Base isolated buildings are well known to provide enhanced performance due to minimized accelerations and decreased interstory drifts. However, the reduced demands are obtained at the expense of large displacements at the isolation layer. This study investigates an innovative system, termed ‘dual isolation’, which applies two layers of isolation, one at the base and one mid-story to resolve this issue. An analytical solution for the equation of motion of the proposed system is developed based on linear isolation theory. This creates a foundation to assess the behavior of various types of seismic protection systems and to select the damping, mass and frequency ratio that leads to an optimal dual isolation design. Time history responses of the dual isolation system with viscous damping are compared to those of a conventional isolation counterpart to examine the effectiveness of the system. The system reduces first floor displacements by 40% on average, while the roof displacement is increased by roughly 15%. This results in reduced design forces for the structure. In addition, accelerations, especially above the second isolation layer, are significantly decreased. By reducing story shears and accelerations, the dual isolation system limits damage to both structural and nonstructural systems and components, thereby increasing global system performance. / Thesis / Master of Applied Science (MASc)

With the rapid growth of seismic data volumes, traditional automated processing methods, which have been in use for decades, face increasing challenges in handling these data, especially in noisy environments. Deep learning (DL) methods, due to their ability to handle large datasets and perform well in complex scenarios, offer promising solutions to these challenges. When I started my Ph.D. degree, although a sizeable number of researchers were beginning to explore the application of deep learning in seismology, almost no one was involved in the development of much-needed automated data annotation tools and deep learning training platforms for this field. In other rapidly evolving fields of artificial intelligence, such automated tools and platforms are often a prerequisite and critical to advancing the development of deep learning. Motivated by this gap, my Ph.D. research focuses on creating these essential tools and conducting critical investigations in the field of earthquake detection and phase picking using DL methods. The first research chapter introduces QuakeLabeler, an open-source Python toolbox that facilitates the efficient creation and management of seismic training datasets. This tool aims to address the laborious process of producing training labels in the vast amount of seismic data available today. Building on this foundational tool, the second research chapter presents Blockly Earthquake Transformer (BET), a deep learning platform that provides an interactive dashboard for efficient customization of deep learning phase pickers. BET aims to optimize the performance of seismic event detection and phase picking by allowing easy customization of model parameters and providing extensions for transfer learning and fine-tuning. The third and final research chapter investigates the performance of DL pickers by examining the effect of training data size and deployment settings on phase picking accuracy. This investigation provides insight into the optimal size of training datasets, the suitability of DL pickers for new target regions, and the impact of various factors on training and on model performance. Through the development of these tools and investigations, this thesis contributes to the application of DL in seismology, paving the way for more efficient seismic data processing, customizable model creation, and a better understanding of DL model performance in earthquake detection and phase-picking tasks.

No description available.

Earthquakes can severely damage building structural and nonstructural systems and components, including active and passive fire protection and egress systems. If the occurrence of such damage is not anticipated at the design stage, the impact of a post-earthquake fire could be significant, as building and fire protection systems may not perform as expected. Unfortunately, even though both the seismic and fire engineering communities utilize performance-based approaches for designing well-performing and resilient buildings under earthquake and fire hazards respectively, each discipline carries out their associated building performance analyses independently. As a result, fire protection engineers have little guidance as to how to estimate structural and nonstructural building systems and component damage as inputs to help them develop post-earthquake building fire scenarios. To help bridge this gap, a conceptual framework is developed that illustrates how performance-based approaches for earthquake and fire engineering analysis and design can become more integrated for the development of post-earthquake fire scenarios. Using a fictional building in an earthquake prone area as an example, the conceptual framework is implemented to show (a) how earthquake-induced damage to building fire protection systems could be estimated using an earthquake performance assessment tool, (b) how the damage estimates might be translated into physical damage parameters in a way that is meaningful for developing post-earthquake building fire scenarios, (c) how the damage states might be implemented in terms of fire and egress modeling input parameters, and (d) how this information could be used to and compare post-earthquake building fire safety performance to a normal(undamaged) building fire conditions.

Small, tight-knit communities, are complex to manage from outside during a disaster. The township of Lyttelton, New Zealand, and the communities of Corsair Bay, Cass Bay, and Rapaki to the east, are especially more so difficult due to the terrain that encloses them, which caused them to be cut-off from Christchurch, the largest city in the South Island, barely 10 km away, after the Mw 7.1 Darfield Earthquake and subsequent Canterbury Earthquake Sequence. Lyttelton has a very strong and deep-rooted community spirit that draws people to want to be a part of Lyttelton life. It is predominantly residential on the slopes, with retail space, service and light industry nestled near the harbour. It has heritage buildings stretching back to the very foundation of Canterbury yet hosts the largest, modern deep-water port for the region. This study contains two surveys: one circulated shortly before the Darfield Earthquake and one circulated in July 2011, after the Christchurch and Sumner Earthquakes. An analytical comparison of the participants’ household preparedness for disaster before the Darfield Earthquake and after the Christchurch and Sumner Earthquakes was performed. A population spatiotemporal distribution map was produced that shows the population in three-hourly increments over a week to inform exposure to vulnerability to natural hazards. The study went on to analyse the responses of the participants in the immediate period following the Chrsitchurch and Sumner Earthquakes, including their homeward and subsequent journeys, and the decision to evacuate or stay in their homes. Possible predictors to a decision to evacuate some or all members of the household were tested. The study also asked participants’ views on the events since September 2010 for analysis.

Thesis (M.App.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 165-175). Also available in electronic format on the Internet.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 24, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Eric Sandvol. Vita. Includes bibliographical references.

Approximately 43% of Canada’s population reside in urban centres at most seismic risk.This research creates practical and proactive tools to support decision making in emergency management regarding earthquake risk. This proactive approach evaluates the potential impact of future earthquakes for informed mitigation and preparedness decisions. The overall aims are to evaluate a community’s operational readiness, reveal limitations and resources gaps in the emergency plan, test potential mitigation and preparedness strategies and provide a realistic earthquake scenario for training activities. Two models, the CanRisk injury model and a disaster Spatial Decision Support System (SDSS), were designed and developed to further evaluate seismic risk on a community scale. The injury model is an extension of the engineering-based CanRisk tool and quantifies an individual’s risk to injury, the number of injuries, and provides an injury profile of life-threatening injuries at the building scale. The model implements fuzzy synthetic evaluation to quantify seismic risk, mathematical calculations to estimate number of injuries, and a decision-matrix to generate the injury profile. The SDSS is an evidence-based model that is designed for the planning phase to evaluate post-earthquake emergency response. Loss estimations from Hazus Canada and the CanRisk injury model are combined with community geospatial data to simulate post-earthquake conditions that are important for immediate post-earthquake response. Fire services, search and rescue operations (including urban search and rescue and police services), emergency medical services, and relief operations are all modelled. A case study was applied to 27 neighbourhoods in Ottawa, Canada, using a M6.0 and M7.25 scenarios. The models revealed challenges to all emergency response units. A critical threshold exists between the M6.0 and M7.25 scenarios whereby emergency response moves from partial but manageable functionality to a complete system breakdown. The models developed in this research show great utility to emergency managers in Canada.

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

A large magnitude, long duration subduction earthquake is impending in the Pacific Northwest, which lies near the Cascadia Subduction Zone (CSZ). Great subduction zone earthquakes are the largest earthquakes in the world and are the sole source zones that can produce earthquakes greater than M8.5. Additionally, the increased duration of a CSZ earthquake may result in more structural damage than expected. Given such seismic hazard, the assessment of reinforced concrete substructures has become crucial in order to prioritize the bridges that may need to be retrofitted and to maintain the highway network operable after a major seismic event. Recent long duration subduction earthquakes occurred in Maule, Chile (Mw 8.8, 2010) and Tohoku, Japan (Mw 9.0, 2011) are a reminder of the importance of studying the effect of subduction ground motions on structural performance. For this purpose, the seismic performance of substandard circular reinforced concrete bridge columns was experimentally evaluated using shake table tests by comparing the column response from crustal and subduction ground motions. Three continuous reinforced columns and three lap-spliced columns were tested using records from 1989 Loma Prieta, 2010 Maule and 2011 Tohoku. The results of the large-scale experiments and numerical studies demonstrated that the increased duration of subduction ground motions affects the displacement capacity and can influence the failure mode of bridge columns. Furthermore, more damage was recorded under the subduction ground motions as compared to similar maximum deformations under the crustal ground motion. The larger number of plastic strain cycles imposed by subduction ground motions influence occurrence of reinforcement bar buckling at lower displacement compared to crustal ground motions. Moreover, based on the experimental and numerical results, subduction zone ground motion effects are considered to have a significant effect on the performance of bridge columns. Therefore, it is recommended to consider the effects of subduction zone earthquakes in the performance assessment of substandard bridges, or when choosing ground motions for nonlinear time-history analysis, especially in regions prone to subduction zone mega earthquakes. Finally, for substandard bridges not yet retrofitted or upgraded seismically, the following performance limit recommendation is proposed: for the damage state of collapse, which is related to the ODOT's Life Safety performance level, the maximum strain in the longitudinal reinforcement should be reduced from 0.09 (in./in.) to a value of 0.032 (in./in.) for locations where subduction zone earthquakes are expected, to take into consideration the occurrence of bar buckling.