitted.

  Next, the obtained area / displacement amount data is compared with the relational expression described above (step 109). FIG. 8 is a method for comparing and determining the relational expression T in the above-mentioned relationship diagram between the “10 m-string four-month displacement advancement amount (displacement amount)” and the “area” and the obtained “area / displacement amount data”. FIG.

  For example, when the “area / displacement amount data” in the measurement target region is in the region A in the figure, both the displacement amount and the area are small, and it is determined that the roadbed and the like are sound at present. On the other hand, when located in the area B in the figure, it is determined that the problem is not on the track side but on the roadbed side. Therefore, it is necessary to repair the roadbed described later. For example, if it is left as it is, the area may further increase (the number of cavities increases), and the displacement of the trajectory may increase rapidly due to the cavities.

  Further, when the “area / displacement amount data” is in the C region, it is estimated that there is a problem not only in the problem of the roadbed cavity but also in the track itself. For example, it is considered that the cement asphalt mortar on the lower surface of the slab or the slab itself is damaged. For this reason, it is necessary to examine the factors on the track side.

  In the conventional evaluation method using only vibration, the point E (FIG. 8) is determined to be a problem of the roadbed, repairing the roadbed, which will be described later, and the like, may not be able to accurately judge the soundness. Further, in the evaluation of only the displacement amount, the point F (FIG. 8) is determined as a problem of only the displacement amount, and the slab may be replaced. According to the present invention, the roadside factor and the trackside factor can be determined depending on whether the relational expression T is below or above the relational expression T. Note that the boundary values of the respective regions may be determined in advance by grasping the data obtained in advance and the state of the roadbed and the track.

  Next, a repair method for the roadbed 1 will be described. FIG. 9 is a diagram illustrating a repair process of the roadbed 1. First, the soundness of the roadbed is diagnosed in each part of the roadbed 1 by the method described above. Next, holes 18 are provided in the roadbed 1 (slab 6 and roadbed concrete 5) as shown in FIG. 8 (a) at the site determined to have a problem on the roadbed side by the above-described method.

  Next, as shown in FIG. 8 (b), concrete 19 as an injection material is filled into the cavity 11 below the roadbed 1 through the hole 18. As described above, the cavity 11 is backfilled with concrete, and subsidence or damage of the roadbed 1 can be prevented. Furthermore, after the concrete 19 is hardened, vibration is similarly applied to obtain the area data again (steps 201 to 206 in FIG. 7), and the repair effect can be confirmed from the obtained area / displacement amount data.

  According to the roadbed soundness determination method according to the present embodiment, since the vibrator 9 is used for vibration oscillation, the vibration can be reliably oscillated in a direction perpendicular to the installation surface of the roadbed 1. Work such as equipment installation is also easy. Moreover, vibration information can be easily obtained by using the vibrator 9.

  In addition, it is possible to determine not only the area value obtained from vibration information but also the displacement data of the track, and use this to determine the roadside factor and the trackside factor, so a more appropriate repair method Etc. can be selected. In addition, by acquiring similar data again after repair, for example, when the data of point F in FIG. 9 is acquired, the injection material is filled under the roadbed, and whether or not the injection material is surely filled in the cavity is determined. I can know. Similarly, when the data of point E is acquired, it is also possible to know the change in vibration data (area) accompanying the repair on the track side after repairing the slab or the like.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1 ……… Subbase 2 ……… Ground 3 ……… Track 5 ……… Subsurface concrete 6 ……… Slab 7 ……… Accelerometer 8 ……… Convex 9 ……… Exciter 11 ……… Cavity 13 ... Analysis device 15 ... Processing device 17 ... Diagnosis device 18 ... Hole 19 ... Concrete

Claims (4)

A method for determining the soundness of a roadbed comprising a track above and comprising roadbed concrete and a slab provided on the roadbed concrete,
An exciter is installed at the approximate center of the track on the upper surface of the roadbed, and an accelerometer is installed at a position away from the exciter by a predetermined distance. Obtain information, orbital displacement information in a predetermined period of the part,
Each of the vibration information obtained at a plurality of reference target parts is Fourier-transformed to calculate an area of a Fourier spectrum in a predetermined frequency range, and from the trajectory displacement information, a trajectory of a predetermined period in each reference target part is calculated. Calculate the displacement amount,
A relational expression between the area and the displacement amount is obtained in advance from the relationship between the area and the displacement amount of each obtained part,
In the measurement target part, the vibration information and the trajectory displacement information are acquired, the area and the displacement amount of the part are respectively calculated, and compared with the relational expression, the roadbed soundness level in the measurement target part and A method for determining the degree of soundness of a roadbed, comprising distinguishing a roadside factor and a trackside factor for soundness.   A convex portion is formed on a part of the roadbed concrete, and the periphery of the convex portion is embedded by the slab so that the upper surface of the slab and the upper surface of the convex portion substantially coincide with each other. 2. The roadbed soundness determination method according to claim 1, wherein a vibrator is installed on an upper surface of the convex portion, and the accelerometer is installed on the roadbed concrete exposed to the side of the slab. . The frequency range for calculating the area is 3 to 50 Hz,
The displacement amount is a displacement amount for 4 months with respect to the length of the track 10 m,
3. The roadbed soundness determination method according to claim 1, wherein the relational expression is calculated by a least square method from a plurality of the areas and the displacement amount. By the roadbed soundness determination method according to any one of claims 1 to 3, the roadbed soundness level in the measurement target part, and the roadbed-side factor and the track-side factor for the soundness level are determined,
Drilling a portion of the roadbed that is determined to be poor due to roadside factors, filling the injection material under the roadbed,
After the injection material is cured, the area and the displacement amount of the part are calculated again, and the repair effect is confirmed by comparing with the data before filling the injection material.

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