Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). Four maps in pocket. Includes bibliographical references (leaves 224-243). Also available via the World Wide Web.

Στην παρούσα εργασία γίνεται μια προσπάθεια μελέτης των μηχανικών χαρακτηριστικών, των τυπικών βλαβών και γενικά της σεισμικής συμπεριφοράς κτηρίων από φέρουσα τοιχοποιία. Έμφαση δίνεται στον προσδιορισμό των μηχανικών χαρακτηριστικών διαφόρων τύπων φέρουσας τοιχοποιίας τριών στρώσεων και γίνεται σεισμική αποτίμηση δυο υφισταμένων κτηρίων από χαρακτηριστικούς τύπους τρίστρωτης τοιχοποιίας που βρίσκονται στα Ιόνια Νησιά. Εκτός από τις εξισώσεις που αναφέρονται σε συμβατικές φέρουσες τοιχοποιίες, δίνεται βάση στην περιγραφή εξισώσεων που προσδιορίζουν τα μηχανικά χαρακτηριστικά φέρουσας τοιχοποιίας τριών στρώσεων. Με τη χρήση των εξισώσεων αυτών και ενός προγράμματος πεπερασμένων στοιχείων, προτείνεται μια διαδικασία προσομοίωσης της τρίστρωτης τοιχοποιίας με μια ισοδύναμη “μονόστρωτη”. Η εξισώσεις αυτές λαμβάνουν υπόψη τα μηχανικά χαρακτηριστικά καθεμιάς από τις τρεις στρώσεις, τον όγκο που καταλαμβάνουν κατά το πάχος της τοιχοποιίας, καθώς και κάποιους διορθωτικούς συντελεστές που ποσοτικοποιούν το βαθμό “συνεργασίας” των στρώσεων. Η διαδικασία αυτή θα εφαρμοστεί στη συνέχεια σε δύο συγκεκριμένους τύπους τρίστρωτης τοιχοποιίας. Πρώτον, για τοιχοποιία με εξωτερικές στρώσεις από αργολιθοδομή και ενδιάμεση στρώση από ασθενές κονίαμα, η οποία αποτελεί συνήθη τύπο τρίστρωτης τοιχοποιίας και απαντάται και σε πλειοψηφία κτηρίων του ιστορικού κέντρου της Κέρκυρας. Δεύτερον, για τοιχοποιία με ασθενείς εξωτερικές στρώσης οπτοπλινθοδομής και πυρήνα οπλισμένου σκυροδέματος, η οποία αποτελεί τρόπο δόμησης μιας τυπολογίας κτηρίων της Ζακύνθου και εισήχθη μετά τον καταστροφικό σεισμό του 1953. Στη συνέχεια, απαριθμούνται τα είδη βλαβών που απαντώνται συχνά σε κτήρια από φέρουσα τοιχοποιία, όπως οι διαγώνιες και δισδιαγώνιες ρωγμές, καθώς και οι κατατακόρυφες ρωγμές που απαντώνται περί το μέσον του τοίχου ή στη θέση συνάντησης δύο τοίχων. Έπειτα, γίνεται εκτενής αναφορά στις μεθόδους και τεχνικές ενίσχυσης κτηρίων από φέρουσα τοιχοποιία. Περιγράφονται μέθοδοι όπως το βαθύ αρμολόγημα, η μέθοδος των οπλισμένων επιχρισμάτων, η τεχνική των ενεμάτων, η τροποποίηση ή κατασκευή οριζοντίων διαζωμάτων, η αντικατάσταση εύκαμπτων πατωμάτων από πλάκες οπλισμένου σκυροδέματος και η κατασκευή μανδύα από οπλισμένο σκυρόδεμα. Ακολουθεί η ανάλυση ενός τυπικού πολυώροφου κτηρίου στο ιστορικό κέντρο της Κέρκυρας. Η ανάλυση αυτή περιλαμβάνει παραμετρική διερεύνηση της συνεισφοράς των οριζόντιων διαφραγμάτων στη σεισμική συμπεριφορά της κατασκευής. Αρχικά, αναλύεται το κτήριο χωρίς καθόλου διαφράγματα, έπειτα προστίθεται στο κτήριο ξύλινη διαδοκίδωση μίας διεύθυνσης και τέλος γίνεται αντικατάσταση της διαδοκίδωσης αυτής από πλάκες οπλισμένου σκυροδέματος. Στη συνέχεια λαμβάνονται αποτελέσματα που αφορούν τις συνολικές μετακινήσεις του κτηρίου, καθώς και τις κύριες εφελκυστικές ή θλιπτικές τάσεις που αναπτύσσονται σε αυτό. Η εισαγωγή της ξύλινης διαδοκίδωσης δεν φαίνεται να συνεισφέρει ουσιαστικά στη βελτίωση της σεισμικής συμπεριφοράς του κτηρίου, καθώς δίνει παρόμοια διαγράμματα τάσεων και μετακινήσεων. Οι μετακινήσεις είναι μέγιστες στην κορυφή του κτηρίου και κυρίως στο μέσον του ανοίγματος τοίχων που δέχονται δράση σεισμού εκτός του επιπέδου τους, ενώ από τα διαγράμματα κυρίων τάσεων, οι κρίσιμες περιοχές του κτηρίου εστιάζονται στους δύο τελευταίους ορόφους στις θέσεις συνάντησης δύο τοίχων. Με την αντικατάσταση της διαδοκίδωσης από πλάκες Ο.Σ. η συμπεριφορά του κτηρίου βελτιώνεται ουσιαστικά. Οι μέγιστες μετακινήσεις μειώνονται έως και 85% και εμφανίζονται στην πλευρά του τελευταίου ορόφου που απέχει περισσότερο από το κέντρο δυσκαμψίας του κτηρίου. Οι μέγιστες κύριες τάσεις μεταφέρονται από την κορυφή στη βάση του κτηρίου. Οι παρατηρήσεις αυτές επιβεβαιώνονται από τους σχετικούς δείκτες βλάβης που υπολογίζονται στις κρίσιμες περιοχές. Τέλος, πραγματοποιείται και η ανάλυση ενός τυπικού διώροφου κτηρίου, το οποίο αποτελείται από τον δεύτερο τύπο τρίστρωτης τοιχοποιίας. Η τοιχοποιία που αποτελεί το κτήριο έχει ιδιαίτερα ασθενείς εξωτερικές οπτοπλινθοδομές σε σχέση με την ενδιάμεση στρώση από Ο.Σ., επομένως δεν αποτελεί χαρακτηριστική τρίστρωτη τοιχοποιία. Αρχικά θα γίνει παραδοχή της τοιχοποιίας αυτής ως τρίστρωτης, η οποία προσομοιώνεται μέσω της προαναφερθείσας διαδικασίας με μία ισοδύναμη “μονόστρωτη”, ενώ στη συνέχεια θα αγνοηθούν οι ασθενείς εξωτερικές στρώσεις και θα συνυπολογιστούν μόνο τα τοιχεία από Ο.Σ. Και στις δυο περιπτώσεις η σεισμική συμπεριφορά του κτηρίου είναι ικανοποιητική και αυτό οφείλεται στην επιμελημένη δόμησή του, καθώς και στα διαζώματα και πλάκες από Ο.Σ. που υπάρχουν. Έπειτα πραγματοποιούνται επεμβάσεις στο κτήριο για αλλαγή χρήσης του ισογείου, οι οποίες περιλαμβάνουν την καθαίρεση τμημάτων εσωτερικών αλλά και εξωτερικών φερόντων τοίχων. Μετά την ανάλυση του “νέου” κτηρίου διαπιστώνεται ανάγκη ενίσχυσης των πεσσών μικρού εμβαδού που απέμειναν στο ισόγειο και επιλέγεται η εφαρμογή αμφίπλευρων μανδυών από εκτοξευόμενο σκυρόδεμα. Αναλύεται εκ νέου το κτήριο και επιβεβαιώνεται η αποδοτικότητα της μεθόδου ενίσχυσης, αφού μειώνονται οι τάσεις στις κρίσιμες περιοχές που ενισχύθηκαν. / In the present thesis, the mechanical characteristics, the typical damages and the overall seismic behaviour of masonry buildings are examined. Emphasising on the determination of the mechanical characteristics of different three-leaf masonry types, the seismic behaviour of two existing buildings is assessed. These buildings are constructed by different, characteristic types of thee-leaf masonry that are commonly used in the Ionian Islands. Firstly, a multi-storey masonry building located at the historical centre of the city of Corfu is analysed. This building consists of two outer stone walls connected to each other with a low strength mortar. The analysis includes a parametric study of the contribution of the horizontal diaphragms on the seismic behaviour of the structure. In the beginning, the building is analysed with no diaphragms at all, then wooden floors are added to the building and finally the wooden floors are replaced by reinforced concrete slabs. Then, the results from the analysis are evaluated leading to the conclusion that the building with no horizontal diaphragms develops very high top displacements. After adding the wooden floors no significant decrease on the top displacements is observed, but after replacing the wooden floors with RC slabs the decrease of the top displacements is drastic and essential. Finally, another existing two-storey building is examined that consists of two outer plain brick walls connected to each other with reinforced concrete. This type of three-leaf masonry was introduced to the Ionian Islands after the devastating earthquake of 1953. After the analysis of this building, the seismic behaviour of the structure was proved to be very satisfying. Then, some interventions are carried out, including the demolition of some bearing and non-bearing walls. After that the building is analysed again and it is found that some small walls need to be reinforced. This reinforcement is done through bilateral shotcrete jackets, which are proved to bring the overall seismic behaviour of the structure to its prior level.

The largest earthquakes occur along the subduction thrust interface known as the seismogenic zone. Until recently, erosive margins like Tonga and Honshu have been thought to be unable to support earthquakes with magnitudes higher than 8.5. However, Mw 9, 2011 Tohoku-oki earthquake in Honshu requires a reevaluation of this notion. The seismic potential of Tonga is likely affected by the vertical spatial extent of the up-dip and down-dip limits, which confines the seismogenic zone. The larger the area of the seismogenic zone, the higher the potential for larger earthquakes. Some models suggest that down-dip limit coincides with the fore-arc Moho while others suggest that they are coincident with thermally controlled mineralogical phase changes during slab descent. Tonga is an ideal place to discriminate between these possibilities, as the incoming Pacific plate is cold and thick with rapid convergence, extending cool isotherms deep into the system. In contrast, the fore-arc Moho is only ~16 km deep. This study tests the hypothesis that the down-dip limit of the Tonga seismogenic zone coincides with the fore-arc Moho and thus ceases the seismicity by initiating a stable sliding between the mantle and the subducting crust. We determine the depth of the down-dip limit in Tonga by mapping the distribution of earthquakes recorded for a six-month period from January 1, 2010 to June 30, 2010 by a deployment of ocean bottom seismographs above the Tonga subduction zone. The earthquakes are located by a combination of grid-search method and least-square inversion of the observed arrival times. We identified a down-dip limit at a minimum depth of about 40 km below the sea level suggesting that the hypothesis is failed. Therefore, the commonly held idea that down-dip limit is coincides with the fore-arc Moho is not true in the Tonga case. It is likely controlled by the degree of serpentinization in the mantle wedge controlling the transition from stick-slip to stable sliding.

Volcanic eruptions and unrest have the potential to have large impacts on society causing social, economic and environmental losses. One of the primary goals of volcanological studies is to understand a volcano’s behaviour so that future instances of unrest or impending eruptions can be predicted. Despite this, our ability to predict the onset, location and size of future periods of unrest remains inadequate and one of the main problems in forecasting is associated with the inherent complexity of volcanoes. In practice, most reliable forecasts have employed a probabilistic approach where knowledge of volcanic activity triggers have been incorporated into scenarios to indicate the probability of unrest. The proposed relationship between large earthquakes and volcanic activity may, therefore, indicate an important precursory signal for volcanic activity forecasting. There have been numerous reports of a spatial and temporal link between volcanic activity and high magnitude seismic events and it has been suggested that significantly more periods of volcanic unrest occur in the months and years following an earthquake than expected by chance. Disparities between earthquake-volcano assessments and variability between responding volcanoes, however, has meant that the conditions that influence a volcano’s response to earthquakes have not been determined. Using data from the MODVOLC algorithm, a proxy for volcanic activity, this research examined a globally comparable database of satellite-derived volcanic radiant flux to identify significant changes in volcanic activity following an earthquake. Cases of potentially triggered volcanic activity were then analysed to identify the earthquake and volcano parameters that influence the relationship and evaluate the mechansisms proposed to trigger volcanic activity following an earthquake. At a global scale, this research identified that 57% [8 out of 14] of all large magnitude earthquakes were followed by increases in global volcanic activity. The most significant change in volcanic radiant flux, which demonstrates the potential of large earthquakes to influence volcanic activity at a global scale, occurred between December 2004 and April 2005. During this time, new thermal activity was detected at 10 volcanoes and the total daily volcanic radiant flux doubled within 52 days. Within a regional setting, this research also identified that instances of potentially triggered volcanic activity were statistically different to instances where no triggering was observed. In addition, assessments of earthquake and volcano parameters identified that earthquake fault characteristics increase the probability of triggered volcanic activity and variable response proportions at individual volcanoes and regionally demonstrated the critical role of the state of the volcanic system in determining if a volcano will respond. Despite the identification of these factors, this research was not able to define a model for the prediction of volcanic activity following earthquakes and, alternatively, proposed a process for response. In doing so, this thesis confirmed the potential use of earthquakes as a precursory indicator to volcanic activity and identified the most likely mechanisms that lead to seismically triggered volcanic unrest.

Cette recherche vise à étudier la double réponse de l'Etat et une partie de la population sud péruvienne de la catastrophe provoquée par le tremblement de terre du 13 Août 1868 aux départements du sud du Pérou. Basé sur la mémoire sismique profondément enracinée dans cette région, produit de souvenirs de grands tremblements de terre au cours des trois cents dernières années, cet événement sismique a été perçu par ses contemporains comme le plus violent de toute l'histoire de la région de la côte sud du Pérou. Aujourd'hui, les sismologues également ont reconnu comme la plus grande ampleur et l'intensité ont eu lieu non seulement dans la région mais à travers le Pérou au cours des cinq derniers siècles. D'autre part, dans la zone touchée ont été réglées centres urbains des centaines d'échelle très différente, allant des grandes villes aux petites villes comme Arequipa seulement des centaines d'habitants autochtones, situés dans les parties supérieures de la montagne. Par conséquent, la catastrophe de 1868 est le résultat de l'interaction initiale de deux facteurs, un fréquent événement géologique dans la région directement touchée structure urbaine diversifiée, vulnérables à l'action d'un phénomène naturel de cette ampleur. À travers le titre que je voulais mettre en évidence tous les éléments impliqués dans cette recherche. D'une part, une situation (la catastrophe) impliquant deux joueurs (la société et de l'Etat), a accéléré directement par un événement naturel (tremblement de terre), qui se produit dans un domaine spécifique (départements péruviens du sud), comparativement à qui développe un processus (reconstruction) s'étendant sur une dizaine d'années (1868-1878). La réaction de l'Etat a été rapide que possible pour faire face à la phase d'urgence et de réhabilitation. Toutefois, la reconstruction a été une période d'une décennie qui mets en évidence les carences de l'État que l'allocation des ressources dans la région touchée n'était pas constant dans le temps et, bien au contraire diminué de quasiment disparaître dans les préoccupations budgétaires des gouvernements successifs des années 1870. Pendant ce temps, l'économie s'est redressée de manière significative, matérialisée dans un processus qui est à la fois une augmentation du volume de la production agricole, en particulier le vin et le commerce intérieur et international. Ne doit pas être négligé que la reconstruction a dû faire face à des difficultés en raison de l'émergence de nouveaux risques naturels influencé aussi les difficultés à maintenir un rythme approprié de récupération. La recherche a également identifié une internationalisation de la catastrophe, c'est à dire, l'ensemble des informations de diverses manières (privé, militaire et diplomatique) a élargi la connaissance des caractéristiques de la catastrophe qui contribuent de manière significative à la création de conditions pour l'organisation et l'orientation l'aide de différentes origines, mais surtout monétaire de la zone touchée. / This research aims to study the dual response of the state and a section of the southern Peruvian population to the catastrophe caused by the earthquake of August 13, 1868 in the departments of southern Peru. Based on seismic memory deeply rooted in that area, souvenir product of large earthquakes in the past three hundred years, this seismic event was perceived by contemporaries as the most violent of all the regional history of the southern coast of Peru. Today, seismologists also recognized as the largest magnitude and intensity occurred not only in the area but throughout Peru in the last five centuries. On the other hand, in the affected area were settled urban centers hundreds of very different scale, ranging from large cities to small towns like Arequipa just hundreds indigenous inhabitants, located in the upper parts of the mountain. Therefore, the catastrophe of 1868 is the result of the initial interaction of two factors, one frequently occurring geological event in the area directly affected diverse urban structure, vulnerable to the action of a natural phenomenon of this magnitude. Through the title I wanted to highlight all the elements involved in this research. On one hand, a situation (the catastrophe) involving two players (the society and the state), accelerated directly by a natural event (the earthquake), which occurs in a specific area (southern Peruvian departments), compared to which develops a process (reconstruction) extending for about a decade (1868-1878). The state's reaction was swift as possible to deal with the emergency and rehabilitation phase. However, the reconstruction was a period over a decade demonstrated the failings of the state as the allocation of resources to the affected area was not constant in time and quite the contrary diminished to virtually disappear in the budgetary concerns of successive governments of the 1870s. Meanwhile, the economy recovered significantly, materialized process both increased volume of agricultural production, especially wine, and domestic and international trade. Should not be overlooked that the reconstruction had to face difficulties due to the emergence of new natural hazards influenced also the difficulties to maintain an appropriate pace of recovery. Research has also identified an internationalization of the disaster, ie, the set of information in various ways (private, military and diplomatic) expanded the knowledge of the characteristics of the disaster significantly contributing to creating conditions for the organization and referral aid of different origins, although mainly Monetary to the affected area.

This paper aims to set decision framework for the earthquake preventions measures. The starting point is the differences between the natural phenomenon and the disaster; although both have frequency in common, the last one is more unpredictable, but in both cases is a question to make probability estimation. In other words, the earthquakes in Peru appear suddenly and they are an inevitable and repetitive phenomenon. According to that, a better prevention measures can be taken, in order to reduce the economical impact, mainly for the lower income people and improving the quality of life for them in social and human terms. Under such conditions, the absences of an adequate policy on this matter make people unsure about their future and this is a brake for human development / Este trabajo apunta a establecer un marco conceptual de decisión para las medidas de prevención respecto de los terremotos. El punto de partida está en diferenciar entre los fenómenos naturales y los desastres; si bien ambos tienen en común la frecuencia, estos últimos son más impredecibles, pero, en ambos casos, la cuestión es una estimación probabilística. Si bien sabemos que los terremotos aparecen súbitamente y son inevitables e impredecibles, el hecho de que ocurra en lugares como Perú provoca que la situación se vuelva compleja. Es así que se pueden tomar mejores decisiones acerca de las medidas de prevención para reducir, de tal manera, el impacto económico, principalmente en la población de bajos ingresos, de forma que puedan mejorar su calidad de vida en términos sociales y humanos. Bajo estas condiciones, la ausencia de una adecuada política sobre la materia provoca un sentimiento de inseguridad para esta gente y se convierte, al mismo tiempo, en freno para el desarrollo humano.

The Perpetual Environmental Station (PES1), designed and developed is robust, modularenvironmental station with a multitude of sensors, to study the precursors of Earthquakes and todisseminate a long term, quality data of various atmospheric parameters. The PES1 has beendesigned based on the Earthquake precursors, postulated in various research articles. Most ofthese postulated precursors have been tested in laboratory environments and PES1 will be thefirst station to validate these precursors on field. The PES1 has been designed from a modularpoint of view, considering perpetuity where modules can be easily added, replaced, or upgradedsuch that a long-term functioning of the system is guaranteed. The PES1 will be installed inIceland where the seismic activity is quite high, serving as an ideal test location.The thesis work outlines the precursors of Earthquakes and the seismicity in Iceland, where thePES1 is to be installed. The design and development of the PES1 is described from the hardwareand software point of view, with specifications of each sensor used in the Environmental Station.

Earthquakes, such as the ones capable of affecting the Lower Mainland of British Columbia, can have a devastating effect on the environment that people live and work in. The purpose of this thesis is to examine methods of dealing with the hazards and problems created by existing, often historically significant, unreinforced buildings in earthquake-prone areas. Gaining an understanding of the complexity of this problem and the issues involved in establishing hazard mitigation policies gives insight into the policy-making process. The research indicates that a number of internal and external factors affect the formulation, adoption, and implementation of hazard mitigation policies. Despite limited awareness of the problem, low political salience of the issue, and limited resources in most communities, there are many steps that can be taken that will reduce the public's exposure to the risks created by unreinforced buildings and strengthen historically significant buildings that hold value, socially, economically, and culturally. Establishing more extensive mitigative measures, such as implementing a seismic retrofit policy, requires a decision-making process that must involve the people who live and work within that community. Each community, through a process of consultation with the stakeholders, needs to decide if it is in their interest to pursue hazard mitigation strategies to reduce the seismic risk. There is a need to integrate hazard mitigation strategies into the daily decision-making process of politicians and planners. The thesis concludes with some points for stakeholders to consider in designing policy to reduce the earthquake hazard that all the communities in the Lower Mainland of British Columbia face. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

Ever since Granger first proposed the idea of quantitatively testing the causal relationship between data streams, the endeavor of accurately inferring the causality in data and using that information to predict the future has not stopped. Artificial Intelligence (AI), by utilizing the massive amounts of data, helps to solve complex problems, whether they include the diagnosis and detection of disease through medical imaging, email spam detection, or self-driving vehicles. Perhaps, this thesis will be trivial in ten years from now. AI has pushed humankind to reach the next technological level in technology. Nowadays, among most machine leaning inquiries, statistical relationships are determined using correlation measures. By feeding data into machine learning algorithms, computers update the algorithm’s parameters iteratively by extracting and mapping features to learning targets until the correlation increases to a significant level to cease the training process. However, with the increasing developments of powerful AI, there is really a shortage of exploring causality in data. It is almost self-evident that ”correlation is not causality." Sometimes, the strong correlation established between variables through machine learning can be absurd and meaningless. Providing insight into causality information through data, which most of the machine learning methods fall short to do, is of paramount importance. The subsequent chapters detail the four endeavors of studying causality in financial markets, earthquakes, animal/human brain signals, the predictivity of data sets. In Chapter 2, we further developed the concept of causality networks into a higher-order causality network. We applied these to financial data and tested their validity and ability to capture the system’s causal relationship. In next Chapter 3, We examined another type of time series-earthquakes. Violent seismic activities decimate people's lives and destroy entire cities and areas. This begs us to understand how earthquakes work and help us make reliably and evacuation-actionable predictions. The causal relationships of seismic activities in different areas are studied and established. Biological data, specifically brain signals, are time-series data and their causal pattern are explored and studied. Different human and mice brain signals are analyzed and clustered in Chapter 4 using their unique causal pattern to understand different brain cell activity. Finally, we realized that the causal pattern in the time series can be used to compress data. A causal compression ratio is invented and used as the data stream’s predictivity index. We describe this in Chapter 5.

This study investigates whether in-uterus earthquake exposure causes long-term labor, human capital, and health effects. The health shock is maternal stress, which generates excessive concentration levels of cortisol in the fetal environment, negatively impacting the development of the fetus. I use multiple earthquakes between the years 1960-1980 in the setting of Colombia. In my definition of earthquake exposure, I consider both the intensity and the extent of the shaking. Difference-in-difference estimates show mixed results. I find a higher likelihood of being disabled when exposed during the first trimester and the favorable effect of more years of schooling when exposed during the final trimester. Separating the analysis by gender indicates that the effect on disability is centered around males, while results indicating favorable effects are found among females. Generally, exposure from high intensity shaking generates larger point estimates. The results are sensitive to the exclusion of specific earthquakes. In addition, when including those exposed to shaking that were either not felt or weak into the treatment group, some estimates indicate a long-term impact from such exposure. Based on these inconsistencies I am not able to make any general or causal claims.