JP6916682B2 - How to estimate the seismic response of any part of the building - Google Patents

Description

The present invention is a method of estimating the response when a building vibrates due to an earthquake.

In the conventional seismic observation system, the degree of damage is evaluated by performing response evaluation and response prediction only for representative points such as sensor installation positions on each floor. In a building with eccentricity or a building that is prone to twisting even on the same floor, the difference in response depending on the position on the plane becomes large, but it was not possible to evaluate the part that is considered to have a larger response.

In Patent Document 1 (Japanese Unexamined Patent Publication No. 2014-21137), the acceleration waveform which is the measurement result of the two sensors installed on the bottom floor and the top floor of the building is recorded, and the bottom floor of the building is recorded by the seismic record response estimation device. The difference between the acceleration waveform of the top floor and the acceleration waveform of the top floor is obtained, and the basic response waveform of the top floor is obtained. The band path waveform is obtained by multiplying the mode coefficients of the corresponding orders of each floor, and the band pass waveforms of each floor are added to obtain the composite response waveform. Installed on a limited floor by adding the acceleration waveforms that are the measurement results of the lowest floor sensor 3 to obtain the absolute acceleration waveform, numerically integrating this absolute acceleration waveform, and converting it into the waveform of speed and displacement during an earthquake. A method for confirming the earthquake response / soundness of a building, which makes it possible to estimate the response of each floor of the building more accurately based on the earthquake response information of the building obtained by the sensor, is disclosed.
This prior invention is a system that estimates the response for a representative point of each floor, and the vibration mode information set in advance is a building-specific frequency and a vibration mode type as design parameters.
In this prior invention, (1) only the representative points of each floor can be evaluated, so that a building with a large difference in response depending on the position on the plane, such as an eccentric building or a building with an elongated plane shape, accurately conveys the damage situation. It is not possible to estimate for buildings for which design data cannot be obtained because (2) design parameters are used, and for buildings that have been completed for many years or have experienced an earthquake. , It is known that the vibration characteristics change, and in an old building, the vibration mode information by the model at the time of design is likely to be different from the actual situation.

Japanese Unexamined Patent Publication No. 2014-21137

An object of the present invention is to develop an earthquake response system capable of estimating an earthquake response based on actual conditions for a building having no analysis model or a building whose vibration properties have changed from the time of design and whose vibration mode is unknown.

The present invention constantly measures microearthquakes, artificial vibrations using a vibration exciter, etc., and based on the limited height direction mode information and horizontal twist mode information of the top and bottom of the building, any part of the building. It is a method of estimating the seismic response of the above, and is a system for judging the seismic response and the damage situation of the earthquake based on this estimation.
The main configurations of the present invention are as follows.
1. 1. It is a method of estimating the seismic response of any part of the building based on the limited vertical mode information in the vertical direction and the horizontal twist mode information that measured the constant micro-vibration or excitation applied to the building. mode information in the height direction is between the upper and lower two points were measured by shifting one by one, you characterized in that the mode information obtained by multiplying the transfer function for each layer to estimate the deformation of the entire building vertical how to estimate the seismic response of any part of the building.
2 . The horizontal twist mode information is mode information obtained by measuring between two points on each floor for each floor, obtaining the transfer function and rotation center between the two points on each floor, and estimating the twist deformation of the floor. It is characterized by being 1. How to estimate the seismic response of any part of the serial placement of the building.
3 . 1. 1. Or 2. A system for estimating the seismic response of an arbitrary part of a building obtained by the method of estimating the seismic response of an arbitrary part of a building described in 1.
4 . 1. 1. Or 2. A system for determining the degree of damage to a structure based on the seismic response of an arbitrary part of a building obtained by the method of estimating the seismic response of an arbitrary part of a building described in 1.

1. 1. The present invention constantly measures micro-vibration and the like for a building that does not have an analysis model or a building whose vibration properties have changed from the time of design and whose vibration mode is unknown, and obtains mode information in the limited height direction above and below the building. Based on the twist mode information in the horizontal direction, the seismic response at any part of the building can be estimated as a response based on the actual situation.
2. In particular, the transfer function of each floor with respect to the reference floor such as the first floor is used by multiplying the vibration information for each layer obtained by measuring the two points on the adjacent upper and lower floors as a measurement set while shifting them one layer at a time. Then, the mode information in the height direction is set from the amplitude information and the phase information with respect to the reference floor.
3. 3. Further, for the planar twist of each floor, the twist mode of the building is set by finding the center of rotation from the vibration between arbitrary two points and stacking them in the height direction.
4. The present invention pays attention to the micro-vibration in the steady state, estimates the vibration mode and the twist mode in the height direction of the building based on the measurement information between two points in the vertical direction and the horizontal direction, and estimates the vibration mode and the twist mode at an arbitrary position. It is a system that can be used for earthquake response.
5. Since the height direction mode information and the twist mode information based on each layer can be obtained, the seismic response of any part of the building can be estimated, and the earthquake response to each part, member, equipment, etc. of the building based on the estimated seismic response can be estimated. The degree of damage can be determined.
6. According to the present invention, it is possible to predict the safety level and the degree of danger of each part by applying the seismic model information to the building by utilizing the seismic response to the grasped arbitrary part of the building and the equipment, such as repair. Can be used for. In addition, the damage to the building can be estimated instantly based on the information of the earthquake actually encountered, which is useful as the coping information immediately after the earthquake. For example, it is possible to determine whether or not evacuation is necessary and the safe operation of equipment.

Schematic diagram of the arrangement of sensors for measurement in the vertical direction and the arrangement of horizontally deployed sensors. The figure which shows the calculation formula of the transfer function for the 1st floor. The concept of flat vibration mode grasping. Transfer function of the end with respect to the reference station on the same floor (Y direction) The concept of grasping the plane vibration mode. The figure which shows the transfer function by multiplication and the transfer function by simultaneous measurement (horizontal expansion) (Y direction). The figure which shows the mode shape (Y direction). The figure which shows the measurement point arrangement. The figure which shows the transfer function by simultaneous measurement. The figure which shows the pattern example of the transfer function multiplication in the divided measurement data. The figure which shows the transfer function (X direction) of each floor by multiplying with the transfer function of each layer. The figure which shows the transfer function (Y direction) of each floor by multiplying with the transfer function of each layer. The figure which shows the relationship between the vibration mode shape by partial movement measurement and the vibration mode by simultaneous measurement. The figure which shows the example of the position (7th floor, 9th floor) for which the rotation spectrum is obtained. The figure which shows the rotation spectrum (9th floor) example. The figure which shows the relationship between the vibration direction and the amplitude in a rotation spectrum. The figure which shows the example of the rotation center (9th floor, 3.2Hz) obtained from the vibration direction. The figure which shows the example of the planar vibration mode and the center of rotation (X1st order mode). The figure which shows the example of the planar vibration mode and the rotation center (θ primary mode). The figure which shows the full-layer response estimation calculation method based on observation data. The figure which shows the example of the system which shows the full-layer response estimation calculation method based on observation data.

The present invention relates to a system for evaluating the response at the time of an earthquake and the degree of damage in earthquake observation of a building, and a system for estimating the response of an unobserved portion from a limited number of observation points.
A method and response estimation that constantly measures micro-vibration and vibration, and estimates the seismic response of any part of the building based on the limited height direction information and horizontal twist mode information above and below the building. It is a system. The vibration to be measured is vibration that is consciously generated by using vibration information or a vibration exciter that is naturally applied to a building such as wind or traffic.

When grasping the vibration characteristics of a building by constant micro-vibration measurement, it is common to place sensors in the entire building and perform simultaneous measurement, but the measuring equipment and wiring work are large and costly and time consuming. In order to reduce the number of sensors, there is a method of measuring while moving other stations after fixing the reference station, but in the present invention, in order to more easily grasp the behavior of the entire building, an earthquake in the height direction We propose a method using data obtained by partially measuring the response characteristics while moving the sensor for each layer with the upper and lower floors as a set.
Further, in the horizontal direction, it is proposed to measure any two points to find the center of rotation in order to grasp the center of rotation for each floor.
Then, with reference to the reference floor such as the first floor, the seismic response characteristics of the building are grasped by using the characteristics in the height direction and the twist characteristics of the entire building as the mode information in the height direction and the twist mode information in the horizontal direction.
Using the seismic response characteristics of this building, it is possible to estimate the damage to the building members and equipment based on the information detected by the sensors installed in the building at the time of the earthquake. Emergency response can be taken before the building damage is confirmed on site, and disaster countermeasures can be taken promptly.
Further, the present invention can predict the damage to a building and can be used for earthquake repair of an existing building.
The present invention can be applied to a building for which there is no building data regarding the seismic response or a building for which the initial design data cannot be used. Moreover, even if there is design data, it can be used as a method for confirming consistency with the design after completion.
Therefore, the present invention constantly measures microearthquakes, artificial vibrations using a vibration exciter, and the like, and based on the limited height direction mode information and horizontal twist mode information of the upper and lower parts of the building, the building It is a system that estimates the seismic response at an arbitrary location and determines the seismic response and the damage status of the earthquake based on this estimation.

<About mode information in the height direction>
The transfer function of each floor with respect to the reference floor such as the first floor is obtained by measuring the measurements of two adjacent upper and lower floors as a set while shifting each layer one by one, and multiplying the obtained transfer functions of each layer.
From the obtained transfer function, the shape of each next mode is obtained from the amplitude information and phase information with respect to the reference floor for the predominant frequency.

(Understanding the vibration mode in the height direction)
Figure 1 shows a simple partial movement measurement assumed in this study. The measurement is performed by shifting the measurements of two adjacent upper and lower floors one layer at a time as a set. In the illustrated example, the rooftop and the 9th floor are measured as a set from the left, and then the 9th and 8th floors are set ... The 2nd and 1st floors are partially moved and measured.
By multiplying the obtained transfer functions for each layer, the transfer function of each floor with respect to the reference floor such as the first floor shown in FIG. 2 is obtained.

<Plane mode information>
In order to grasp the torsional vibration mode shape, a contour diagram is used in which the dominant frequency and the vibration direction can be obtained at the same time for two points on the plane.

FIG. 3 shows a concept of a method for grasping a planar vibration mode accompanied by twisting. Twist vibration mode To grasp the shape, use a contour map that can obtain the dominant frequency and vibration direction at the same time for two points on the plane. The contour maps used here are referred to as rotation spectra in the following documents (a) and (b), and the same applies to the present specification.
(A) Hitoshi Hinata, Takenori Hida, Takeshi Takada: Identification of eccentric building eigenmodes using seismic observation records, Architectural Institute of Japan Conference Academic Lecture Abstract, Structure II, pp.263-264, September 2015
(B) Kiminobu Eto, Masashi Hayashi, Tsutomu Ota, Shigeru Tako: Examination of the twist axis of a building by constant microtremor measurement-Dynamic analysis using public hall architecture as an example-, Architectural Institute of Japan Conference Academic Lecture Abstracts, pp.973- 974, 1998.9
For the rotation spectrum, time history data (FIGS. 3 (a) and (b)) recorded at the same time in two orthogonal directions are vector-combined (FIG. 3 (c)), and further, in a constant angle step from 0 degree to 180 degree. The Fourier amplitude obtained by Fourier transforming the time history data of the normal projection component of the vector with respect to the coordinate axes rotated in (Fig. 3 (d)) is arranged with the horizontal axis as the frequency and the vertical axis as the angle (vibration direction). It is represented by a contour graph. It is possible to grasp in which direction the vibration is large at an outstanding frequency.
Assuming a rigid floor, the intersection of two lines on the plane that are orthogonal to the vibration predominant direction is the center of rotation of vibration in that mode.
Normally, the measurement data at the end is used so that there is a difference in the vibration direction at the two points, but in the present invention, a place that is easy to measure, such as around the staircase, is selected. The center of rotation can be obtained from two relatively close measurement points. For tenant buildings, etc., flexibly select a place that is easy to use, such as around the staircase, which is a common area with few security problems, as a measurement point.

<Measurement outline>
Image of partial movement measurement of constant fine movement Fig. 1 shows a simple partial movement measurement imaged in the present invention. The transfer function of each floor with respect to the reference floor such as the first floor is obtained by measuring while shifting the adjacent upper and lower floors one layer at a time and multiplying them by the transfer function of each layer. In addition, the three-dimensional behavior of the entire building is grasped by measuring two points, the reference point and the end, on the same floor, calculating the horizontal transfer function, and performing the same multiplication. We are considering the use of sensors that synchronize and transmit data wirelessly. For example, if we measure one layer at a time in the staircase, wiring is not required because wireless communication is not interrupted easily, and security is required even in tenant buildings for measurement of common areas. In addition, it is possible to perform measurements with less burden, such as being relatively easy to tolerate.
Here, for verification, simultaneous measurement of all layers is performed, and the effectiveness of this method is verified by using data in different time zones.

Building Overview The target building is an SRC office building with 9 floors above ground, 2 floors below ground, and an eaves height of 31 m, which was built before 1975. The planar shape of the reference floor is shown in FIG. 7 together with the measurement points. Seismic retrofitting work is being carried out at the target building. In addition, a multi-storey car park is located on the north side of the building (atrium).

Constant fine movement measurement The case was divided into the case where the core part of all layers was measured in the XY direction (CX, CY) and the case where it was horizontally deployed on the representative floors (3rd, 7th, and 9th floors). FIG. 7 shows the arrangement of measurement points in each case in which the sensor is arranged. In FIG. 7 (a), there is one location on the core of all layers, and in FIG. 7 (b), which is arranged horizontally, there are five locations.
One measurement was for 30 minutes. The sensor used was a servo-type speedometer (VSE-12) manufactured by Tokyo Seisakusho.

<Analysis of vibration characteristics of buildings>
Multiplication of transfer functions (all-layer core part)
Divide the measured 30-minute data into 9 equal parts, obtain the transfer function for each layer every 3 minutes and 20 seconds (Fig. 10), and multiply the transfer functions in different time zones (Equation in Fig. 2) on the first floor. The transfer function of each floor was obtained. The result in the Y (short side) direction is shown. FIG. 11 shows 9 types of transfer functions in which the combination of multiplications is changed, and the transfer functions of each floor directly obtained from the simultaneous measurement data for the first floor. The variation of the transfer function due to the multiplication is slight, and the shape is almost the same as that of the simultaneous measurement. The shape near the peak was also well matched, and the natural frequency was 1.5 Hz in the primary mode and 4.5 Hz in the secondary mode.

Multiplication of transfer functions (horizontal expansion)
On the 3rd, 7th, and 9th floors where the sensor is horizontally deployed, the horizontal transfer function of the station at the end of the building with respect to the reference station on the same floor (9NY / 9CY, 9SY / 9CY for the 9th floor) (Fig. 4). , The transfer function (9NY / 1CY, 9SY / 1CY) for the first floor at the end of the building was obtained by multiplying it with the vertical transfer function (9CY / 1CY) for the first floor obtained in the previous section. For the 9th floor, the transfer function by multiplication is shown in FIG. 5 overlaid with the transfer function in simultaneous measurement. The same shape as in the case of simultaneous measurement can be obtained, and the twist mode can be confirmed around 3.0 Hz.

Mode shape For 9 transfer functions with different multiplication patterns, pick up the peak values at the primary natural frequency (1.5Hz) and the secondary natural frequency (4.5Hz), and set the order with the maximum amplitude to 1. It was standardized and obtained as the vibration mode. FIG. 6 shows a comparison with the case of simultaneous measurement. It can be seen that the magnitude relationship of the magnitude of the shaking depending on the floor can be accurately grasped.

Assuming the partial movement measurement of constant fine movement, the transfer function of the entire building for the first floor was calculated by multiplying the transfer functions for each part. Although short data of about 3 minutes is used for each time, the transfer function by multiplication has almost the same shape as that by simultaneous measurement, and the overall behavior can be grasped accurately by partial movement measurement.

<Constant tremor measurement of existing buildings>
1.1 Target building The target building is an SRC office building with 9 floors above ground, 2 floors below ground, 3 floors of the building, and an eaves height of 31 m. The planar shape of the reference floor is shown in FIG. 7 together with the measurement points. The standard floor plan shape is a rectangle of 34.7m x 24.5m, although there are some irregularities on the right side. It was built before 1975 and is undergoing seismic retrofitting work such as pillar reinforcement.

1.2 Measurement conditions In order to use for verification, simultaneous measurement was performed for a long time, and verification was performed assuming partial movement measurement of two points by the method described later in 4.1 (1). The measurement cases include the case of measuring the XY direction of all floors from the 1st floor to the 1st floor (R floor) of the staircase (all-layer core measurement) and the representative floors (7th and 9th floors) including the ends. It was divided into cases (horizontal expansion measurement) in which multiple points were measured. The arrangement of measurement points in each case is shown in FIG.
The front road has two lanes each way and the traffic volume is relatively heavy, but the wind on the day of measurement is not strong, and it is carried out under conditions where tremors are considered to be close to steady at all times.
One measurement was for 30 minutes, and the sampling frequency was 100 Hz. The sensor used was a servo-type speedometer (VSE-12) manufactured by Tokyo Seisakusho.

3. 3. Analysis of vibration characteristics using simultaneous measurement data The time history data of each measurement point obtained was Fourier transformed to obtain the amplitude ratio of the Fourier spectrum of each floor to the first floor (hereinafter referred to as the transfer function). In the calculation of the Fourier spectrum, the time history data was divided into 40.96 seconds and averaged, and a 0.1 Hz Parzen window was applied.
The transfer function of the 9th floor measuring the end and the 5th floor, which is the middle floor, is shown in FIG.
The natural frequency was 2.2 Hz in the primary mode in the X direction, 7.6 Hz in the secondary mode, and 1.4 Hz in the primary mode and 4.5 Hz in the secondary mode in the Y direction. The twist (θ) primary mode was 3.2 Hz, which had a large amplitude at the end.
As a reference, when the attenuation constant of the first-order mode was obtained from the transfer function by the 1 / √2 method, it was 7.9% in the X-first-order mode and 4.4% in the Y-first-order mode.

<Example of grasping mode information in the height direction of an existing building>
4.1 Verification of grasping vibration mode in the height direction (1) Handling of data for method verification Although this measurement is performed simultaneously for 30 minutes, in the present invention, partial movement measurement is performed at two points each. The measurements may all be performed at different times. In order to verify the partial movement measurement using the data of the simultaneous measurement, in the verification of grasping the vibration mode in the height direction, the data of the simultaneous measurement is divided in the time history and the data is handled. When the data of 30 minutes (1800 seconds) is divided into 9 equal parts in the time history to obtain the data of 3 minutes and 20 seconds (200 seconds) each, the transfer function for each layer is obtained, and the transfer functions are multiplied. Everything is a cross of different times.
As shown in FIG. 9, the crossing pattern (assuming which layer was measured at which time zone) was set to 9 patterns in which the floors were descended in order. Compared with the case where the partial movement measurement is actually performed, the measurement is performed within a short time of 30 minutes, but these nine combinations are compared with the case of the simultaneous measurement.

(2) Transfer function and natural frequency The time history data obtained by dividing the full-layer core measurement into nine equal parts was Fourier-transformed to obtain the transfer function for each layer. In the calculation of the Fourier spectrum, the Parzen window of 0.1 Hz is applied by dividing and averaging every 40.96 seconds.
The transfer functions for each layer by the partial movement measurement are shown in FIG. 10 (a) in the X direction and in FIG. 11 (a) in the Y direction.
The transfer function for each layer represents a local characteristic, and the predominant frequency of the entire building does not appear.
As shown in FIG. 9, the transfer functions for each layer were multiplied by the equation shown in FIG. 2, assuming 9 patterns, and the transfer function for each floor with respect to the 1st floor was obtained.
In this way, the transfer function of each floor for the first floor obtained by multiplying the transfer functions of the partial movement measurement and the corresponding transfer function obtained by the simultaneous measurement data are superimposed and shown in FIGS. 10 (b) and 11 (b). show. The variation of the transfer function due to the partial movement measurement is slight, and the shape is almost the same as that of the simultaneous measurement. The shape near the peak also matches well, and the natural frequency is the same as 2.2Hz in X1st mode, 7.6Hz in X2nd mode, 1.4Hz in Y1st mode, and 4.5Hz in Y2rd mode. .. As a reference, when the attenuation constant of the first-order mode was obtained by the 1 / √2 method from the transfer function by partial movement measurement, it was 7.3 to 8.4% in the X-first-order mode and 4.0 to 4.9% in the Y-first-order mode.

(3) Vibration mode The first-order natural frequency (2.2Hz in the X direction, 1.4Hz in the Y direction) and the second-order natural frequency (X) in the transmission functions of each floor for the nine first floors obtained by multiplying by partial movement measurement. The peak value in the direction (7.6Hz in the direction and 4.5Hz in the Y direction) was picked up to determine the vibration mode shape. It is shown in FIG. 12 in comparison with the peak value picked up from the transfer function of the simultaneous measurement. I was able to accurately grasp the magnitude relationship of the magnitude of the shaking depending on the floor.

<Understanding the planar vibration mode of an existing building>
4.2 Verification of grasping the plane vibration mode (1) Rotational spectrum The rotation spectrum is obtained by using the records of two points measured at the same time in the X and Y directions on the 7th and 9th floors where the horizontal expansion measurement was performed. .. The positions of the evaluation points for obtaining the rotation spectrum are shown by ● and ■ in FIG. The rotation spectrum of the position of the central evaluation point CC is obtained from the data of the measurement points CX and CY, and the position of the central evaluation point CC'is obtained from the data of the measurement points CX and C'Y. In addition, the rotation spectrum of the position of the evaluation point WS is obtained from the data of the measurement points WX and SY, and the corner evaluation points (WS, WN, ES, Obtain the rotation spectrum of EN).
In the calculation of the rotation spectrum, first, by synthesizing the waveform in the X direction and the waveform in the Y direction, the waveform was projected at an angle of 1 degree, and 180 waveforms from 0 degree to 180 degrees were obtained. FIG. 14 shows a rotation spectrum obtained by Fourier transforming them, with the horizontal axis representing the frequency and the vertical axis representing the vibration direction (angle), and expressing the amplitude in a contour diagram.
0 degrees and 180 degrees indicate the X direction, and 90 degrees indicate the Y direction. Since the peak seen at 1.4 Hz has a peak at 90 degrees at any evaluation point, it can be seen that it is a translation mode in the Y direction. On the other hand, it can be seen that the peaks of 2.2 Hz and 3.2 Hz vibrate with twisting because the peak vibration direction differs depending on the station.
Since it is difficult to read the peak vibration direction and amplitude in detail in FIG. 14 due to the nature of the contour diagram, the X1 (2.2 Hz), Y1 (1.4 Hz), and θ1 (3.2 Hz) modes are shown. A cross section in terms of frequency is taken, and FIG. 15 shows the horizontal axis as the vibration direction and the vertical axis as the Fourier amplitude. From FIGS. 15 (a) and 15 (b), in the 1.4 Hz Y primary mode, there is a peak near 90 degrees at every evaluation point, and the vibration is performed with the same amplitude.
On the other hand, in the 3.2 Hz mode on the 9th floor shown in FIG. 15 (e), which involves twisting, the vibration is the largest in the 20-degree direction at the evaluation point CC, whereas it is the largest in the 150-degree direction at the evaluation point CC'. The vibration is large. As shown in FIG. 16, the center of rotation of the ninth floor in this mode can be geometrically obtained as the intersection of the lines passing through the evaluation point and orthogonal to the direction of the largest vibration.

(2) Rotation center and torsional vibration mode As described in 4.2 (1), the rotation center was determined for the modes with twist (2.2Hz, 3.2Hz). The centers of rotation obtained from the central evaluation points (CC, CC') and corner evaluation points (WS, WN, ES, EN) on the 7th and 9th floors are shown by ● and ○ in FIGS. 17 and 18, respectively. ..
In the positional relationship between the two points for evaluating the rotation spectrum and the center of rotation, when the lines connecting the two points and the center of rotation are close to parallel (when the angle is small), an error is likely to occur at the intersection. Since a rigid bed is assumed, the ratio of Fourier amplitudes in the target mode (amplitude ratio) is considered to be proportional to the ratio of the distance between the center of rotation and the distance between the two points (radial rotation ratio). The turning radius ratio was found, and the one close to 1 was found as the probable center of rotation. FIG. 17 plots the amplitude ratio / turning radius ratio of 0.8 to 1.2. At the center of rotation obtained from the central evaluation point, the value of the amplitude ratio / radius of gyration ratio is 0.9 to 1.1 for each of the two modes of the 7th and 9th floors, which is considered to be probable. The positions of the rotation centers obtained from the central evaluation points and the corner evaluation points are slightly different in the X-first mode (2.2Hz) in which the rotation center is outside the building plane, as shown in FIG. 17, but are shown in FIG. It fits well in the θ1 primary mode (3.2Hz) where the center of rotation is in the building plane.
The twist mode shape obtained from the evaluation point at the center and the twist mode shape obtained from the transfer function of the measurement points at the ends by simultaneous measurement are compared and shown by a solid line and a dotted line in FIG. The twist mode shape due to the center of rotation is almost the same as the twist mode obtained from the transfer function of simultaneous measurement.

In the constant fine movement measurement of an existing building, which is often restricted by the installation of measurement points, in this embodiment, in order to grasp the behavior of the entire building by simple measurement, two points are used as an alternative method to simultaneous multipoint measurement of the entire building. The effectiveness of the partial movement measurement method, in which each measurement is repeated while moving, was confirmed.
Based on the measurement data of the existing 9-story building, the natural frequency and vibration mode shape of each mode can be obtained from the data of about 3 minutes per measurement time, and the same vibration properties as the simultaneous measurement can be obtained. The following findings were obtained by verifying that.
(1) By multiplying the transfer function for each layer, the transfer function for the first floor of each floor and the mode shapes in the primary and secondary height directions could be grasped accurately.
(2) The rotation center of the twist and the mode shape can be obtained by using the rotation spectra of two points on the plane, and the mode shape is well matched with the mode shape obtained from the transfer function by simultaneous measurement.
(3) In the target building, the rotation center of the twist mode can be obtained from the two points and three components separated by one span (about 7 m) on the same floor near the staircase, and the twist mode shape can be obtained by measuring only around the staircase. I can grasp it.

<Earthquake impact determination method>
Seismic response performance is determined for the building, and sensors are placed on the limited floors of this building, and the actual exposed seismic data is used as observation data to cover all layers of seismic response (impact, damage, damage). ) Can be estimated. It is a method that can take earthquake countermeasures immediately after the disaster without actually checking each part of the building, and realizes the system.

(Development of full-thickness response estimation method at the time of earthquake with limited observation floor)
The method of estimating the response of all N floors for a building with N floors and response observation floors at S points (1 ground motion observation point, response observation point S point) is shown.
The 1st to Sth specific modes Φ shall be set in advance by vibration measurement, design model, etc. Here, the target mode order is S, which matches the number of response observation points.
FIG. 19 shows a full-layer response estimation calculation method based on the observation data.

Theoretically, this method has the same observed and estimated values for all observation floors, so it is considered to be highly practical as a disaster prevention system without causing confusion for users.

FIG. 20 shows an example of an earthquake response determination system applied to a building.
Seismic sensors are placed at four locations in the building. The information obtained from these sensors at the time of a disaster is input to the arithmetic treatment device, the degree of damage at any part of the building is estimated, and the information is output to the display unit.
In the arithmetic processing unit, mode information in the height direction and the horizontal direction is acquired in advance for this building by constantly using micro-vibration or the like. The observation data from the seismic sensor is applied to this mode information, and the response calculation by the mode superimposition method is performed to estimate the degree of damage at any location.

As shown in this embodiment, by constantly using micro-vibration to measure each floor above and below and at any two points of each layer, the mode information in the height direction over all layers and the plane by the twist mode Mode information can be obtained accurately. Therefore, even for buildings for which there is no design information or for which the seismic response has changed due to repairs from the beginning of completion, sensors are placed at the same location over all floors, and the height does not need to be measured all at once. The direction and twist information will be known.
Since the mode in the height direction and the twist mode can be determined, the seismic response at an arbitrary point of the building can be estimated by inputting the assumed seismic information into the mode.
Then, it is possible to estimate the influence on building members such as columns, beams, walls, stairs, etc. existing at this arbitrary point, or equipment, etc., reflecting the physical properties such as the unique strength of each building member and It is possible to determine the degree of damage to structures related to buildings such as equipment.
That is, it can be determined by applying the mode superimposition method to the seismic response estimation of the obtained building.
As a system for determining the degree of damage to a structure based on an earthquake response, use a known system as disclosed in JP-A-2016-109607, JP-A-2016-97013, and Patent No. 6001740. Can be done.

Claims (4)

It is a method of estimating the seismic response of any part of the building based on the limited vertical mode information in the vertical direction and the horizontal twist mode information that measured the constant micro-vibration or vibration applied to the building.
Mode information in the height direction is between the upper and lower two points were measured by shifting one by one, you characterized in that the mode information obtained by multiplying the transfer function for each layer to estimate the deformation of the entire building vertical how to estimate the seismic response of any part of the building. The horizontal twist mode information is mode information obtained by measuring between two points on each floor for each floor, obtaining the transfer function and rotation center between the two points on each floor, and estimating the twist deformation of the floor. method of estimating the seismic response of any portion of claim 1 Symbol placement of buildings, characterized in that there. A system for estimating the seismic response of an arbitrary part of a building obtained by the method of estimating the seismic response of an arbitrary part of a building according to claim 1 or 2. A system for determining the degree of damage to a structure based on the seismic response of an arbitrary part of a building obtained by the method of estimating the seismic response of an arbitrary part of a building according to claim 1 or 2.

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