Pub Date : 2024-07-30DOI: 10.1177/87552930241262044
Chenhao Wu, Henry V Burton
The number of ground motions used in nonlinear response history analysis (NRHA) determines the precision of the parameter estimates obtained in seismic performance assessments. While this issue has been extensively studied in the earthquake engineering literature, the relationship of probability model misspecification to parameter estimation uncertainty, and the implication to the required number of ground motions needed for NRHA, has not been examined. Probability model misspecification has the potential to increase estimation uncertainty and hence requires a greater number of ground motions to achieve the same precision compared to when misspecification is disregarded. This study develops a procedure to determine the required number of ground motions in seismic code-prescriptive and risk-based assessments with possible probability model misspecification. Specifically, we employ the quasi-maximum likelihood estimation (QMLE), which is robust to probability model misspecification, to evaluate estimation uncertainty. The QMLE approach is applied to an archetype California bridge under the two seismic assessment scenarios. In the code-prescriptive assessment, misspecification errors are identified for dispersion estimates of the bridge column ductility demand. In the most extreme case of the risk-based evaluation, misspecification increases the estimation uncertainty of the mean annual frequency of exceeding a limit state by as much as three times, which substantially increases the required number of ground motions. Based on the findings from this study, we advocate for the use of QMLE to detect and rectify the implications of model misspecification to estimation uncertainty and the number of ground motions used in probabilistic seismic performance assessments.
{"title":"Effects of probability model misspecification on the number of ground motions required for seismic performance assessment","authors":"Chenhao Wu, Henry V Burton","doi":"10.1177/87552930241262044","DOIUrl":"https://doi.org/10.1177/87552930241262044","url":null,"abstract":"The number of ground motions used in nonlinear response history analysis (NRHA) determines the precision of the parameter estimates obtained in seismic performance assessments. While this issue has been extensively studied in the earthquake engineering literature, the relationship of probability model misspecification to parameter estimation uncertainty, and the implication to the required number of ground motions needed for NRHA, has not been examined. Probability model misspecification has the potential to increase estimation uncertainty and hence requires a greater number of ground motions to achieve the same precision compared to when misspecification is disregarded. This study develops a procedure to determine the required number of ground motions in seismic code-prescriptive and risk-based assessments with possible probability model misspecification. Specifically, we employ the quasi-maximum likelihood estimation (QMLE), which is robust to probability model misspecification, to evaluate estimation uncertainty. The QMLE approach is applied to an archetype California bridge under the two seismic assessment scenarios. In the code-prescriptive assessment, misspecification errors are identified for dispersion estimates of the bridge column ductility demand. In the most extreme case of the risk-based evaluation, misspecification increases the estimation uncertainty of the mean annual frequency of exceeding a limit state by as much as three times, which substantially increases the required number of ground motions. Based on the findings from this study, we advocate for the use of QMLE to detect and rectify the implications of model misspecification to estimation uncertainty and the number of ground motions used in probabilistic seismic performance assessments.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.1177/87552930241262766
Alexandra Sarmiento, Danielle Madugo, Andi Shen, Timothy Dawson, Chris Madugo, Stephen Thompson, Yousef Bozorgnia, Stéphane Baize, Paolo Boncio, Albert Kottke, Grigorios Lavrentiadis, Silvia Mazzoni, Christopher Milliner, Fiia Nurminen, Francesco Visini
New predictive models for fault displacement and surface rupture hazard analysis developed through the Fault Displacement Hazard Initiative (FDHI) research program require a high-quality empirical database to apply advanced statistical methods and improve hazard estimates. This article discusses the development and contents of the FDHI Project database. We systematically collected, reviewed, and organized fault displacement measurements, surface rupture maps, and supporting information from the scientific literature. A framework was developed and implemented to classify principal and distributed faulting. Best-estimate net displacement amplitudes were calculated from slip component measurements and quality codes were assigned to all net displacement values. The database contains 75 historical, surface-rupturing crustal earthquakes ranging from M 4.9 to 8.0. Thirty-five earthquakes have a strike-slip faulting mechanism, while 25 and 15 events are reverse/reverse-oblique and normal/normal-oblique, respectively. Although most of the earthquakes are from Western North America, Japan, and other active tectonic regions, there are nine reverse faulting events from the stable continental region of Australia. The database contains over 40,000 individual fault displacement measurements for various slip components from roughly 28,000 observation sites. Geographic coordinates are included for all data, and event-specific coordinate systems are provided for each earthquake that transform data into an along-strike dimension. Our new database provides a standardized collection of surface rupture and fault displacement data and metadata that is the result of a comprehensive effort to create a reliable and stable product for the FDHI model development teams and the geoscience community.
{"title":"Database for the Fault Displacement Hazard Initiative Project","authors":"Alexandra Sarmiento, Danielle Madugo, Andi Shen, Timothy Dawson, Chris Madugo, Stephen Thompson, Yousef Bozorgnia, Stéphane Baize, Paolo Boncio, Albert Kottke, Grigorios Lavrentiadis, Silvia Mazzoni, Christopher Milliner, Fiia Nurminen, Francesco Visini","doi":"10.1177/87552930241262766","DOIUrl":"https://doi.org/10.1177/87552930241262766","url":null,"abstract":"New predictive models for fault displacement and surface rupture hazard analysis developed through the Fault Displacement Hazard Initiative (FDHI) research program require a high-quality empirical database to apply advanced statistical methods and improve hazard estimates. This article discusses the development and contents of the FDHI Project database. We systematically collected, reviewed, and organized fault displacement measurements, surface rupture maps, and supporting information from the scientific literature. A framework was developed and implemented to classify principal and distributed faulting. Best-estimate net displacement amplitudes were calculated from slip component measurements and quality codes were assigned to all net displacement values. The database contains 75 historical, surface-rupturing crustal earthquakes ranging from M 4.9 to 8.0. Thirty-five earthquakes have a strike-slip faulting mechanism, while 25 and 15 events are reverse/reverse-oblique and normal/normal-oblique, respectively. Although most of the earthquakes are from Western North America, Japan, and other active tectonic regions, there are nine reverse faulting events from the stable continental region of Australia. The database contains over 40,000 individual fault displacement measurements for various slip components from roughly 28,000 observation sites. Geographic coordinates are included for all data, and event-specific coordinate systems are provided for each earthquake that transform data into an along-strike dimension. Our new database provides a standardized collection of surface rupture and fault displacement data and metadata that is the result of a comprehensive effort to create a reliable and stable product for the FDHI model development teams and the geoscience community.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"68 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Turkey–Syria earthquakes that occurred on February 6, 2023, have caused significant human casualties and economic damage. Emergency services require quick and accurate assessments of widespread building damage in affected areas. This can be facilitated by using remote sensing methods, specifically all-day and all-weather Synthetic Aperture Radar (SAR). In this study, we aimed to improve the detection of building anomalies in earthquake-affected areas using SAR images. To achieve this, we employed Recurrent Neural Network (RNN) to train coherence time series and predict co-seismic coherence. This approach allowed us to generate a Damage Proxy Map (DPM) for building damage assessment. The results of our study indicated that the estimated proportion of building damage in Kahramanmaras was approximately 24.08%. These findings were consistent with the actual damage observed in the field. Moreover, when utilizing the mean and standard deviation of coherence time series, our method achieved higher accuracy (0.761) and a lower false alarm rate (0.136) compared to directly using coherence with only two views of SAR data. Overall, our study demonstrates that this method provides an accurate and reliable approach for post-earthquake building damage assessment.
{"title":"Large-scale building damage assessment based on recurrent neural networks using SAR coherence time series: A case study of 2023 Turkey–Syria earthquake","authors":"Yanchen Yang, Chou Xie, Bangsen Tian, Yihong Guo, Yu Zhu, Ying Yang, Haoran Fang, Shuaichen Bian, Ming Zhang","doi":"10.1177/87552930241262761","DOIUrl":"https://doi.org/10.1177/87552930241262761","url":null,"abstract":"The Turkey–Syria earthquakes that occurred on February 6, 2023, have caused significant human casualties and economic damage. Emergency services require quick and accurate assessments of widespread building damage in affected areas. This can be facilitated by using remote sensing methods, specifically all-day and all-weather Synthetic Aperture Radar (SAR). In this study, we aimed to improve the detection of building anomalies in earthquake-affected areas using SAR images. To achieve this, we employed Recurrent Neural Network (RNN) to train coherence time series and predict co-seismic coherence. This approach allowed us to generate a Damage Proxy Map (DPM) for building damage assessment. The results of our study indicated that the estimated proportion of building damage in Kahramanmaras was approximately 24.08%. These findings were consistent with the actual damage observed in the field. Moreover, when utilizing the mean and standard deviation of coherence time series, our method achieved higher accuracy (0.761) and a lower false alarm rate (0.136) compared to directly using coherence with only two views of SAR data. Overall, our study demonstrates that this method provides an accurate and reliable approach for post-earthquake building damage assessment.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"146 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141863235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/87552930241261486
Lukas Bodenmann, Jack W Baker, Božidar Stojadinović
Seismic fragility models provide a probabilistic relation between ground-motion intensity and damage, making them a crucial component of many regional risk assessments. Estimating such models from damage data gathered after past earthquakes is challenging because of uncertainty in the ground-motion intensity the structures were subjected to. Here, we develop a Bayesian estimation procedure that performs joint inference over ground-motion intensity and fragility model parameters. When applied to simulated damage data, the proposed method can recover the data-generating fragility functions, while the traditionally used method, employing fixed, best-estimate, intensity values, fails to do so. Analyses using synthetic data with known properties show that the traditional method results in flatter fragility functions that overestimate damage probabilities for low-intensity values and underestimate probabilities for large values. Similar trends are observed when comparing both methods on real damage data. The results suggest that neglecting ground-motion uncertainty manifests in apparent dispersion in the estimated fragility functions. This undesirable feature can be mitigated through the proposed Bayesian procedure.
{"title":"Accounting for ground-motion uncertainty in empirical seismic fragility modeling","authors":"Lukas Bodenmann, Jack W Baker, Božidar Stojadinović","doi":"10.1177/87552930241261486","DOIUrl":"https://doi.org/10.1177/87552930241261486","url":null,"abstract":"Seismic fragility models provide a probabilistic relation between ground-motion intensity and damage, making them a crucial component of many regional risk assessments. Estimating such models from damage data gathered after past earthquakes is challenging because of uncertainty in the ground-motion intensity the structures were subjected to. Here, we develop a Bayesian estimation procedure that performs joint inference over ground-motion intensity and fragility model parameters. When applied to simulated damage data, the proposed method can recover the data-generating fragility functions, while the traditionally used method, employing fixed, best-estimate, intensity values, fails to do so. Analyses using synthetic data with known properties show that the traditional method results in flatter fragility functions that overestimate damage probabilities for low-intensity values and underestimate probabilities for large values. Similar trends are observed when comparing both methods on real damage data. The results suggest that neglecting ground-motion uncertainty manifests in apparent dispersion in the estimated fragility functions. This undesirable feature can be mitigated through the proposed Bayesian procedure.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"46 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/87552930241260263
Elizabeth Vintzileou, Vasiliki Palieraki
Unreinforced stone masonry buildings represent a significant part of the building stock in the areas affected by the recent devastating earthquakes of 6 February 2023 in Turkey. Most of them were built before 2000, and, hence, they are not compliant with current seismic provisions. Severe damage or collapse was observed in a large number of low-rise stone masonry buildings, including many listed as monuments ones. The structural systems of masonry buildings in the historical center of two cities (namely, Gaziantep and Antakya) are presented herein, along with the typical damage observed. The causes of damage are qualitatively interpreted, wherever relevant evidence is available. To this purpose, the observed damage is compared to that occurred in other parts of the world, in structural systems similar to those of the area affected. Furthermore, the detrimental effect of inadequate pre-earthquake interventions is identified, while a critical discussion regarding frequently applied interventions, and the availability of design rules in current Codes and Guidelines, is initiated to pave the way toward efficient measures to be taken for the protection of surviving stone masonry buildings in Turkey and beyond.
{"title":"Damage to stone masonry buildings in historical centers due to the 2023 earthquake sequence in Turkey","authors":"Elizabeth Vintzileou, Vasiliki Palieraki","doi":"10.1177/87552930241260263","DOIUrl":"https://doi.org/10.1177/87552930241260263","url":null,"abstract":"Unreinforced stone masonry buildings represent a significant part of the building stock in the areas affected by the recent devastating earthquakes of 6 February 2023 in Turkey. Most of them were built before 2000, and, hence, they are not compliant with current seismic provisions. Severe damage or collapse was observed in a large number of low-rise stone masonry buildings, including many listed as monuments ones. The structural systems of masonry buildings in the historical center of two cities (namely, Gaziantep and Antakya) are presented herein, along with the typical damage observed. The causes of damage are qualitatively interpreted, wherever relevant evidence is available. To this purpose, the observed damage is compared to that occurred in other parts of the world, in structural systems similar to those of the area affected. Furthermore, the detrimental effect of inadequate pre-earthquake interventions is identified, while a critical discussion regarding frequently applied interventions, and the availability of design rules in current Codes and Guidelines, is initiated to pave the way toward efficient measures to be taken for the protection of surviving stone masonry buildings in Turkey and beyond.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"129 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/87552930241255091
Bo Xu, Xiaowei Wang, Chuang-Sheng Walter Yang, Yue Li
Reinforcement corrosion has been recognized as an influential factor in the seismic fragility, both demand and capacity models, of aging reinforced concrete (RC) bridges. For capacity models, accurate and applied prediction tools accounting for aging effects are yet to be well established. Current practices usually perform numerical analyses to obtain time-variant capacity models, which are time-consuming particularly when multi-source structural and environmental uncertainties are considered and sometimes even suffer computational non-convergence. To address these issues, this study leverages a rigorously optimized artificial neural network architecture to develop data-driven models for rapid estimates of probabilistic curvature capacity of corroded circular RC bridge columns with flexural failure modes. An extensive database of multi-level curvature limit states (i.e. slight, moderate, severe, and complete) is created through experimentally validated moment–curvature analyses. A new threshold for the moderate limit state is defined based on the strain of core concrete, rather than cover concrete, to account for the potential full erosion of the cover with drastic corrosion. The data-driven probabilistic capacity models are applied to aid the lifetime seismic fragility assessment of a typical highway bridge, where the spectral acceleration at 1.0 s (Sa-10), peak ground velocity (PGV), and Housner intensity (HI) are found consistently, for the first time, as optimal intensity measures for probabilistic demand modeling of RC columns with different extents of aging effects. For the ease of application, the database and code for the data-driven probabilistic capacity models are accessible at https://bit.ly/3uAa8EY .
{"title":"Probabilistic curvature limit states of corroded circular RC bridge columns: Data-driven models and application to lifetime seismic fragility analyses","authors":"Bo Xu, Xiaowei Wang, Chuang-Sheng Walter Yang, Yue Li","doi":"10.1177/87552930241255091","DOIUrl":"https://doi.org/10.1177/87552930241255091","url":null,"abstract":"Reinforcement corrosion has been recognized as an influential factor in the seismic fragility, both demand and capacity models, of aging reinforced concrete (RC) bridges. For capacity models, accurate and applied prediction tools accounting for aging effects are yet to be well established. Current practices usually perform numerical analyses to obtain time-variant capacity models, which are time-consuming particularly when multi-source structural and environmental uncertainties are considered and sometimes even suffer computational non-convergence. To address these issues, this study leverages a rigorously optimized artificial neural network architecture to develop data-driven models for rapid estimates of probabilistic curvature capacity of corroded circular RC bridge columns with flexural failure modes. An extensive database of multi-level curvature limit states (i.e. slight, moderate, severe, and complete) is created through experimentally validated moment–curvature analyses. A new threshold for the moderate limit state is defined based on the strain of core concrete, rather than cover concrete, to account for the potential full erosion of the cover with drastic corrosion. The data-driven probabilistic capacity models are applied to aid the lifetime seismic fragility assessment of a typical highway bridge, where the spectral acceleration at 1.0 s (Sa-10), peak ground velocity (PGV), and Housner intensity (HI) are found consistently, for the first time, as optimal intensity measures for probabilistic demand modeling of RC columns with different extents of aging effects. For the ease of application, the database and code for the data-driven probabilistic capacity models are accessible at https://bit.ly/3uAa8EY .","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"64 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/87552930241256287
Vasco Bernardo, Shaghayegh Karimzadeh, Daniel Caicedo, Sayed Mohammad Sajad Hussaini, Paulo B Lourenço
Traditional unreinforced masonry structures are extremely vulnerable to seismic events, featuring large losses in many countries worldwide. This study focuses on the seismic assessment of a traditional masonry structures located in Faial Island—Azores (Portugal), which was hit by an earthquake of M w = 6.2 on 9 July 1998. A set of analyses was conducted through a probabilistic performance-based seismic approach, employing a stochastic finite-fault ground-motion simulation method to derive region-specific records and nonlinear numerical models to compute the capacity of the building. Subsequently, analytical fragility curves were derived considering different seismic scenarios. The results show a significant probability of the structural typology to reach moderate to extensive damage in the case of the specific earthquake, as observed in reality. The study holds significant importance in regions with limited recorded seismic activity, as they offer potential benefits for seismic risk management and mitigation strategies.
传统的非加固砌体结构在地震事件中极其脆弱，在世界许多国家都造成了巨大损失。本研究的重点是对位于葡萄牙法伊亚尔岛的传统砌体结构进行抗震评估，1998 年 7 月 9 日，该岛发生了 M w = 6.2 级地震。通过基于概率性能的抗震方法进行了一系列分析，采用随机有限故障地动模拟方法得出特定地区的记录，并采用非线性数值模型计算建筑物的承载能力。随后，考虑到不同的地震情况，得出了分析脆性曲线。结果表明，在特定地震情况下，结构类型极有可能达到中度至严重破坏，这与实际情况相符。这项研究对地震活动记录有限的地区具有重要意义，因为它们为地震风险管理和减灾战略提供了潜在的益处。
{"title":"Fragility-based seismic assessment of traditional masonry buildings on Azores (Portugal) using simulated ground-motion records","authors":"Vasco Bernardo, Shaghayegh Karimzadeh, Daniel Caicedo, Sayed Mohammad Sajad Hussaini, Paulo B Lourenço","doi":"10.1177/87552930241256287","DOIUrl":"https://doi.org/10.1177/87552930241256287","url":null,"abstract":"Traditional unreinforced masonry structures are extremely vulnerable to seismic events, featuring large losses in many countries worldwide. This study focuses on the seismic assessment of a traditional masonry structures located in Faial Island—Azores (Portugal), which was hit by an earthquake of M<jats:sub> w</jats:sub> = 6.2 on 9 July 1998. A set of analyses was conducted through a probabilistic performance-based seismic approach, employing a stochastic finite-fault ground-motion simulation method to derive region-specific records and nonlinear numerical models to compute the capacity of the building. Subsequently, analytical fragility curves were derived considering different seismic scenarios. The results show a significant probability of the structural typology to reach moderate to extensive damage in the case of the specific earthquake, as observed in reality. The study holds significant importance in regions with limited recorded seismic activity, as they offer potential benefits for seismic risk management and mitigation strategies.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"30 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/87552930241263621
Haizhong Zhang, Rui Zhang, Yan-Gang Zhao
With the rapid development of energy-based seismic design, probabilistic seismic hazard analysis (PSHA) in terms of the input energy spectrum, E I, has become increasingly important. Generally, implementing E I-based PSHA requires a ground-motion prediction equation (GMPE) for E I. However, although a GMPE for E I can be constructed in regions with abundant earthquake data based on regression analyses, it is difficult to obtain in regions lacking strong ground-motion records. Therefore, this study proposes a new approach for performing E I-based PSHA in regions with limited earthquake data. Instead of using a GMPE for E I directly, a model of Fourier amplitude spectrum (FAS) is adopted, which can be determined using a small number of earthquake data with small-to-moderate magnitudes. Then, the E I of the ground motion is obtained from FAS based on the relationship between E I and FAS. Furthermore, to calculate the annual intensity exceedance rate within the proposed framework of adopting the FAS model, a highly efficient method, namely, the moment method, is applied. Several numerical examples indicate that the proposed approach not only is suitable for regions lacking strong ground-motion records but also performs very efficiently in calculating the annual intensity exceedance rate.
随着基于能量的抗震设计的快速发展，输入能量谱 E I 的概率地震危险性分析（PSHA）变得越来越重要。然而，虽然在地震数据丰富的地区可以根据回归分析构建 E I 的 GMPE，但在缺乏强烈地动记录的地区却很难获得。因此，本研究提出了一种新方法，用于在地震数据有限的地区执行基于 E I 的 PSHA。不直接使用 GMPE 来计算 E I，而是采用傅立叶振幅谱（FAS）模型。然后，根据 E I 与 FAS 之间的关系，从 FAS 得出地面运动的 E I。此外，为了在采用 FAS 模型的拟议框架内计算年烈度超限率，还采用了一种高效方法，即矩量法。几个数值实例表明，建议的方法不仅适用于缺乏强烈地动记录的地区，而且在计算年烈度超限率方面也非常有效。
{"title":"Novel approach for energy-spectrum-based probabilistic seismic hazard analysis in regions with limited strong earthquake data","authors":"Haizhong Zhang, Rui Zhang, Yan-Gang Zhao","doi":"10.1177/87552930241263621","DOIUrl":"https://doi.org/10.1177/87552930241263621","url":null,"abstract":"With the rapid development of energy-based seismic design, probabilistic seismic hazard analysis (PSHA) in terms of the input energy spectrum, E<jats:sub> I</jats:sub>, has become increasingly important. Generally, implementing E<jats:sub> I</jats:sub>-based PSHA requires a ground-motion prediction equation (GMPE) for E<jats:sub> I</jats:sub>. However, although a GMPE for E<jats:sub> I</jats:sub> can be constructed in regions with abundant earthquake data based on regression analyses, it is difficult to obtain in regions lacking strong ground-motion records. Therefore, this study proposes a new approach for performing E<jats:sub> I</jats:sub>-based PSHA in regions with limited earthquake data. Instead of using a GMPE for E<jats:sub> I</jats:sub> directly, a model of Fourier amplitude spectrum (FAS) is adopted, which can be determined using a small number of earthquake data with small-to-moderate magnitudes. Then, the E<jats:sub> I</jats:sub> of the ground motion is obtained from FAS based on the relationship between E<jats:sub> I</jats:sub> and FAS. Furthermore, to calculate the annual intensity exceedance rate within the proposed framework of adopting the FAS model, a highly efficient method, namely, the moment method, is applied. Several numerical examples indicate that the proposed approach not only is suitable for regions lacking strong ground-motion records but also performs very efficiently in calculating the annual intensity exceedance rate.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"61 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/87552930241258295
Kemal Onder Cetin, Faik Cuceoglu, Bilal Umut Ayhan, Sefa Yildirim, Seckin Aydin, Sarper Demirdogen, Yasemin Er, Ayhan Gurbuz, Robb Eric S Moss
The earthquake sequence that occurred on 6 February 2023 in Türkiye, Kahramanmaraş, had a significant impact on 140 dams, most of which are located within a distance of 50 km from surface projection of the fault rupture. These dams experienced moderate to high levels of seismic intensity, with peak ground acceleration (PGA) estimated to vary between 0.1 and 1.3 g during the Pazarcık earthquake and 0.15 to 0.45 g during the Elbistan earthquake, depending on their proximity to the fault rupture. Although all dams were able to maintain water-retaining capabilities, some of them suffered from moderate to large permanent deformations. As part of the emergency response measures, the water levels at two of these dams, namely Sultansuyu and Arıklıkaş, were lowered in a controlled manner. Following the earthquakes, a comprehensive survey of all hydraulic structures within the influence zone was conducted, and the findings are represented in this study. These findings revealed that earthfill and rockfill dams sustained more significant damage compared with concrete dams, particularly in areas close to the fault rupture, where the shaking intensity was most pronounced. The amount of permanent displacements was observed to consistently increase with the height of the dam’s transverse section.
{"title":"Performance of hydraulic structures during 6 February 2023 Kahramanmaraş, Türkiye, earthquake sequence","authors":"Kemal Onder Cetin, Faik Cuceoglu, Bilal Umut Ayhan, Sefa Yildirim, Seckin Aydin, Sarper Demirdogen, Yasemin Er, Ayhan Gurbuz, Robb Eric S Moss","doi":"10.1177/87552930241258295","DOIUrl":"https://doi.org/10.1177/87552930241258295","url":null,"abstract":"The earthquake sequence that occurred on 6 February 2023 in Türkiye, Kahramanmaraş, had a significant impact on 140 dams, most of which are located within a distance of 50 km from surface projection of the fault rupture. These dams experienced moderate to high levels of seismic intensity, with peak ground acceleration (PGA) estimated to vary between 0.1 and 1.3 g during the Pazarcık earthquake and 0.15 to 0.45 g during the Elbistan earthquake, depending on their proximity to the fault rupture. Although all dams were able to maintain water-retaining capabilities, some of them suffered from moderate to large permanent deformations. As part of the emergency response measures, the water levels at two of these dams, namely Sultansuyu and Arıklıkaş, were lowered in a controlled manner. Following the earthquakes, a comprehensive survey of all hydraulic structures within the influence zone was conducted, and the findings are represented in this study. These findings revealed that earthfill and rockfill dams sustained more significant damage compared with concrete dams, particularly in areas close to the fault rupture, where the shaking intensity was most pronounced. The amount of permanent displacements was observed to consistently increase with the height of the dam’s transverse section.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"11 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141769428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to develop adjustment factors for ground-motion models such as Pezeshk et al., which were developed for regions outside the Coastal Plain to be used for sites within the Coastal Plain region. The adjustment factors developed are a function of sediment thickness and rupture distance [Formula: see text] in the Coastal Plain region. We use the newly developed sediment thickness contour maps by Boyd et al. Also, the adjustment factors are developed using a combined data set, which consists of the Next Generation Attenuation (NGA)-East original data set, the data set from Chapman and Guo, and the newly compiled and verified data set by Thompson et al. We calculate residuals by taking the difference between the logarithms of the observed data and those predicted by the Pezeshk et al. ground-motion model (GMM), considering the site amplification model of Stewart et al. and utilizing the combined data set. This model is applicable for [Formula: see text] as far as 1000 km. We perform residual analyses using a mixed-effects regression to partition the total residuals into between-event and within-event components. To develop the correction factors for stations within the Coastal Plain region, we fit the within-event residuals to an equation that is a function of sediment thickness and [Formula: see text]. The results indicate that for stations within the Coastal Plain region, for most periods, the residual trend has been eliminated (with respect to sediment thickness, [Formula: see text], and time-averaged shear wave velocity in the first 30 m under the surface, V S30) using the proposed adjustment factors. The results of this study can be utilized in seismic hazard and risk analyses for sites within the Coastal Plain.
{"title":"Adjusting Central and Eastern United States ground-motion models for use in the Coastal Plain considering the sediment thickness","authors":"Mohsen Akhani, Mehran Davatgari-Tafreshi, Shahram Pezeshk","doi":"10.1177/87552930241258354","DOIUrl":"https://doi.org/10.1177/87552930241258354","url":null,"abstract":"This study aims to develop adjustment factors for ground-motion models such as Pezeshk et al., which were developed for regions outside the Coastal Plain to be used for sites within the Coastal Plain region. The adjustment factors developed are a function of sediment thickness and rupture distance [Formula: see text] in the Coastal Plain region. We use the newly developed sediment thickness contour maps by Boyd et al. Also, the adjustment factors are developed using a combined data set, which consists of the Next Generation Attenuation (NGA)-East original data set, the data set from Chapman and Guo, and the newly compiled and verified data set by Thompson et al. We calculate residuals by taking the difference between the logarithms of the observed data and those predicted by the Pezeshk et al. ground-motion model (GMM), considering the site amplification model of Stewart et al. and utilizing the combined data set. This model is applicable for [Formula: see text] as far as 1000 km. We perform residual analyses using a mixed-effects regression to partition the total residuals into between-event and within-event components. To develop the correction factors for stations within the Coastal Plain region, we fit the within-event residuals to an equation that is a function of sediment thickness and [Formula: see text]. The results indicate that for stations within the Coastal Plain region, for most periods, the residual trend has been eliminated (with respect to sediment thickness, [Formula: see text], and time-averaged shear wave velocity in the first 30 m under the surface, V<jats:sub> S30</jats:sub>) using the proposed adjustment factors. The results of this study can be utilized in seismic hazard and risk analyses for sites within the Coastal Plain.","PeriodicalId":11392,"journal":{"name":"Earthquake Spectra","volume":"73 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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