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This paper explores the historical origins of the Mafia and its roots in the Sicilian latifundia. By employing earthquake intensity as an instrumental variable to tackle endogeneity concerns, our study reveals a significant relationship between the presence of the Mafia during its initial historical appearances in the second half of the 19th century and the characteristics of latifundia. Latifundia, distinguished by large landowners and extensive agriculture, including the rotation of single-crop, pasture, and fallow lands, is found to be closely linked to this heightened Mafia presence. Moreover, our analysis rules out contemporary socio-economic factors by considering a set of control variables such as agricultural proxies. These findings highlight a persistent historical pattern of inequality, proxied by the spread of latifundia, underscoring the enduring influence of the medieval feudal system, transformed into latifundia, on social dynamics. Our findings suggest that policies aimed at reducing the concentration of land ownership and promoting land reform could effectively have curbed the emergence of organized crime in areas with a history of comparatively higher land ownership inequality. [ABSTRACT FROM AUTHOR]

The permanent deformation after earthquakes is an important seismic safety performance indicator for rockfill dams. Based on dynamic triaxial tests, taking grading reduced coarse-grained materials as the test object, the influence of factors including density, particle grading, confining pressure, consolidation stress ratio, and number of vibration cycles on its residual deformation was discussed. On this basis, a numerical model in power function form was established for elaborating the earthquake permanent deformation for rockfill dams, an assumed homogeneous rockfill dam and a practical core rockfill dam were taken as research objects, respectively; by conducting nonlinear dynamic Finite Element (FE) analysis and combining with the single factor sensitivity analysis, the relationship between the main influence factors and dam permanent deformation was explored, which indicated that the influence of above factors on the permanent deformation of rockfill dams is consistent with the relationship between these factors and the residual deformation of coarse-grained materials in the triaxial tests. Finally, a fitting analysis method searching for the maximum permanent deformation of rockfill dams under different seismic intensities was proposed. Then corresponding suggestions were recommended from both design and construction aspects to improve the seismic resistance of super-high rockfill dams, which may have reference significance for similar projects. [ABSTRACT FROM AUTHOR]

Background: There were more than 700 earthquakes with a magnitude of more than 5.0 over the past 100 years in the Special Region of Yogyakarta, Indonesia. Due to the high intensity of seismic activities, it is essential to perform seismic hazard analysis by considering local site effects. Therefore, this study aimed to analyze the peak ground acceleration (PGA) value based on the earthquake scenario of May 27, 2006, with a magnitude of 6.3, which occurred on the eastern side of the Opak Fault. Methods: The study was conducted in the southern part of the Progo River, the Special Region of Yogyakarta, using 31 boreholes and 18 microtremor measurement points. The analysis was carried out using four methods: Kanai (In: Proceeding of Japan Earthquake Engineering Symposium 1–4, 1966) equation using microtremor data, deterministic equations with Ground Motion Prediction Equations Next Generations Attenuation West 2 (GMPE NGA West 2), Kanno et al (Bull Seismol Soc Am 96:879–897, 2006) attenuation equation, and probabilistic method referring to the Indonesian Seismic code. Results: Results indicated that the highest value of PGA was obtained using the deterministic GMPE NGA West 2 weighted attenuation equation, which varied from 0.475 to 0.549 g. Meanwhile, Kanno et al (Bull Seismol Soc Am 96:879–897, 2006) attenuation equation resulted in values ranging from 0.266 to 0.394 g. In contrast, PGA values obtained through microtremor measurement resulted in a smaller value, in the range of 0.126–0.214 g. Probabilistic analysis in the study area produces values ranging from 0.373 to 0.450 g. Conclusion: The location on the central side of the Progo River shows a lower PGA value than the other sides. PGA values will tend to be higher at locations near the earthquake source. The low PGA value that resulted from microtremor analysis was due to the consideration of local site effects in determining earthquake parameters in the study area. Determining the seismic hazard analysis method in infrastructure planning requires a comprehensive analysis by considering various parameters, such as the planning and design objectives, the location proximity to earthquake sources, historical seismic conditions, and the presence of the local site effects. [ABSTRACT FROM AUTHOR]

The assessment of the intensity of seismic impacts on a site by the classical method is the scalar sum of the seismic impacts caused by potential seismic sources in all orientations within the earthquake influence area around the site, not only overestimating the intensity of seismic ground motion of the site but also failing to consider the difference in the seismic impact modes and directions caused by the seismic waves with different incident directions. Based on the analysis framework consisting number of seismic sources, magnitude grades, and distance ring domains in the classical method, azimuth sectors are further added, thus forming an improved seismic hazard analysis method considering the orientation distribution of potential seismic sources. The improved method was applied in Baoji area, China. The analysis results of the improved method can provide multiple sets of seismic impact evaluation parameters caused by the seismic sources in different orientations, and each set of parameters corresponds to the seismic impacts of potential seismic sources in one of azimuth sectors around the site. What's more, the improved analysis method lays a foundation for clarifying the directions of seismic actions on a site, and significantly improves the overestimation of the site seismic action intensity by the classical method. The improved method takes the effect of potential seismic source orientation on site seismic actions into account, and provides the possibility for engineering earthquake resistance to consider earthquake damage modes. [ABSTRACT FROM AUTHOR]

To study the influence of random seismic responses on the structure of a large-span double-deck steel truss cable-stayed bridges under the effects of high-intensity rare earthquakes, a new power spectral model was proposed based on improvements to existing power spectra for fitting the improved power spectra of random seismic responses. The bridge finite element model established using ANSYS was employed as an engineering example for computational analysis to investigate whether the improved spectrum exhibited better adaptability and feasibility under high-intensity rare earthquake compared with other power spectra. The results indicated that the power spectral model, based on improvements to the original power spectra, had a more pronounced filtering effect on the low-frequency and high-frequency portions. Moreover, under the consistent three-dimensional excitation, the vertical displacement of the main beam was the greatest, indicating that the improved spectrum had better adaptability than other power spectra in studying the high-intensity rare earthquakes affecting bridges. It also reflected the feasibility of using the improved spectrum for studying the random responses to high-intensity rare earthquakes, providing a reference for bridge design concerning rare earthquakes in large-span bridges. [ABSTRACT FROM AUTHOR]

Split reinforced concrete column (SRCC), recognized for their exceptional ductility as seismic members, have faced developmental challenges due to the complexities of on-site casting. This study presents an innovative steel sleeve dry connection assembled SRCC, which is highly modular and simplifies construction, aiming to promote the engineering application of this innovative ductile seismic structural system. This study used a validated 3D finite element (FE) method to analyze internal joint forces. Key parameters influencing joint performance, such as the axial compression ratio (u) and cross-sectional equal division ratio (n), were analyzed in detail. Subsequently, a comparative of dynamic analysis of SRCC and normal reinforced concrete column (NRCC) frames was conducted, leading to recommendations for structural strengthening. The analysis revealed that the sleeve can provide effective protection for the core area of the joint. The ductility of SRCC is 2–3 times higher than that of NRCC. A detailed formula for calculating the shear-bearing capacity of SRCC joints was derived, showing strong agreement with numerical simulations. At a high seismic intensity of 9°, the acceleration response of the SRCC frame is significantly reduced compared to the NRCC frame, with the maximum base shear (MBS) decreasing by approximately 4 times, which significantly enhances its seismic performance. However, due to the larger inter-story displacements, it is necessary to incorporate energy-dissipating braces to comply with code requirements. Collectively, these findings underscored that the proposed SRCC system significantly enhances seismic performance by improving ductility and energy dissipation, providing a robust foundation for future studies and practical applications in seismic design. [ABSTRACT FROM AUTHOR]

Macroseismic intensity data are the only source of information for historical earthquakes; it is therefore necessary to devise methods that allow us to retrieve as many source parameters as possible on the basis of these data. We present the inversion of macroseismic data as a first validation of an improved version of the kinematic function, KF. Following the previous results of some earthquakes on Italian territory and several validations by Californian events provided with instrumental solutions, we have now simplified the KF by reducing some degrees of freedom of the parameters and rearranging the code for parallel calculation. This approach will allow for a more extensive application of the KF technique. We present the inversion of the macroseismic intensity pattern of the Mwp6 earthquake of 27 March 1928 (8:32 GMT), which occurred in Northeastern Italy (Carnia), and we retrieved source parameters that are compatible with the solutions of other authors who independently treat instrumental data. The 1928 event is located a few tens of kilometers west of the more destructive Mw6.5 of 6 May 1976 and northeast of the subsequent earthquake Mwp6.1 of 18 October 1936. The inversion was performed as a blind test, without prior knowledge for fault plane solutions and tectonic information; it resulted in a minimum variance model with a strike of 62°, a dip of 10°, and a rake of 101°. This solution is not consistent with the entire tectonic framework of the eastern Southalpine chain, but it is in agreement with the But-Chiarsò line. This result encourages us to test further improvements to the KF method and to treat other cases from the Italian macroseismic catalog. [ABSTRACT FROM AUTHOR]

This study presents an integrated approach for the seismic assessment of the 13th-century San Michele Arcangelo Cathedral Bell Tower in Caserta Vecchia, Italy, utilizing a detailed photogrammetric survey and Finite Element (FE) modelling. The analysis focuses on the structural vulnerability and seismic response of the historical masonry tower to assess its response against earthquake-induced damage. By employing Ambient Vibration Tests (AVTs) present in literature and calibrating the FE model accordingly, the research identifies the principal vibrational modes and natural frequencies of the tower, enhancing the model's accuracy. Various earthquake intensities were inputted to the structural model to evaluate the bell tower's structural performance and potential collapse mechanisms. The findings reveal a significant susceptibility of damage under severe seismic conditions, emphasizing the critical need for tailored conservation strategies to preserve such irreplaceable cultural heritage. The study underscores the importance of integrating historical documentation, structural analysis, and modern engineering techniques to safeguard historical architecture in seismically active areas. [ABSTRACT FROM AUTHOR]

Change in the fundamental period of a structure during strong earthquakes (the change from the linear to nonlinear period) can be a good indicator of the damage level of the structure. Given that the incremental dynamic analysis (IDA) has played an effective role in investigating the nonlinear behavior of engineering structures, in this article, we try to use the nonlinear (fundamental) period of the structure as a damage criterion in IDA curves for multi-degree-of-freedom (MDOF) systems, which was previously introduced for single-degree-of-freedom (SDOF) systems. In this regard, the nonlinear period at different seismic intensity levels and the collapse threshold period of steel moment-resisting frame (SMRF) structures are studied by considering the spectral shape indicators of earthquake records, and the strength and stiffness deterioration parameter. For this purpose, three regular SMRF buildings with 3, 10, and 20 stories as representatives of low-, medium-, and high-rise buildings are investigated. Fast Fourier transform (FFT) is used to calculate the nonlinear period of the structures, and the eigenvalue analysis method by using the instantaneous characteristics (stiffness) of the structure is implemented to confirm it. To perform the time history analysis, the bilinear modified Ibarra-Medina-Krawinkler (IMK) model is used in modeling the structural hysteretic behavior. One of the important applications of the nonlinear period of structures is in the process of scaling records for time history analysis. This study intends to evaluate the scaling period range by computing the nonlinear period based on the records scaled to the design spectrum. The results demonstrate that the spectral shape parameters and the structural deterioration affect the nonlinear period of the case study structures in a regular manner, while the effect of the mentioned spectral parameters on the collapse threshold period does not follow a clear trend. Also, it is shown that the upper bound period (1.5 or 2 ) mode period for scaling ground motions is too conservative for structures with a special SMRF load-resisting system having a low deterioration. [ABSTRACT FROM AUTHOR]

Known worldwide for its rich and well-preserved pre-Columbian and Spanish architecture, the city of Cusco (Peru) is listed as a World Heritage Site since 1983. However, less well known is the seismic hazard, which represents a major threat to the city's 400,000 inhabitants and its cultural outreach. Despite the moderate magnitudes recorded in the area, macroseismic data inferred from historical earthquakes (1650, 1950) argues for strong amplification effects of the unconsolidated sediments of the Cusco Basin during ground motion. In order to address this aggravating factor for the first time, we conducted a large-scale passive geophysical survey in the historical city center of Cusco, combining Microtremor Horizontal-to-Vertical Spectral Ratio (MHVSR) measurements and Microtremor Array Measurements (MAM). Through joint data inversion, we proposed a subsurface wave velocity model and estimated the depth of the engineering bedrock. The site response analysis not only provides an insight into the thickness of the soft sediment, but also suggests the existence of a strong geological discontinuity beneath the city center of Cusco, consistent with the trace of the Cusco fault. Moreover, the results highlight the complexity of earthquake site amplification assessment in dense urban areas. Our work paves the way for a comprehensive seismic microzonation of the entire Cusco Basin and opens up new perspectives on the potential of the MHVSR method for fault detection. [ABSTRACT FROM AUTHOR]

Compared to conventional reinforced concrete (RC) piers, self-centering rocking piers exhibit better seismic resilience and sustain minor damage. However, their construction typically relies on prefabrication. Moving large, prefabricated components can be challenging in mountainous areas with limited transportation access. Therefore, using concrete-filled steel tube (CFST) piers is a practical alternative. The steel tube both serves as a construction permanent formwork and enhances the compressive performance of concrete through confinement effects. To apply CFST self-centering rocking piers in mountainous regions with high seismic intensity, a fast construction system was designed and a 1:4 scale specimen was developed for testing. Lateral cyclic loading tests revealed that the specimen exhibited good deformation and self-centering capabilities, with a residual drift ratio of only 0.17% at a drift ratio of 7.7%. Most of the horizontal displacement was contributed through a rocking gap opening, resulting in minimal damage to the pier itself. The damage was concentrated primarily in the energy-dissipating rebars, while the prestress strands remained elastic, though prestress loss was observed. [ABSTRACT FROM AUTHOR]

In-service reinforced concrete (RC) structures trigger complex deterioration mechanisms in seismic performance due to corrosion, leading to difficulties in evaluating the seismic capacity. To scientifically evaluate the seismic capacity of corroded RC frame structures, this paper proposes a quantifiable framework for absolute seismic capacity evaluation. The study establishes numerical models of typical RC frame structures considering the number of stories, service years, seismic fortification intensity, and different versions of design codes. Additionally, classification criteria for structural failure states based on the proportion of component damage are proposed. The seismic capacity of corroded RC frame structures under different failure states is determined using elastoplastic time-history analysis, and the influence of various parameters on the structural seismic capacity is investigated. Based on the results of the structural seismic capacity evaluation, a prediction model for the seismic capacity of corroded RC frame structures is developed using the BP neural network to establish the nonlinear mapping relationship between key parameters and structural seismic capacity. The results indicate that the seismic capacity of corroded RC frame structures continuously decreases with an increase in the service years and the number of stories. Earlier versions of design codes result in smaller residual seismic capacity of RC frame structures under different failure states, with a faster degradation rate. The sensitivity of the structural seismic capacity to various parameters is ranked as follows: structural failure states, the number of stories, seismic fortification intensity, service years, and versions of design codes. [ABSTRACT FROM AUTHOR]

Strip foundations are the most prevalently used shallow foundations in low-rise residential buildings in hilly regions. The strip foundations in many of these structures are often placed on rock slopes. In a seismic event, the behavior of the foundation–rock slope system is complex. It is characterized by a reduced bearing capacity in the strip foundation for low-intensity shaking and rock slope instability at higher seismic intensity. The quantification of this behavior is essential for the seismic design of these foundations. This work presents an analytical formulation to estimate the critical seismic loading for a given geometry and material properties of a rock slope that is represented by the Hoek–Brown (HB) failure criterion, up to which the stability of the slope is ensured. An extensive study that uses pseudo-static finite-element limit analysis (FELA) is carried out to parametrically analyze the effect of the slope angle and seismic acceleration on the seismic bearing capacity factor of a footing on rock slopes with a wide range of rock mass properties. The results of the FELA are utilized to develop a design tool (Rock-Bearing) to estimate the bearing capacity of strip foundations that are placed on rock slopes. The developed tool could be used instead of the computationally expensive numerical analysis for the preliminary design of foundations in seismically active hilly areas. Practical Applications: The assessment of the seismic bearing capacity of a geomaterial that sustains a strip foundation is a crucial element in the design of strip foundations that rest on it. Using the code-based presumptive values for the bearing capacity for the seismic design might lead to unsafe designs where the strip foundation is near the edge of a slope in hilly areas. The seismic design of these foundations demands a comprehensive analysis, which preliminarily investigates the global stability of the slope and further incorporates the effect of horizontal seismic acceleration and vicinity of the slope in the reduction of the bearing capacity. The previously illustrated design requirements demand a sophisticated analysis of the design. This work develops a design aid tool that could be used instead of the computationally expensive numerical analysis for the preliminary design of foundations in seismically active hilly areas. [ABSTRACT FROM AUTHOR]

Seismic-induced liquefaction of sandy soils can fail foundations in the vicinity of buildings. To investigate the effect of a non-free field subsurface seismic history on the ability of saturated sandy soils to resist liquefaction, four shaking events with different accelerations were input to the sandy soils in the non-free-field. The results of the study revealed that: (1) Shallow soils that are not free-field undergo acceleration amplification effects after being subjected to seismic loading. (2) Building overburden pressure reduces the sensitivity of the shallow soils directly below in small and moderate earthquakes, which are more prone to rearranging and forming unstable structures under strong seismic effects. The excess pore pressure response on the load side resembles that of a free site, with the depth range of the liquefaction strength of soils affected by the seismic history, increasing progressively as input seismic intensity increases. (3) After experiencing earthquakes of different intensities, the excess pore pressure directly below the building overburden pressure at 0.1 m and 0.2 m is greater than that at the side. At the same time, the side of the building structure is more prone to liquefaction than the soil directly below it. [ABSTRACT FROM AUTHOR]

The geotechnical engineering community widely uses the one-dimensional (1D) Equivalent Linear Site Response Analysis (EQLSRA). However, the literature review reveals that surface ground motion characteristics predicted employing EQLSRA are often overdamped, especially at high frequencies. Recent studies have pointed out that the algorithm used within EQLSRA for obtaining the Equivalent Shear Strain (ESS) is one of the primary reasons for its unsatisfactory performance. Usually, for a given strain time history, the corresponding ESS is taken as Strain Ratio (STR) times the absolute peak strain. Conventionally, a constant value (usually ranging from 0.40 to 0.75 and typically 0.65) is manually set as STR. Though ESS plays a pivotal role in EQLSRA, not much attention has been given to the estimation of STR. This work aims to resolve such issues. Here, a new notion for the computation of STR is proposed, which can be easily integrated within EQLSRA. The coined idea takes into account the frequency content and intensity in the induced seismic strain waveform for the determination of STR. The suitability of the modified EQLSRA (mod-EQLSRA) incorporating the proposed technique of STR calculation is tested with the help of 15 Kiban Kyoshin Network (KiK-net) stations and 110 ground motions. It is found that the average absolute error in the surface Peak Horizontal Acceleration (PHA) predicted employing the mod-EQLSRA reduces by approximately 54% when compared to that estimated via the traditional EQLSRA. [ABSTRACT FROM AUTHOR]

Many seismic damage field observations of masonry structures indicate that buildings constructed in different eras differ in terms of seismic risk and vulnerability under time-varying deterioration. However, the age deterioration effect is rarely considered in structural seismic vulnerability analysis, challenging the accuracy of the developed seismic risk model assessment. This paper considers the impact of age deterioration on seismic hazard and vulnerability, and an innovative probabilistic seismic hazard and risk model was developed. Using earthquake hazard theory and 1452,582 accelerations monitored by 11 stations during the 2008 Wenchuan earthquake in China, dynamic time history and response spectrum curves were generated considering the directionality of ground motion. Using the innovative model developed, the seismic vulnerability grade of 1228 low-rise masonry structures (Dujiangyan city) affected by the Wenchuan earthquake that the author investigated was evaluated, and a failure probability matrix of low-rise masonry structures considering the influence of age deterioration was established. A nonlinear fitting function was proposed to assess the seismic vulnerability of low-rise masonry structures, and vulnerability curves were generated via the developed empirical dataset. According to multiple onsite structural damage observations, there is a correlation between adjacent vulnerability and intensity grades. To study the correlation between the adjoining vulnerability grades of low-rise masonry structures under the influence of aging and different seismic intensity measures, an innovative structural seismic risk index model considering empirical and probabilistic algorithms (vulnerability correlation index (VCI) and intensity–vulnerability correlation index (IVCI)) has been proposed. On the basis of the seismic damage dataset, seismic risk curves for low-rise masonry structures were generated, considering the influence of age deterioration. [ABSTRACT FROM AUTHOR]

The Taiwan Ground Deformation Index (TGDI) is proposed to quantify site vulnerability using a non-linear soil deformation model, PGA parameters from the Taiwan seismic intensity scale, and microtremor analysis. Site vulnerability is graded into four levels: low (TGDI < 2.4), moderate (2.4 ≤ TGDI < 4.2), high (4.2 ≤ TGDI < 7.4), and very high (TGDI ≥ 7.4), based on susceptibility to seismic damage. Validating TGDI with 13 disaster events in Tainan during the 2016 Meinong earthquake showed 12 cases of moderate-to-high vulnerability. Since weak ground and strong amplification properties favor TGDI increases, this index serves as an early warning parameter for disasters. [ABSTRACT FROM AUTHOR]

Indonesia is the country with the second highest earthquake intensity in the world because Indonesia is passed by the confluence of 3 tectonic plates, namely: the Indo-Australian Plate, the Eurasian Plate, and the Pacific Plate. Earthquakes occur due to the movement of tectonic plates that move freely and interact with each other. The impact of the earthquake includes: Tsunamis, collapsed buildings, fires, rock collapses, and ground cracks. The purpose of writing this study is to determine the intensity of earthquakes that occur on the island of Java using the K-Means Clustering method. The earthquake data used in this study uses magnitude, depth, and geographical location parameters obtained from existing data. The K-Means Clustering method is used to group earthquake data into several clusters based on their seismic characteristics. The result of this study is to identify seismic zones with similar earthquake intensity. The results of the cluster obtained, it was used to make data visualization of areas with high earthquake intensity using GeoMap. [ABSTRACT FROM AUTHOR]

The underground structure with stiffness mutation at the culvert-frame connection suffers from discrepant dynamic responses when earthquakes strike. This paper studies the seismic responses of an underground structure consisting of two portions of box frames and twin jacked culverts in soft soil. The two portions of box frames (Part A and Part C) have the same 2-storey and 3-span cross sections, rigidly connected to the two parallel jacked culverts (Part B) with F-type sockets between joints. A series of 1g shaking table tests is conducted on the modeled soil–structure system. Accelerometers are installed within the model soil, upon culverts, and on the top of mid slabs of box frames. Joint extensions and closures of culverts are measured. The white noise case is carried out to assess dynamic characteristics of the model system. Four synthetic earthquake cases are conducted to investigate the model system's seismic responses under earthquakes with varying intensities. Ground acceleration responses of the model soil at different distances from Part A are compared. The extent of discrepancy in acceleration of culverts and box frames is quantified by the correlation coefficient. The characteristics of the joint extension and closure are summarized. [ABSTRACT FROM AUTHOR]

The definition of the targeted engineering demand parameters (EDPs) is important to probabilistic seismic demand modeling (PSDM), which produces probability density functions of EDPs conditioned on seismic intensity measure (IM). The targeted EDPs are usually defined at the group level to account for multiple components/units. Thus, they are affected by the considered range of units, i.e., the sample positions. For instance, the maximum peak floor acceleration (PFA) within the whole building differs from the maximum among only the important positions related to seismic loss. Additional uncertainties are induced in the PSDM of PFA if the sample positions vary when architectural function and non‐structural elements change. In this study, the aforementioned influence is termed random‐positioned‐sampling (RPS) effect, and it is investigated by targeting a modularized suspended building, which features the tuning mechanism, multiple major modes, uneven response envelopes, and notable non‐structural‐object‐structure interactions (NSOSI). Results show that the RPS effect lowers the maximum‐based group‐level EDP and increases the dispersion within the EDP sample sets, indicating that conventional PSDMs without considering the RPS effect are biased. The significance of the influence is positively correlated to the position‐wise coefficient of variation of EDP but negatively correlated to the density of sample positions. The combined influence of the NSOSI and the RPS effect is two‐sided for PSDM. The NSOSI amplifies the RPS effect via enlarging position‐wise dispersion of EDP, whereas, the RPS effect waives part of the detrimental scattered contributions from NSOSI. Overall, the IM performance is handicapped, even with IM optimization. However, it can be compensated if architectural function region information is acquired beforehand since the sample positions are restrained. [ABSTRACT FROM AUTHOR]

To evaluate the seismic safety of components in a structure, an in-structure response spectrum (ISRS) must be obtained, and this also applies to seismically isolated structures. The main variables for designing seismic isolators are effective stiffness and effective damping, which can be given as the characteristic strength and secondary stiffness in seismic isolators for nonlinear behaviors. Many studies on the ISRS of isolated structures have been conducted to evaluate the effects of these two variables of isolators, but the effect of other variables related to the hysteresis curve of isolators also needs to be studied. This study focused on the effect of the initial stiffness of isolators on an ISRS because there were no clear criteria for determining the initial stiffness in isolator design standards, which has an effect on the ISRS that cannot be ignored. As a result, the initial stiffness contributed significantly to the ISRS not only at the natural frequency of the structure but also at low frequencies. An analysis was also performed in terms of the uncertainty of each variable. The sharpness of the yield point in the hysteresis curve was implemented using the Bouc–Wen model, and its impact was analyzed. In addition, the frequency content of the ISRS depending on the seismic intensity, which can considerably change the nonlinear hysteresis behavior, was examined. Through this study, although secondary stiffness and characteristic strength are the most important characteristics of seismic isolation design, it was confirmed that other variables also have a significant impact on the frequency content of an ISRS. Based on this study, the considerations when developing the ISRS of an isolated structure can be established. [ABSTRACT FROM AUTHOR]

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Our archaeoseismological studies of the ruins of a medieval Christian temple located at the foot of Kilisa–Kaya Mountain in the southeast of the Crimean Peninsula have shown that the building structures have obvious traces of significant seismic damages: tilts, shifts, and rotations of both entire building elements and individual stone blocks or their packages. Extended subvertical interblock cracks break the walls of the temple to their entire residual height. Oblique cracks that occur under conditions of longitudinal compression cut elongated building blocks. The stone pavement of the temple is also damaged: there are depressions in it. Judging by the fact that the temple was repaired, and sections of the repaired walls were also deformed, the structure was affected by two seismic events. The last of them left traces in the apse and the northern portal. Seismic oscillations spread in the sublatitudinal direction. The damage caused by this earthquake apparently includes shifts and tilts of brickwork in the submeridionally oriented walls, as well as the loss of domed and arched parts of the building. The first earthquake led to the appearance of deformations (shifts) in the walls of the sublatitudinal strike, after which the temple was repaired. The second seismic event, apparently, led to the formation of a landslide in the upper reaches of the dry creek in the valley of which the temple was located. The lake formed above the dam once broke through the barrier, and a mudslide passed down the valley. The mudflow material filled the interior of the temple and formed sediments around the building. Mudslide deposits covered and preserved the walls of the temple, as well as deformations in them for hundreds of years. Judging by the severity of the damage to the religious building, built with special quality, the intensity of seismic oscillations during both seismic events was at least VIII points. The exact dates of the construction of the temple and the earthquakes still need to be clarified, for which further research of the monument is necessary. Since its construction is tentatively dated from the second half of the 12th century to the first half of the 13th century, the first earthquake occurred after the specified date. It is known that the temple was almost completely buried under a layer of soil by the end of the 18th century. Accordingly, the second seismic event can be dated to this time. [ABSTRACT FROM AUTHOR]

This study presents a novel methodology for the seismic vulnerability assessment of ground-supported liquid storage tanks, with a particular emphasis on tanks exhibiting deformed shells. The framework is built around the development of a simplified two-degree-of-freedom (2DoF) system, specifically designed to enable efficient probabilistic analysis through incremental dynamic analysis. The 2DoF model is calibrated using detailed nonlinear finite element simulations, which account for fluid–structure interaction and complex geometric effects. This approach allows for a significant reduction in computational effort while maintaining a high level of accuracy in predicting seismic fragility. A key feature of the proposed methodology is the explicit inclusion of deformed tank geometries, which are often encountered in real cases and can critically impact seismic performance. The study identifies and quantifies the effects of these deformations on various damage states, such as local buckling, overturning, and liquid overspill. Fragility curves are developed to characterize the probability of exceeding these damage states under different levels of seismic intensity. The proposed methodology is validated through a representative case study, demonstrating its ability to capture the key features of tank behavior and provide robust fragility estimates. The results highlight the potential of the 2DoF system to serve as a practical tool for seismic risk assessment, enabling engineers and researchers to evaluate tank vulnerabilities more efficiently. [ABSTRACT FROM AUTHOR]

As large-scale depletion of shallow coal seams and increasing mining depths intensify, the frequency and intensity of mining-induced earthquake events have significantly risen. Due to the complex formation mechanisms of high-energy mining-induced earthquakes, precise identification and early warning cannot be achieved with a single monitoring method, posing severe challenges to coal mine safety. Therefore, this study conducts an in-depth risk analysis of two high-energy mining-induced earthquake events at the 3308 working face of Yangcheng Coal Mine, integrating microseismic monitoring, stress monitoring, and seismic source mechanism analysis. The results show that, by combining microseismic monitoring, seismic source mechanism inversion, and dynamic stress analysis, critical disaster-inducing factors such as fault activation, high-stress concentration zones, and remnant coal pillars were successfully identified, further revealing the roles these factors play in triggering mining-induced earthquakes. Through multi-dimensional data integration, especially the effective detection of the microseismic "silent period" as a key precursor signal before high-energy mining-induced earthquake events, a critical basis for early warning is provided. Additionally, by analyzing the spatiotemporal distribution patterns of different risk factors, high-risk areas within the mining region were identified and delineated, laying a foundation for formulating precise prevention and control strategies. The findings of this study are of significant importance for mining-induced earthquake risk management, providing effective assurance for safe production in coal mines and other mining environments with high seismic risks. The proposed analysis methods and control strategies also offer valuable insights for seismic risk management in other mining industries, ensuring safe operations and minimizing potential losses. [ABSTRACT FROM AUTHOR]

This research aims to comprehensively estimate seismicity parameters and create seismotectonic and isoseismal maps for the state of Meghalaya, located in the North-East (NE) region of India using an earthquake catalog collected between 1861 and 2022. The seismic influence zone considered for the study is a circular area with a radius of 350 km around Shillong city (latitude 25.57° N and longitude 91.88° E). Distinct magnitude classes, such as 3.50–3.99, 4.00–4.99, 5.00–5.99, 6.00–6.99, and ≥ 7.00, are considered for analysis, and corresponding completeness periods are obtained as 40, 60, 100, 160, and 130 years, respectively. The study area seismicity parameters a and b values of the Gutenberg–Richter (G–R) relationship are obtained with values ranging from 5.50 to 6.23 and 0.70 to 0.75, respectively. This study further estimates earthquake magnitude occurrence probabilities for 1, 50, and 100 years, as well as the associated return periods. Additionally, seismotectonic maps are developed to provide crucial insights into seismic hazards within the study area. These maps delineate fault lines, active tectonic structures, and seismic zones, facilitating the assessment of potential seismic risks. Intensity-based isoseismal maps are generated to assess the influence of the past five major earthquake occurrences within the study area. It is observed that, if a recurrence of past seismic events occurs at or near the same region, a maximum intensity XI on the Medvedev–Sponheuer–Karnik (MSK) intensity scale might be felt in the study area. The outcome of this study will serve as a valuable resource for seismic hazard assessment specific to the Meghalaya region. [ABSTRACT FROM AUTHOR]

This paper presents a procedure for simplified collapse probability prediction of RC frame buildings when subjected to ground motion intensities commonly used in designing buildings. For this purpose, seismic collapse probability of a range of RC moment resisting frame buildings are assessed at the design basis earthquake (DBE) and the maximum considered earthquake (MCE) levels of seismic intensity by conducting more than a thousand nonlinear response history analyses (NRHA) using a suite of 40 seismic ground motion records. The 13 buildings included in the investigation have different heights (5–15 storeys) and footprints (3–6 bays), are designed to different target maximum inter‐storey drifts (within the code specified limit), and have critical members detailed to sustain different levels of confinement and anti‐buckling demands. The NRHA results consistently demonstrate that the design inter‐storey drift and the anti‐buckling detailing of longitudinal rebars in the critical frame members strongly influence the collapse probability of RC frame buildings. The results also show that while RC frame buildings designed to reach 2.5% (or less) inter‐storey drifts and detailed for ductile seismic performance can successfully avoid collapse at DBE, avoidance of collapse at DBE cannot be guaranteed if RC frames are designed to reach a target drift of more than 2% and not detailed for full ductility. At MCE, collapse probability is found to consistently exceed 10% unless the building is designed to incur no more than 1% plastic drift and the frame members have ductile detailing. Based on the NRHA results of the 13 case study buildings, easy‐to‐use equations relating their seismic collapse probability at MCE with the design drift and a quantifiable measure of ductile detailing are generated and validated by comparing with the collapse probability obtained by NRHA of an independent RC frame building. The proposed equations provide a rapid, yet reasonably reliable tool for performance‐based seismic design of RC frame buildings, and enable designers to estimate seismic collapse probability of RC frame buildings without having to conduct cumbersome NRHA. [ABSTRACT FROM AUTHOR]

The article discusses a long-runout loess landslide triggered by a 6.2 magnitude earthquake in Qinghai, China, resulting in significant casualties and property damage. The study highlights the geological and topographic factors controlling groundwater in the loess layer, emphasizing that long-term irrigation activities are not the primary cause of groundwater accumulation. The research aims to elucidate the failure process and motion characteristics of the landslide, providing insights into the mechanisms and prevention measures of deep-seated flows triggered by earthquakes in the region. [Extracted from the article]

This paper considers two earthquakes which occurred on October 18, 2017 and October 25, 2017 in western Transbaikalia. In spite of the moderate energy level of both events, they can be treated as significant for the study area, because such earthquakes have been recorded there relatively rarely compared with the adjacent high-seismicity areas in the Baikal Rift Zone. The mechanisms of both earthquakes based on surface wave amplitude spectra showed that these events occurred under a dominating east–west near-horizontal compression and an inclined or nearly vertical NW‒SE tension, which is typical for western Transbaikalia. For both earthquakes, we also computed source parameters: scalar seismic moment M0 = 5.0 × 1015 N m, moment magnitude Mw = 4.4, and source depth h = 7 km for the October 18, 2017 event; M0 = 3.5 × 1015 N m, Mw = 4.3, and h = 29 km for the October 25, 2017 event. These earthquakes have caused noticeable macroseismic effects in the near-field; the maximum observed shaking intensity was IV–V (MSK-64) during the October 18, 2017 earthquake and V during the October 25, 2017 earthquake. These data were the basis for our analysis of present-day activity of faults in the study area. The results may be helpful for more accurate assessment of earthquake hazard and seismic risk in western Transbaikalia. [ABSTRACT FROM AUTHOR]

This paper introduces cross-fade sampling, a computationally efficient Markov Chain Monte Carlo simulation method that uses a semi-analytical approach to quickly solve Bayesian inverse problems that do not themselves have an analytical solution. Cross-fading is efficient in two ways. First, it requires fewer samples to obtain the same quality simulation of the target probability density function (PDF). Secondly, it is much faster to evaluate the posterior probability of each sample than conventional sampling methods for simulating Bayesian posterior PDFs. Conventional methods require evaluating the prior probability (which describes your a priori constraints) and data likelihood (which describes the fit between the observations and the predictions of the model) for each sample model. However, cross-fading does not require evaluating the data likelihood, meaning that 'big data' can be fit with zero additional computational cost. Further, the cross-fading approach can be used to calculate the marginal likelihood associated with a model design, facilitating model comparison and Bayesian model averaging. Topics covered in this paper include derivation of the cross-fade approach and how it can be used to simulate Bayesian posterior PDFs and compute the marginal likelihood, discussion of the class of problems to which cross-fading can be applied (with examples from earthquake statistics, earthquake ground motion modelling, volcanic eruption forecasting, and finite fault slip modelling), demonstration of efficiency relative to existing sampling methods and discussion of how cross-fading can be used to account for prediction errors (i.e. epistemic errors) as part of the geophysical inverse problem. [ABSTRACT FROM AUTHOR]

The scientific process of earthquake forecasting involves estimating the probability and intensity of earthquakes in a specific area within a certain timeframe, based on seismic activity features and observational data. Among the various methodologies, epidemic-type aftershock sequence (ETAS) models, rooted in seismic empirical laws, stand as widely used tools for earthquake forecasting. In this study, we introduce the CL-ETAS model, a novel approach that integrates convolutional long short-term memory (ConvLSTM), a deep learning model, with the ETAS model. Specifically, we leverage the forecasting outputs of ETAS to enhance both the training and forecasting processes within the ConvLSTM framework. Through forecasting tests, our findings illustrate the effectiveness of the CL-ETAS model in capturing the trends observed in earthquake numbers (⁠|$M \ge 3$|⁠) in Southern California following three main shocks. Overall, our model outperforms both a simple ETAS model and ConvLSTM in this context. [ABSTRACT FROM AUTHOR]

For the risk analysis of spatially distributed structures, the joint prediction of ground motion intensities at multiple sites is required. Therefore, many researchers have come up with spatial correlation models for seismic intensity measures (IMs). The spatial correlation model requires site-specific non-ergodic ground motions. One of the chosen approaches for correlation studies is physics-based simulations (PBS), which account for the complexities related to earthquake source, path and site. The present study evaluates the efficiency of the artificial neural network-based broadband response spectra generator (BBANN) of Sharma et al. (2023) in terms of residual analysis and spatial correlation. The Turkey earthquakes of 6th February 2023 are taken as the case study. The model-predicted values corresponding to a short period are compared with the recorded values for the events. We found that the model was able to capture ground motion trends without any bias in residuals. Also, in the spatial correlation scale, the model predictions are comparable with recorded values. The results highlighted the efficiency of the BBANN model in effectively capturing the spatial pattern of ground motion intensity measures. The study draws attention to the ability of PBS to generate non-ergodic ground motion and, hence, can be useful in seismic hazard and risk frameworks. [ABSTRACT FROM AUTHOR]

In view of the construction difficulties and other problems faced by structure construction in areas with high-altitude, high-intensity seismic regions, a dry-connection fully precast concrete frame structure was proposed. The connections in this structure eliminate the need for templates or auxiliary supports, facilitating simultaneous component installation on multiple floors and at multiple locations. This significantly reduces construction labor intensity and enhances the construction efficiency. To investigate the seismic performance of the structure, a 3-story test structure with a scale ratio of 1/2 was designed, and shaking table tests were conducted to study the dynamic characteristics and damage progression of the test structure under various intensities of earthquakes. The test results show that the structure performs well as designed. Then, a finite-element model of the structure was established, and numerical simulations were performed to investigate the seismic response characteristics and seismic vulnerability. The numerical simulation results indicated that the seismic performance of the fully precast concrete frame structure is slightly lower than that of the cast-in-place concrete frame structure, but sufficient to survive rare earthquakes without collapsing even under the action of near-field earthquakes. [ABSTRACT FROM AUTHOR]

This journal article titled "An open access dataset for strong-motion data (PGA, PGV, and Site VS30) of 2023 M6.2 Jishishan, Gansu, China earthquake" provides a dataset of strong-motion data from the 2023 M6.2 Jishishan earthquake in China. The dataset includes records of peak ground acceleration (PGA) and peak ground velocity (PGV) from 741 sensors, as well as site VS30 data. The article discusses the instruments used to collect the data and the processing scheme for the records. The authors also present methods used to estimate VS30 values for various locations in China, including field investigations and a model that incorporates observations and topographic slope. The authors compare their model to other existing models and find that it performs the best. The dataset is available online for access. The authors acknowledge their support and declare no conflicts of interest. [Extracted from the article]

The Xianshuihe fault, located in the southeastern Tibetan Plateau, stands as one of the most active faults in China. As assessing earthquake hazard relies on access to long‐term paleoseismological archives, this paper seeks to optimize the interpretation of paleoseismological records. We retrieved nine sediment cores from three lakes over a 30 km fault segment. Earthquake‐related deposits were identified through grain‐size analysis, XRF core scanning, and SEM observations of thin sections. Age models based on short‐lived radionuclides correlate these events with historical earthquakes, which are recorded with varying sensitivities to seismic intensity across the three lakes. We developed a code that evaluates the plausibility of rupture scenarios against sedimentary evidence: Each site is used as a binary paleoseismometer, indicating whether or not an earthquake reached a local intensity threshold. The combined evidence from the three sites allows to evaluate rupture scenarios on the Xianshuihe fault, according to rupture length‐magnitude scaling laws and intensity prediction equations. The most probable scenarios allow to discriminate the rupture area and magnitude range providing a good agreement with historical reconstructions. Our work demonstrates the potential of combining earthquake records to infer the magnitude and rupture zone of paleo‐earthquakes, even with a limited data set. Our approach, applicable across diverse geological settings and timescales, offers enhanced precision in understanding long‐term paleoseismology covering multiple earthquake cycles. However, establishing the synchronicity of events in such an active area—where earthquake return times are typically <100 years—demands highly accurate age models, which remains challenging. Key Points: Multi‐proxy analysis and short‐lived radioelement dating revealed earthquake deposits in three small mountain lakes in SE TibetThe lakes documented the historical seismicity of the Xianshuihe fault, showing varying sensitivities to seismic intensitiesComparing lacustrine records, a code using seismic scaling laws and fault geometry could discriminate possible paleo‐earthquake locations [ABSTRACT FROM AUTHOR]

Fragility curves are fundamental tools in seismic risk assessments, providing insights into the vulnerability of structures to earthquake-induced damages. These curves, which plot the probability of a structure reaching or exceeding various damage states against earthquake intensity, are critical for developing effective modification strategies. This review aims to present the characteristics between building- and site-specific fragility curves, which incorporate detailed local characteristics, and generic fragility curves that apply broader, more generalized parameters. We utilize the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology to systematically review the literature to address key research questions about the methodological differences, applications, and implications of these curve types in assessing seismic risks. The methods involved a comprehensive search and combination of existing studies on the topic, focusing on how these curves are developed and applied in real-world scenarios. The results from this review show that building- and site-specific curves, while more precise, require extensive data and are therefore more complex and costly to develop. In contrast, generic curves, though less accurate, offer a cost-effective solution for preliminary risk assessments over large areas. The conclusions drawn from this review suggest that while each type has its merits, the choice between building- and site-specific and generic fragility curves should be guided by the specific requirements of the seismic risk assessment task, including available resources and the need for precision in the vulnerability estimations. [ABSTRACT FROM AUTHOR]

This paper proposes a procedure to design low‐rise base‐isolated structures achieving a specific target level of earthquake‐induced loss (e.g., dollars, downtime) while complying with a predefined minimum level of structural reliability. The procedure is "direct" since the target loss is specified at the first step of the process, and virtually no design iterations are required. Direct loss‐based design (DLBD) is enabled by a simplified loss assessment module involving: (1) surrogate probabilistic seismic demand models representing the probability distribution of peak horizontal displacements and accelerations on top of the isolation layer conditional on different ground‐motion intensity levels; (2) approximations of the superstructure response; (3) simplified consequence models for isolation system and superstructure based on damage‐to‐loss ratios (economic loss or repair time); (4) simplified consequence models for acceleration‐ and drift‐sensitive non‐structural components, based on storey loss functions of a potential inventory of components. Given some basic geometrical parameters of the superstructure, DLBD provides the isolation system's force‐displacement curve and the required superstructure's strength complying with a selected loss target. The members' structural detailing follows the principles of direct displacement‐based design, sectional analysis, and the general theory of base isolation. The procedure is illustrated by designing six reinforced concrete wall buildings (two‐, three‐, and four‐storeys) base isolated with lead rubber bearings, to achieve predefined targets of expected repair time. Repair time is benchmarked against a more refined method adopting a cloud‐based non‐linear time history analysis, finding a maximum underestimation of 17%, thus confirming the dependability of DLBD. Such error is almost entirely attributable to the simplified estimation of peak floor accelerations, and it could be potentially eliminated by refining such estimation. [ABSTRACT FROM AUTHOR]

The slope of a linear approximation of a probabilistic seismic hazard curve, when it is represented in the log‐log scale, is a key parameter for seismic risk assessment based on closed‐form solutions, and other applications. On the other hand, it is observed that different hazard models can provide, at the same site, comparable ground shaking, yet appreciably different slopes for the same exceedance return period. Moreover, the slope at a given return period can increase or decrease from low‐ to high‐hazardous sites, depending on the models the probabilistic seismic hazard analysis (PSHA) is based on. In the study, the sensitivity of the slope to the main model components involved in PSHA was explored, that is: the earthquake rate, the magnitude and source‐to‐site distance distributions, and the value of the residual of ground motion models (GMM). With reference to a generic site, affected by an ideal seismic source zone, where magnitude follows the Gutenberg‐Richter (G‐R) relationship, it was found that the local slope of hazard curve increases with the following factors in descending order of importance: (i) increasing distance from the source; (ii) decreasing maximum magnitude and increasing b$b$‐value of the G‐R model; (iii) increasing rate of earthquakes of interest; (iv) increasing residual of the GMM. These results help explain the systematic differences in hazard curve slopes found in three authoritative hazard models for Italy, and the related impact on simplified risk assessment. [ABSTRACT FROM AUTHOR]

The global energy crisis is increasingly severe, and the construction industry, as a high-energy-consuming sector, is one of the main sources of carbon emissions. As a result, the development of green buildings has become imperative. Shear walls, as a common structural form in buildings, have their wall layout ratio significantly influencing the amount of building materials used, which is crucial for material reduction and carbon emission reduction during construction. This paper innovatively introduces the concept of the optimal shear wall layout ratio, focusing on the analysis of the variation patterns of wall ratios and their associated carbon emissions in both traditional and optimal models. Various optimal models are designed with shear wall length as the variable, and the relationship between shear wall layout ratio and carbon emissions is examined. Under a seismic fortification intensity of level 7 (0.1 g), the layout ratio of the optimal models does not exceed that of the traditional model (4.24%), and the carbon emissions are reduced by approximately 11%. A reasonable design of the shear wall layout ratio not only reduces carbon emissions in buildings and improves reverse performance but also promotes a dual enhancement in both economic and environmental benefits in the construction industry. [ABSTRACT FROM AUTHOR]

With the aim of achieving a graded-protection braced frame structure and minimizing the excessive residual deformation of traditional metal dampers under intense seismic action, a graded-yield-type metal self-centering brace (SC-GYMB) is proposed. The brace is composed of X-shaped and U-shaped steel plates with different yield point displacements, which jointly dissipate energy. Additionally, it employs a composite disc spring as a self-centering element to provide restoring force for the brace. The brace's basic structure and working mechanism are described, and the theoretical model for its restoring force is derived. The ABAQUS finite element software (ABAQUS 2021) is utilized to investigate the hysteretic performance of the SC-GYMB under low-cycle reciprocating load, while thoroughly discussing the influence of various model parameters on its key mechanical behavior. The results demonstrate a strong agreement between the theoretical restoring force model and the numerical simulation results. The hysteretic curves of the braces exhibit a distinct "flag" characteristic, indicating excellent energy dissipation capacity and self-centering performance. Moreover, these curves display a hierarchical yield behavior that satisfies the seismic performance requirements for different intensity earthquakes. The deformation mechanism of X-shaped steel sheets transitions from bending deformation during the initial loading stage to tensile deformation in the subsequent loading stage. Increasing the initial pre-compression force of the combined disc spring enhances the restoration performance of the brace. Augmenting the thickness of X-shaped or U-shaped steel sheets modifies the displacement and load at both the first and second yield points, thereby enhancing energy dissipation capacity and bearing capacity of the brace; however, it also leads to increased residual deformation. [ABSTRACT FROM AUTHOR]

In earthquake-prone regions, the seismic performance assessment of reinforced concrete (RC) continuous bridges is critical for ensuring their resilience and safety. This study proposes a fragility curve developed through a hybrid pushover–incremental dynamic (PO-ID) analysis to accurately evaluate the seismic vulnerability of RC continuous bridges. The proposed method integrates the advantages of pushover analysis, which provides insights into the bridge's capacity, with incremental dynamic analysis, which captures the bridge's response under varying earthquake intensities. The resulting fragility curves offer a more comprehensive understanding of the likelihood of bridge failure at different seismic intensities. Incremental dynamic analysis (IDA) effectively illustrates a bridge's response to increasing seismic demands but does not account for ultimate displacement under static lateral loads. Pushover analysis (POA) is useful for capturing maximum displacement capacity under static forces, yet it falls short of addressing the dynamic effects of near-fault ground motions. The hybrid approach combines the strengths of both IDA and POA, and this hybrid method's heightened sensitivity to damage states allows for earlier detection and conservative displacement estimates, improving seismic assessments, informing design and retrofitting practices, and enhancing safety by addressing transverse displacements and weak axis vulnerabilities. [ABSTRACT FROM AUTHOR]

The transverse-direction post-seismic running safety of a longitudinally connected ballastless track-continuous girder bridge (LCBTCGB) system considering earthquake damage state (EDS) was studied. In this study, a simulation model of an LCBTCGB was established, and the post-earthquake damage law of the LCBTCGB was analyzed by selecting the ground motion that had the greatest influence from within the existing studies. The EDS of key interlayer components and the residual deformation law of each layer structure of the LCBTCGB system were defined. Subsequently, the residual deformations and EDS from the simulation model were imported into a coupled dynamic model of the train, track, and bridge. Evaluation of running safety evaluation after an earthquake was carried out with and without considering EDS, and a running safety guidance diagram for after an earthquake is provided. The results revealed that under conditions of rare earthquakes, without considering EDS, the running safety judgment after the earthquake were underestimated, and the risk increased by 13.6%. Following the designed earthquake, the running safety risk after the earthquake increased by 18.7% if EDS was not considered. The risk of the running safety index exceeding the limit did not increase linearly with earthquake intensity with and without considering EDS. When the EDS was considered, derailment coefficients and wheel axle lateral forces exceeded the safety limit value at an earthquake intensity of 0.2 g, whereas these limit values were only exceeded at an earthquake intensity of 0.3 g when EDS is ignored. When the earthquake intensity reached 0.5 g, the influence on the derailment coefficient was greater but the difference in the wheel axle lateral forces was not significant with or without considering EDS. It is suggested that EDS should be considered when post-seismic running safety of LCBTCGBs are analyzed; otherwise, it will lead to misjudgment of running safety after an earthquake. [ABSTRACT FROM AUTHOR]

On 18 December 2023, a 6.2-magnitude earthquake struck Jishishan, affecting multiple counties and cities in Gansu and Qinghai Provinces. The seismic intensity of the meizoseismal area was VIII, resulting in extensive structural damage and building collapses. A damage assessment was conducted of the epicenter and surrounding high-intensity zones. To understand the typical structures and characteristics of the buildings that were damaged in these high-intensity zones, this study summarizes the characteristics of the damage to typical rural houses, compares the damage of the rural houses across different sites, and analyzes the causes behind these variations. The findings of the study indicate the following: (1) Timber and some brick–timber structures, due to their age, insufficient material strength, and lack of adequate connections between parts of the building, primarily experienced severe damage or total collapse, characterized by through-wall cracks, partial collapses, or complete collapses. (2) Brick–concrete structures predominantly suffered moderate to severe damage due to factors such as improper layout, uneven façades, and inadequate or incomplete seismic measures. The observed damage included significant wall cracks and extensive damage to two-story buildings. (3) Frame structures, mainly used for public facilities like schools, hospitals, and health centers, exhibited strong integrity and excellent seismic performance, resulting in minimal to no damage, with damage largely confined to non-load-bearing components. (4) The amplification effects of seismic waves in thick loess basin areas, slope sites, and the hanging wall effect of faults exacerbated structural damage to rural houses located in certain villages within the high-intensity areas. The results of this study can serve as a reference for post-disaster reconstruction and seismic retrofitting of buildings and contribute positively to enhancing the disaster resilience of rural housing. [ABSTRACT FROM AUTHOR]

This article presents the results of the LNEC-3D shaking table tests on a full-scale masonry cross vault without and with the textile reinforced mortar used as strengthening solution. The specimen has been tested in the scope of the European project SERA. TA 07 "Seismic Response of Masonry Cross Vaults: Shaking table tests and numerical validations". The specimen replicates a generic cross-section of a central bay located in a lateral nave of a three-nave church, derived from the intersection of two semi-circular barrel vaults with low rise. It is representative of a generic monumental church in Central Italy, generated by a squared base groin vault with a net span of 3.13 m and 1.13 m rise at full scale. A unidirectional seismic action is applied to develop shear damage in the shell of the vault. A detailed description of the two tests and the conclusions are presented. The response is evaluated based on the displacements, damage, and collapse mechanisms developed as a function of an increasing intensity earthquake testing protocol, in which a pre-processed strong ground motion component of the L'Aquila (Italy) earthquake (April 6, 2009) was used. [ABSTRACT FROM AUTHOR]

Jailolo, the capital of West Halmahera Regency, faces earthquake risks due to its proximity to a Jailolo volcano and a double subduction zone in Eastern Indonesia. This study is aimed at investigating the seismic hazard characteristics in Jailolo through the analysis of statistic and signal parameters. Analyzing seismic hazard characteristics in this region is crucial for assessing earthquake risks and understanding how local soil conditions influence ground shaking. Earthquake catalogs from several databases spanning from 1970 to 2018 were utilized. Additionally, 40 locations around Jailolo were surveyed using a short‐period seismometer to gather microtremor data. The earthquake catalogs underwent b value analysis using the maximum likelihood method, while microtremor data were examined for f0 and A0 using the horizontal‐to‐vertical spectrum ratio (HVSR) method. VS30 profiles were derived using the H/V curve inversion method. The b value characterizes earthquake size distribution, HVSR evaluates ground properties, especially the shallow subsurface, and VS30 represents the time‐averaged shear wave velocity in the upper 30 m of the Earth's surface. The findings revealed the average b value around Jailolo is 1.36 with a 15% deviation, categorizing the area as earthquake prone and volcanic. The values of f0 and A0 ranged from 0.536 to 2.44 Hz and 8.97 to 21.2, respectively. The results of f0 and A0 suggested that the Jailolo area is predominantly characterized by thick sediment. The H/V curve analysis provided a VS30 profile ranging from 109 to 460 m/s, indicating that the area is dominated by sediment consisting of stiff soil, very dense soil, and soft rock. In conclusion, Jailolo is highly prone to earthquakes due to its seismic and volcanic activity, supported by soil characteristics that can amplify seismic waves and increase ground shaking intensity during earthquakes. These findings stress the need for long‐term seismic monitoring and community involvement to mitigate seismic risks. [ABSTRACT FROM AUTHOR]

The nonlinearity of the ballastless track-simply supported girder bridge primarily manifests in the bearings and track structure during earthquakes. While existing research has elucidated the effects of bearing nonlinearity on running safety during earthquakes, the effects of track structure nonlinearity remain unclear. Therefore, this study further explores the effects of track structure nonlinearity on running safety during earthquakes. First, a dynamic analysis of the train–track–bridge coupled system (TTBCS) incorporating track structure nonlinearity, was performed using the ANSYS-TRBF (train–rail–bridge-foundation coupled system dynamic analysis software, TRBF) co-simulation approach to assess running safety during earthquakes. Then, by comparing results from the TTBCS models both with and without track structure nonlinearity, this study clarified the effects of track structure nonlinearity on dynamic response and running safety assessment (RSA) indices. It was found that neglecting track structure nonlinearity during earthquakes can result in an overestimation of the Nadal, leading to an inaccurate RSA. Moreover, this effect intensifies as the seismic intensity increases. By explaining these results, this study elucidates the mechanism by which track structure nonlinearity affects running safety. Finally, this study specified the necessary seismic intensities and vehicle speed ranges needed to consider track structure nonlinearity, and established a comprehensive influence domain. This study reveals the effects of track structure nonlinearity on running safety during earthquakes, contributing to a more accurate RSA during earthquakes. [ABSTRACT FROM AUTHOR]

Taking the typical brick–wood structure houses in northern China as the research object, two 1/2‐scale brick–wood structure house models with the same size and layout were tested using large‐scale shaking table test technology. Model 1 has seismic measures of ring beams, structural columns, wall tie bars, reinforced concrete lintels for doors and windows, and purlin bottom plates. Model 2 has the same structural layout, dimensions, and construction technical conditions as Model 1 but lacks the seismic measures of ring beams and structural columns as Model 1, and the other construction measures are the same. In the test, the Wenchuan record, EL‐Centro record, and Lanzhou artificial record were selected to simulate the horizontal seismic action on the models. Through the analysis and comparison of the seismic damage process and seismic response characteristics of the two models, the results showed that horizontal shear failure was the main failure mode of single‐story brick–wood houses, and the protruding gable wall parts of the crosswall were the weak points for seismic resistance. The seismic measures adopted in the test effectively improved the seismic performance of the houses, with Model 1 and Model 2 achieving the basic seismic fortification of intensity VIII and IX, respectively. The relevant research results presented in this paper clarify the seismic response law and seismic failure mechanism of brick–wood houses. Meanwhile, the corresponding seismic technical measures proposed based on these results have certain guiding significance for the construction of suburban or rural houses. [ABSTRACT FROM AUTHOR]

Two new structure-specific scalar intensity measures for plane reinforced concrete moment resisting frames under far-fault ground motions are proposed. These intensity measures, of the spectral acceleration and spectral displacement type, are characterized as multi-modal and multi-level. They encompass the effects of the first four natural periods and are defined for four performance levels, including considerations of inelasticity up to the collapse prevention level. This is achieved with the aid of equivalent linear modal damping ratios previously developed by the authors for performance-based seismic design purposes. These modal damping ratios, dependent on period, soil type, and deformation, are associated with the transformation of the original multi-degree-of-freedom (MDOF) nonlinear structure into an equivalent MDOF linear one. The proposed intensity measures are conceptualized to be simple and elegant, incorporating all the aforementioned features rationally, without the artificial combination of terms, definition of period ranges, or addition of coefficients determined by optimization procedures. This approach sets it apart from existing measures that attempt to account for multiple modes and inelasticity. A comparison of the proposed intensity measures against ten of the most popular existing ones in the literature, focusing on efficiency, practicality, proficiency, scaling robustness and sufficiency, demonstrate their advantages. [ABSTRACT FROM AUTHOR]

ASMI, the Italian Archive of Historical Earthquake Data, is a data collection distributed online that provides seismological data on more than 6600 earthquakes that occurred in the Italian peninsula and surrounding areas from 461 BC to the present day, based on more than 460 seismological data sources. ASMI is the Italian node of AHEAD, the European Archive of Historical Earthquake Data, which is, in turn, the European node providing data on historical earthquakes to EPOS ERIC, the European Plate Observing System, a European Research Infrastructure Consortium. ASMI distributes earthquake parameters, sets of macroseismic intensity data and other details about earthquake effects, together with the bibliographical reference of the data source and, if possible the data source itself. ASMI's web portal allows users to query the data by earthquake or by data source, and to download the earthquake parameters and macroseismic intensities and represent them on interactive maps and tables. ASMI is updated regularly with new data on past and recent earthquakes. ASMI is the basic source of data for the Italian Macroseismic Database (DBMI) and the Parametric Catalogue of Italian Earthquakes (CPTI). This article describes the archive content and structure, its main features and functionalities, and its potential seismological research applications. [ABSTRACT FROM AUTHOR]

To study the evolution mechanism of fracture failure on dangling concrete pavement slab in high seismic intensity areas along river during operation, the formation process of cracks at the top and bottom of dangling concrete pavement slab in high seismic intensity areas along river was analyzed, and the dangling concrete pavement slab generated by river erosion was studied through fracture mechanics. By establishing the physical and mechanical models of the dangling pavement along the river in high seismic intensity areas, the dangling pavement slab model of the double-crack primary control structural surface was obtained. With the fracture mechanics double-crack model of dangling pavement slab along river in high seismic intensity areas, the forces at different acting positions were divided into physical forces and surface forces through elastic theory. The corresponding type I stress intensity factors K I S and K I V and type II stress intensity factors K II S and K II V were calculated, respectively. According to the superposition principle of stress intensity factors, KI and KII were obtained. For the fracture problem of plane composite materials under the action of types I and II loads, the joint stress intensity factor Ke can be obtained from the maximum tensile stress criterion satisfied by any point in the cracking direction of the main control structure. Through the example analysis, the variation law of the stability coefficients of the double-crack main control structure surface in the dangling concrete pavement slab under different seismic intensities, vehicles, and action positions was obtained. The recommended driving values for the dangling pavement slab were given by backward pushing method. Finally, numerical simulation for correlation verification was carried out. In this paper, the double-crack main control structural plane of the dangling concrete pavement slab is regarded as the vertical form of the top and bottom sections. Furthermore, follow-up studies will be conducted on the fracture damage problem of the dangling concrete pavement slabs with more complex multi-crack main control structures. [ABSTRACT FROM AUTHOR]