Earthquake risk evaluation device, earthquake risk evaluation method, and program

Abstract

To provide an earthquake risk evaluation device, an earthquake risk evaluation method, and a program which can easily and accurately evaluate an earthquake risk of the ground.SOLUTION: An earthquake risk evaluation device 1 includes a ground risk calculation section 114 for calculating a Fourier spectrum amplitude ratio between horizontal and vertical motions of the ground as an evaluation object from microtremor information on the ground, so as to calculate a ground amplification factor on the basis of the Fourier spectrum amplitude ratio. The ground risk calculation section 114 calculates a ground risk index indicating the susceptibility of the ground to disaster from a peak frequency and a peak value of the ground amplification factor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an earthquake risk assessment device, an earthquake risk assessment method, and a program for quantitatively assessing earthquake risks of buildings and ground. [Background technology]

[0002] Various methods have been developed to evaluate the earthquake risk, earthquake resistance, etc. of buildings. The method described in Patent Document 1 measures microtremors between the building and the ground, and evaluates the earthquake resistance performance of the building based on the natural period, degree of resonance, and amplification calculated from the Fourier spectrum of the measured microtremors.

[0003] In addition, the method of Patent Document 2 acquires the natural frequency of the building and the natural frequency of the ground, and evaluates the earthquake resistance of the building based on the difference between the acquired natural frequency of the building and the natural frequency of the ground. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-348949 [Patent Document 2] Special Publication No. 2004-534935 Summary of the Invention [Problem to be solved by the invention]

[0005] In assessing a building's earthquake risk, earthquake resistance, etc., the risk of damage to the building in an earthquake varies depending on the type of ground on which the building is built. However, in the assessment method of Patent Document 1, although ground measurement data is used to assess the vibration characteristics of the building, the natural frequency of the ground is not taken into consideration, and the building's susceptibility to resonance is not evaluated. In addition, no risk assessment of the ground itself is performed. Therefore, it is difficult for the method of Patent Document 1 to accurately assess the risk of a building that takes into account the impact of the risk posed by the ground. Furthermore, the method of Patent Document 1 is a technology targeted at two-story houses, and is not targeted at mid- to high-rise buildings.

[0006] The method of Patent Document 2 states that the seismic resistance of a building may be evaluated taking into account the properties of the ground. Furthermore, Patent Document 2 states that data specific to the ground should be obtained from geographical maps, previous research, etc. Therefore, if there is no data specific to the ground obtained in advance, it is difficult to reflect the properties of the ground in the seismic risk assessment. Furthermore, separately obtaining data related to the assessment of a building and data related to the assessment of its ground requires a lot of effort and expense, making it difficult to easily and accurately assess the seismic risk of a building. Furthermore, no risk assessment of the ground itself is performed, and the method of Patent Document 2 makes it difficult to accurately assess the risk of a building that takes into account the impact of risks posed by the ground.

[0007] The present invention has been made in consideration of the above circumstances, and aims to provide an earthquake risk assessment device, an earthquake risk assessment method, and a program that can easily and accurately assess the risk of an earthquake on the ground. [Means for solving the problem]

[0008] In order to achieve the above object, an earthquake risk assessment device according to a first aspect of the present invention comprises: Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; The ground risk calculation unit calculates a ground risk index that indicates the susceptibility of the ground to damage from the peak frequency and peak value of the ground amplification factor.

[0009] The Fourier spectrum amplitude ratio is calculated using the following formula:

number

number

[0010] Further, the ground amplification factor is estimated using a trained model that has been machine-learned using the Fourier spectrum amplitude ratio as an input and the ground amplification factor as an output. This may also be the case.

[0011] In addition, in the earthquake risk assessment method according to the second aspect of the present invention, Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; A ground risk index that indicates the susceptibility of the ground to damage is calculated from the peak frequency and peak value of the ground amplification factor.

[0012] Furthermore, a program according to a third aspect of the present invention comprises: Computer, Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; a ground risk calculation unit that calculates a ground risk index that indicates the susceptibility of the ground to damage from the peak frequency and peak value of the ground amplification factor; Function as. [Effects of the Invention]

[0013] According to the earthquake risk assessment device, earthquake risk assessment method, and program of the present invention, it is possible to easily and accurately assess the risk of an earthquake occurring in the ground to be assessed. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a functional block diagram of an earthquake risk assessment device according to an embodiment of the present invention. [Figure 2] 1 is a flowchart showing the flow of earthquake risk assessment according to an embodiment. [Figure 3] 10 is a flowchart showing the flow of calculation of a building resonance risk index. [Figure 4] 1 is a graph showing an example of the relationship between the natural frequency of a building and the number of floors of the building. [Figure 5] 1 is a graph showing an example of the relationship between the natural frequency of the ground and the natural frequency of a building. [Figure 6] 10 is a flowchart showing the flow of calculation of a ground risk index. [Figure 7] FIG. 10 is a diagram showing an example of the relationship between MHVR, pseudo ground amplification factor, and ground risk index. [Figure 8] FIG. 10 is a diagram showing an example in which the comprehensive risk index is divided into nine categories. [Figure 9] FIG. 10 is a diagram showing an example in which the comprehensive risk index is divided into five categories. [Figure 10] 1 is a graph showing an example of a vibration spectrum of a building. [Figure 11] FIG. 11 is a diagram showing the relationship between the MHVR, pseudo ground amplification factor, and ground risk index of the building in FIG. 10 . [Figure 12] 11 is a graph showing an example of a vibration spectrum of a building different from that shown in FIG. 10. [Figure 13] FIG. 13 is a diagram showing the relationship between the MHVR, pseudo ground amplification factor, and ground risk index of the building in FIG. 12 . DETAILED DESCRIPTION OF THE INVENTION

[0015] An earthquake risk assessment device 1 according to an embodiment of the present invention will be described below with reference to the drawings. The earthquake risk assessment device 1 is a device that assesses the earthquake risk of buildings and ground. As shown in the functional block diagram of FIG. 1, the earthquake risk assessment device 1 according to this embodiment includes a control unit 11, a memory unit 12, a display unit 13, and an input unit 14.

[0016] The control unit 11 is composed of a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc., and controls the operation of the earthquake risk assessment device 1. The control unit 11 also calculates a risk index for building B during an earthquake based on vibration information about building B, which is the assessment target, and the ground G near building B, and performs earthquake risk assessment. The control unit 11 loads various operating programs and data stored in the ROM, memory unit 12, etc. of the control unit 11 into the RAM and operates the CPU, etc., thereby realizing each function of the control unit 11 shown in FIG. 1. As a result, the control unit 11 operates as a building vibration data acquisition unit 111, a ground vibration data acquisition unit 112, a building resonance risk calculation unit 113, a ground risk calculation unit 114, and a comprehensive risk assessment unit 115.

[0017] The building vibration data acquisition unit 111 acquires building vibration data, which is vibration information measured for building B. The acquired building vibration data is microtremor information consisting of time-series data related to microtremors measured inside building B, and is information acquired for each of a first horizontal direction and a second horizontal direction that are orthogonal to each other in a horizontal plane. The orientations of the first and second horizontal directions are not particularly limited, but it is preferable to set the first horizontal direction to the NS (north-south) direction and the second horizontal direction to the EW (east-west) direction so as to facilitate comparison with information from other buildings. In this embodiment, the first horizontal direction is set to the NS direction and the second horizontal direction is set to the EW direction.

[0018] In addition, the building vibration data is vibration information measured on both the top and bottom floors of building B, in order to take into account the degree of amplification of vibration in the height direction of building B.

[0019] In addition, the building vibration data acquisition unit 111 may instantly acquire the output of a vibration pickup 22 connected to the earthquake risk assessment device 1, or may acquire building vibration data that has been acquired in advance and stored in the memory unit 12 or an external server 21 connected via a network.

[0020] The ground vibration data acquisition unit 112 acquires ground vibration data, which is vibration information acquired about the ground G near building B. The acquired ground vibration data is microtremor information consisting of time-series data related to microtremors measured near building B, for example, at a point approximately 10 m away from building B, and is vibration information measured in a first horizontal direction and a second horizontal direction that are perpendicular to each other in a horizontal plane, as well as in the up-down (vertical) direction. The orientations of the first horizontal direction and the second horizontal direction are assumed to be the same directions as the vibration measurement orientation of building B, and in this embodiment, the first horizontal direction is set to the NS direction and the second horizontal direction is set to the EW direction. This makes it easy to compare the vibration information of building B with that of other grounds.

[0021] Furthermore, the ground vibration data acquisition unit 112 may instantly acquire the output of a vibration pickup 22 connected to the earthquake risk assessment device 1, or may acquire ground vibration data that has been measured in advance and stored in the memory unit 12 or an external server 21 connected via a network.

[0022] The building resonance risk calculation unit 113 calculates a building resonance risk index R representing the resonance risk of building B based on the building vibration data acquired by the building vibration data acquisition unit 111 and the ground vibration data acquired by the ground vibration data acquisition unit 112.

[0023] Specifically, the building resonance risk calculation unit 113 performs a Fourier transform on the building vibration data, which is time-series waveform data for each direction, to perform frequency spectrum decomposition, and calculates the first-order natural frequency f 1x ,f 1yThe building resonance risk calculation unit 113 also calculates the spectral amplitude ratio between the horizontal motion and the vertical motion of the ground G (hereinafter also referred to as the horizontal motion / vertical motion spectral amplitude ratio or MHVR), and calculates the natural frequency f of the ground from the calculated MHVR. gMHVR Then, calculate the first natural frequency f of building B. 1x ,f 1y and the natural frequency of the ground, f gMHVR Based on the difference between these values, a building resonance risk index R is calculated. The detailed method for calculating the building resonance risk index R will be described later.

[0024] The ground risk calculation unit 114 calculates a ground risk index K based on the ground vibration data acquired by the ground vibration data acquisition unit 112. g Specifically, the ground risk calculation unit 114 calculates the MHVR of the ground G, and calculates the ground amplification factor SAF from the calculated MHVR. Then, the peak frequency f g and peak value A g The disaster susceptibility index calculated from the above is used as the ground risk index K g Ground risk index K g The detailed calculation method will be described later.

[0025] The comprehensive risk assessment unit 115 calculates the building resonance risk index R calculated by the building resonance risk calculation unit 113 and the ground risk index K calculated by the ground risk calculation unit 114. g Based on this, a comprehensive risk assessment is carried out that represents the risk to the building taking into account the risk to the ground.

[0026] The storage unit 12 is a nonvolatile memory such as a hard disk or a flash memory, and stores a building resonance risk index R and a ground risk index K based on the building vibration data and the ground vibration data. g It stores information such as programs for calculating the above, various vibration data, and calculated risk indexes.

[0027] The display unit 13 is a display device, such as a liquid crystal panel, provided in the earthquake risk assessment device 1. The display unit 13 displays various spectral data, risk indexes, etc. calculated by the control unit 11.

[0028] The input unit 14 is an input device for inputting parameter setting values ​​for calculating various risk indices, etc. The input unit 14 is a keyboard, a touch panel, a mouse, etc., provided in the earthquake risk assessment device 1.

[0029] Next, an earthquake risk assessment method using the earthquake risk assessment device 1 will be described with reference to the flowchart of FIG.

[0030] (Vibration data acquisition process) In the vibration data acquisition step, the building vibration data acquisition unit 111 of the earthquake risk assessment device 1 acquires building vibration data, which is vibration information measured for the building B to be assessed (step S1). The acquired building vibration data is time-series data related to microtremors measured using the vibration pickups 22 on the top and bottom floors of building B. The building vibration data according to this embodiment is vibration data in the NS direction, which is a first horizontal direction, and the EW direction, which is a second horizontal direction, which are orthogonal to each other in a horizontal plane.

[0031] The building vibration data acquisition unit 111 according to this embodiment acquires building vibration data by reading building vibration data that has been measured in advance and stored in the server 21 connected via a network to the earthquake risk assessment device 1. To perform processing to reduce the effects of noise, the acquired building vibration data is preferably data that is 10 minutes or longer in length.

[0032] Next, the ground vibration data acquisition unit 112 of the earthquake risk assessment device 1 acquires ground vibration data, which is vibration information measured on the ground G near building B (step S2). The acquired ground vibration data is time-series data related to microtremors measured using the vibration pickup 22 at a point approximately 10 m away from building B. The ground vibration data according to this embodiment is vibration data in the NS direction, which is a first horizontal direction, the EW direction, which is a second horizontal direction, and the up-down direction, which are orthogonal to each other in a horizontal plane.

[0033] The ground vibration data acquisition unit 112 according to this embodiment acquires ground vibration data by reading ground vibration data that has been measured in advance and stored via a network in a server 21 connected to the earthquake risk assessment device 1. To perform processing to reduce the effects of noise, it is preferable that the acquired ground vibration data be 10 minutes or longer.

[0034] (Building resonance risk calculation process) Next, as a building resonance risk calculation step, the building resonance risk calculation unit 113 calculates a building resonance risk index R (step S3).

[0035] Specifically, as shown in the flowchart of Fig. 3, the building resonance risk calculation unit 113 extracts multiple pieces of data for a predetermined interval from the building vibration data for the NS and EW directions on the top floor and the NS and EW directions on the bottom floor (step S11). The predetermined extraction interval may be set within a range that allows for analysis of a significant frequency range that includes the natural frequency of the building through spectral decomposition. For example, in this embodiment, the peak frequency of the Fourier spectrum used in the analysis is in the range of 1.0 to 20.0 Hz, so the predetermined extraction interval is set to 20.48 seconds.

[0036] The number of cut-out sections is not particularly limited, but may be, for example, 3 to 10 sections for each direction of building vibration data. The method for selecting the cut-out sections is not particularly limited, and it may be possible to use a method of cutting out sections at predetermined time intervals, or a method in which the user selects and cuts out sections with little noise. By cutting out multiple cut-out sections of a predetermined length from building vibration data of sufficient length and performing the averaging process described below, it is possible to reduce the influence of noise and perform a highly reliable earthquake risk assessment.

[0037] The building resonance risk calculation unit 113 performs a Fourier transform on each piece of building vibration data for the extracted section to calculate a frequency spectrum (step S12). The building resonance risk calculation unit 113 also smooths the calculated spectrum (step S13). In this embodiment, smoothing is performed by applying a 0.3 Hz Parzen window to the calculated spectrum. The building resonance risk calculation unit 113 also averages the smoothed spectra for the NS and EW directions on the top floor and the NS and EW directions on the bottom floor (step S14). This allows the average spectra for the NS and EW directions on the top floor and the NS and EW directions on the bottom floor to be obtained.

[0038] The building resonance risk calculation unit 113 calculates a spectrum (hereinafter referred to as an amplification spectrum) by dividing the spectrum of the top floor by the spectrum of the bottom floor for each of the NS and EW directions using the average spectra for the NS and EW directions for the top floor and the NS and EW directions for the bottom floor calculated in step S14 (step S15). This makes it possible to quantify the degree of amplification of vibrations related to building B.

[0039] The building resonance risk calculation unit 113 calculates the peak frequency of the amplification spectrum calculated in step S15 as the first natural frequency f 1x , the first natural frequency in the EW direction f 1y(Step S16). This allows the natural frequencies of the analysis target building B in the NS and EW directions to be calculated with high accuracy while reducing the influence of noise. In this embodiment, the first-order natural frequency is used as the natural frequency. This makes it possible to easily calculate the building resonance risk without using the second-order natural frequency, etc., the degree of influence of which is difficult to evaluate.

[0040] Fig. 4 is a graph showing an example of the first-order natural frequency f1 of a building calculated by the above-mentioned procedure. As shown in Fig. 4, the relationship between the number of building floors and the natural frequency can be approximated by the building structure, and it can be seen that the vibration characteristics of a building can be expressed by the natural frequency according to this embodiment.

[0041] In addition, the building resonance risk calculation unit 113 calculates the natural frequency f g Specifically, the building resonance risk calculation unit 113 extracts multiple pieces of data for a predetermined interval from the ground vibration data for each of the NS and EW directions and the up-down direction of the ground G acquired in step S2 (step S17). The predetermined extraction interval may be set within a range that allows analysis of a significant frequency range including the natural frequency of the ground by spectral decomposition. For example, in this embodiment, the peak frequency of the Fourier spectrum used in the analysis is in the range of 1.0 to 20.0 Hz, so the predetermined extraction interval is set to 20.48 seconds.

[0042] The number of cut-out sections is not particularly limited, but may be, for example, 3 to 10 sections for each direction of ground vibration data. The method for selecting the cut-out sections is not particularly limited, and it may be possible to use a method of cutting out sections at predetermined time intervals, or a method in which the user selects and cuts out sections with little noise. As with the building vibration data, by cutting out multiple cut-out sections of a predetermined length from ground vibration data of a sufficient length and performing the averaging process described below, it is possible to reduce the influence of noise and perform a highly reliable earthquake risk assessment.

[0043] The building resonance risk calculation unit 113 performs a Fourier transform on each piece of ground vibration data in the extracted section to calculate a frequency spectrum (step S18). The building resonance risk calculation unit 113 also smooths the calculated spectrum (step S19). In this embodiment, smoothing is performed by applying a Parzen window of 0.3 Hz to the calculated spectrum. The building resonance risk calculation unit 113 also averages the smoothed spectra for each of the NS and EW directions and the up-down direction of the ground G (step S20). This allows the average spectra for the NS and EW directions and the up-down direction of the ground G to be obtained.

[0044] The building resonance risk calculation unit 113 calculates the horizontal motion / vertical motion Fourier spectrum amplitude ratio (MHVR) of the ground G using the average spectra of the NS direction (first horizontal direction), EW direction (second horizontal direction), and vertical direction of the ground G calculated in step S20 (step S21). The MHVR is calculated using the following equation (1).

number

[0045] The building resonance risk calculation unit 113 calculates the peak frequency of the MHVR calculated in step S21 as the first natural frequency f of the ground G. gMHVR (Step S22) As a result, the natural frequency of the ground G can be calculated with high accuracy while reducing the influence of noise.

[0046] Next, the building resonance risk calculation unit 113 calculates a building resonance risk index R (step S23). Specifically, the building resonance risk calculation unit 113 calculates a resonance risk index R, which indicates the risk due to resonance of the building B, based on the magnitude of the difference between the natural frequency of the building B and the natural frequency of the ground G for each of the NS direction and the EW direction. x(NS direction),R y (EW direction) is calculated.

[0047] Figure 5 shows the natural frequency of the building, f1, and the natural frequency of the ground, f gMHVR As shown in FIG. 5, the natural frequency f1 of the building and the natural frequency f of the ground are gMHVR When the natural frequency of the building f1 and the natural frequency of the ground f gMHVR The closer the distance is, the higher the risk of resonance is.

[0048] The building resonance risk calculation unit 113 calculates the resonance risk index R by the following equations (2) and (3): x ,R y Calculate the following.

number

[0049] Furthermore, the building resonance risk calculation unit 113 calculates a resonance risk index R for each direction by the following formula (4): x ,R y A building resonance risk index R, which represents the risk due to resonance of building B, is calculated from

number

[0050] As shown in the above formulas (2) and (3), the closer the natural frequency of building B is to the natural frequency of ground G, the larger the value of the building resonance risk index R, and the easier it can be evaluated to resonate. Furthermore, the lower the natural frequency of building B, such as in the case of a high-rise building, the larger the value of the building resonance risk index R, and the easier it can be evaluated to resonate. The earthquake risk assessment device 1 according to this embodiment quantitatively assesses the earthquake risk of a building using the building resonance risk index R in this way, and can therefore easily and accurately assess the risk of a building during an earthquake.

[0051] (Ground risk calculation process) Next, as a ground risk calculation step, the ground risk calculation unit 114 calculates the ground risk index K g The disaster susceptibility index is calculated as follows (step S4).

[0052] 6, the ground risk calculation unit 114 calculates the MHVR of the ground G (step S31). The MHVR calculated in step S21 above may be used.

[0053] The ground risk calculation unit 114 calculates the site amplification factor SAF from the MHVR calculated in step S31 (step S32). The calculation method for the site amplification factor SAF can be, for example, a method using a trained model that inputs the MHVR and outputs the site amplification factor SAF, which has been machine-learned using data on known MHVRs and site amplification factors SAFs (D. Pan, H. Miura et al., “Deep-Neural-Network-Based Estimation of Site Amplification Factor from Microtremor H / V Spectral Ratio,” Bulletin of the Seismological Society of America, Volume 112, Number 3, pp. 1630-1646, 2022). This allows the pseudo site amplification factor pSAF, which is an estimate of the site amplification factor SAF, to be derived from the MHVR calculated in step S31.

[0054] In this embodiment, the pseudo ground amplification factor pSAF estimated using the trained model is used as the ground amplification factor SAF. This makes it possible to easily calculate the ground amplification factor SAF from the MHVR, which is also used to calculate the building resonance risk index R, without having to acquire additional data on the vibration characteristics of the ground.

[0055] The ground risk calculation unit 114 calculates the peak frequency f of the ground amplification factor SAF calculated in step S32. gSAFand peak value A gSAF From the ground risk index K g The disaster susceptibility index is calculated as the ground risk index K (step S33). g is calculated by the following formula (5).

number

[0056] Figure 7 shows the MHVR, pseudo-site amplification factor pSAF, and site risk index K g In this example, the peak frequency f of the pseudo ground amplification factor pSAF estimated based on the MHVR is gSAF = 4.2Hz and peak value A gSAF = 12.0, the ground risk index K g =34.1 is calculated.

[0057] (Comprehensive risk assessment process) Subsequently, as a comprehensive risk assessment step, the comprehensive risk assessment unit 115 calculates the building resonance risk index R calculated in the building resonance risk calculation step and the ground risk index K calculated in the ground risk calculation step. g Based on the above, a comprehensive risk assessment is performed (step S5).

[0058] The overall risk index that takes into account the resonance risk of building B and the risk of ground G is calculated by multiplying the magnitude of the building resonance risk index R by the magnitude of the ground risk index K, as shown in Figure 8. g It is evaluated in several categories based on the combination of the size of

[0059] Specifically, the resonance risk of building B is divided into three categories based on the value of the building resonance risk index R. The risk of the ground is also divided into three categories based on the value of the ground risk index K. g Based on these classifications, the larger the value of the building resonance risk index R, and the larger the value of the ground risk index K, g The larger the value of , the higher the overall risk is evaluated to be. The number of classifications of the overall risk index is not limited to the nine levels shown in Fig. 8, and may be, for example, five levels as shown in Fig. 9.

[0060] The control unit 11 stores the comprehensive risk index evaluated in step S5 in the memory unit 12 and displays it on the display unit 13 (step S6), and ends the earthquake risk evaluation. The control unit 11 also stores the comprehensive risk index, the building resonance risk index R, the ground risk index K, g may be stored in the storage unit 12 and displayed on the display unit 13.

[0061] As described above, according to the earthquake risk assessment device and earthquake risk assessment method of this embodiment, the resonance risk and ground risk of the building are calculated from vibration data of the building to be assessed and the ground in the vicinity of the building, and the earthquake risk of the building is assessed based on these. Therefore, it is possible to easily and accurately assess the earthquake risk of a building that takes into account the characteristics of the ground, without measuring or acquiring other vibration information.

[0062] (Evaluation example) An example of earthquake risk assessment of a building using the earthquake risk assessment method according to the above embodiment will be described. Fig. 10 is a graph showing the measurement results of microtremors of a certain building B1. The building B1 is a 10-story building (1st to 10th floors above ground) made of steel-framed reinforced concrete (SRC). As shown in Fig. 10, the first-order natural frequency f1 of the building B1 is f 1x =1.37Hz, f 1y = 1.32Hz. In addition, the first natural frequency f of the ground G1 near the building B1 was gMHVR is f gMHVR = 3.76Hz. The first natural frequency f1 of building B1 and the first natural frequency f of ground G1 gMHVR From the above, the building resonance risk index is R x =1.07, R y =1.04, and the building resonance risk index R for building B1 is calculated as R=1.07.

[0063] In addition, the MHVR of ground G1 and the pseudo ground amplification factor pSAF estimated from the MHVR using the trained model are shown in Figure 11. The peak frequency f gSAF is 3.9Hz, peak value A gSAFThe ground risk index K calculated based on the estimated pseudo-ground amplification factor pSAF was 12.5. g is K g =40.1.

[0064] Figure 12 is a graph showing the measurement results of microtremors for building B2, which is different from building B1. Building B2 is a six-story building (one basement floor and six above ground floors) made of steel-framed reinforced concrete (SRC). As shown in Figure 12, the first natural frequency f1 of building B2 is f 1x = 2.30 Hz, f 1y = 3.17Hz. In addition, the first natural frequency f of the ground G2 near the building B2 was gMHVR is f gMHVR = 1.71Hz. The first natural frequency f1 of building B2 and the first natural frequency f of ground G2 gMHVR From the above, the building resonance risk index for the first horizontal direction (NS direction) and the second horizontal direction (EW direction) is R x =3.29, R y =1.49, and the building resonance risk index R for building B2 is calculated as R=3.29.

[0065] In addition, the MHVR of ground G2 and the pseudo ground amplification factor pSAF estimated from the MHVR using the trained model are shown in Figure 13. The peak frequency f gSAF is 1.7Hz, peak value A gSAF The ground risk index K calculated based on the estimated pseudo-ground amplification factor pSAF was 12.5. g is K g =91.9.

[0066] The building resonance risk index R and ground risk index K for the above buildings B1 and B2 gBased on this, when the overall risk index of buildings B1 and B2 is evaluated on a 9-point scale using the table in Figure 8, the overall risk index of building B1 can be evaluated as B, and the overall risk index of building B2 as B. As described above, the resonance risk and ground risk of buildings can be calculated from the vibration data of buildings B1 and B2 to be evaluated and ground G1 and G2 near the buildings, and by combining these, the earthquake risk of buildings that takes into account the characteristics of the ground can be easily and accurately evaluated.

[0067] In the above embodiment, the building resonance risk index R and the ground risk index K g The earthquake risk assessment device 1 calculates a comprehensive risk index that represents the earthquake risk of a building by combining the building resonance risk R, which represents the earthquake risk of the building, and the ground risk index K, which represents the earthquake risk of the ground. g This allows easy and accurate comparative evaluation of the earthquake risk of multiple buildings and the earthquake risk of the ground at multiple points.

[0068] The earthquake risk assessment according to the above embodiment can be realized using a normal computer system. For example, a computer program for executing the earthquake risk assessment according to the above embodiment can be distributed via a network such as the Internet, and the computer program can be installed on a computer to cause the computer to function as the earthquake risk assessment device. [Industrial Applicability]

[0069] The present invention is suitable for assessing the earthquake risk of ground and buildings. [Explanation of symbols]

[0070] 1 earthquake risk assessment device, 11 control unit, 111 building vibration data acquisition unit, 112 ground vibration data acquisition unit, 113 building resonance risk calculation unit, 114 ground risk calculation unit, 115 comprehensive risk assessment unit, 12 memory unit, 13 display unit, 14 input unit, 21 server, 22 vibration pickup

Claims

1. Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; A ground risk calculation unit is provided which calculates a ground risk index representing the susceptibility of the ground to damage from the peak frequency and peak value of the ground amplification factor. An earthquake risk assessment device characterized by:

2. The Fourier spectrum amplitude ratio is calculated using the following formula: [Equation 1] The ground risk index is calculated using the following formula: [Equation 2] 2. The earthquake risk assessment device according to claim 1.

3. The ground amplification factor is estimated using a machine-learned trained model with the Fourier spectrum amplitude ratio as an input and the ground amplification factor as an output.

3. The earthquake risk assessment device according to claim 2.

4. Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; A ground risk index representing the susceptibility of the ground to damage is calculated from the peak frequency and peak value of the ground amplification factor.

1. A method for assessing earthquake risk.

5. Computer, Calculating a Fourier spectrum amplitude ratio between horizontal and vertical ground motions from microtremor information of the ground to be evaluated, and calculating a ground amplification factor based on the Fourier spectrum amplitude ratio; a ground risk calculation unit that calculates a ground risk index that indicates the susceptibility of the ground to damage from the peak frequency and peak value of the ground amplification factor; A program that functions as a

Images