Dissertations / Theses on the topic 'Earthquake Scenario'

Disasters can occur without warning and severely test society’s capacity to cope, significantly altering the relationship between society and the built and natural environments. The scale of a disaster is a direct function of the pre-event actions and decisions taken by society. Poor pre-event planning is a major contributor to disaster, while effective pre-event planning can substantially reduce, and perhaps even avoid, the disaster. Developing and undertaking effective planning is therefore a vital component of disaster risk management in order to achieve meaningful societal resilience. Disaster scenarios present arguably the best and most effective basis to plan an effective emergency response to future disasters. For effective emergency response planning, disaster scenarios must be as realistic as possible. Yet for disasters resulting from natural hazards, intricately linked secondary hazards and effects make development of realistic scenarios difficult. This is specially true for large earthquakes in mountainous terrain. The primary aim of this thesis is therefore to establish a detailed and realistic disaster scenario for a Mw8.0 earthquake on the plate boundary Alpine fault in the South Island of New Zealand with specific emphasis on secondary effects. Geologic evidence of re-historic earthquakes on this fault suggest widespread and large-scale landsliding has resulted throughout the Southern Alps, yet, currently, no attempts to quantitatively model this landsliding have been undertaken. This thesis therefore provides a first attempt at quantitative assessments of the likely scale and impacts of landsliding from a future Mw8.0 Alpine fault earthquake. Modelling coseismic landsliding in regions lacking historic inventories and geotechnical data (e.g. New Zealand) is challenging. The regional factors that control the spatial distribution of landsliding however, are shown herein to be similar across different environments. Observations from the 1994 Northridge, 1999 Chi-Chi, and 2008 Wenchuan earthquakes identified MM intensity, slope angle and position, and distance from active faults and streams as factors controlling the spatial distribution of landsliding. Using fuzzy logic in GIS, these factors are able to successfully model the spatial distribution of coseismic landsliding from both the 2003 and 2009 Fiordland earthquakes in New Zealand. This method can therefore be applied to estimate the scale of landsliding from scenario earthquakes such as an Alpine fault event. Applied to an Mw8.0 Alpine fault earthquake, this suggests that coseismic landsliding could affect an area >50,000 km2 with likely between 40,000 and 110,000 landslides occurring. Between 1,400 and 4,000 of these are expected to present a major hazard. The environmental impacts from this landsliding would be severe, particularly in west-draining river catchments, and sediment supply to rivers in some catchments may exceed 50 years of background rates. Up to 2 km3 of total landslide debris is expected, and this will have serious and long-term consequences. Fluvial remobilisation of this material could result in average aggradation depths on active alluvial fans and floodplains of 1 m, with maximum depths substantially larger. This is of particular concern to the agriculture industry, which relies on the fertile soils on many of the active alluvial fans affected. This thesis also investigated the potential impacts from such landsliding on critical infrastructure. The State Highway and electrical transmission networks are shown to be particularly exposed. Up to 2,000 wooden pole and 30 steel pylon supports for the transmission network are highly exposed, resulting in >23,000 people in the West Coast region being exposed to power loss. At least 240 km of road also has high exposure, primarily on SH6 between Hokitika and Haast, and on Arthur’s and Lewis Passes. More than 2,750 local residents in Westland District are exposed to isolation by road as a result. The Grey River valley region is identified as the most critical section of the State Highway network and pre-event mitigation is strongly recommended to ensure the road and bridges here can withstand strong shaking and liquefaction hazards. If this section of the network can remain functional post-earthquake, the emergency response could be based out of Wellington using Nelson as a forward operating base with direct road access to some of the worst-affected locations. However, loss of functionality of this section of road will result in >24,000 people becoming isolated across almost the entire West Coast region. This thesis demonstrates the importance and potential value of pre-event emergency response planning, both for the South Island community for an Alpine fault earthquake, and globally for all such hazards. The case study presented demonstrates that realistic estimates of potential coseismic landsliding and its impacts are possible, and the methods developed herein can be applied to other large mountainous earthquakes. A model for developing disaster scenarios in collaboration with a wide range of societal groups is presented and shown to be an effective method for emergency response planning, and is applicable to any hazard and location globally. This thesis is therefore a significant contribution towards understanding mountainous earthquake hazards and emergency response planning.

Thesis (Ph. D.)--University of California, San Diego, 2008.
Title from first page of PDF file (viewed June 12, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Federal, state and local officials are planning for a (M) 7.8 San Andreas Earthquake Scenario in the Southern California Catastrophic Earthquake Response Plan that would require initial emergency food and water resources to support from 2.5 million to 3.5 million people over an eight-county region in Southern California. However, a model that identifies locations of affected populations—with consideration for social vulnerability, estimates of their emergency logistical resource requirements, and their resource requirements over time—has yet to be developed for the emergency response plan.

The aim of this study was to develop a modeling methodology for emergency logistical resource requirements of affected populations in the (M) 7.8 San Andreas Earthquake Scenario in Southern California. These initial resource requirements, defined at three-days post-event and predicted through a probabilistic risk model, were then used to develop a relative risk ratio and to estimate resources requirements over time. The model results predict an “at-risk” population of 3,352,995 in the eight-county study region. In Los Angeles County, the model predicts an “at- risk” population of 1,421,415 with initial requirements for 2,842,830 meals and 4,264,245 liters of water. The model also indicates that communities such as Baldwin Park, Lancaster-Palmdale and South Los Angeles will have long-term resource requirements.

Through the development of this modeling methodology and its applications, the planning capability of the Southern California Catastrophic Earthquake Response Plan is enhanced and provides a more effective baseline for emergency managers to target emergency logistical resources to communities with the greatest need. The model can be calibrated, validated, generalized, and applied in other earthquake or multi-hazard scenarios through subsequent research.

2011/2012
Seismic hazard assessment can be performed following a neo-deterministic approach (NDSHA), which allows to give a realistic description of the seismic ground motion due to an earthquake of given distance and magnitude. The approach is based on modelling techniques that have been developed from a detailed knowledge of both the seismic source process and the propagation of seismic waves. This permits to define a set of earthquake scenarios and to simulate the associated synthetic signals without having to wait for a strong event to occur. NDSHA can be applied at different geographic scale with different detail levels of modelling. At local scale the source and site characteristics can be take account, whereas at the regional scale seismograms at the nodes of a regular grid are computed. Finite fault simulation is needed to compute realistic ground motions close to a ruptured fault. No reasonable deterministic prediction for many details of a future fault motion can be expected and their variability can be treated in practice only from a statistical viewpoint. Therefore, their effect is simulated through Monte-Carlo approach. To test the accuracy of the method, the L’Aquila earthquake occurred on April 6, 2009 has been modelled. The use of a realistic model for the representation of the extended fault introduces a stochastic element in NDSHA. So the variability due to the stochastic component of seismic source has been evaluated. In standard NDSHA at regional scale, seismograms are computed for an upper frequency content of 1 Hz. The use of a more realistic source model than the scaled point source that takes account of effective duration of rupture process allowed to extend the maximum frequency of computation of seismograms of national scale maps to 10 Hz. A first estimation of uncertainty due to the random representation of the source in national scale maps has been obtained by parametric tests on EU-India Grid infrastructure. NDSHA defines the hazard as the maximum ground motion at the site and it does not supply information about the frequency of occurrence of the expected ground motion. The standard procedure of NDSHA has been modified here, to take into account the additional information of recurrence. The introduction of recurrence estimates in NDSHA allows the generation of ground motion maps for specified return periods that permits a straightforward comparison between the NDSHA and the PSHA maps. Furthermore the map of the recurrence has been associated with standard map of ground motion.
La valutazione della pericolosità sismica può essere effettuata seguendo un approccio neo-deterministico (NDSHA) che permette di dare una descrizione realistica del moto del suolo dovuto a un terremoto di data distanza e magnitudo. L’approccio è basato su tecniche di modellazione che sono state sviluppate da una conoscenza dettagliata sia della sorgente che della propagazione delle onde sismiche. Questo permette di definire un set di terremoti di scenario e di simulare i segnali sintetici associati senza dover aspettare l’accadimento di un forte evento. La metodologia neo-deterministica può essere applicata a diverse scale geografiche cui corrispondono differenti livelli di dettaglio nella modellazione. A scala locale è possibile tenere conto delle caratteristiche specifiche della sorgente e del sito considerati, mentre a scala regionale vengono calcolati i sismogrammi ai nodi di una griglia regolare. Per simulare in modo realistico il moto del suolo in prossimità di una faglia è necessario usare un modello di sorgente estesa. Molti dettagli del processo di rottura sulla sorgente non possono essere predetti in modo deterministico e la loro variabilità può essere trattata solo da un punto di vista statistico. Di conseguenza i loro effetti vengono simulati attraverso una approccio Monte-Carlo. Per testare l’accuratezza del metodo è stato modellato il terremoto dell’Aquila del 6 aprile 2009. L’uso di un modello realistico di sorgente per la rappresentazione della sorgente estesa introduce un elemento stocastico nel metodo neo-deterministico. Si è quindi valutata la variabilità dei valori di picco dovuta alla modellazione della sorgente. Nella metodologia neo-deterministica scala regionale i sismogrammi vengono calcolati con una frequenza massima di 1 Hz. L’uso di un modello di sorgente piu` realistico rispetto a quello della sorgente puntiforme in grado di tener in conto dell’effettiva durata del processo di rottura ha consentito di estendere la frequenza massima di calcolo dei sismogrammi delle mappe di pericolosità nazionali a 10 Hz. Una prima stima dell’incertezza legata alla simulazione stocastica della sorgente sulle mappe a scala nazionale è stata ottenuta con l’uso di test parametrici condotti utilizzando l’infrastruttura informatica EU-India Grid. Il metodo neo-deterministico definisce la pericolosità come il massimo scuotimento al sito e non fornisce alcuna informazione sulla ricorrenza del moto del suolo atteso. La procedura è stata modificata per tener conto dell’informazione aggiuntiva della ricorrenza. In questo modo è stato possibile generare delle mappe di scuotimento per specifici periodi di ritorno che consentono un diretto confronto con le mappe probabilistiche. Inoltre alle mappe di massimo scuotimento sono state associate le rispettive mappe di ricorrenza del moto del suolo.
XXV Ciclo
1983

Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.
Bruce R. Ellingwood, Committee Chair ; Abdul-Hamid Zureick, Committee Member ; James I. Craig, Committee Member ; Reginald DesRoches, Committee Member ; Kenneth M. Will, Committee Member.

A seismic hazard assessment was carried out for the Catania and Siracusa towns providing a comprehensive re-examination and re-processing of all the available seismic data. The site approach and the seismotectonic one were used and compared. The hazard assessment, using both methods, was performed following a logic-tree approach in order to consider and reduce the epistemic uncertainties. The combined use and comparison of these approaches is recommended since it allows to verify the robustness of the hazard estimates and allowed us to obtain useful elements to define the seismic hazard in Catania and Siracusa. Experimental data and numerical modeling were used to study the effect of local geology on the seismic response in the Catania area. Available boreholes data and elastic parameters were used to reconstruct a geotechnical model in order to perform 1D numerical modeling. Seismic urban scenarios were simulated considering destructive (Mw=7.0), strong (Mw=6.2) and moderate (Mw=5.7) earthquakes. PGA and spectral acceleration at different periods were obtained in the urban area through the equivalent linear numerical code EERA, and contour maps of different levels of shaking were drawn. Standard and horizontal-to-vertical spectral ratios were achieved making use of a dataset of 172 seismic events recorded at ten stations located on the main outcropping lithotypes. Spectral ratios inferred from earthquake data were compared with theoretical transfer functions. Both experimental and numerical results confirm the role of the geologic and morphologic setting of Catania. A study aimed to investigate on the dynamic properties of main lithotypes outcropping in the Siracusa area and their relationships with the local seismic response was performed. Non-invasive seismic prospecting techniques using the vertical component of surface waves (MASW and ReMi) were adopted, as well as ambient noise measurements, processed through the Nakamura technique. Moreover, a cluster analysis was performed to subdivide into homogeneous groups the experimentally obtained noise spectral ratios. Results pointed out that the use of combined different methods provides a more robust way to characterized the investigated soils and to reduce the problems linked to the non-uniqueness of solutions during the interpretation of geophysical data. The role of local geology and topography on the site response of a small hill, located in the northern part of Catania, was investigated. Ambient noise and earthquake data were processed through standard and horizontal-to-vertical spectral ratios. Directional effects were also investigated by computing the spectral ratios after rotating the horizontal components of motion and performing polarization analysis. Results of noise and earthquakes analysis, although show significant differences in amplitude, are comparable in frequency, especially in the sedimentary terrains. Pronounced directional effects are mostly observed on the slopes rather than at the hill top. Our findings appear linked to the complex wavefield generated by the lithologic heterogeneities existing in the area which seem to have a stronger influence with respect to the simple topographic effect. Seismic noise recorded by mobile stations in the Ortigia peninsula (downtown Siracusa) was analyzed through H/V spectral ratios, to investigate local site effects. Moreover, shear wave velocities were investigated through non-invasive techniques (MASW and ReMi) in order to assess the theoretical resonant frequency of the hill. Experimental results coming out from the spectral ratios show peaks in the frequency range 1.0-3.0 Hz which are consistent with the theoretical resonance frequency at Ortigia. The H/V azimuthal spectral analysis shows a clearly predominant E-W directional effect, transversal to the main axis of the peninsula, which is also confirmed by the polarization analysis in the time domain.

Soprattutto nei centri storici, la sicurezza degli evacuanti dopo un terremoto è collegata all'ambiente circostante ma diversi fattori possono ostacolare l’individuazione e il raggiungimento delle zone sicure. Inoltre, la scarsa familiarità col luogo, il piano d’emergenza e i percorsi sicuri, aumenta drasticamente le possibilità d’incidente nel mettersi in salvo. Studi sulla valutazione del rischio, la pianificazione d’emergenza e la gestione dell'evacuazione hanno avuto grande sviluppo, ma sono principalmente focalizzati sull'emergenza antincendio in ambienti indoor. Solo recentemente sono state emanate linee guida specifiche per l'emergenza sismica in contesti urbani. Tuttavia, sono approcci piuttosto semplificati che non supportano efficacemente i sopravvissuti. In tale contesto, la capacità di evacuare autonomamente e mettersi in salvo, chiamata anche "self-help", è la principale risorsa che i sopravvissuti possono attuare. Il presente lavoro inizia analizzando la letteratura consolidata, per poi proporre nuove metodologie per la pianificazione dell’emergenza e l'evacuazione post-sisma nei centri storici. Adottando un approccio prestazionale, sono valutate le criticità derivanti dalle interazioni uomo-ambiente e proposte possibili soluzioni. A tal fine, sono stati definiti diversi campi di studio ed offerti nuovi metodi e strumenti laddove necessario. I metodi proposti, applicati a un caso di studio, sono testati utilizzando un software di simulazione comportamentale specializzato per l'emergenza sismica. Degli indicatori prestazionali sono adottati per quantificare le performances evacuative e valutare l'efficacia dei metodi di pianificazione e di guida proposti. La combinazione degli studi proposti con metodi tradizionali potrebbe essere utile ai pianificatori di emergenza durante le fasi di analisi e progettazione. Inoltre, può essere una pratica di ottimizzazione considerevole in caso di risorse limitate o in scenari con vincoli rilevanti come quelli storici.
When an earthquake occurs, survivors start to evacuate. Especially in historical centres, their safety is connected to the surrounding environment but several factors can increase their difficulty to locate and reach safe zones. Furthermore, the scarce familiarity with the place, the emergency plan and the safe paths, drastically raise the probability they can be involved into fatalities while trying to get themselves safe. Studies about risk evaluation, emergency planning and evacuation management had a large development but they have been focused especially for fire emergency and indoor environment. Only recently, specific guidelines for earthquake emergency in urban scenarios have been produced. However, they are quite simplified approaches focusing on rescuers’ perspective, not effectively supporting survivors. In a such context, the ability to autonomously evacuate and gain safe place, also called ‘self-help’, is the main resource survivors can carry out. The current work starts analysing the consolidated literature, then, new methodologies for urban emergency planning and post-earthquake evacuation in historical centres are proposed. A performance-based approach is adopted to evaluate the criticalities deriving from the men-environment interactions and to offer possible solutions. To this aim, several fields of study are defined and new methodologies and tools are offered where necessaries. The proposed methods, applied to a case study, are tested using a behavioural simulation software specialized for earthquake emergency. Key Performance Indicators are adopted to quantify the evacuation performances and evaluate the effectiveness of the proposed planning and guidance methods. Combining the proposed studies with traditional methods could be useful to emergency planners during the analyse and designing phases. Furthermore, it can be a considerable optimization practice in case of limited resources, or in scenarios with relevant constrains as the historical ones.

碩士
國立臺灣大學
海洋研究所
100
One of the most important issues of the recent development of seismology and earthquake engineering is the capability to predict strong ground motion for future large earthquake based on state-of-the-art knowledge and observations. However, it is very difficult to achieve realistic ground motion response by numerical simulation due to the poor resolution of underground structure and high computational consuming. In this study, we present three approaches to extend the simulating frequency band and to establish the feature of realistic strong ground motion pattern. There are two major parts in this study. First part focuses on the developments and tests of the three approaches to realize broadband ground motion simulation. The three approaches are (1) Hybrid method, (2) Frequency ratio method and (3) High frequency numerical simulation. These three approaches are applied on the 2010 Jiashian (M6.4) and 2009 Nanto (M5.13) earthquakes. In the second part, the hybrid broadband simulation technique is considered to apply on Hengchun scenario earthquake. Results indicate that using hybrid method with characteristic source model approach can provide a physics-based simulation result to predict strong ground motion of large earthquake that could occur in the future. The long term goal of this study will be to give contributions to the earthquake mitigation and seismic hazard assessment.

碩士
國立臺灣科技大學
營建工程技術學系
81
The purpose of this study is initiated to estabilish a counter- measure to conteract the stroke of severe earth- quake and to provide some quide lines in consideration of disaster prevention, avoideing and rescuing during the disaster. In the process of developing the ways to solve the problems,eqk. his- analysis the degree of damage. site was inspected and photographed. Basing on the assumed damage condition which are the failure of the structures, the cut-off roadways, damage of utilities and lossing thousands of lifes, due to the strike of the 8.0 degree earth quake. The relatives agencies should develop some workable reaction plans. They should be organized for this imergency duty for the rescue and repair work. In the process of research the ways to rescuing, four main-quide are suggested. It is (1) 「 Heart 」 revival (2)Zoning administration (3)recon- struction of frog-jump (4) 「 Arterial circulation 」 -Highway.

Whether it is for pre-event prevention and preparedness or for post-event response and recovery of a catastrophic earthquake, estimates of damage, death and downtime (3d) losses are needed by engineers, owners, and policy makers. In this research, a quantitative "scenario-based" risk analysis approach as developed to investigate the 3d losses for buildings. The "Redbook Building" is taken as the typical New Zealand construction exemplar and analyzed for the 22 February 2011 Christchurch Earthquake. Losses are presented in the form of attenuation curves that also include the associated uncertainties. The spatial distribution of 3d damages over the height of buildings is also considered. It is thus shown that it is possible to discriminate between losses that lead to building replacement versus less severe losses that require structures to be repaired. The 3d loss results show that within the Christchurch city (17 km radial distance from the earthquake epicenter): (a) the expected physical damage loss ratio is about 50% of the property value; (b) the expected probability that someone is killed or seriously injured is about 4%; and (c) the expected downtime for the building being out of service is about 24 weeks. However, when considering various uncertainties, one can have 90% confidence that these loss estimations will be as high as: (a) complete loss (100% physical damage), implying structure has a great chance of collapse; (b) 8% possibility of fatality, implying deaths and significant injuries are likely; and (c) 1-year downtime due to post-event reconstruction demand surge. These informative results demonstrate that even though structures, such as the "Redbook Building", may have been well designed and constructed to contemporary standards, significant damage can still be expected and the downtime loss is particularly large. In order to solve this problem, new building structures should ideally be built stronger, include recentering attributes, and use Damage Avoidance Design (DAD) armoring connection details.

碩士
國立臺灣大學
地質科學研究所
104
The Longitudinal Valley (LV) in the eastern Taiwan is considered as the suture zone between the Eurasia Plate and the Philippine Sea Plate. Thousands of earthquakes are occur in this area every year. The Longitudinal Valley Fault (LVF) is a seismically active structure, which is located along the LV. During the time period from October to December in 1951, lots of large earthquakes occurred between Hualien and Taitung area, including four major earthquakes (M > 6.9) and thousands of aftershocks. This earthquake series is known as the Longitudinal Valley Earthquake sequence. Coseismic surface rupture with a total length of approximate 90 km were observed along LV. In order to understand the characteristics of source rupture and resultant strong ground motion, this study is comprised of two different parts. In first part, we reconstructed the source model and strong ground motion time history of this earthquake sequence. Inversion of the coseismic displacement data was first conducted. Based on the inverted slip distribution, we performed 3D forward simulation using the Spectral Element Method. Therefore, the second part of the thesis focuses on ground motion prediction for scenario earthquakes. We performed wave propagation simulation with ten stochastic rupture scenarios and examined the results collectively. The numerical simulation results showed that the PGA larger than 250 cm/s2 distributed along LV in eastern Taiwan in all cases. If the rupture started in the middle of LVF, PGA larger than 80 cm/s2 could be detected in the entire island. In the particular stochastic source rupture models, the PGA might be larger than expected in some places far from LVF due to source radiation and directivity effect, such as Taipei basin, Ilan and southern part of Taiwan. The models we presented in this thesis for both historical and scenario events can serve as reference for future in-depth seismotectonic studies and hazard assessment.

碩士
國立臺北科技大學
土木與防災技術研究所
92
The Ji-Ji earthquake, which resulted in serious damage of public properties, took place in the middle part of Taiwan. Haz-Taiwan is an earthquake loss estimation and scenario simulation system modified from HAZUS, a system used in the US. Due to the difference in national conditions, divisions of administrative boundaries, and the lack of related databases, the Haz-Taiwan system must be revised. Taiwan Earthquake Loss Estimation System (TELES) is developed by the National Center for Research on Earthquake Engineering (NCREE) to replace Haz-Taiwan, and is used to analyze the state of damage caused by earthquakes in the Taiwan area. However, the lifeline module has not yet been implemented in TELES. After the Ji-Ji earthquake, the fragility analysis of buried pipelines focused on the disaster area. Some of the analysis has been completed, such as damage of potable water pipelines, natural gas pipelines, and wastewater pipelines. The results can be used to evaluate the relationship between the damage of pipelines and the magnitude of earthquakes. This study is the first of its kind to incorporate the damage functions of water pipelines into a rapid earthquake loss estimation and scenario simulation system of lifelines. The rapid earthquake loss estimation and scenario simulation system of lifelines can be used to simulate the state of damage of water pipelines caused by earthquakes and the results can be used for disaster preparedness. When a real earthquake occurs, the system can be activated automatically by an e-mail from the Central Weather Bureau to calculate the possible damage distribution, and forward the results to decision makers and emergency crew via e-mails and SMS messages. Thus, the response time can be reduced and more property loss can be prevented.

碩士
國立臺北科技大學
土木與防災技術研究所
92
Underground vital lifelines system ( as the water system, and the natural gas system, and the power system...etc.) is the basic facilities for people to hold together, the more high to lean on the city the more high in urbanization； now Taiwanese region metropolis population has attained 70% of the total number of populations above, due to the city population concentration, is very huge to the livelihood of the influence of the society, economy, the mind and body of dweller...etc. after the disaster, once vital lifelines to suffer the large-scale breakage ( as gas system) after earthquake, can bring about the fire, and develop for two times or for three times disaster. This research mainly is to aim at to analyze the damage conditions of water and natural gas pipelines of Chia-Yi City, make use of the geography information system to digitize and build the related data, and make use of the earthquake repair rate that mesh analysis beg, make with earthquake parameter data to digitize to the estimations damages caused by earthquake events, and match with the fire regression analysis formula and earthquakes supply water etc. urgently analytical, the related measure in emergency response does the emulation after aiming at the earthquake, hoping this to study result can help after draw-up earthquake meet an emergency the project, to ease the dead and injured of the people and the loss of the properties.

Seismic design, analysis and retrofitting of structures demand an intensive assessment of potential ground motions in seismically active regions. Peak ground motions and frequency content of seismic excitations effectively influence the behavior of structures. In regions of sparse ground motion records, ground-motion simulations provide the synthetic seismic records, which not only provide insight into the mechanisms of earthquakes but also help in improving some aspects of earthquake engineering. Broadband ground-motion simulation methods typically utilize physics-based modeling of source and path effects at low frequencies coupled with high frequency semi-stochastic methods. I apply the hybrid simulation method by Mai et al. (2010) to model several scenario earthquakes in the Marmara Sea, an area of high seismic hazard. Simulated ground motions were generated at 75 stations using systematically calibrated model parameters. The region-specific source, path and site model parameters were calibrated by simulating a Mw4.1 Marmara Sea earthquake that occurred on November 16, 2015 on the fault segment in the vicinity of Istanbul. The calibrated parameters were then used to simulate the scenario earthquakes with magnitudes Mw6.0, Mw6.25, Mw6.5 and Mw6.75 over the Marmara Sea fault. Effects of fault geometry, hypocenter location, slip distribution and rupture propagation were thoroughly studied to understand variability in ground motions. A rigorous analysis of waveforms reveal that these parameters are critical for determining the behavior of ground motions especially in the near-field. Comparison of simulated ground motion intensities with ground-motion prediction quations indicates the need of development of the region-specific ground-motion prediction equation for Istanbul area. Peak ground motion maps are presented to illustrate the shaking in the Istanbul area due to the scenario earthquakes. The southern part of Istanbul including Princes Islands show high amplitudes of shaking. The study serves as a step towards dynamic risk quantification for the Istanbul area that integrates physics based ground-motion simulations into an innovative dynamic exposure model to quantify risk.

This dissertation work concerns the effects of earthquake source geometry on nearfield ground-motions. Through numerical simulations, we investigate the following topics: (1) the effects of listricity on near-field ground motions, and (2) possible ground shaking levels in the Gulf of Aqaba region through multiple earthquake scenarios characterized by several fault segments rupturing either separately or jointly. Listric faults are defined as curved faults in which dip decreases with depth, resulting in a concave upwards profile. The profiles in this study are created by applying a specific shape function: by varying the initial dip and the degree of listricity, we create an ensemble of listric faults. We then define heterogeneous rupture speeds and slip distributions to generate a variety of kinematic source models. Finally, we compare them in terms of peak ground velocities to ground motion prediction equations and find two general features: (1) as listricity increases, the PGVs decrease on the footwall and increase on the hanging-wall; (2) constructive interference of seismic waves emanated from the listric fault causes PGVs over two times higher than those observed for the planar fault. The Gulf of Aqaba region has seen rapid growth in recent years, mainly fuelled by the increasing population, tourism, and investments in national projects. Such projects include the 26.500 km2 city of NEOM, backed by a 500 billion dollar investment by the Saudi Investment Fund and the King Salman bridge across the Straits of Tiran. The recency of the seismic network in the area provides limited information; moreover, no large earthquakes have occurred since its installation. The corresponding lack of data presents engineers with a severe knowledge gap. To contribute to closing this gap, we compute synthetic earthquake ground motions to study the consequences of large magnitude (Mw ~ 7.2) scenario seismic events. To this end, we conduct kinematic rupture simulations that mimic dynamic source behavior including both single- and multi-segment ruptures. Our simulations show higher ground velocities than predicted by GMPEs for the Straits of Tiran and lower for the NEOM area.

A novel stochastic earthquake ground motion model is formulated in association with physically interpretable parameters that are capable of efficiently characterizing the complex evolutionary nature of the phenomenon. A multi-modal, analytical, fully non-stationary spectral version of the Kanai-Tajimi (K-T) model is introduced achieving a realistic description of the evolutionary spectral energy distribution of seismic ground motions. The functional forms describing the temporal evolution of the model parameters can efficiently model highly non-stationary power spectral characteristics. The analysis space, where the analytical forms describing the evolution of the model parameters are established, is the energy domain instead of the typical use of the time domain. This space is used in conjunction with a newly defined energy-associated amplitude modulating function. The Spectral Representation Method supports the simulation of sample ground motions realizations. A predictive stochastic model for simulation of earthquake ground motions is developed, using a user-specified earthquake scenario description as input, and resulting in fully nonstationary ground acceleration time-histories at a site of interest. The previously formed analytical non-stationary K-T ground motion model lies at the core of the developed predictive model. An extensive Californian subset of the NGA-West2 earthquake ground motion database is used to develop and calibrate the predictive stochastic model. Sample observations of the model parameters are obtained by fitting the K-T model to the database records, and their resulting marginal distributions are effectively described by simple probability models. Advanced random-effect regression models are established in the normal probabilistic space, capable of linking the stochastic K-T model parameters with the moment magnitude Mw, closest distance Rrup and average shear-wave velocity VS30 at a Californian site of interest. The included random effects take effectively into account the correlation of ground motions pertaining to the same earthquake event, and the fact that each site is expected to have its own effect on the resulting ground motion. The covariance structure of the normal K-T model parameters is next estimated, allowing finally for the complete mathematical description of the predictive stochastic model for a given earthquake scenario. The entirety of the necessary steps for the simulation of the developed predictive stochastic model is provided, resulting in the generation of any number of fully non-stationary ground acceleration time-series that are statistically consistent with the specified earthquake scenario. In an effort to assess the performance and versatility of the developed predictive stochastic model, a list of simple engineering metrics, associated with the characterization of the earthquake ground motion time-series, is studied, and results from simulated earthquake ground acceleration time-series of the developed predictive model are compared with corresponding predictions of pertinent Ground Motion Prediction Equations (GMPEs) for a variety of earthquake and local-site characteristics. The studied set of ground acceleration time-series features includes the Arias intensity IA, the significant duration T5-95 of the strong ground shaking, and the spectral-based mean period of the earthquake record Tm. The predictive stochastic model is next validated against the state-of-the-art NGA-West2 GMPE models. The statistics of elastic response spectra derived by ensembles of synthetic ground motions are compared with the associated response spectra as predicted by the considered NGA-West2 ground motion prediction equations for a wide spectrum of earthquake scenarios. Finally, earthquake non-linear response-history analyses are conducted for a set of representative single- and multi-degree-of-freedom hysteretic structural systems, comparing the seismically induced inelastic structural demand of the considered systems, when subjected to sets of both real strong ground motion records, and associated simulated ground acceleration time-histories as well. The comparisons are performed in terms of seismic structural demand fragility curves.

碩士
中國文化大學
地學研究所地質組
101
Earthquake is one of the major natural disasters caused massive destruction in the Taipei metropolitan area. Sanchiao fault is a western boundary fault of the Taipei basin located in northern Taiwan, close to the densely populated Taipei metropolitan area. Combined with the marine and terrestrial parts, the total fault length of Sanchiao fault could over 50 kilometers. For the past 400,000 years, the bedrock of Tertiary sedimentary basin continued to subside due to the activity of the Sanchiao fault, resulting the thickness of Quaternary sediments of the basin up to 700 meters in the northwest side. Displacement measured by GPS in northern Taiwan, on both sides of the Sanchiao fault, revealed up to 5-8 mm per year of movement. It may be reactivated in the future. This study is based on the “RECIPE” for predicting strong ground motion proposed by Kojiro Iriura and Hiroe Miyake （2011）. The characteristic source parameters include: fault length, rupture area, seismic moment, the fault plane momentum slip, asperity and propagation pattern of rupture etc. Based on these assumptions in the characteristic source model, Sanchiao fault has been inferred to have the potential to produce an earthquake with moment magnitude (Mw) larger than 7.0. Three-dimensional seismic simulation using Spectral-Element Method (SEM), the 3D spectral-element method simulation results indicate that Peak Ground Acceleration (PGA) is significantly stronger along the fault trace. The basin effects play an important role when wave propagates in the Taipei basin which cause seismic wave amplified and prolong the shaking for a very long time. In order to increase the universality and breadth of simulation study, we assumed multiple of possible earthquake scenarios. Among them, rupture direction from north to south of the situation is comparatively serious. Owing to the shock direction as well as the basin effect, Taipei basin has high PGA, especially on the northwest side. This clearly shows that it is closely related to the basin sediments. Through statistical analysis, the results of this numerical simulation will provide important earthquake disaster and earthquake engineering reference data.

Recent earthquakes have highlighted that the consideration of isolated seismic events, although necessary, may not be sufficient to prevent building collapse. In fact, the occurrence of a large number of aftershocks with significant intensity, as well as the occurrence of tsunamis, fires, and explosions, poses a safety threat that has not been addressed properly in the design and assessment of building structures over the last decade. Although research has been developed in order to evaluate the impact of multiple and/or cascading hazards in structural safety and economical losses, there is no established framework to perform such analysis. In addition, the available numerical tools lack a unified implementation in a widely used software in order to allow for the development of large numerical simulations involving these hazard events. This work proposes a probabilistic framework for quantifying the robustness of structures considering the occurrence of a major earthquake (mainshock) and the subsequent cascading hazard events, namely fire and aftershocks. These events can significantly increase the probability of collapse of buildings, especially for structures that are damaged during the mainshock. In order to assess the structural performance under post-earthquake hazards, it is of paramount importance to accurately simulate the damage attained during the earthquake, which is strongly correlated to the residual structural capacity to withstand cascading events. In this context, the influence of ground motion characteristics, namely ground motion duration, has been identified as one of the parameters that may induce significant bias on damage patterns associated with the mainshock. Thus, ground motion duration influence on structural damage is analyzed in this work. Steel moment resisting frame buildings designed according to pre-Northridge codes are analyzed using the proposed framework. These buildings are representative of the design practice in the US and Europe for decades, and the conclusions of this work can be significant in the assessment/retrofit of thousands of buildings. Fragility curves and reliabilitybased robustness measures are obtained using the proposed framework. The fragility curve parameters obtained herein can be used in the development of future probabilistic-based studies considering post-earthquake hazards. The results highlight the importance of the post-earthquake hazard events in the structural safety assessment. Further work is needed in order to better characterize these hazards as to include them in the code-based design and assessment methodologies.

碩士
國立臺灣科技大學
建築系
89
The research was aimed at the urban fire of Taipei city. By using the factors of structure、distance、angle and cover, the building types and distribution in Wanhua area、Jungjeng area and Daan area are investigated to review the possibility of the urban fire exposure spreading in Taipei city. Now, the fire-resistance is the main building type in blocks of Taipei. The ratio of the fire-resistance in the investigated area is over 70% before 1945 and after 1945 is over 90%. Therefore, the radiation exposure spreading fire from the building’s opening parts is the main reason in Taipei city. The exposure spreading fire happened more easily in the blocks of highly concentrated wood structure. By using the frame coefficient, if only considering the exposure spreading fire in the vertical direction, it wouldn’t spread road of 6m、8m and 10m between the blocks. Because of the continuous combustible in horizontal, highly concentrated commercial using area is probably results in the fire spreading, and will increase the peril of the across buildings through the opening parts. Therefore, the character of combustible、the fire spread speed and the wind velocity around the opening parts are the key point whether the radiation exposure spreading will happening or not. Combine all the result of analysis, the danger area of higher fire spreading possibility is delimited in the blocks and the results can be provided for the urban fire compartment.

Proactive evaluation of road safety is one of the most important objectives of transportation engineers. While current practice typically relies on crash-based analysis after the fact to diagnose safety problems and provide corrective countermeasures on roads, surrogate measures of safety are emerging as a complementary evaluation that can allow engineers to proactively respond to safety issues. These surrogate measures attempt to address the primary limitations of crash data, which include underreporting, lack of reliable insight into the events leading to the crash, and long data collection times.

Traffic conflicts are one of the most widely adopted surrogate measures of safety because they meet the following two conditions for crash surrogacy: (1) they are non-crash events that can be physically related in a predictable and reliable way to crashes, and (2) there is a potential for bridging crash frequency and severity with traffic conflicts. However, three primary issues were identified in the literature that need to be resolved for the practical application of conflicts: (1) the lack of consistency in the definition of traffic conflict, (2) the predictive validity from such events, and (3) the adequacy of traffic conflict observations.

Tarko (2018) developed a theoretical framework in response to the first two issues and defined traffic conflicts using counterfactual theory as events where the lack of timely responses from drivers or road users can produce crashes if there is no evasive action. The author further introduced a failure-based definition to emphasize conflicts as an undesirable condition that needs to be corrected to avoid a crash. In this case, the probability of a crash, given failure, depends on the response delay. The distribution of this delay is adjusted, and the probability is estimated using the fitted distribution. As this formal theory addresses the first two issues, a complete framework for the proper identification of conflicts needs to be investigated in line with the failure mechanism proposed in this theory.

The objective of this dissertation, in response to the third issue, is to provide a generalized framework for proper identification of traffic conflicts by considering the failure-based definition of traffic conflicts. The framework introduced in this dissertation is built upon an empirical evaluation of the methods applied to identify traffic conflicts from naturalistic driving studies and video-based tracking systems. This dissertation aimed to prove the practicality of the framework for proactive safety evaluation using emerging technologies from in-vehicle and roadside instrumentation.

Two conditions must be met to properly claim observed traffic events as traffic conflicts: (1) analysis of longitudinal and lateral acceleration profiles for identification of response due to failure and (2) estimation of the time-to-collision as the period between the end of the evasion and the hypothetical collision. Extrapolating user behavior in the counterfactual scenario of no evasion is applied for identifying the hypothetical collision point.

The results from the SHRP2 study were particularly encouraging, where the appropriate identification of traffic conflicts resulted in the estimation of an expected number of crashes similar to the number reported in the study. The results also met the theoretical postulates including stabilization of the estimated crashes at lower proximity values and Lomax-distributed response delays. In terms of area-wide tracking systems, the framework was successful in identifying and removing failure-free encounters from the In-Depth understanding of accident causation for Vulnerable road users (InDeV) program.

This dissertation also extended the application of traffic conflicts technique by considering estimation of the severity of a hypothetical crash given that a conflict occurs. This component is important in order for conflicts to resemble the practical applications of crashes, including the diagnostics of hazardous locations and evaluating the effectiveness of the countermeasures. Countermeasures should not only reduce the number of conflicts but also the risk of crash given the conflict. Severity analysis identifies the environmental, road, driver, and pre-crash conditions that increase the likelihood of severe impacts. Using dynamic characterization of crash events, this dissertation structured a probability model to evaluate crash reporting and its associated severity. Multinomial logistic models were applied in the estimation; and quasi-complete separation in logistic regression was addressed by providing a Bayesian estimation of these models.

碩士
國立中央大學
地球物理研究所
98
We used seismic station array on the margin of the Western Pacific to examine the controlling factors of earthquakes in the Izu-Bonin-Mariana subduction zone to excite T waves. The observed excited T waves in turn were used to investigate the decisive parameters for receiver-side acoustic-to-elastic conversion, in a quantitative fashion by the Gamma calculation. Having examined earthquakes in 2005, 17 out of 48 are T-excited events. We have discovered a preferential source-receiver pair for observations of T waves, namely, earthquakes in the southern Mariana Arc as recorded by stations in East Taiwan coastline. Additionally, the T-excited events correlate strongly with normal faulting type of earthquakes. While the strong curvature of the mid-SOFAR isobaths in the South Mariana Arc and the nearly perpendicular incidence to the receiver shoreline of earthquakes herein are conceptually attributed the preferential pair, the correlation with normal-faulting earthquakes needs to be cautiously examined by further studies. On the receiver side, the steeply dipping slopes of the East Taiwan coasts act as efficient interfaces for acoustic-to-elastic conversion. The converted T-waves can be recorded by stations even 50 km inland. The angles between incidence and receiving shoreline also determine the efficiency of receiver-side conversion.

Residents in urban areas depend on infrastructure systems to return to functionality quickly after disruptions from natural and man-made disasters to support their livelihood and well-being. This work seeks to improve the accuracy of infrastructure recovery time estimates by introducing mutually exclusive damage state modeling into the Graph Model for Operational Resilience (GMOR) and utilizing this capability for road recovery assessment in two case studies in the District of North Vancouver, British Columbia. The first case study also explores the recovery of water, wastewater, and power networks in the District, and demonstrates that power and road systems recover more slowly and are more variable in their recovery time than water distribution and wastewater collection systems. The second study specifically addresses important sections of road within the District and shows that intelligent prioritization of resource allocation for road repairs can improve recovery times by up to 37% compared to random ordering.
Graduate

In planning the design of structures in a region of potential seismic activity, a specification of the “strength” of the earthquake ground motion, or the most likelihood ground motion level, is needed. The earthquake occurrence, and its effects, is described as a stochastic process. Thus its realization is linked to state variables defined over a a known space through a continuous function. The Ground Motion Predictive Equation (GMPE) realize this function and, despite its shortcoming as an effective design tool to control damage (Priestly, 2003), it is still the most widely used representation of earthquake ground motion employed in engineering practice. As a consequence the majority of hazard estimations are based on the GMPE providing a ground motion specification as a function of a certain number of variables. In fact in many situation there are not enough data to allow a direct empirical specification of ground motion. Only few regions, i.e. Japan, have strong-motion network and data-banks sufficient to carry out seismic hazard assessment without the benefit of regionally-derived ground motion predictive model. The central role they hold in the hazard assessment motivates the recent efforts in better synthesize all available regional informations and general knowledge about earthquakes. The representation of the ground motion through the GMPE is simple compared to the complexity of the physical process involved. If only the magnitude and distance are taken into account, the GMPEs predict isoseismal curves that are expected to be isotropic around the hypocenter and uniform if no other effects are considered (i.e. site effects). Instead, the presence of a fault plane, across which a process of failure in shear develops, make this general formulation divert from the observations on a specific case. In fact the dynamic propagation of rupture results in anisotropy effects not included in the predictions although back-analyses of ground motions from past earthquakes have shown that such effects have a strong influence on the spatial distribution of ground motion.Although the anisotropy effects resulting from the propagation of rupture have been generally recognized and finally incorporated in predictions, its effect has not been tested yet in an hazard context. On the contrary, all the aforementioned issues motivate an in depth analysis of its contribution on the present tools of seismic hazard assessment. This work is mainly addressed to conduct such analysis. One guidance is provided answering to the following questions: Does directivity improves the performance of ground motion prediction in real time applications? Is directivity still effective in a PSHA framework? What deterministic hazard model can tell about directivity ?
Università degli studi di Genova, Istituto Nazionale di Geofisica e Vulcanologia
Unpublished
3T. Pericolosità sismica e contributo alla definizione del rischio
4T. Fisica dei terremoti e scenari cosismici
open