Liquefaction induced settlement is an earthquake hazard engineers face when developing infrastructure. Current methods for estimating liquefaction induced settlement are done in a free field condition. This assumption is not an accurate way to describe the soil because in most cases the soil will bear some kind of infrastructure. Evaluation of liquefaction induced settlement in a non-free-field condition is a more appropriate way. Using the Bullock et al. CAV model, Bullock et al liquefaction induced settlement model, and probabilistic seismic hazard software from the USGS, a full performance-based procedure for the estimation of liquefaction-induced building settlement in the non-free-field condition was created. To test the validity of the program, various locations, structures, and soil profiles were tested. The output of settlement hazard curves showed results consistent to liquefaction induced settlement trends described in other research. Areas with higher seismicity had higher expected liquefaction induced settlement. Analysis of individual location revealed that soil profile, structure, and foundation all play a role in the estimation of liquefaction induced settlement. Test cases with loose soil predicted higher liquefaction induced settlement than areas with dense soils. Structure and foundation parameters are related through the bearing pressure. These parameters seem to be most influenced by bearing pressure. Test cases with higher bearing pressures showed a higher predicted liquefaction induced settlement than those with smaller bearing pressures.

Recent seismic events have confirmed the long-standing belief that unreinforced masonry structures are critically vulnerable to failure during earthquakes. A substantial number of older structures in the United States have unreinforced masonry construction. Among these are important historic structures, vital to preserving regional and national heritage. Since earthquakes can likely damage these buildings, they must be protected against failure. RetrOfitting these structures should be a sensitive process, reaching beyond pure safety issues and recognizing the historical qualities of the structure. Fire Station No. One, Roanoke, Virginia, an unreinforced masonry bearing wall building, is one of the most treasured landmarks in the Roanoke Valley. Completed in 1908, the Fire Station is still operational, serving as a lifeline structure. Built in absence of any seismic codes, this structure may be at risk of failure during an earthquake. The purpose of this study is to analyze the various seismic risks that exist in Fire Station No. One and to identify any seismic deficiencies within the structure. Additionally, this thesis will suggest possible seismic strengthening measures that would be appropriate, based upon preservation and aesthetic considerations. / Master of Science

This dissertation examines the influence of paramilitary professional cultural attributes on the speed at which disaster response organizations (DROs) recognize, respond, organize, and take action in the immediate aftermath of a disaster. Three agencies are examined: the U.S. Coast Guard, the Federal Emergency Management Agency, and the U.S. military's Southern Command/Joint Task Force-Haiti. The 2010 Haiti earthquake is used as a case study to explore the influence of three independent variables: (1) paramilitarism; (2) career ladders (i.e., recruitment and professional development of staff); and (3) workforce autonomy. The purpose is to determine if paramilitary cultures help or hinder an agency's speed into action, thereby helping improve the disaster response organizations of the future. In the case of Haiti, it finds that the combination of thick paramilitary culture, insider career ladders, and high workforce autonomy best enabled responders' speed into action. / Ph. D.

This study evaluates the seismically induced displacements of a slope using the Finite Element Method (FEM) in comparison to the results of twelve empirical predictive approaches. First, the existing methods to analyze the stability of slopes subjected to seismic loads are presented and their capabilities to predict the onset of failure and post-failure behavior are discussed. These methods include the pseudostatic method, the Newmark method, and stress-deformation numerical methods. Whereas the pseudostatic method defines a seismic coefficient for the analysis and provides a safety factor, the Newmark method incorporates a yield coefficient and the actual acceleration time history to estimate permanent displacements. Numerical methods incorporate advanced constitutive models to simulate the coupled stress-strain soil behavior, making the process computationally more costly. In this study, a model slope previously studied at laboratory scale is selected and scaled up to prototype dimensions. Then, the slope is subjected to 88 different input motions, and the seismic displacements obtained from the numerical and empirical approaches are compared statistically. From correlation analyses between seven ground motion parameters and the numerical results, new empirical predictive equations are developed for slope displacements. The results show that overall the FEM displacements are generally in agreement with the numerically developed methods by Fotopoulou and Pitilakis (2015) labelled "Method 2" and "Method 3", and the Newmark-type Makdisi and Seed (1978) and Bray and Travasarou (2007) methods for rigid slopes. Finally, functional forms for seismic slope displacement are proposed as a function of peak ground acceleration (PGA), Arias intensity (Ia), and yield acceleration ratio (Ay/PGA). These functions are expected to be valid for granular slopes such as earth dams, embankments, or landfills built on a rigid base and with low fundamental periods (Ts<0.2). / Master of Science / A landslide is a displacement on a sloped ground that can be triggered by earthquake shaking. Several authors have investigated the failure mechanisms that lead to landslide initiation and subsequent mass displacement and proposed methodologies to assess the stability of slopes subjected to seismic loads. The development of these methodologies has to rely on field data that in most of the cases are difficult to obtain because identifying the location of future earthquakes involves too many uncertainties to justify investments in field instrumentation (Kutter, 1995). Nevertheless, the use of scale models and numerical techniques have helped in the investigation of these geotechnical hazards and has led to development of equations that predict seismic displacements as function of different ground motion parameters. In this study, the capabilities and limitations of the most recognized approaches to assess seismic slope stability are reviewed and explained. In addition, a previous shaking-table model is used for reference and scaled up to realistic proportions to calculate its seismic displacement using different methods, including a Finite Element model in the commercial software Plaxis2D. These displacements are compared statistically and used to develop new predictive equations. This study is relevant to understand the capabilities of newer numerical approaches in comparison to classical empirical methods.

On August 31, 1886 a large scale earthquake occurred in Summerville, S.C. causing severe damage in the coastal city of Charleston. Although intensive geological and geophysical studies have been conducted in the area, uncertainty remains about the details of the event. Recently evidence from seismic reflection profiles have shed light on the tectonic environment of the area. The epicentral area of the 1886 event lies within the South Georgia Rift, a Mesozoic rift terrane. Previous studies have revealed clues to the geologic structure and evolution of this feature. SEISDATA4 is the largest seismic reflection profile recorded in the area. By re-processing the line, information about the tectonic structure of the area was revealed. The early Mesozoic extensional basin that hosted the 1886 earthquake and is host to the modern seismicity recorded in the area, extends several kilometers to the south and west of Charleston, along SEISDATA4. Cenozoic and Mesozoic faults were resolved within the basin and along its northwestern boundary that is distinguished by a strong gradient in the magnetic field. However, the question as to which fault was responsible for the rupture of 1886 still remains. The refraction analysis provides better resolution of the lithology in Lower Mesozoic section. The termination of the strong reflection at the base of the Atlantic Coastal Plain occurs in a section of the profile that shows major disruption of the underlying reflections, and suggests that the termination of a lower Mesozoic basalt flow responsible for the reflection may be related to tectonic deformation. / Master of Science

The response of an aggregate pier foundation system during seismic loading was investigated. The factors and phenomena governing the performance of the aggregate pier and the improved ground were identified and clarified. The key factors affecting the performance of the aggregate pier include soil density, stiffness modulus, and drainage capacity. The improved ground is influenced by soil stratification, soil properties, pore pressure dissipation, and earthquake time history. Comprehensive numerical modeling using FLAC were performed. The focus of the study in this research was divided into three parts: the studies of the ground acceleration, the excess pore water pressure ratio and the shear stress in soil matrix generated during seismic loading. Two earthquake time histories scaled to different peak acceleration were used in the numerical modeling: the 1989 Loma Prieta earthquake (pga = 0.45g) and the 1988 Saguenay earthquake (pga = 0.05g). The main results of the simulation showed the following effects of aggregate pier on liquefiable soil deposits: 1) The aggregate pier amplifies the peak horizontal acceleration on the ground surface (amax), 2) The aggregate pier reduces the liquefaction potential up to depth where it is installed, 3) Pore pressures are generally lower for soils reinforced with aggregate pier than unreinforced soils except for very strong earthquake, 4) The maximum shear stresses in soil are much smaller for reinforced soils than unreinforced soils. The excess pore water pressure ratio and the shear stress in the soil matrix calculated by FLAC were generally lower than those predicted by available procedures. / Master of Science

No description available.

This report contributes to the ArtEmis project, a multidisciplinary initiative designed to enhance earthquake forecasting through sensor technology. By utilizing a sensor unit that measures radon levels—a potential precursor to seismic activity—the project seeks to develop predictive capabilities. Central to this report is the evaluation and enhancement of the acquisition electronics critical to sensor functionality. The study involves testing and monitoring of the initial set of sensor systems deployed across various locations in Southern Europe, with specific attention given to electronic components like the gateway and its connectivity options. The findings reveal that the D-Link DWR-932 router, originally used for network connectivity, is unsuitable due to poor performance. Consequently, this report recommends replacing the D-Link router with more reliable alternatives such as the SIM7600G-H modem and the Rut241 router, either individually or in combination, to enhance the system’s reliability and overall performance.

ArtEmis is an EU project that today consists of 14 differentinstitutions collectively working towards the final goal of buildinga system that can make trustworthy earthquake predictions withthe help of radon gas. The purpose of this report is to analyse theconcentration of radon measured by four out of six prototype sensorsinstalled by the ArtEmis project. In the occurrence of an earthquake, tectonic plates slide together,causing stress levels to rise within the Earth’s crust and microcracksbegin to form. When these microcracks form, specific elements suchas radon gas can ascend toward the surface and reach groundwater.Once in groundwater, the concentration of radon can be measuredby analysing the amount of γ rays at certain energies using γ-rayspectroscopy. With energy spectra measured by these sensors, an energy intervalcorresponding to the presence of the isotope 222Rn could be identified,namely the interval around 609 keV. This stems from a daughterisotope of 222Rn. Further analysis on the activity over time, andcomparisons to instances when earthquakes occurred, could thenbe done. These measurements were also tested against a statisticalmodel based on Gaussian distribution, showing correlation in severalcases. One sensor location had an extra interesting find. Here it wasable to see, on two different occasions, a distinct increase in 222Rnconcentration roughly 10 days prior to an earthquake.Considering that these sensors are active for the very first timeduring the time span of this report, unintended behaviour occurredon several occasions. A large focus of the project currently lies onfixing these issues. This leads to limited conclusions being able tobe drawn from such a short time span, but could give indication ofpositive results moving forward.

Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Water-retaining structures are commonly used in South Africa for the storage of potable water and waste water. However, a South African code pertaining to the design of concrete water-retaining structures do not currently exist and therefore use is made of the British Standard BS 8007 (1987). For the design of concrete water-retaining structures in South Africa, only the hydrostatic loads are considered while forces due to seismic activity are often neglected even though seismic excitations of moderate magnitude occur within some regions of the country. Hence, the primary aim of this study was to determine whether seismic activity, as it occurs in South Africa, has a significant influence on water-retaining structures and whether it should be considered as a critical load case. In order to assess the influence of seismic activity on the design of water-retaining structures the internal forces in the wall and the required area of reinforcement were compared. Comparisons were made between the seismic analyses and static analyses for both the ultimate and serviceability limit states. In order to obtain the internal forces in the wall use was made of an appropriate Finite element model. Three Finite element models were investigated in this study and the accuracy of each model was assessed based on the fundamental frequency, base shear force and overturning moment. These values were compared to the values obtained with the numerical method presented by Veletsos (1997) which was verified with Eurocode 8: Part 4 (2006). The results obtained indicated that seismic excitations of moderate magnitude do have a significant influence on the reinforcement required in concrete water-retaining structures. For both the ultimate limit state and serviceability limit state the required reinforcement increased significantly when seismic loads were considered in the design. As in the case for static design of water-retaining structures, the serviceability limit state also dominated the design of these structures under seismic loading. / AFRIKAANSE OPSOMMING: Beton waterhoudende strukture in Suid-Afrika word op ‘n gereelde basis gebruik vir die stoor van drink- sowel as afvalwater. ‘n Suid-Afrikaanse kode vir die ontwerp van hierdie strukture bestaan egter nie en dus word die Britse kode BS 8007 (1987) hiervoor gebruik. Vir ontwerp doeleindes word soms slegs die hidrostatiese kragte beskou terwyl kragte as gevolg van seismiese aktiwiteite nie noodwendig in berekening gebring word nie. Seismiese aktiwiteite van gematigde grootte kom egter wel voor in sekere dele van Suid-Afrika. Die hoofdoel van hierdie studie was dus om die invloed van seismiese aktiwiteite, soos voorgeskryf vir Suid-Afrikaanse toestande, op beton waterhoudende strukture te evalueer asook om te bepaal of dit ‘n kritiese lasgevalle sal wees. Vir hierdie doel is die interne kragte asook die area staal bewapening vir elk van die statiese en dinamiese lasgevalle vergelyk. Vergelykings is getref tussen die dinamiese en statiese resultate vir beide die swigtoestand en die diensbaarheidstoestand. Vir die bepaling van die interne kragte is gebruik gemaak van eindige element modelle. Tydens hierdie studie was drie eindige element modelle ondersoek en die akkuraatheid van elk geëvalueer op grond van die fundamentele frekwensie, die fondasie skuifkrag en die omkeermoment. Hierdie waardes was ondermeer bereken met twee numeriese metodes soos uiteengesit in Veletsos (1997) en Eurocode 8: Part 4 (2006). Die resultate dui daarop dat die invloed van seismiese aktiwiteite op beton waterhoudende strukture in Suid-Afrika nie weglaatbaar klein is nie en wel in berekening gebring behoort te word tydens die ontwerp. Die interne kragte vir beide die swigtoestand en diensbaarheidstoestand is aansienlik hoër vir die seismiese lasgeval as vir die statiese geval. Die diensbaarheidstoestand het deurentyd die ontwerp van beton waterhoudende strukture vir seismiese toestande oorheers.