JP2013120139A - Method for estimating earthquake damage of reinforced concrete building - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for estimating earthquake damage of a reinforced concrete building which can estimate earthquake damage properly, in the case of estimating earthquake damage in accordance with a range in which prior investigation can be performed, in the case of having to estimate accurate earthquake damage, or the like.SOLUTION: The method includes a first procedure for obtaining facts essential to assume earthquake damage, such as seismic resistance characteristics of a target reinforced concrete building; a second procedure for selectively and preliminarily performing processing required in the case of analyzing one mass system such as microtremeter measurements, and processing expected to improve the estimation accuracy by using boring data or the like on the basis of a processing result by the first procedure; and a third procedure for selectively performing processing for estimating earthquake damage of the target reinforced concrete building by using a damage evaluation matrix on the basis of an earthquake record and a processing result obtained in the second procedure, and processing for performing an elastoplastic response analysis to estimate earthquake damage of the target reinforced concrete building on the basis of the plasticity rate obtained from the analysis.

Description

  The present invention relates to a method for estimating damage to a reinforced concrete building due to an earthquake.

  There are various types of earthquake countermeasures. For example, an electric power company assumes earthquake damage to electric power facilities and takes necessary equipment measures. The shaking assumed at the site where the power company's office is set up (hereinafter referred to as the “site of the office”) is based on the predicted seismic intensity at various locations, that is, representative points, by the national and local governments. However, if the ground condition of the business site is significantly different from the representative point, the actual shaking at the business site may be far from the predicted seismic intensity or the seismic intensity at the observation point. For this purpose, microtremor measurement is always performed at the site and the nearest observation point, and the difference between the seismic intensity of the seismic intensity information announced at the nearest site and the seismic intensity assumed at the site is corrected. This is useful for damage prediction. As a seismic intensity correction method, there is the following prior art (for example, see Non-Patent Document 1).

This method uses the spectrum of fine movement horizontal movement and vertical movement (fine movement H / V spectrum), and obtains the measured seismic intensity at a point where no borehole data exists by the following estimation methods.
A. Estimation method 1

In this estimation method, it is obtained by a relational expression obtained from the relationship between the ratio of the maximum value of the fine movement H / V spectrum between two points and the difference in measured seismic intensity.
B. Estimation method 2

In this estimation method, the fine tremor H / V spectrum is obtained by a method assumed to represent the S-wave amplification characteristics of the ground where it is observed.
C. Estimation method 3

In this estimation method, the estimation method No. 1 and the estimation method No. 2 are obtained by a method that selectively uses the difference between the dominant periods at two points.
D. Estimation method 4

In this estimation method, the measured seismic intensity is estimated based on the logical H / V spectrum of the Rayleigh wave basic mode.
E. Estimation method 5

  In this estimation method, the estimation method 4 is obtained by a method considering the non-linearity of the ground.

  Thus, five estimation methods have been proposed for the seismic intensity correction method. In addition to this, for example, there is a system for estimating and evaluating earthquake damage as follows (for example, see Patent Document 1). In this system, seismometers are installed at designated regional facilities for disaster prevention, and earthquake detection information, observation / estimation information such as seismic intensity distribution in the facility, and damage estimation information are calculated and output from the observation results.

JP 2002-168963 A

Journal of Architectural Institute of Japan Chugoku Chapter Vol.31 “Surface Interpolation of Seismic Intensity Using Tremor H / V Spectrum-Part 6 Examination of Practicality in Kure City” March 2008

  However, the seismic intensity correction method described above has the following problems. In this method, the earthquake damage of the building on the site of the office is estimated by five estimation methods. In this case, there are cases where the earthquake damage needs to be obtained with a small amount of processing, and conversely, the earthquake damage needs to be estimated in detail and accurately. In such a case, it is undecided which estimation method to select and proceed with the analysis.

  On the other hand, the system for estimating and evaluating earthquake damage has the following problems. In this system, it is necessary to install seismometers, and in particular, when observing seismic intensity distribution in a facility, it is necessary to install a large number of seismometers. Installation of such a seismometer requires cost and human work.

  In addition, each prefecture's institution has published a seismic intensity map, which is created based on the seismic intensity scale at the reference point. However, the seismic intensity map does not display the correct seismic intensity scale of the target point if there is a difference in ground characteristics such as the surface layer ground between the reference point and the target point.

  The object of the present invention is to solve the above-mentioned problems and to accurately estimate the earthquake damage according to the case where the earthquake damage is estimated according to the range that can be investigated in advance or when it is necessary to accurately estimate the earthquake damage. It is to provide an estimation method of earthquake damage of a reinforced concrete building that enables estimation of the earthquake.

  In order to solve the above-mentioned problem, the invention of claim 1 is a method for estimating earthquake damage of a target reinforced concrete building due to an earthquake, and assumes earthquake damage like the earthquake resistance characteristic of the target reinforced concrete building. For example, the first procedure for obtaining essential items, the processing necessary for analyzing a one-mass system, such as the tremor measurement of the target reinforced concrete building, and the use of boring data, etc. The second procedure for selectively performing the processing that is expected to improve the accuracy of the estimation and based on the processing result of the first procedure, the earthquake record by the occurrence of the earthquake, and the second procedure are obtained. Based on the processing result obtained, the processing for estimating the earthquake damage of the target reinforced concrete building using the damage evaluation matrix, and the processing result obtained by the earthquake record and the second procedure are used. A third step of performing an elasto-plastic response analysis and selectively performing a process of estimating the earthquake damage of the target reinforced concrete structure from the plasticity ratio obtained by the analysis. This is an earthquake damage estimation method.

  The invention of claim 2 is the method of estimating earthquake damage of a reinforced concrete building according to claim 1, wherein instead of the earthquake record used in the third procedure, predicted earthquake motion of an earthquake that is expected to occur in the future is used. It is characterized by that.

  According to the invention of claim 1, the earthquake damage of the target reinforced concrete building is estimated using the damage evaluation matrix in the selection in the second procedure or the third procedure, or the target reinforced concrete structure is used using the plasticity rate. Since it is possible to select whether to estimate the earthquake damage of the building, it is possible to accurately estimate the earthquake damage depending on the extent to which the pre-investigation can be performed or when it is necessary to accurately estimate the earthquake damage. Enables estimation of.

  According to the invention of claim 2, by using the predicted ground motion instead of the earthquake record, it is possible to accurately predict the damage caused by the future earthquake that is expected to occur at the present time.

It is a figure which shows the flowchart of the estimation method of the earthquake damage of the reinforced concrete building by Embodiment 1 of this invention. It is a figure which shows the flowchart of the estimation method of the earthquake damage of the reinforced concrete building by Embodiment 1 of this invention. It is a figure which shows the flowchart of the estimation method of the earthquake damage of the reinforced concrete building by Embodiment 1 of this invention. It is a figure which shows the flowchart of the estimation method of the earthquake damage of the reinforced concrete building by Embodiment 1 of this invention. It is a superposition conceptual diagram of RD method. It is a figure which shows the relationship between the estimated value of an attenuation constant, and a bandwidth rate. It is a figure which shows the skeleton curve of a history model. Shows the relationship between S wave velocity, P wave velocity, and density It is a figure which shows a damage evaluation matrix. It is a figure which shows a response | compatibility of a deformation angle, a plasticity rate, and a damage degree. It is a conceptual diagram of an empirical Green function considering the non-linearity of the ground. It is a figure which shows the flow of nonlinear characteristic identification. It is a conceptual diagram of the positional relationship and waveform synthesis of a small earthquake and a large earthquake. It is a figure which shows the mode of an observation point and a target reinforced concrete building.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
The flowchart of the estimation method of the earthquake damage of the reinforced concrete building by this embodiment is shown in FIGS. The estimation method of earthquake damage of reinforced concrete buildings shown in these flowcharts is formed by the following six methods.
a. One-mass system model of target reinforced concrete building
b. Simplified underground structure model of target reinforced concrete building site
c. Simplified underground structure model of nearby seismic stations
d. Measurement seismic intensity difference between the target reinforced concrete building site and nearby seismic stations (estimation method)
e. Seismic damage estimation of target reinforced concrete buildings immediately after the earthquake (method)
f. Seismic damage estimation of target reinforced concrete buildings against assumed earthquakes (method)

Further, the above methods a to f include detailed processing steps. Below, each step of FIGS. 1-4 is demonstrated, explaining each method in order. Note that the one-mass system model used in “a one-mass system model of the target reinforced concrete building” of the above a represents the target reinforced concrete building assuming that the weight of the target reinforced concrete building is at the center of gravity of the target reinforced concrete building. It is a technique. In addition, the _IS value used in the above-mentioned “evaluation of earthquake damage of the target reinforced concrete building immediately after the occurrence of the earthquake” e is a value representing the earthquake resistance of the target reinforced concrete building, and the greater the value, the higher the earthquake resistance. Further, the reference numerals in “()” in the flowchart represent related document numbers as described below.
a. One-mass model of target reinforced concrete building a1. Determination of target reinforced concrete buildings and collection of data

  Select the target reinforced concrete building to estimate the earthquake damage of the reinforced concrete building due to the earthquake, and collect the seismic diagnosis result of the building and the boring data of the site or vicinity of the building. In this case, select the borehole data for which the standard penetration test has been performed.

This method of “determination of target reinforced concrete building and collection of materials” corresponds to steps S1 to S3 and steps S7, S13, and S14.
a2. Microtremor measurement in target reinforced concrete buildings

  In the proposed method, the elastic period of the target reinforced concrete building and the damping constant in the period are estimated from the microtremor record obtained by the microtremor measurement, and the spectrum ratio (H / V spectrum) of horizontal and vertical motion of the ground is calculated. .

  Microtremor measurement is performed at the same time on the building rooftop (or top floor), the first floor (on the foundation) and the ground. The measurement point in the building is preferably the rigid center of the building, but it is changed as needed depending on the situation at the site. The ground measurement points are preferably separated from the building by a distance corresponding to the height of the building, but are appropriately arranged in consideration of the distance to the adjacent building and safety. The minimum necessary fine motion component is two horizontal motion components that are orthogonal to each other inside the building (the roof and the first floor), and two horizontal motion components that are orthogonal to the ground and the vertical direction. At this time, it is desirable that the direction of horizontal movement is matched with the long side direction and the short side direction of the building.

  About measurement time, 30 minutes or more are required for estimation of the attenuation constant by RD method mentioned later.

ここでＩはデータ番号、Ｎは１ブロック当たりのデータ数（１００Ｈｚサンプリングならば、Ｎ＝２０４８）である。
３）ブロックごとに地盤の微動に対する屋上（あるいは最上階）の微動のフーリエスペクトル比（伝達関数）を算出する。
４）算出された全ての伝達関数を周波数ごとに平均する（平均伝達関数）。
５）次式に示す評価関数Ｓ_１を用いて、平均伝達関数と各ブロックの伝達関数の差を算出し、この差が最も大きい伝達関数のブロックを削除する。

ここで、ｎ_１、ｎ_２は平均と各ブロックの伝達関数の差を算出する差異に対象とする下限と上限の周波数に対応するデータ番号、Ｎ^ｎは対象となるデータ数、ＴＦは各ブロックの伝達関数、ＴＦ^ａｖｇは平均伝達関数である。
６）残ったブロックの数が２０になるまで、４）、５）の操作を繰り返し、残った２０ブロックの平均を対象鉄筋コンクリート造建物の伝達関数とする。
７）求められた伝達関数のピークから対象鉄筋コンクリート造建物の固有周波数（固有周期）を読み取る。 Steps S4, S8 to S10, and step S15 correspond to the technique of “fine movement measurement in the target reinforced concrete building”.
a3. Estimating the natural period of a building from the measured fine movement record 1) The measured fine movement record is set to a recording length of one block of 20.48 seconds, and is shifted by 10.24 seconds to a plurality of blocks (174 for 30 minutes measurement). Divided into blocks).
2) The Fourier spectrum of the horizontal motion of each divided block is calculated. At this time, a COS-type taper TP (I) expressed by the following equation is applied to each block. Appropriate smoothing is also performed.

Here, I is a data number and N is the number of data per block (N = 2048 for 100 Hz sampling).
3) The Fourier spectrum ratio (transfer function) of the fine movement of the roof (or the top floor) to the fine movement of the ground is calculated for each block.
4) Average all the calculated transfer functions for each frequency (average transfer function).
5) The difference between the average transfer function and the transfer function of each block is calculated using the evaluation function S ₁ shown in the following equation, and the block of the transfer function having the largest difference is deleted.

Here, n ₁ and n ₂ are data numbers corresponding to lower and upper frequency frequencies targeted for the difference for calculating the difference between the average and the transfer function of each block, N ⁿ is the number of target data, and TF is each block. The transfer function TF ^avg is an average transfer function.
6) The operations of 4) and 5) are repeated until the number of remaining blocks reaches 20, and the average of the remaining 20 blocks is taken as the transfer function of the target reinforced concrete building.
7) Read the natural frequency (natural period) of the target reinforced concrete building from the peak of the calculated transfer function.

Steps S11 and S12 correspond to the method of “estimating the natural period of the building based on the measured fine movement recording”.
a4. Estimating building damping constants from measured microtremor records.

  The method for estimating the attenuation constant (RD method) is as follows.

そこで、Δｆ／ｆ_０と推定される減衰定数ｈ^＊の関係を図６のようにモデル化する。この仮定したモデルにおけるΔｆ／ｆ_０とｈ^＊の関係は次式のようになる。

The RD method is a method in which a random response waveform is divided into many small samples having a length T and these are simply overlapped. At this time, the initial value of each small sample is divided so as to be the maximum value of the random response waveform. By superimposing many small samples, random components are averaged and disappear, and only free vibration waveform components remain. FIG. 5 illustrates this concept. Each peak amplitude is measured with respect to the obtained free vibration waveform, a logarithmic attenuation rate is obtained by a least square method, and an attenuation constant is calculated. The damping constant estimated from the RD method depends on the analysis conditions such as the characteristics of the band-pass filter used when extracting the narrow-band wave of the natural frequency component of the system and the overlay method. Here, the RD method in which repeated calculation by Kobayashi (2008) is introduced is used. According to Kobayashi (2008), there is the following relationship between the damping constant h of the system and the optimum bandwidth Δf _a / f _{0 of the} RD method (value obtained by dividing the bandwidth of the bandpass filter by the natural frequency of the system). .

Therefore, the relationship between Δf / f ₀ and the estimated attenuation constant h ^* is modeled as shown in FIG. The relationship between Δf / f ₀ and h ^* in this assumed model is as follows.

となる。あるΔｆ／ｆ_０を初期パラメータとして、ＲＤ法を用いｈ^＊の値が求まると、両者の関係と数５式を用いて、論理的に系の減衰定数ｈ_ｔを推定する事ができる。この論理値ｈ_ｔから数３式より最適なΔｆ_ａ／ｆ_０を再度設定し、繰り返しＲＤ法を行うことで減衰定数を精度よく推定できる。繰り返し計算を用いたＲＤ法の解析手順を以下に示す。
１）初期パラメータとしてΔｆ／ｆ_０＝０．０５、０．５の２点設定し、ＲＤ法を用いｈ^＊を推定する。
２）推定された２点のｈ^＊とΔｆ／ｆ_０の関係から、数５式を用い系の減衰定数の仮定値ｈ_ｔを算出する。
３）ｈ_ｔから数３式を用い最適な解析パラメータであるΔｆ／ｆ_０を求め、Δｆ／ｆ_０＝Δｆ_ａ／ｆ_０と設定し、再度ＲＤ法を用い提案法の推定値ｈ^＊を求める。
４）ｈ^＊≒ｈ_ｔなら提案法による最終的な減衰定数をｈ^＊として終了。ｈ^＊がｈ_ｔから離れていれば手順２）へ。 From Equation 3, Equation 4 is

It becomes. Certain Delta] f / f ₀ as initial parameters, the value of h ^* is determined using the RD method, a relationship between the two and equation (5), can be estimated attenuation constant h _t logically system. The optimum Δf _a / f ₀ is set again from this logical value _ht from the equation (3), and the attenuation constant can be accurately estimated by repeatedly performing the RD method. The analysis procedure of the RD method using iterative calculation is shown below.
1) Two points of Δf / f ₀ = 0.05 and 0.5 are set as initial parameters, and h ^* is estimated using the RD method.
2) from the relationship between the estimated two points h ^* and Δf / f _0, and calculates the assumed value h _t of the attenuation constant of the system using equation (5).
3) Find Δf / f ₀ which is the optimal analysis parameter using Equation 3 from h _t , set Δf / f ₀ = Δf _a / f _0, and use the RD method again to estimate the estimated value h ^* of the proposed method. Ask.
4) If h ^* ≈h _{t, the} final damping constant according to the proposed method is set as h ^{* and the process} is completed. h ^* is to step 2) If away from _{h t.}

Step S5 corresponds to the technique of “estimation of the building attenuation constant based on the measured microtremor record”.
a5. One-mass model of the target reinforced concrete building

In this study, the target reinforced concrete building is modeled as a one-mass system, following Sakai et al. (2002). The restoring force model is Takeda model (Takeda et al., 1970), the elastic period of the model is the natural period estimated by microtremor measurement, the unloading stiffness reduction index is 0.5, and the damping is instantaneous stiffness type. The value obtained from the microtremor measurement is given as a damping constant for the elastic period. The shear force at the time of cracking was 0.3 times the yield shear force, the equivalent stiffness at yield was 0.25 times that of the initial synthesis, and the stiffness after yielding was 0.01 times that of the initial synthesis (FIG. 7). Base shear coefficient was the _C T · _{S D} of the secondary diagnosis in reference to the Kambara Hasegawa (2002).

ここでＩはデータ番号、Ｎは１ブロック当たりのデータ数（１００Ｈｚサンプリングならば、Ｎ＝２０４８）である。
３）ブロックごとに以下の式にしたがって、Ｈ／Ｖスペクトルを算出する。

ここで、ＨＶはＨ／Ｖスペクトル、Ｆ_Ｈ１、Ｆ_Ｈ２はそれぞれ水平動のフーリエスペクトル、Ｆ_ＵＤは上下動のフーリエスペクトルを表す。
４）算出された全てのＨ／Ｖスペクトルを周波数ごとに平均する（平均Ｈ／Ｖスペクトル）。
５）次式に示す評価関数Ｓ_２を用いて、平均Ｈ／Ｖスペクトルと各ブロックのＨ／Ｖスペクトルの差を算出し、この差が最も大きいＨ／Ｖスペクトルのブロックを削除する。

ここで、ｎ_１、ｎ_２は平均と各ブロックの伝達関数の差を算出する際に対象とする下限と上限の周波数に対応するデータ番号、Ｎ^ｎは対象となるデータ数、ＨＶは各ブロックのＨ／Ｖスペクトル、ＨＶ^ａｖｅは平均Ｈ／Ｖスペクトルである。
６）残ったブロックの数が２０になるまで４）、５）の操作を繰り返し、残った２０ブロックの平均を対象鉄筋コンクリート造建物敷地の観測Ｈ／Ｖスペクトルとする。 Step S6 corresponds to the technique of “one mass point system model of the target reinforced concrete building”.
b. Simplified underground structure model of target reinforced concrete building site b1. Observation H / V spectrum of the target reinforced concrete building site 1) The tremor record measured on the ground is set to 20.48 seconds for one block, and multiple flocks (if 30 minutes measurement) are shifted by 10.24 seconds. 174 blocks).
2) Calculate the Fourier spectrum of two horizontal movement components and one vertical movement component of each divided block. At this time, the COS type data TP (I) shown in the following equation is multiplied for each block. Appropriate smoothing is also performed.

Here, I is a data number and N is the number of data per block (N = 2048 for 100 Hz sampling).
3) Calculate the H / V spectrum according to the following formula for each block.

Here, HV represents an H / V spectrum, F _H1 and F _H2 represent horizontal motion Fourier spectra, and F _UD represents a vertical motion Fourier spectrum, respectively.
4) All the calculated H / V spectra are averaged for each frequency (average H / V spectrum).
5) by using the evaluation function S ₂ shown in the following equation to calculate the difference between the H / V spectra of the average H / V spectrum and each block, to remove this difference is greatest H / V spectra of the block.

Here, n ₁ and n ₂ are data numbers corresponding to lower and upper frequency frequencies to be used when calculating the difference between the average and the transfer function of each block, N ⁿ is the number of target data, and HV is each block. H / V spectrum and HV ^ave are average H / V spectra.
6) Repeat steps 4) and 5) until the number of remaining blocks reaches 20, and set the average of the remaining 20 blocks as the observed H / V spectrum of the target reinforced concrete building site.

Step S16 corresponds to the method of “observation H / V spectrum of target reinforced concrete building site”.
b2. Creating a simplified model of the underground structure of the target reinforced concrete building site

  When creating a simplified model of underground structure, it is desirable to collect boring data as close as possible to the target reinforced concrete building. At this time, the standard penetration test result needs to be described in the boring data.

  The underground structure simplified model is an underground structure model satisfying those of the observed H / V spectrum whose peak period, trough, and period of the theoretical H / V spectrum are determined by b1 (observed H / V spectrum of the target reinforced concrete building site). A method of estimation (inverse analysis) by trial and error is used. In the research from 2005 to 2007 and in this research, we have considered expressing the underground structure in two layers, the surface layer and the basement, but here the measured ground / engineering surface with high reproducibility of the measured H / V spectrum A three-layer structure of the base and base is adopted. However, when the peak of the observed H / V spectrum is 3 or less in any period, a two-layer structure with no surface layer is formed. There are four physical property values set for each layer: layer thickness, S-wave velocity, P-wave velocity, and density. The P-wave velocity and density are determined by Ludwig et al. Estimate from S wave velocity according to (1970). FIG. 8 shows Ludwig et al. (1970) shows the relationship between S wave velocity, P wave velocity, and density. The surface layer thickness is the thickness of the layer whose N value in the boring data is less than 50, and the S wave velocity is estimated by inverse analysis with an initial value of about 100 to 300 m / sec depending on the N value. The S-wave velocity of the engineering base is about 400 to 500 m / sec, and the layer thickness is estimated by inverse analysis. The S wave velocity of the base is fixed at 1200 m / sec, and the layer thickness is semi-infinite. If there is no borehole data, borehole data at a nearby seismic observation point described later is used instead. Alternatively, a simple model of underground structure at nearby seismic stations is used as an initial value for inverse analysis. In the inverse analysis, the S-wave velocity is mainly searched for the surface layer, and the layer thickness is searched for the engineering basis. However, if the observed H / V spectrum peak or trough period cannot be satisfied, the surface layer thickness or engineering We will also search for target-based S-wave velocities. For calculation of the theoretical H / V spectrum, the program Tremor Data View recorded on the CD attached to the former name Fujiwara (2008) can be used, and is available from the National Institute of Disaster Science and Technology.

Step S <b> 17 corresponds to the method of “creating a simplified model of the underground structure of the target reinforced concrete building site”.
c. Simplified underground structure model of nearby seismic stations c1. Selection of nearby seismic stations

Candidates for seismic observation points in the vicinity of the target reinforced concrete building are K-NET, KiK-net, and prefectural seismic intensity meter installation points where tremor measurement has already been performed. Considering the number of seismic records that have already been observed and the quickness of seismic wave records, K-NET or KiK-net can be used as the nearby seismic stations that serve as reference points for estimating seismic intensity at the target reinforced concrete building site. The observation point is appropriate. These records are on the strong motion observation network website of the National Institute of Disaster Science and Technology:
http: // www. kyoshin. bosai. go. jp / kyoshin /
Is available from

Steps S21 and S22 correspond to the method of “selection of nearby seismic observation points”.
c2. Observation H / V spectrum at nearby seismic stations

  Microtremor measurements at K-NET, KiK-net, and prefectural seismometers in the Chugoku region have been carried out through research up to FY2007. In addition, an observed H / V spectrum of fine movement calculated from the record has already been calculated. The calculation method is the same as b1 (observed H / V spectrum of the target reinforced concrete building site).

Steps S29 to S31 correspond to the method of “observation H / V spectrum of nearby earthquake observation point”.
c3. Creating a simple model of underground structure at nearby seismic stations

  The method for creating the simplified model of the underground structure at the nearby seismic observation point is the same as b2 (creating the simplified model of the underground structure of the target reinforced concrete building site). However, when the selected nearby seismic stations are K-NET and KiK-net stations, the borehole data and PS logging results are published at K-NET stations, and PS logging results are published at KiK-net stations. Yes. Therefore, the initial value is set based on the information and the inverse analysis is performed.

Steps S32 to S34 correspond to the method of “creating a simplified model of the underground structure of the nearby seismic observation point”.
d. Difference in measured seismic intensity between the target reinforced concrete building site and nearby seismic stations d1. Calculation of measured seismic intensity at nearby seismic stations

  The measured seismic intensity is calculated according to the method of calculating the measured seismic intensity determined by the Japan Meteorological Agency (Japan Meteorological Agency 1996).

Steps S27 and S64 correspond to this “calculation of measured seismic intensity at nearby seismic observation points”.
d2. Calculation of basement ground motion at nearby seismic stations

Ground motion at the base of nearby seismic stations based on the one-dimensional overlapping reflection theory using the simplified underground structure model created in c3 (creating a subsurface structure simplified model of nearby seismic stations) from the ground motion observed on the ground surface (engineering) Input earthquake ground motion). At this time, the Q values of the S wave and the P wave of each layer are assumed to be Q _S = 10 and Q _P = 20, respectively.

Steps S23 and S66 correspond to this “calculation of base earthquake motion at nearby seismic observation points”.
d3. Calculation of ground motion of the target reinforced concrete building site

  If the nearby seismic observation point is close to the target reinforced concrete building site, the basement ground motion calculated in d2 (calculation of the basement ground motion at the nearby seismic observation point) may be used as the basement ground motion of the target reinforced concrete building site. . However, if the distance between these two points is far and the distance from the epicenter of the target earthquake is significantly different, Morikawa et al. (2010) in d5 (calculation of the measured seismic intensity of the target reinforced concrete building site) described later. Make corrections.

Steps S24 and S67 correspond to this “calculation of base earthquake motion of the target reinforced concrete building site”.
d4. Calculation of surface ground motion of target reinforced concrete building site

Based on the ground motion of the target reinforced concrete building site obtained in d3 (Calculation of base ground motion of the target reinforced concrete building site) Use to calculate the ground motion on the ground surface of the target reinforced concrete building site based on the one-dimensional double reflection theory. At this time, the Q values of the S wave and the P wave of each layer are assumed to be Q _S = 10 and Q _P = 20, respectively.

Steps S25 and S68 correspond to this “calculation of surface earthquake motion of the target reinforced concrete building site”.
d5. Calculation of measured seismic intensity of the target reinforced concrete building site

  The measured seismic intensity is calculated based on the same method (meteorological agency, 1996) as d1 (calculation of the measured seismic intensity at the nearby seismic observation point). However, if the distance between the target reinforced concrete building site and the nearby seismic observation point is 2 km or longer and the epicenter distance of the target earthquake is different, the following processing is performed.

ただし、ｐｒｅは計測震度の予測値、Ｍ_Ｗはモーメントマグニチュード、Ｘは断層最短距離（ｋｍ）である。各係数は、二段階回帰分析により、ａ_１＝０．６３、ｂ_１＝−０．００１８、ｃ_１＝−０．２４、ｄ_１＝０．００３０、ａ_２＝０．４８、ｂ_２＝−０．００３１、ｃ_２＝１．０８と決められている。 Morikawa et al. (2010) have proposed a distance attenuation formula for the measured seismic intensity, and two regression models are set with the epicenter depth of 30 km as the boundary.

However, pre is a predicted value of the measured seismic intensity, _{M W} is moment magnitude, X is fault distance (miles). Each coefficient is calculated by two-step regression analysis, a ₁ = 0.63, b ₁ = −0.0018, c ₁ = −0.24, d ₁ = 0.0030, a ₂ = 0.48, b ₂ = _-0.0031, it is determined and c 2 = 1.08.

Here, it is assumed that the relative difference of the seismic intensity measured at the base of the reference point and the target point is equal to the relative difference of the predicted value by the distance attenuation formula at each point. Therefore, the measured seismic intensity I _new of the target point corrected for the difference between the two epicenter distances is the measured seismic intensity I _old before correction, the predicted value pre _r of the measured seismic intensity of the reference point by the distance attenuation formula, and the measured seismic intensity of the target point. using the predicted values pre _o, it is expressed by the following equation.

Steps S26 and S69 correspond to this “calculation of the measured seismic intensity of the target reinforced concrete building site”.
d6.2 Estimation of seismic intensity difference between two points

  The calculations shown in this chapter are performed for all seismic records observed at nearby seismic stations. As a result of calculation, records whose measured seismic intensity is negative at any point are excluded because the amplitude of such records is very small and the accuracy is low. For the remaining records, calculate the difference in measured seismic intensity between the target reinforced concrete building site and nearby seismic stations. These measured seismic intensity differences are averaged, and this average value is taken as the difference in measured seismic intensity between the target reinforced concrete building site and nearby seismic stations.

Step S28 corresponds to the method of “estimating the measured seismic intensity difference between two points”.
e. Damage estimation of the target reinforced concrete building immediately after the earthquake e1. Estimation of measured seismic intensity at the target reinforced concrete building site

  There are two methods for estimating the measured seismic intensity at the target reinforced concrete building site. The first is to calculate the measured seismic intensity from the seismic records observed at the nearby seismic stations, and then to measure the target reinforced concrete building site and nearby seismic stations determined by d6 (estimating the measured seismic intensity difference between the two points). This is a method of adding the seismic intensity difference. Second, from the records obtained at the nearby seismic stations, follow the procedure from d2 (Calculation of base ground motion at nearby seismic stations) to d5 (Calculate measured seismic intensity at the target reinforced concrete building site). This is a method for estimating the measured seismic intensity. The latter must be used when estimating earthquake damage of reinforced concrete buildings by one-mass point elasto-plastic response analysis described later.

Steps S61, S62, and S65 correspond to this “estimation of measured seismic intensity at the target reinforced concrete building site”.
e2. Estimating earthquake damage of reinforced concrete buildings using damage assessment matrix of Okubo et al. (2003)

Okubo et al. (2003), replacing the maximum speed of the ground motion is an explanatory variable Fragility curve Lin et al. (2000) to measure seismic intensity, proposes I _S value and the seismic intensity by damage assessment matrix as shown in FIG. 9 The earthquake damage of the target reinforced concrete building is estimated according to this matrix. I _S values used in this case, a1 by the minimum I _S values of various fields in the secondary diagnosis result of seismic diagnosis collected in (subject reinforced concrete buildings determination and collection of documents).

Steps S70 and S71 correspond to the method of “estimation of earthquake damage of a reinforced concrete building by the damage evaluation matrix of Okubo et al. (2003)”.
e3.1 Estimation of seismic damage of reinforced concrete buildings by mass-based elasto-plastic response analysis

  Using the seismic motion at the target reinforced concrete building site obtained in e1 (estimating the measured seismic intensity at the target reinforced concrete building site) as an input, the bullet of the one mass system model created at a5 (one mass point model of the target reinforced concrete building) Perform plastic response analysis. The numerical integration at this time is based on the linear acceleration method. As a result, the earthquake damage of the target reinforced concrete building is estimated from the obtained plasticity ratio based on the relationship of FIG.

Steps S71, S73, and S74 correspond to the technique of “estimation of earthquake damage of reinforced concrete buildings by one-mass point elasto-plastic response analysis”.
f. Estimation of seismic damage of target reinforced concrete buildings against assumed earthquakes

  e Targets for earthquakes that are expected to occur in the future by using predicted earthquake motions of earthquakes that are expected to occur in the future instead of the observed earthquake motions in (Estimation of earthquake damage of target reinforced concrete buildings immediately after the earthquake occurs) It is possible to predict earthquake damage of reinforced concrete buildings. Here, a method of predicting seismic motion that is expected to occur in the future by using an empirical Green's function method (Hartzell, 1978; Irikura, 1983, etc.) that takes into account the nonlinearity of the ground is adopted.

The analysis procedure of the empirical Green's function method considering the nonlinearity of the ground is shown below. A conceptual diagram is shown in FIG.
1) An engineering base wave is estimated from observation records of small and medium earthquakes on the ground surface using an underground structure model and one-dimensional elastic wave theory (for example, Schnabel et al., 1972).
2) Synthesize engineering fundamental wave using empirical Green's function method.
3) Estimate the ground motion from the composite wave estimated in step 2) using a nonlinear model of ground and one-dimensional equivalent linearization theory.

Step S41 corresponds to this method.
f1. Detailed model of underground structure at nearby seismic stations

  In order to evaluate the non-linear characteristics of the ground separately, a more accurate underground structure model is required. This method is described here with reference to the 2009 report.

  In this research, the underground structure model is estimated by performing a reverse analysis using the horizontal component Fourier spectrum ratio of the ground motion and the ground surface (hereinafter referred to as the earthquake H / H spectrum) as the correct value.

ここに、ＳＳ_ＮＳ、ＳＳ_ＥＷはそれぞれ地表で観測された地震動のＮＳ成分、ＥＷ成分のフーリエスペクトルであり、ＳＢ_ＮＳ、ＳＢ_ＥＷは地中で観測された地震動のＮＳ成分、ＥＷ成分のフーリエスペクトルである。なお、フーリエスペクトルの算出には観測された波形のＳ波初動を目視で読み取り、その初動から２０．４８秒間の記録を用いる。平滑化にはＰａｒｚｅｎ ｗｉｎｄｏｗを用い、バンド幅は一律０．２Ｈｚとする。本件研究では用いた記録のうち、比較的ＳＮ比が高いと考えられる５記録を選定し、平均することで、各観測点における地震Ｈ／Ｈスペクトルを算出する。 The earthquake record used when calculating the earthquake H / H spectrum is determined from the following conditions.
1. 1. Maximum ground motion acceleration of 200 gal or less Magnitude 4.0 or higher Earthquake epicenter distance within 300km Earthquake H / H spectrum is calculated from the following formula.

Here, SS _NS and SS _EW are the NS spectra and EW components of the ground motion observed on the ground surface, respectively. SB _NS and SB _EW are the NS spectra and EW components of the ground motion observed in the ground. It is. For the calculation of the Fourier spectrum, the S wave initial motion of the observed waveform is visually read, and a recording of 20.48 seconds from the initial motion is used. For smoothing, Parzen window is used, and the bandwidth is uniformly 0.2 Hz. In this study, five records that are considered to have a relatively high S / N ratio are selected and averaged, and the earthquake H / H spectrum at each observation point is calculated.

The physical properties of the underground structure model are the layer thickness H, density ρ, S wave velocity V _S , and Q value of each layer in the ground. Here, it is assumed that the Q value does not depend on the frequency. When the layer thickness is shallower than the engineering foundation, the layer thickness is divided according to the soil classification described in the boring data, and the layer thickness of 5 m or more is equally divided so that the layer thickness is 5 m or less. In the case of deeper than the engineering foundation, the layer thickness described in the boring data was used. Density is determined by Ludwig et al. From the empirical relationship according to (1970), it was given as a dependent parameter of S wave velocity. Here, the value described in the boring data is used as the S wave velocity when calculating the density.

  The S wave velocity and the Q value are estimated by inverse analysis using a genetic algorithm (hereinafter referred to as GA) (Yamanaka / Ishida, 1995). The target of inverse analysis is the earthquake H / H spectrum estimated in the previous section, and within the specified range so that this and the logical transfer function estimated based on the one-dimensional overlapping reflection theory match. Set wave speed and Q factor. The search range is set with reference to the values described in the boring data. However, when the lowest layer of the boring data is an inversion layer, the value of the previous layer is used to replace the first layer, and the search range is set. In addition, when an extreme inversion layer is observed in addition to the lowermost layer, the S wave velocity is averaged so as not to change the total transmission time, and the layer is replaced with one layer. Furthermore, when the inversion layer is artificially created as a result of the analysis, the analysis range is set so that the inversion layer does not occur, and the analysis is performed again.

ここにＮはデータ数、Ａ_ｏｂｓ（ｆ_ｋ）は地震Ｈ／Ｈスペクトル、Ａ_ｃａｌ（ｆ_ｋ）は１次元重複反射理論から算定した理論伝達関数である。 In the analysis, the number of individuals is 40, the probability of crossing is 70%, the mutation rate is 1%, the number of generations is 1000 generations, and the initial value of the random number is changed and 10 trials are performed. In this study, the solution that minimizes the error calculated from the evaluation function shown in Equation 13 is used as the solution.

Here, N is the number of data, A _obs (f _k ) is the earthquake H / H spectrum, and A _cal (f _k ) is the theoretical transfer function calculated from the one-dimensional overlapping reflection theory.

Step S48 corresponds to the method of “creating a detailed model of the underground structure of the nearby seismic observation point”.
f2. Non-linear model of ground

  Regarding the nonlinear model of the ground, it is desirable to identify the ground nonlinear model specific to the observation point based on the observation record at the point where the record is obtained on the ground surface and in the ground like the KiK-net observation point. . The method is shown below. If the ground nonlinear model cannot be identified based on the observation record, an existing ground nonlinear model (for example, Furuyamada et al., 2003) is used.

ここで、Ｇ／Ｇ_０はせん断剛性比、ｈは減衰定数、γはせん断ひずみ、ｈ_ｍｉｎは最小減衰定数であり、各層に対する未知パラメータは、規準せん断ひずみγ_ｒｅｆ、最大減衰定数ｈ_ｍａｘとなる。 Here, one-dimensional seismic response analysis DYNEQ (Yoshida / Suetomi, 1996) based on the equivalent linearization method and inverse analysis combining genetic algorithm (GA) (Yamanaka / Ishida, 1995) are used to identify nonlinear characteristics of the ground. . The flow of identification is shown in FIG. It is assumed that the spectral ratio of ground motion to ground motion observed at the observation point where strong ground records are obtained in the ground and the ground surface can be explained by one-dimensional seismic response analysis by the one-dimensional equivalent linearization method. The physical property values of each layer necessary for the seismic response analysis of the ground are the layer thickness H, density ρ, S wave velocity V _S , and nonlinear characteristics (G-γ, h-γ curve). Among these, it is assumed that the layer thickness H, the density ρ, and the initial S wave velocity V _S0 are known, and the nonlinear characteristics are given by the following equation in the Hardin-Drnevic (HD) model (Hardin et al., 1972).

Here, G / G ₀ is the shear stiffness ratio, h is the damping constant, γ is the shear strain, h _min is the minimum damping constant, and the unknown parameters for each layer are the standard shear strain γ _ref and the maximum damping constant h _max. .

ここに、Ｎはスペクトル比のデータ数、Ａ_ｏｂｓ（ｆ_ｋ）、Ａ_ｃａｌ（ｆ_ｋ）はそれぞれ周波数ｆ_ｋにおける観測および論理スペクトル比である。 Inverse analysis searches for optimal parameters that can adequately explain the spectral ratio of observed ground-to-surface ground motion, that is, identifies ground parameters that minimize the evaluation function F (misfit) of the following equation: It becomes.

Here, N is the number of spectral ratio data, and A _obs (f _k ) and A _cal (f _k ) are the observation and logical spectral ratios at the frequency f _k, respectively.

Step S49 corresponds to this “non-linear model of the ground”.
f3. Fault model of assumed earthquake

If there is an assumed earthquake fault model, it is used. If not set, the fault model is set based on the strong ground motion recipe proposed by the National Earthquake Research Committee (Earthquake Research Promotion Division).
Step S42 corresponds to this “fault model of an assumed earthquake”.
f4. Selection of small and medium earthquake records at nearby seismic stations

  It is desirable that the seismic source used as the empirical Green's function is as close as possible to the location of the assumed seismic source, the propagation path of the seismic wave can be considered the same, and the mechanism is as similar as possible.

Steps S43 and S44 correspond to the method of “selection of small and medium earthquake records at nearby earthquake observation points”.
f5. Estimation of ground motion of small and medium earthquakes at the base of nearby seismic stations

Ground motions at the base of nearby seismic stations based on the one-dimensional overlapping reflection theory using the underground structure detailed model created in f1 (creates the detailed model of the underground structure at nearby seismic stations) from the ground motion observed on the ground surface Input earthquake ground motion). At this time, the value of the ground nonlinear model obtained by f2 (non-linear model of ground) at the time of minute strain is used as the Q value of the S wave and P wave of each layer. _Let Q _P = Q _S × 2.

Step S45 corresponds to the technique of “estimation of ground motion of small and medium earthquakes at the base of the nearby earthquake observation point”.
f6. Basement ground motion of hypothetical earthquakes at nearby seismic stations

  The ground motion of the assumed earthquake at the base of the nearby seismic station is synthesized by the empirical Green's function method.

  The empirical Green's function method evaluates the ground motion of a large earthquake by considering the observation records of small and medium earthquakes whose focal mechanisms and fracture propagation paths are the same as those of a large earthquake as a Green function and overlaying them in accordance with the fault rupture process. Is the method. This method was proposed by Hartzell (1978) and was initially applied to the problem of evaluating long-period ground motion assuming uniform fault rupture. However, in the field of engineering that targets shorter-period ground motion, it has been attracting attention as a method for predicting input ground motion, and the evaluation method has been improved. Here, the evaluation formula of Miyake et al. (1999) used in this study is shown.

ここに、Ｕ（ｔ）は大地震に対する合成波形、ｕ（ｔ）は小地震に観測波形、ｎ_Ｌ、ｎ_Ｗ、ｎ_Ｄは重ね合わせ数、Ｃは応力降下量の比、＊はたたみ込み積分を意味する。Ｆ（ｔ）は大地震と小地震のすべり速度関数の違いを表現した補正関数であり、Ｔは大地震の立ち上がり時間である。Ｖ_ｓはせん断波速度、Ｖ_ｒは破壊伝播速度である。 Consider the case where the positional relationship between a small earthquake and a large earthquake is shown in FIG. At this time, the waveform synthesis evaluation formula is expressed by the following formula.

Where U (t) is the composite waveform for a large earthquake, u (t) is the observed waveform for a small earthquake, n _L , n _W , n _D are the number of overlays, C is the ratio of the stress drop, and * is the convolution Means integration. F (t) is a correction function that expresses the difference in slip velocity function between a large earthquake and a small earthquake, and T is the rise time of a large earthquake. V _s is the shear wave velocity, and _{V r} is the rupture velocity.

ここで、Ｕ_０、ｕ_０は大地震および小地震の変位振幅スペクトルの平坦レベル、Ｍ_０、ｍ_０は大地震および小地震の地震モーメントである。なお、大地震と小地震の断層パラメータ間に相似則を仮定すると重ね合わせ数は、

と表され、数２０式は、

と置換することができる。一方、大地震および小地震の加速度振幅スペクトルの平坦レベルの間には、

と表すことができる。ここで、Ａ_０、ａ_０はそれぞれ大地震および小地震の加速度振幅スペクトルの平坦レベルである。したがって、３つの重ね合わせ数を特に区別する必要がある場合を除き、数２２式および数２２式を用いて、重ね合わせ数、応力降下量を評価することも可能である。 N _L , n _W , n _D , and C, which are parameters for waveform synthesis, are derived from the displacement of the large and small earthquakes and the flat level of the acceleration amplitude spectrum.

Here, U ₀ and u ₀ are flat levels of the displacement amplitude spectrum of large earthquakes and small earthquakes, and M ₀ and m ₀ are earthquake moments of large and small earthquakes. Assuming a similarity law between the fault parameters of large and small earthquakes,

And the formula 20 is

Can be substituted. On the other hand, between the flat levels of the acceleration amplitude spectrum of large and small earthquakes,

It can be expressed as. Here, A ₀ and a ₀ are the flat levels of the acceleration amplitude spectrum of a large earthquake and a small earthquake, respectively. Therefore, the number of overlays and the amount of stress drop can be evaluated using the formula 22 and the formula 22 except when it is necessary to particularly distinguish the three overlay numbers.

Step S46 corresponds to the method of “base earthquake motion of the assumed earthquake at the nearby earthquake observation point”.
f7. Ground motion of a hypothetical earthquake at a nearby seismic station

  Based on the ground motion synthesized by f6 (base earthquake motion of the assumed earthquake at the nearby seismic station), the ground motion using the non-linear model of the ground of f2 (non-linear model of the ground) and the one-dimensional equivalent linearization theory presume. As a one-dimensional equivalent linearization theory program, SHAKE (Schnabel et al., 1972), DYNEQ (Yoshida / Suetomi, 1996) and the like can be used.

  Step S47 corresponds to the method of “the ground motion of the assumed earthquake at the nearby earthquake observation point”.

  As described above, each of the processing steps forming the six methods “a one-mass system model of the target reinforced concrete building” in a to “an earthquake damage estimation of the target reinforced concrete building with respect to the assumed earthquake” in the above f will be described in detail. did. Next, how these methods are used will be described with reference to the flowcharts of FIGS.

  Currently, each prefecture's institution publishes a seismic intensity map, which is created based on the seismic intensity scale at the reference point. However, the seismic intensity map does not display the correct seismic intensity scale of the target point if there is a difference in ground characteristics such as the surface layer ground between the reference point and the target point. Therefore, as shown in FIG. 14, in order to calculate the seismic intensity of the target reinforced concrete building from the measured seismic intensity at the observation point, the seismic intensity is calculated by measuring the ground of the target reinforced concrete building and the tremor of the target reinforced concrete building. To do. For this purpose, the method for estimating earthquake damage of reinforced concrete buildings uses a systematic preliminary survey process and a systematic estimation process. As shown in FIGS. 1 to 3, the preliminary survey process includes steps S1 to S17, steps S21 to S34, and steps S41 to 47, and the estimation process includes steps as shown in FIG. S61 to S74 are applicable.

In particular, in the preliminary survey process, the following processes are essential.
・ Determine target reinforced concrete building (step S1)
・ Results of seismic diagnosis of the target reinforced concrete building (Step S2)
・ Determine the position of fine tremor measurement for the target reinforced concrete building (Step S8)
・ Fine tremor measurement of the target reinforced concrete building (Step S9)
・ Fine record of the ground of the target reinforced concrete building site (Step S15)
-Selection of nearby observation points (step S21)
・ Seismic motion at nearby observation points (surface) (step S22)
・ Fine tremor measurement at nearby observation points (step S29)
・ Recording of ground movement at nearby observation points (Step S30)

In the pre-investigation process, the following processes can be derived from these essential processes.
・ Is (secondary diagnosis) of the target reinforced concrete building (step S7)
・ H / V spectrum of target reinforced concrete building site (step S16)
-Simplified underground structure model of the target reinforced concrete building site (Step S17)
・ Seismic ground motion at the nearby observation point (base) (step S23)
・ Earthquake motion (base) of the target reinforced concrete building site (step S24)
・ Earthquake motion (surface of the target reinforced concrete building site) (Step S25)
・ Measured seismic intensity of the target reinforced concrete building site (step S26)
・ Measured seismic intensity at nearby observation points (step S27)
-Difference in measured seismic intensity between two points (step S28)
-H / V spectrum at nearby observation points (step S31)
-Simplified underground structure model of nearby observation points (Step S32)

In the pre-investigation process, the following processes are necessary for analyzing a one-mass system. Note that a one-mass system process is not essential.
・ C _TU・_SD of the target reinforced concrete building (secondary diagnosis) (Step S3)
・ Fine tremor record on the upper floor of the target reinforced concrete building (Step S4)
-Decay constant of the target reinforced concrete building (Step S5)
・ One-mass system model of the target reinforced concrete building (Step S6)
・ Fine tremor record of the target reinforced concrete building (Step S10)
・ Transfer function of target reinforced concrete building (Step S11)
・ Natural period of target reinforced concrete building (step S12)

Furthermore, in the preliminary survey process, the following processes are expected to improve accuracy. The accuracy improvement process is not essential.
・ Boring data of the target reinforced concrete building site (Step S13)
・ N-value structure of target reinforced concrete building site (Step S14)
・ PS logging and boring data at nearby observation points (step S33)
・ N value and velocity structure of nearby observation points (step S34)

The following processes are required when estimating damage due to an assumed earthquake. In addition, the damage estimation process by an assumed earthquake is not essential. The damage estimation process due to the assumed earthquake corresponds to the part of the flowchart shown in FIG.
・ Setting of scenario of assumed earthquake (step S41)
-Fault model setting (step S42)
・ Selection of small and medium earthquakes at nearby observation points (step S43)
・ Small and medium-scale ground motion at nearby observation points (surface) (step S44)
・ Small and medium-scale ground motions at nearby observation points (base) (step S45)
・ Earthquake ground motion at nearby observation points (base) (step S46)
・ Earthquake ground motion at nearby observation points (surface) (step S47)
-Detailed model of underground structure at nearby observation points (step S48)
・ Non-linear model of the ground (Step S49)

On the other hand, in the estimation process, the following processes are essential.
-Earthquake occurrence (step S61)
-Earthquake records at nearby observation points (step S62)
・ Okubo et al. Damage assessment matrix (step S70)

In the estimation process, the following processes can be derived from these essential processes.
・ Measured seismic intensity at nearby observation points (step S64)
・ Measured seismic intensity of the target reinforced concrete building site (step S69)
・ Estimation of earthquake damage of target reinforced concrete buildings (step S71)

In the estimation process, there are the following processes required when analyzing a one-mass system.
・ Seismic motion at nearby observation points (surface) (step S65)
-Ground motion at nearby observation points (base) (step S66)
・ Earthquake motion at the target reinforced concrete building site (base) (step S67)
・ Earthquake motion on the reinforced concrete building site (surface) (step S68)
・ One mass system elasto-plastic response analysis (step S73)
・ Plastic modulus (Step S74)

  In this embodiment, a preliminary survey process for performing a preliminary survey or the like is performed. In the pre-investigation process, after step S1 (determination of target reinforced concrete building), step S2 (result of seismic diagnosis of target reinforced concrete building), step S8 (determination of measurement position of target reinforced concrete building), step S13 (target) It is divided into (boring data of a reinforced concrete building site), step S21 (selection of nearby observation points), and step S41 (setting of scenario of assumed earthquake). At this time, essential processing is performed in parallel, and processing from which a result can be derived from these essential processing is automatically performed after the essential processing. The same processing applies to the following processes.

When step S2 is performed following step S1, the process is divided depending on whether or not the one-mass point system analysis is performed. When the one-mass system is not analyzed, after step S7 (Is (secondary diagnosis) of the target reinforced concrete building), the process proceeds to the estimation process. At this time, Is of the target reinforced concrete building in step S7 is used in step S70 of the estimation process. When analyzing a one-mass system, after step S3 ( _CTU • _SD of the target reinforced concrete building (secondary diagnosis)) and step S6 (one-mass system model of the target reinforced concrete building), the process proceeds to an estimation process. At this time, in step S73 of the estimation process, the one-mass system model of the target reinforced concrete building created in step S6 is used. In step S6, step S3 and step S5 are combined into one. This is because the attenuation constant of the target reinforced concrete building in step S5 described later and the natural period of the target reinforced concrete building in step S12 described later. Is used in step S6. The same applies to the following processing.

  If step S13 is performed subsequent to step S1, after step S14 (N-value structure of the target reinforced concrete building site) and step S17 (subsurface structure simplified model of the target reinforced concrete building site), the process proceeds to an estimation process. At this time, in step S68 of the estimation process, the simplified underground structure model of the target reinforced concrete building site created in step S17 is used. In step S17, step S14 and step S16 are combined.

  If step S8 is performed subsequent to step S1, step S9 (measurement of fine movement of the target reinforced concrete building) is performed. Thereafter, the process is divided into step S4 (fine movement recording of the upper floor of the target reinforced concrete building), step S10 (1F fine movement recording of the target reinforced concrete building), and step S15 (fine movement recording of the ground of the target reinforced concrete building site). When step S4 is performed, step S5 (attenuation constant of the target reinforced concrete building) is performed. After this, step S6 and subsequent steps are performed. When step S10 is performed, step S11 (transfer function of the target reinforced concrete building) and step S12 (natural period of the target reinforced concrete building) are performed. In step S11, step S4, step S10, and step S15 are combined. After this, step S6 and subsequent steps are performed. When step S15 is performed, step S16 (H / V spectrum of the target reinforced concrete building site) is performed, and thereafter, the processing after step S17 is performed.

  When step S21 (selection of nearby observation points) is performed subsequent to step S1, step S22 (earthquake motion of nearby observation points (surface)), step S29 (measurement of fine movements of nearby observation points), step S33 (PS of nearby observation points) (Logging / boring data), which is divided into step S43, which will be described later.

  If step S22 is performed following step S21, it will be divided into step S23 (earthquake motion at the nearby observation point (base)) and step S27 (measured seismic intensity at the nearby observation point). When step S23 is performed, step S24 (earthquake motion of the target reinforced concrete building site (base)), step S25 (earthquake motion of the target reinforced concrete building site (ground surface)), step S26 (measured seismic intensity of the target reinforced concrete building site), step S28 (difference in measured seismic intensity between two points) is performed. In step S23, step S22 and step S32 are combined. After step S28, the process goes to estimation processing. In step S69 of the estimation process, the difference in measured seismic intensity between the two points in step S28 is used. If step S27 (measured seismic intensity at a nearby observation point) is performed after step S22, step S28 and subsequent steps are performed. In step S25, step S17 and step S24 are combined.

  When step S29 is performed subsequent to step S21, step S30 (fine movement recording of the ground at the nearby observation point), step S31 (H / V spectrum of the nearby observation point), and step S32 (the simplified underground structure model of the nearby observation point) are performed. Do. In step S32, step S31 and step S34 are combined. When the estimation process is performed after step S32, the underground structure simplified model of the nearby observation point in step S32 is used in step S66.

  If step S33 is performed subsequent to step S21, step S34 (N value / velocity structure of neighboring observation points) is performed. Thereafter, step S32 and subsequent steps are performed.

  If the estimation process is continued from step S21, the process proceeds to step S62 of this process. At this time, the earthquake record of the nearby seismic observation point selected in step S21 is used in step S62 of the estimation process.

  By the way, if step S41 is performed subsequent to step S1, it is divided into step S42 (setting of a fault model) and step S48 (detailed model of underground structure of nearby observation points). After performing step S42, step S43 (selection of small and medium earthquakes at nearby observation points), step S44 (small and medium ground motions at nearby observation points (ground surface)), step S45 (small and medium earthquake motions at the nearby observation points (base)), Step S46 (assumed ground motion at the nearby observation point (base)) and step S47 (assumed ground motion at the nearby observation point (ground surface)) are performed. In step S43, step S42 and step S21 are combined, in step S45, step S48 and step S44 are combined, and in step S47, step S46 and later-described step S49 are combined. After step S47, the process goes to estimation processing. At this time, instead of the earthquake record in step S62 of the estimation process, the assumed earthquake motion at the nearby observation point in step S47 is used in the estimation process. Further, when step S48 is performed subsequent to step S41, it is possible to select whether to perform step S49 (non-linear model of the ground) or to perform step S45 and subsequent steps. After step S49, step S47 and subsequent steps are performed. Furthermore, if step S21 is performed following step S1, step S43 and subsequent steps can be performed.

  In the method for estimating the earthquake damage of a reinforced concrete building, if an earthquake occurs or a simulation is performed, step S61 (earthquake occurrence) and step S62 (earthquake recording of nearby observation points) are performed. In step S62, step S21 and step S61 are combined. After step S62, when the time waveform is not calculated in step S63, step S64 (measured seismic intensity at the nearby observation point), step S69 (measured seismic intensity at the target reinforced concrete building site), step S70 (Okubo et al. Damage evaluation matrix) ), Step S71 (estimation of earthquake damage of the target reinforced concrete building) is performed. In step S69, step S28 and step S64 are combined, and in step S70, step S7 and step S69 are combined.

  Further, when the time waveform is calculated in step S63, a one-mass point system analysis is performed. That is, after step S63, step S65 (earthquake motion of the nearby observation point (surface)), step S66 (earthquake motion of the nearby observation point (basement)), step S67 (earthquake motion of the target reinforced concrete building site (basement)), step S68. (Seismic ground motion (surface) of the target reinforced concrete building site). In step S66, step S32 and step S65 are combined, and in step S68, step S17 and step S67 are combined. After step S68, when response analysis is not performed in step S72, steps S69 to S71 are performed. When response analysis is performed in step S72, step S73 (one mass point system elastoplastic response analysis) and step S74 (plasticity ratio) are performed, and then step S71 is performed. In step S73, step S6 and step S68 are combined.

  As described above, in the method for estimating earthquake damage of a reinforced concrete building according to this embodiment, it is necessary to analyze the essential processing, the processing that can derive the result from the essential processing, the processing that is not essential, and the analysis of one mass system. The system is divided into processes that are not required and processes that are not required, and processes that are not required and that are not required, so you can analyze one mass system at each location, or improve accuracy. Since it is possible to select whether to perform processing, etc., the procedure that enables estimation processing with the minimum essential processing, the procedure that enables high-precision estimation processing, although the number of steps increases. You can choose.

For example, the procedure for performing the estimation process with the minimum number of required steps is step S1 (determination of target reinforced concrete building), step S2 (result of seismic diagnosis of target reinforced concrete building), step S7 (target reinforced concrete building After 3 steps of Is (secondary diagnosis)), the process goes to step S70 (damage evaluation matrix) of the estimation process. At this time, step S1 and step S2 are essential in the preliminary survey process, and step S61, step S62, and step S70 are essential in the estimation process, which is a total of five steps. Also, for example, after step S2 (result of seismic diagnosis of the target reinforced concrete building), go to step S3 ( _CTU • _SD (secondary diagnosis) of the target reinforced concrete building) to analyze the single mass system. Is possible.

  In addition, according to this embodiment, by performing steps S41 to S49, predicted earthquake motion is used instead of earthquake records in the estimation process, so that damage due to future earthquakes that are expected to occur is accurately predicted at the present time. Make it possible to do.

  That is, according to this embodiment, it is possible to systematize a method for estimating earthquake damage of a reinforced concrete building, and to make damage assumption by routine work. As a result, according to this embodiment, the earthquake damage of the target reinforced concrete building is estimated using the damage evaluation matrix based on the measured seismic intensity of the target reinforced concrete building and the earthquake resistance of the target reinforced concrete building. From the plasticity ratio obtained by elasto-plastic response analysis based on the mass system, the selection of whether to estimate the earthquake damage of the target reinforced concrete building, and further the processing when performing damage assumption due to the assumed earthquake, that is, steps S41 to S49 Since it is possible to select whether to use it, it is possible to accurately estimate earthquake damage as needed.

  The seismic intensity map did not display the correct seismic intensity scale of the target point if there was a difference in the ground characteristics such as the surface ground at the reference point and the target point. However, according to this embodiment, in the above-mentioned a2 “Measurement of tremor in the target reinforced concrete building”, that is, in steps S4, S8 to S10, S15, the ground of the target reinforced concrete building, the target reinforced concrete building By measuring microtremors, the seismic intensity of the target reinforced concrete building can be calculated from the measured seismic intensity at the observation point, and the earthquake damage of the target reinforced concrete building can be estimated based on the calculation result.

(Embodiment 2)
In this embodiment, in order to use the method for estimating earthquake damage of a reinforced concrete building according to Embodiment 1 with a computer, this method is softwareized. For this reason, for example, when an instruction not to analyze the one-mass system is input from the input device, the process proceeds without performing steps S3 to S6, steps S10 to S12, steps S65 to S68, and steps S73 and S74. If an instruction not to assume damage assumption due to the earthquake is input from the input device, the process proceeds without performing steps S41 to S49. At such a branch point, if a modification such as selecting a process by an instruction from a computer input device is performed, the method of estimating the earthquake damage of a reinforced concrete building can be easily softwareized.

Steps S1 to S17, Steps S21 to S34, Steps S41 to S47 Steps S61 to S74 of the preliminary survey process Steps of the estimation process

Claims (2)

A method for estimating the earthquake damage of a reinforced concrete building that estimates the earthquake damage of a target reinforced concrete building caused by an earthquake,
A first procedure for obtaining essential items for assuming earthquake damage, such as the seismic properties of the target reinforced concrete building;
As in the case of microtremor measurement of the target reinforced concrete building, a process that is required when analyzing a one-mass system and a process that is expected to improve estimation accuracy by using boring data, And the 2nd procedure performed beforehand based on the processing result by the 1st procedure,
A process of estimating earthquake damage of the target reinforced concrete building using a damage evaluation matrix based on the earthquake record due to the occurrence of the earthquake and the processing result obtained in the second procedure, the earthquake record and the second procedure A third procedure for selectively performing an elasto-plastic response analysis based on the processing result obtained in step (a), and estimating the earthquake damage of the target reinforced concrete building from the plasticity ratio obtained by the analysis;
A method for estimating seismic damage of reinforced concrete buildings characterized by including Instead of the earthquake record used in the third procedure, a predicted earthquake motion of an earthquake that is expected to occur in the future is used.
The method for estimating earthquake damage of a reinforced concrete building according to claim 1.

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