JP3285787B2 - Countermeasure effect judgment method and countermeasure effect judgment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the effects of seismic isolation devices,
The present invention belongs to a countermeasure effect judging method and a countermeasure effect judging device for judging an effect of ground improvement, particularly an effect of an earthquake countermeasure of a structure.

[0002]

2. Description of the Related Art Conventionally, seismic measures have been taken to prevent a structure from being collapsed or deformed by an earthquake. In particular, after the Great Hanshin Earthquake, seismic reinforcement measures for structures are strongly desired. However, the effect varies depending on the selection of seismic measures, construction method, etc. Therefore, it is advisable to check whether reinforcement measures have been implemented as intended. Therefore, it is important to determine whether the reinforcement measures have been effective.

[0003] Various devices have been developed and provided as an effect determination device for such reinforcement measures. Typical examples are a method of forcibly vibrating a structure and a method of using microtremor.

[0004]

However, the prior art has the following problems. The method of forcibly vibrating the structure requires a large-scale machine (such as an exciter) to actually vibrate the existing structure. Therefore, a lot of cost, labor, and space were required for the judgment.

Further, noise and vibration are scattered around. In addition, handling the exciter and the like was dangerous. Also, a special power supply was required. Also, a so-called sweep experiment took a lot of time. In addition, since the method using the microtremor uses the natural frequency and the natural vibration mode,
Complicated calculations were required, and reading of the natural frequency required skill.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a countermeasure effect judging method and a countermeasure effect judging device which can achieve the following objects.

[0007] Cost, labor and space are not required for the judgment. Noise and vibration are not scattered around. It is safe. No special power supply is required. Does not take much time. No complicated calculations are required. Even an unskilled person can make a judgment.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the gist of the countermeasure effect judging method according to the present invention is to measure the microtremors of the structure before and after the countermeasures, respectively, and obtain the microtremors obtained by the measurement. Is converted into respective spectra P1 and P2, and both spectra P1 and P2 are converted.
2, the spectrum ratio P1 / P2 is obtained, and the spectrum ratio P1 / P2 is graphed in relation to the frequency. If this graph represents a peak and a valley with 1.0 as a boundary, it is considered that there is a reinforcing measure effect. The feature is to judge. Further, the countermeasure effect determining apparatus according to the present invention includes a vibration receiving unit capable of measuring a microtremor of the structure before and after the countermeasure, and data in a time domain related to the microtremor obtained from the vibration receiving unit. A conversion unit that converts data into each spectrum data, a comparison unit that obtains spectrum ratio data from each spectrum data obtained by the conversion unit, and a relationship between the spectrum ratio data obtained by the comparison unit and the frequency. , And a storage unit for storing at least time domain data related to the microtremor before the reinforcement measure obtained by the vibration receiving unit. In addition, the countermeasure construction method according to the present invention measures the microtremor constantly before and after the countermeasure construction, respectively,
Each data in the time domain relating to the microtremor obtained by this measurement is converted into spectra P1 and P2, and a spectrum ratio P1 / P2 is obtained from both spectra P1 and P2.
The spectral ratio P1 / P2 is graphed in relation to the frequency, and countermeasure construction is performed until the graph represents a peak and a valley corresponding to the countermeasure effect calculated in advance with 1.0 as a boundary. . Further, the method for constructing a structure according to the present invention measures the microtremor at least twice over a predetermined time during the construction of the structure, and converts each data in the time domain relating to the microtremor obtained by this measurement into each spectrum. P1 and P2, and a spectrum ratio P1 / P2 is obtained from the two spectra P1 and P2.
/ P2 is graphed in relation to the frequency, and when this graph does not represent peaks and valleys with 1.0 as a boundary, necessary measures are taken to construct.

[0009] The "countermeasure effect" in the present invention is:
It refers to those suitable for implementing the present invention, such as the effect of the seismic isolation device, the effect of ground improvement, and the effect of earthquake countermeasures for structures.

The "spectrum" can be a spectrum suitable for practicing the present invention, such as a velocity spectrum, a displacement spectrum, and an acceleration spectrum.

Further, P1 may be the spectrum before the reinforcement measure, P2 may be the spectrum after the reinforcement measure,
2 may be the spectrum before the reinforcement measure and P1 may be the spectrum after the reinforcement measure.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG. 1, an effect judging device A according to the present embodiment is a device for judging the effect of a reinforcement measure for the purpose of earthquake countermeasures, and includes a pickup PU (vibration receiving unit), an amplifier 10 , A hard disk 21 (storage unit), an arithmetic processing unit 20, and a monitor 30 (display unit).

The pickup PU is capable of constantly measuring the slight movement of the structure before and after the reinforcement measure, and is suitable for carrying out the present invention, for example, a flow line type fine movement meter.

The amplifier 10 amplifies the vibration waveform data obtained before and after the reinforcement measure in the time domain obtained by the pickup PU.

The hard disk 21 includes a pickup PU
Is stored in the time domain regarding the microtremor before and after the reinforcement measure obtained by the above.

As shown in FIG. 2, the arithmetic processing unit 20 includes a conversion unit 22 and a comparison unit 23. Conversion unit 2
Reference numeral 2 denotes a circuit which obtains two Fourier spectrum data by Fourier transforming each time domain data into frequency domain data. The comparison unit 23 includes a conversion unit 22
And a circuit for comparing the Fourier spectrum data obtained from the above and obtaining Fourier spectrum ratio data. Note that a velocity spectrum is used as the spectrum in the present embodiment.

The monitor 30 displays a graph showing the relationship between the spectrum ratio data obtained by the comparing section 23 and the frequency. Such an effect determination device A is operated by a commercial AC power supply.

Next, an effect judging method using the effect judging device A having such a configuration will be described. First, as shown in FIG.
The pickup PU is installed on the structure B before the reinforcement measure, and the microtremor is constantly measured. The installation floor is preferably above the structure B. The installation place can be installed in a place suitable for carrying out the present invention, such as a column, a beam, a floor, a wall, and the like. The microtremor of the time domain data obtained from the pickup PU is stored in the hard disk 21.

Next, reinforcement measures are taken for the structure B. Next, after the reinforcement measures are completed, the pickup PU is installed again at the installation position as shown in FIG.

Next, each data in the time domain relating to the microtremor stored in the hard disk 21 is
a and Pb are separately converted. In the present embodiment,
The spectrum Pb is the frequency domain data before the reinforcement measure, and the spectrum Pa is the frequency domain data after the reinforcement measure.

Next, the spectrum ratio Pa / Pb is determined from both spectra Pa and Pb, and the spectrum ratio Pa / Pb is graphed in relation to the frequency. Although the spectra Pa and Pb are not shown on the monitor 30 in the present embodiment, it is assumed that the spectra have shapes as shown in FIG. When the spectrum ratio Pa / Pb is obtained from the spectra Pa and Pb, a line shown in FIG. 6 is drawn. Such a spectral ratio Pa / P
b is displayed on the monitor 30, and the person who judges the effect judging device A makes a judgment by looking at the monitor 30. The graphs shown in FIGS. 5 and 6 and FIGS. 7 and 8 described later are logarithmic graphs.

As shown in FIG. 6, the spectral ratio Pa / Pb
Is determined to have a reinforcement countermeasure effect when the graph indicates peaks and valleys with 1.0 as a boundary. If the peaks and valleys do not appear clearly, it is determined that there is no reinforcing effect. For example, when the graph showing the spectrum ratio Pa / Pb is approximately 1.0 (when the spectrum Pa and the spectrum Pb are the same),
When the peaks and valleys are small (spectrum Pa and spectrum P
b is slightly shifted in the frequency direction). 7 and 8 show typical examples of the spectral ratio Pa / Pb when there is no reinforcing effect.

Since the names according to the embodiment are configured as described above, the following effects are obtained.

Since only micromotion is always measured, a large-scale machine for exciting a structure is not required. Therefore, it does not require much cost, labor, time and place. Also, there is no danger of handling large machines. No noise or vibration is scattered around. Also,
Since it is operated by a commercial AC power supply, no special power supply is required.

Further, each data in the time domain relating to the microtremor is converted into respective spectra Pa and Pb, and both spectra P and Pb are converted.
Since only the spectrum ratio Pa / Pb is obtained from a and Pb, complicated calculations can be eliminated.

Also, looking at a graph showing the relationship between the spectrum ratio Pa / Pb and the frequency displayed on the monitor 30,
Since it is only determined whether or not to represent a mountain and a valley with 1.0 as a boundary, even an unskilled person can make the determination.
Further, according to the above configuration, even one person can operate. In addition, it can be measured and determined even in a narrow place or where there is no wide space.

Although the structure in the present embodiment is a building, the present invention is not limited to this. For example, a structure suitable for applying the present invention, such as a bridge, viaduct, dam, general house, and the like. Can be applied to

The present invention can also be used to determine the effect of the seismic isolation device and the effect of ground improvement. In judging the effect of the seismic isolation device, the dominant period of the microtremor after the installation of the seismic isolation device became larger than the dominant period before the installation. Appears so that a decision can be made.

Further, the frequency domain data obtained by the conversion unit and the spectrum ratio obtained by the comparison unit are stored in the hard disk 2.
1 can also be stored.

Further, it may be provided with a hard disk 21 and other storage devices for recording data, a writing device for writing data on a magnetic disk, a magneto-optical disk and other storage media.

The spectral ratio may be Pb (before reinforcement measures) / Pa (after reinforcement measures). In such a case, the spectral ratio Pb / Pa increases as the frequency increases,
Appear in valley order.

In addition, the display section can be made suitable for practicing the present invention, such as a plotter, instead of a monitor. Further, a plotter or the like may be added together with the monitor. Further, the effect determination device can be operated by a battery.

Further, the microtremors of the structure before and during the countermeasures are respectively measured, and the respective data in the time domain relating to the microtremors obtained by the measurement are taken as spectra P1, P2.
2 and the spectrum ratio P1 / P2 is determined from the two spectra P1 and P2, and a graph is drawn of the spectrum ratio P1 / P2 in relation to the frequency.
The countermeasure construction can be performed until the peak and the valley corresponding to the countermeasure effect calculated in advance with 0 as a boundary are represented. In such cases, change the strength and cross-sectional area of the beams and columns, adjust the brace turnbuckle, expand and change the range and depth of ground improvement, change the area and thickness of the earthquake-resistant wall, etc. be able to.
Further, when the judgment is made after the completion of the reinforcing work, it is practically impossible to additionally perform the reinforcing work. However, according to the present embodiment, since the determination can be made easily without interrupting or interrupting the reinforcement work without taking up space, the reinforcement can be completely performed.

During the construction of the structure, the microtremor is measured at least twice through a predetermined time, and the data in the time domain relating to the microtremor obtained by the measurement are converted into spectra P1 and P2. Both spectra P1,
The spectrum ratio P1 / P2 is determined from P2, and the spectrum ratio P1 / P2 is graphed in relation to the frequency. If the graph does not represent peaks and valleys with a boundary of 1.0, a necessary measure is taken. Can also be performed to build. In such a case, optimal seismic measures can be taken during construction. In addition, if it is determined after the completion of the construction work of the structure, it is practically impossible to perform additional reinforcement work. However, according to the present embodiment, without taking up space,
Since the judgment can be made easily without interrupting or interrupting the construction work, a structure having vibration resistance or seismic isolation can be constructed.

Further, the number, position, shape, etc. of the above-mentioned constituent members are not limited to the above-mentioned embodiment, but can be set to suitable numbers, positions, shapes, etc., for implementing the present invention. In the drawings, the same components are denoted by the same reference numerals.

[0036]

According to the present invention, since only micromotion is constantly measured, a large-scale machine for exciting a structure is not required. Therefore, as compared with the related art, it is possible to reduce the cost required for the determination, reduce the labor, reduce the time, and reduce the occupied place. Also, there is no danger of handling large machines. No noise or vibration is scattered around. Further, a special power supply for driving the vibration exciter or the like is not required.

Further, each data in the time domain relating to the microtremor is converted into spectra P1 and P2, and both spectra P1 and P2 are converted.
Since only the spectral ratio P1 / P2 is obtained from P1 and P2, complicated calculations can be eliminated.

Looking at the graph shown on the display,
Since it is only determined whether or not to represent a mountain and a valley with 1.0 as a boundary, even an unskilled person can make the determination.

According to the third or fourth aspect of the present invention, since a large-scale exciter or the like is not required, the reinforcement work and the construction work of the structure can be performed continuously without interruption or interruption. it can.

[Brief description of the drawings]

FIG. 1 is a schematic front view of an effect determination device.

FIG. 2 is a block diagram of an arithmetic processing unit.

FIG. 3 is a conceptual side view showing a structure before reinforcement.

FIG. 4 is a conceptual side view showing a structure after reinforcement.

FIG. 5 is a diagram showing spectra of microtremors before and after reinforcement.

FIG. 6 is a diagram showing a relationship between a spectrum ratio and a frequency when there is a reinforcing effect.

FIG. 7 is a diagram illustrating a relationship between a spectrum ratio and a frequency when there is no reinforcing effect.

FIG. 8 is a diagram showing a relationship between a spectrum ratio and a frequency when there is no reinforcing effect.

[Explanation of symbols]

 B Structure Pa / Pb Spectrum ratio A Effect judging device PU Pickup (vibration receiving unit) 10 Amplifier (amplifying unit) 20 Arithmetic processing unit 21 Hard disk (storage unit) 22 Conversion unit 23 Comparison unit 30 Monitor (display unit)

Claims (4)

(57) [Claims] 1. A microtremor of a structure before and after a countermeasure is measured, and each data in a time domain relating to the microtremor obtained by the measurement is converted into spectra P1 and P2, and a spectrum is obtained from the spectra P1 and P2. The ratio P1 / P2 is obtained, and the spectrum ratio P1 / P2 is graphed in relation to the frequency. If the graph represents peaks and valleys with 1.0 as a boundary, it is determined that the reinforcing measures are effective. A method for determining the effect of a countermeasure characterized by 2. A vibration receiving unit capable of measuring a microtremor of a structure before and after the countermeasure, and each data in a time domain relating to the microtremor obtained from the vibration receiving unit is converted into frequency domain data. A conversion unit for converting the spectrum ratio data from the respective spectrum data obtained by the conversion unit; and a graph showing the relationship between the spectrum ratio data and the frequency obtained by the comparison unit. A countermeasure effect judging device comprising: a display unit; and a storage unit that stores, at least in a time domain, data on microtremors before reinforcement countermeasures obtained by the vibration receiving unit. 3. The microtremor of the structure before the countermeasure and during the construction of the countermeasure are respectively measured, and each data in the time domain related to the microtremor obtained by the measurement is converted into spectra P1 and P2, and both spectra P1 and P2 are measured. , P2 to the spectral ratio P
1 / P2 is determined, and the spectrum ratio P1 / P2 is graphed in relation to the frequency. The countermeasure construction is performed until the graph indicates a peak and a valley corresponding to the countermeasure effect calculated in advance with 1.0 as a boundary. A countermeasure construction method characterized by being performed. 4. During the construction of the structure, the microtremor is measured at least twice through a predetermined time, and each data in the time domain relating to the microtremor obtained by the measurement is converted into spectra P1 and P2. Both spectra P1, P2
From the spectrum ratio P1 / P2, and the spectrum ratio P
If 1 / P2 is graphed in relation to the frequency and the graph does not represent peaks and valleys at 1.0,
A method for constructing a structure characterized by performing necessary measures and constructing the structure.