Probabilistic Seismic Hazard Analysis Method Research Articles

Study on seismic risk assessment model of water supply systems in mainland China

Abstract. Using the peak ground acceleration (PGA) under four exceedance probabilities calculated via a probabilistic seismic hazard analysis method for China, the probability density function of PGA was obtained by fitting with the Cornell seismic hazard exceedance probability PGA function model. Combined with the seismic fragility function of the water supply system calculated on the basis of the empirical matrix of actual earthquake damage and the exposure of fixed assets, the expected seismic loss and expected loss rate models of the water supply system were established, and the classification standard with the expected seismic loss rate of the water supply system as the index was proposed. The seismic fragility of the water supply system was classified, and the exposure of the water supply system was analyzed. The total fixed assets in the Statistical Yearbook of Urban Water Supply, henceforth called Water Supply Yearbook, were taken as the exposure to earthquake in the region. The accuracy of the fragility model in this paper was verified through the actual earthquake damage losses in Deyang. Taking the water supply system of 720 cities in mainland China as an example, the distribution maps of expected seismic loss and expected loss rate were calculated and drawn. The expected loss rate model was verified by the key earthquake prevention areas in mainland China. The assessment model based on the expected loss and expected loss rate was taken as the seismic risk assessment model of water supply systems in mainland China.

Analysis of Soil Vulnerability Level Due to Earthquake in Tarutung Region and Its Surroundings Using Probabilistic Seismic Hazard Analysis Method

Analysis of Soil Vulnerability Level Due to Earthquake in Tarutung Region and Its Surroundings Using Probabilistic Seismic Hazard Analysis Method

Analisis Aselerasi Riwayat Waktu pada Wilayah Spesifik di Yogyakarta dengan Sumber Gempa Subduksi Berdasarkan Peta Gempa 2002

Indonesia is a country that is very prone to earthquake disasters. Earthquakes cause damage especially to buildings. In building planning, the usual earthquake load is the earthquake load from the spectral response. The use of earthquake loads from time history is very rarely used because of the difficulty of finding accurate data for an area. In this study, Alana Hotel and Apartment were chosen as research objects to find artificial time history. All earthquake data affecting Yogyakarta region were collected from several sources. Seismic hazard analysis in this study uses the PSHA (Probabilistic Seismic Hazard Analysis) method by calculating the main earthquake only. The selection of attenuation functions is based on the similarity of geological and tectonic conditions in Indonesia. These attenuation functions produce a seismic hazard curve and a uniform hazard spectrum response. The selection of time history data for bedrock is based on the results of the deaggregation process in the form of dominant magnitude and dominant distance from the subduction earthquake source. It is necessary to adjust the spectrum response in the time history data to fit the research location. Furthermore, earthquake waves from the bedrock are propagated to the surface. The results show that the peak time history acceleration value after surface propagation increased by 1.51 times than the time history in bedrock.

PENENTUAN PREMI MURNI DI KABUPATEN KEPAHIANG PROVINSI BENGKULU DENGAN MEMPERHITUNGKAN PELUANG KEJADIAN GEMPA BUMI DAN RASIO KERUSAKAN BANGUNAN

Indonesia is a country that is very vulnerable to earthquakes, one of which is in Bengkulu Province, especially Kepahiang Regency. To deal with risks or losses caused by earthquakes, insurance can be purchased. Therefore, in this study, earthquake insurance premiums will be determined by taking into account the probability of an earthquake occurring and the ratio of damage to buildings in Kepahiang Regency. The PSHA (Probabilistic Seismic Hazard Analysis) method is used to determine the probability of an earthquake occurring. In the PSHA process, earthquake data will be collected and analyzed to identify earthquake sources, characterize earthquake sources, and calculate earthquake hazard (the probability of an earthquake). Damage data on buildings will be processed to obtain a ratio of building damage. After that, a pure premium will be obtained, by multiplying the EADR (Expected Annual Damage Ratio) value with the sum insured of the building, where EADR is the estimated level of annual damage due to earthquakes in an area

Response Spectrum Design Based on Site Class and Site-Specific Analysis in the Transition Zone

The building structure design needs to pay attention to the seismic code and all its consequences. Building A which will be built in Sleman, Special Region of Yogyakarta is 12.20 km from the Opak Fault causing the Bantul Earthquake of Mw 6.3 in 2006, needs seismic analysis properly using SNI 1726:2019. Based on the site near fault criteria on seismic code, Building A does not belong to the site near fault category, so it used the Probabilistic Seismic Hazard Analysis method. However, considering its distance and magnitude, the value is in the range of the requirements limit. Hence, it is still relevant when compared to the Deterministic Seismic Hazard Analysis method for designing the response spectrum. Based on the site classification in the seismic code, a site that is vulnerable to liquefaction belongs to the site class F and therefore requires site-specific analysis. The site-specific surface response spectrum is taken from the equivalent-linear and non-linear site response analysis using Deepsoil v7.0 software. The response spectrum is also calculated based on site class according to the shear wave velocity (v s) and N-SPT criteria. The site-specific spectral acceleration results are compared to 80% of the site class E spectral acceleration, as required. The site belongs to site class D using v s criteria and belongs to site class E using the N-SPT criteria. Only the equivalent-linear site response spectrum in the modified maximum horizontal direction spectrum is eligible when compared to requirements. Most of the non-linear site response spectrum results or the geometric mean response spectrum of the equivalent-linear site response results can satisfy the requirements compared to 80% of the site class D spectral acceleration because the site response analysis uses the v s parameter. The non-linear site response spectral acceleration is smaller than the equivalent-linear site response spectral acceleration.

Seismic Hazard Analysis of China’s Mainland Based on a New Seismicity Model

Based on the seismic source model in the Fifth Generation Seismic Ground Motion Parameters Zonation Map of China (FGSGMPZMC), a new seismic fault model, the new zonation of seismic risk areas (SRAs), and the estimation of seismicity rates for 2021–2030, this study constructed a new time-dependent seismic source model of China’s mainland, and used the probabilistic seismic hazard analysis method to calculate seismic hazard by selecting the ground motion models (GMMs) suitable for seismic sources in China. It also provided the probabilities of China’s mainland being affected by earthquakes of modified Mercalli intensity (MMI) VI, VII, VIII, IX, and ≥ X in 2021–2030. The spatial pattern of seismic hazards presented in this article is similar to the pattern of the FGSGMPZMC, but shows more details. The seismic hazards in this study are higher than those in the FGSGMPZMC in the SRAs and fault zones that can produce large earthquakes. This indicates that the seismic source model construction in this study is scientific and reasonable. There are certain similarities between the results in this study and those of Rong et al. (2020) and Feng et al. (2020), but also disparities for specific sites due to differences in seismic source models, seismicity parameters, and GMMs. The results of seismic hazard may serve as parameter input for future seismic risk assessments. The hazard results can also be used as a basis for the formulation of earthquake prevention and mitigation policies for China’s mainland.

A non-extensive approach to probabilistic seismic hazard analysis

Abstract. We modify the probabilistic seismic hazard analysis (PSHA) formulation by replacing the Gutenberg–Richter power law with the SCP (Sotolongo-Costa and Posadas) non-extensive model for earthquake size distribution and call it NEPSHA. The SCP claimed to model the regional seismicity better than the classical models. The proposed method (NEPSHA) is implemented in the Tehran region, and the results are compared with the classic PSHA method. The hazard curves show that NEPSHA gives a higher hazard, especially in the range of practical return periods. The uniform hazard spectra of NEPSHA provide more spectral accelerations, especially for the medium-height buildings, which are the most common urban structures.

Distribution of seismicity hazard levels using PGA analysis with the PSHA method in the Ciletuh Geopark Area, Sukabumi, Indonesia

The regional structure in Java Island, Indonesia, was influenced by the collisional activity of the Eurasian and Indo-Australian plates, which resulted from mélange rocks outcrops in Ciletuh. Ciletuh is one of the geotourism conservation areas included in the UGG (UNESCO Global Geoparks). This area is in the path of the Cimandiri Fault and the Sunda Strait Megathrust, resulting in a unique geological diversity and a place where the oldest rocks are exposed in West Java. In addition, the potential impact of seismicity on the Ciletuh geopark area is quite significant. The potential for seismicity can be analyzed and calculated. In this study, PGA (Peak Ground Acceleration) analysis on bedrock was conducted using the PSHA (Probabilistic Seismic Hazard Analysis) method. The data used for the PSHA method is in the form of background, fault, and megathrust provided by the National Earthquake Study Center (PuSGeN). This research shows that the PGA value in the Ciletuh Geopark area is influenced by how close it is to the location of the earthquake source. Pelabuhanratu Subdistrict has the highest PGA value based on all earthquake sources when combined.

Communication Network Reliability Under Geographically Correlated Failures Using Probabilistic Seismic Hazard Analysis

The research community’s attention has been attracted to the reliability of networks exposed to large-scale disasters and this has become a critical concern in network studies during the last decade. Earthquakes are high on the list of those showing the most significant impacts on communication networks, and simultaneously, they are the least predictable events. This study uses the Probabilistic Seismic Hazard Analysis method to estimate the network element state after an earthquake. The approach considers a seismic source model and ground prediction equations to assess the intensity measure for each element according to its location. In the simulation, nodes fail according to the building’s fragility curves. Similarly, links fail according to a failure rate depending on the intensity measure and the cable’s characteristics. We use the source-terminal, and the diameter constrained reliability metrics. The approach goes beyond the graph representation of the network and incorporates the terrain characteristics and the component’s robustness into the network performance analysis at an affordable computational cost. We study the method on a network in a seismic region with almost 9000 km of optical fiber. We observed that for source-terminal that are less than 500 km apart the improvements are marginals while for those that are more than 1000 km apart, reliability improves near a 30% in the enhanced designs. We also showed that these results depend heavily on the robustness/fragility of the infrastructure, showing that performance measures based only the network topology are not enough to evaluate new designs.

Earthquake Risk Probability Evaluation for Najin Lhasa in Southern Tibet

The probabilistic seismic hazard analysis (PSHA) method is effectively used in an earthquake risk probability evaluation in seismogenic regions with active faults. In this study, by focusing on the potential seismic source area in Najin Lhasa, southern Tibet, and by incorporating the PSHA method, we determined the seismic activity parameters and discussed the relationship of ground motion attenuation, the seismic hazard probability, and the horizontal bedrock ground motion acceleration peak value under different transcendence probabilities in this area. The calculation results show that the PSHA method divides the potential source area via specific tectonic scales and detailed tectonic markers, which reduces the scale of the potential source area and better reflects the uneven spatial distribution of seismic activity in the vicinity of Najin. The corrected attenuation relationship is also in line with the actual work requirements and is suitable for earthquake risk analysis. In addition, the major influences on the peak acceleration of ground motion in the study area are mainly in the potential source areas of Qushui (M7.5), Dangxiong (M8.5), and Kangma (M7.5). The peak horizontal ground motion acceleration (PGA) with a transcendence probability of 10% in 50 years is 185.9 cm/s2, and that with a transcendence probability of 2% in 50 years is 265.9 cm/s2.

Penerapan Teorema Probabilitas Total dalam Analisis Resiko Gempa

Total probabilistic theorem was applied to analyze seismic risk by mean Probabilistic Seismic Hazard Analysis (PSHA). Earthquake as natural earthquakes as a random natural event was approached by the concept of uncertainty. The PSHA method is described in 5 (five) stages of work, called identificating the source of the earthquake, characterizing the earthquake source, characterizing the seismicity, determinating the movement of soil surface occurring at a location due to the earthquake, the combining the uncertainty of the location of the earthquake, magnitude of the earthquake and prediction of soil surface movement parameters. Ez-Frisk computer Program was used to perform earthquake risk calculation. Earthquake risk analysis for the city of Bontang, East Kalimantan taken as a case study. Peak Ground Acceleration (PGA) in Bontang base rocks for some periodic of time presented in chart form as result of earthquake risk analysis.

A practical probabilistic earthquake hazard analysis tool: case study Marmara region

Earthquakes have a damaging impact on the economic welfare and resilience of communities, particularly in developing countries. Seismic hazard assessment is the first step towards performing prevention, preparedness, and response or recovery actions to reduce seismic risk. This paper presents a computation tool for predicting the seismic hazard at the macro level as a part of a comprehensive multi-hazard framework on earthquake risk assessment. The probabilistic seismic hazard analysis (PSHA) procedure is based on the Monte-Carlo approach, and particular attention is paid to the definition of source zones assigned in the study area. Both Poisson and time dependent (renewal) models are adopted to quantify the effect of temporal dependencies between seismic events,while near-field rupture directivity effects are also taken into account. Marmara region in Turkey is selected as a case study area to perform a new seismic hazard analysis and verify the accuracy of the proposed tool. The results show good agreement with results from the recent SHARE project and the latest Turkish Earthquake Design code hazard maps. This confirms that the proposed PSHA method can be an attractive alternative to the direct integration based methods due to its practicality and powerful handling of uncertainties.

ANALISIS PENDUGAAN BAHAYA KEGEMPAAN DI BATUAN DASAR UNTUK WILAYAH LAMPUNG MENGGUNAKAN METODE PSHA

Analysis of seismic hazard estimation is one method for estimating the effect of earthquakes. The purpose of this study was to determine the maximum value of ground acceleration in bedrock or PGA values for the Lampung Province region. This analysis of seismic hazard estimation is carried out by a probabilistic seismic hazard analysis (PSHA) method. In the process of estimating the influence of earthquakes, the PSHA method principally uses 3 types of earthquake sources, namely the source of background earthquakes, subduction earthquakes (earthquake subduction) and fault earthquakes (faut). The calculation of the estimated seismic hazard value is carried out using the 2007 USGS PSHA program. The distribution of seismic hazard values for the Lampung Province region on bedrock with a 500-year return period or a 10% probability on the PGA condition (T = 0) is 0.1 g to 1, 3 g and a 2500 year return period or a probability of 2% in the PGA condition (T = 0) is 0.1 g to 1.3 g.

Probabilistic seismic landslide hazard assessment: a case study in Tianshui, Northwest China

Probabilistic analysis in the field of seismic landslide hazard assessment is often based on an estimate of uncertainties of geological, geotechnical, geomorphological and seismological parameters. However, real situations are very complex and thus uncertainties of some parameters such as water content conditions and critical displacement are difficult to describe with accurate mathematical models. In this study, we present a probabilistic methodology based on the probabilistic seismic hazard analysis method and the Newmark’s displacement model. The Tianshui seismic zone (105°00′–106°00′ E, 34°20′–34°40′ N) in the northeastern Tibetan Plateau were used as an example. Arias intensity with three standard probabilities of exceedance (63%, 10%, and 2% in 50 years) in accordance with building design provisions were used to compute Newmark displacements by incorporating the effects of topographic amplification. Probable scenarios of water content condition were considered and three water content conditions (dry, wet and saturated) were adopted to simulate the effect of pore-water on slope. The influence of 5 cm and 10 cm critical displacements were investigated in order to analyze the sensitivity of critical displacement to the probabilities of earthquake-induced landslide occurrence. The results show that water content in particular, have a great influence on the distribution of high seismic landslide hazard areas. Generally, the dry coverage analysis represents a lower bound for susceptibility and hazard assessment, and the saturated coverage analysis represents an upper bound to some extent. Moreover, high seismic landslide hazard areas are also influenced by the critical displacements. The slope failure probabilities during future earthquakes with critical displacements of 5 cm can increase by a factor of 1.2 to 2.3 as compared to that of 10 cm. It suggests that more efforts are required in order to obtain reasonable threshold values for slope failure. Considering the probable scenarios of water content condition which is varied with seasons, seismic landslide hazard assessments are carried out for frequent, occasional and rare earthquake occurrences in the Tianshui region, which can provide a valuable reference for landslide hazard management and infrastructure design in mountainous seismic zones.

A földrengéskockázat elemzése valószínűségi módszerrel

The goal of seismic hazard engineering analyses is to ensure that the planned structures can withstand a given level of ground shaking. There is a great deal of uncertainty about the location, size and resulting ground motion intensity of future earthquakes. Probabilistic Seismic Hazard Analysis (PSHA) tries to quantify these uncertainties, and combine them to produce an explicit description of the future shaking that may occur at a site.This work demonstrates the application of the method by specific calculative example. The probability (that is more than the average) of ground motion intensity is calculated by PSHA equations in the most dangerous zone of Hungary regarding earthquakes.We can read only a little about the mathematical background of the PSHA method in Hungarian journals or books. The aim of this work is to help the reader understand the application and the limitations of PSHA with the help of the probability theory.

Grid Source Event-Based Seismic Hazard Assessment of Iran

In classical probabilistic seismic hazard analysis method, some basic assumptions are considered in modeling seismic sources. This is done to simplify the procedure and also to handle the lack of information. Many methods assume the homogeneity in the location of future earthquake events within the seismic sources. But some newer researches propose the method of Monte-Carlo simulation for determining the location of future earthquake events based on the observed data as presented in the earthquake catalogues. Another source of uncertainty is raised from assuming that the relative seismicity of different magnitude bins is uniform all over the defined sources, especially for area sources. Dividing the entire country into a few large seismotectonic provinces and the delineation of these major seismotectonic provinces as area sources has been widely used in classical seismic hazard assessment. To determine such provinces, geological, geophysical and tectonic data are required as well as observed earthquake data. The knowledge in these areas is limited and full of uncertainty. This study introduces the grid source event-based method to alleviate the mentioned problem with modeling the spatial pattern of seismicity more faithfully. Iran is chosen as a case study to evaluate the method utilizing 117 years of instrumental recorded earthquake data. The PGA values evaluated in the current study are generally lower than the results of previous studies except for some few spots due to crossing the historical events out and also lesser smoothed seismicity distribution.

Comparative study of three probabilistic methods for seismic hazard analysis: case studies of Sochi and Kamchatka

This study examines the effect of the procedures used in three different probabilistic seismic hazard analysis (PSHA) methods for estimating the rates of exceedance of ground motion. To evaluate the effect of these procedures, the Cornell–McGuire and Parametric-Historic methods, and the method based on Monte Carlo simulations are employed, and the seismic source model, based on spatially smoothed seismicity, is used in the calculations. Two regions in Russia were selected for comparison, and seismic hazard maps were prepared for return periods of 475 and 2475 years. The results indicate that the choice of a particular method for conducting PSHA has relatively little effect on the hazard estimates. The Cornell–McGuire method yielded the highest estimates, with the two other methods producing slightly lower estimates. The variation among the results based on the three methods appeared to be virtually independent of the return period. The variation in the results for the Sochi region was within 6%, and that for the Kamchatka region was within 10%. Accordingly, the considered PSHA methods would provide closely related results for areas of moderate seismic activity; however, the difference among the results would apparently increase with an increase in seismic activity.

Tsunami hazard assessment along the Chinese mainland coast from earthquakes in the Taiwan region

Tsunami disasters have been documented several times in Chinese history, mostly in the Taiwan region. To assess the tsunami hazard along the coast of mainland China from sources in Taiwan, this study analyzed historical tsunamis and undersea seismic events around Taiwan and found that the frequency and magnitude of earthquakes around Taiwan are significantly higher than in the adjacent Ryukyu and Manila trenches. The probabilistic seismic hazard analysis method was adopted to estimate the maximum possible earthquake magnitude around Taiwan. Then, six tsunami sources were assumed in those places where both earthquakes and tsunamis have occurred previously. Numerical models of the tsunamis were used to calculate the probable maximum tsunami amplitude and tsunami arrival time. The largest tsunami amplitude and the shortest arrival time were drawn on a GIS map. The modeling results provided a summary of tsunami hazards along the coast of mainland China from tsunami sources in Taiwan. The results showed that tsunamis triggered by the maximum possible earthquakes in the Taiwan region would arrive first at Zhejiang, Fujian, Guangdong, and Hainan Provinces within 3 h; the largest tsunami amplitude was up to 3.3 m. Thus, parts of Zhejiang, Fujian, and Guangdong Provinces were identified as regions with the highest hazard levels.

Effect of alternative distributions of ground motion variability on results of probabilistic seismic hazard analysis

Probabilistic seismic hazard analysis (PSHA) is a regularly applied practice that precedes the construction of important engineering structures. The Cornell–McGuire procedure is the most frequently applied method of PSHA. This paper examines the fundamental assumption of the Cornell–McGuire procedure for PSHA, namely the log-normal distribution of the residuals of the ground motion parameters. Although the assumption of log-normality is standard, it has not been rigorously tested. Moreover, the application of the unbounded log-normal distribution for the calculation of the hazard curves results in nonzero probabilities of the exceedance of physically unrealistic amplitudes of ground motion parameters. In this study, the distribution of the residuals of the logarithm of peak ground acceleration is investigated, using the database of the strong-motion seismograph networks of Japan and the ground motion prediction equation of Zhao and co-authors. The distribution of residuals is modelled by a number of probability distributions, and the one parametric law that approximates the distribution most precisely is chosen by the statistical criteria. The results of the analysis show that the most accurate approximation is achieved with the generalized extreme value distribution for a central part of a distribution and the generalized Pareto distribution for its upper tail. The effect of replacing a log-normal distribution in the main equation of the Cornell–McGuire method is demonstrated by the calculation of hazard curves for a simple hypothetical example. These hazard curves differ significantly from one another, especially at low annual exceedance probabilities.

Determination of the Spatial Distribution Function of Bohai Seismic Tectonic Area

The spatial distribution function assigns seismicity parameters of seismic zone and belt to the potential earthquake source area seismic by the magnitude interval, determination of the spatial distribution function is one of the key technologies to comprehensive probabilistic seismic hazard analysis methods, and the results will directly influence seismic hazard analysis results of the calculated sites. However, the spatial distribution functions are hard to get by statistics due to serious lack of seismic samples, and evaluation factors used in the actual work are too complex and not independent, the spatial distribution function is lack of reliability. In this paper, Bohai seismic tectonic area is chosen as an example; geological data are obtained from the newly built offshore oil platform engineering in recent decades, while seismic activity data are obtained by checking from historical difficult seismic parameters. Five factors are adopted in this area, including potential seismic focus area, seismic tectonic, seismic activity level, long-term forecasts, and strong earthquake recurrence interval and construct empty segment. Spatial distribution function of Bohai Sea earthquake structure area is obtained by weighted comprehension; it reflects the spatial and temporal heterogeneity of seismic activities in the area, and provides the calculation parameters for the probabilistic seismic hazard analysis.