In this study, ambient noise wavefield was used for the first time to image spatial and temporal upper crustal seismic structures in NW-Bohemia/Vogtland region. The data come from 111 stations and were collected from continuous recordings of the permanent station networks of Germany and Czech Academy of Sciences as well as temporary stations of the BOHEMA and PASSEQ experiments. Rayleigh and Love waves travelling between each station-pair are extracted by cross-correlating long time series of ambient noise data recorded at the stations. Group velocity dispersion curves are obtained by time-frequency analysis of cross-correlation functions between 0.1 and 1 Hz, and are tomographically inverted to provide 2-D group velocity maps. At shorter periods Rayleigh wave group velocity maps are in good agreement with surface geology where low velocity anomalies appear along Mariánské Lázně Fault and Eger rift. A low velocity zone is observed at the northern edge of Mariánské Lázně Fault which shifts slightly to the south with increasing period and correlates well with the main focal zone of the earthquake swarms at 5 s period. We invert the 2-D group velocity maps into a 3-D shear wave velocity model. In this step Love waves were excluded from further analysis because of their high level of misfit to modelled dispersion curves. Horizontal and vertical sections through the model reveal a clear low velocity zone above the Nový Kostel seismic focal zone which narrows towards the top of the seismic activity and ends above the shallowest hypocenters at 7 km depth. We investigate temporal variation of seismic velocity within and around the Nový Kostel associated with 2008 and 2011 earthquake swarms by employing Passive Image Interferometry method using 7 continuous seismograms recorded by the WEBNET network. The results reveals stable seismic velocities without a clear post seismic velocity change during earthquake swarms in the Nový Kostel area.

A method for numerical simulation of train induced track vibration and wave propagation in subgrade has been proposed. The method uses a mass to simulate the bogie of a train and considers the effect of rail roughness. For this method, rail roughness is considered as a randomly generated signal and a filter is used to block the undesired components. The method predicts the particle velocity around the track and can be applied to many kinds of railroad trackbeds including traditional ballast trackbed and modern Hot mix asphalt (HMA) trackbed. Results from ballast and HMA trackbeds are compared and effects of HMA layer on damping track vibration and dissipating wave propagation are presented. To verify the credibility of the method, in-track measurements were also conducted. Site measurements included performing geophysical tests such as spectral analysis of surface wave test and seismic refraction test to determine the subsurface conditions at the test site. Ballast and HMA samples were tested in the laboratory by resonant column test to obtain the material properties. Particle velocities were measured and analyzed in the frequency domain. Results from in-track tests confirm the applicability of the numerical method. The findings and conclusions are summarized and future research topics are suggested.

Traditional methods of imaging the Earth’s subsurface using seismic waves require an identifiable, impulsive source of seismic energy, for example an earthquake or explosive source. Naturally occurring, ambient seismic waves form an ever-present source of energy that is conventionally regarded as unusable since it is not impulsive. As such it is generally removed from seismic data and subsequent analysis. A new method known as seismic interferometry can be used to extract useful information about the Earth’s subsurface from the ambient noise wavefield. Consequently, seismic interferometry is an important new tool for exploring areas which are otherwise seismically quiet, such as the British Isles in which there are relatively few strong earthquakes. One of the possible applications of seismic interferometry is the ambient noise tomography method (ANT). ANT is a way of using interferometry to image subsurface seismic velocity variations using seismic (surface) waves extracted from the background ambient vibrations of the Earth. To date, ANT has been used to successfully image the Earth’s crust and upper-mantle on regional and continental scales in many locations and has the power to resolve major geological features such as sedimentary basins and igneous and metamorphic cores. In this thesis I provide a review of seismic interferometry and ANT and apply these methods to image the subsurface of north-west Scotland and the British Isles. I show that the seismic interferometry method works well within the British Isles and illustrate the usefulness of the method in seismically quiet areas by presenting the first surface wave group velocity maps of the Scottish Highlands and across the British Isles using only ambient seismic noise. In the Scottish Highlands, these maps show low velocity anomalies in sedimentary basins such as the Moray Firth and high velocity anomalies in igneous and metamorphic centres such as the Lewisian complex. They also suggest that the Moho shallows from south to north across Scotland, which agrees with previous geophysical studies in the region. Rayleigh wave velocity maps from ambient seismic noise across the British Isles for the upper and mid-crust show low velocities in sedimentary basins such as the Midland Valley, the Irish Sea and the Wessex Basin. High velocity anomalies occur predominantly in areas of igneous and metamorphic rock such as the Scottish Highlands, the Southern Uplands, North-West Wales and Cornwall. In the lower crust/upper mantle, the Rayleigh wave maps show higher velocities in the west and lower velocities in the east, suggesting that the Moho shallows generally from east to west across Britain. The extent of the region of higher velocity correlates well with the locations of British earthquakes, agreeing with previous studies that suggest British seismicity might be influenced by a mantle upwelling beneath the west of the British Isles. Until the work described in Chapter 6 of this thesis was undertaken in 2009, seismic interferometry was concerned with cross-correlating recordings at two receivers due to a surrounding boundary of sources, then stacking the cross-correlations to construct the inter-receiver Green’s function. A key element of seismic wave propagation is that of source-receiver reciprocity i.e. the same wavefield will be recorded if its source and receiver locations and component orientations are reversed. By taking the reciprocal of its usual form, in this thesis I show that the impulsive-source form of interferometry can also be used in the opposite sense: to turn any energy source into a virtual sensor. This new method is demonstrated by turning earthquakes in Alaska and south-west USA into virtual seismometers located beneath the Earth’s surface.

Analyse pétrophysique et anisotropie des roches détritiques dans des systèmes en compression et sous influence de failles actives : Exemple des prismes de Taiwan et du prisme de Nankai (Japon)L'objectif de cette thèse est l'étude de la déformation enregistrée par des roches d'origine détritique dans des domaines sujets au raccourcissement tectonique sub-horizontal (Layer Parallel Shortening) et à des failles actives. Cette étude est basée sur la caractérisation de diverses propriétés physiques et de leur anisotropie à l'échelle de l'échantillon dans le but de décrire à plus grande échelle la structure d'un prisme d'accrétion. Deux prismes ont ainsi été échantillonnés, le premier est le prisme inactif de Taiwan dans le cadre du projet TCDP et le second considéré comme actif celui de Nankai dans le cadre du projet NanTroSeiZE. La microstructure d'une roche sédimentaire, y compris en l'absence de déformation tectonique, présente toujours une ou plusieurs caractéristique(s) anisotrope(s) liée(s) à la forme, à l'orientation préférentielle ou à l'arrangement de ses éléments constitutifs. De nombreux travaux ont porté sur les conséquences de ces anisotropies sur les propriétés physiques, d'abord dans un but prédictif, puis selon une démarche inverse visant à caractériser, à l'aide de modèles, microstructures et histoire tectonique associée. Dans cette thèse la confrontation des résultats obtenus pour différentes propriétés physiques (principalement vitesses des ondes acoustiques, susceptibilité magnétique et aimantation rémanente) met en évidence des réponses sélectives liées à un fort contrôle de la lithologie.Au niveau de prisme de Taiwan, deux résultats majeurs ont été obtenus. D'une part, la comparaison des anisotropies magnétiques et acoustiques a permis de montrer une évolution différentielle de la déformation entre les roches riches en matrice (siltite) par et celles plus riches en grain sableux (grès). D'autre part, les résultats combinés de l'anisotropie des ondes P, l'étude microstructurale et la minéralogie magnétique, montrent un comportement particulier des échantillons situé dans le mur de la faille FZB1136, considérée comme responsables du séisme de Chi-Chi en 1999. Un réseau de structures dilatantes fortement perméable à permis la circulation de fluides, de néo-cristallisation de calcite et de néoformation de minéraux magnétique. Sur le prisme de Nankai, une estimation de la quantification de la déformation enregistrée par les échantillons du prisme est modélisée en utilisant le modèle de March et les paramètres de susceptibilité magnétique. Les différents travaux réalisés dans cette thèse mettent en évidence un couplage direct de certaines propriétés physiques mesurées avec certains effets de déformation, chaque propriété caractérisant un point précis de la fabrique enregistré dans les roches.Mots-clefs : Anisotropie, susceptibilité magnétique, vitesses d'ondes ultrasoniques, déformation, fabrique, microstructures, faille inverse, TCDP, NanTroSeiZE. / Petrophysics of sedimentary rocks in compressive regime near active faults: examples of the Taiwan and Nankai accretionary prismsThe objective of this PhD is to study the deformation recorded by detrital rocks in areas subject to sub-horizontal tectonic shortening (Layer Parallel Shortening) and active faults. This study is based on the characterization of various physical properties and their anisotropy at sample scale in order to describe larger-scale structure of an accretionary prism. Two prisms have been sampled, the first is the inactive in Taiwan prism (TCDP project) and the second active the Nankai prism (NanTroSeiZE project).Sedimentary rocks microstructures, regardless of the degree to which they were loaded tectonically, always present some anisotropic characteristic emerging from a preferential shape, orientation or distribution of its constituents. Numerous studies have focused on the effect of such anisotropies on physical properties, first for prediction purposes, then to conversely get diffuse strain insight through the use of various effective medium models. In this thesis, the comparison between results obtained in discrete samples for various physical properties (essentially acoustic wave velocities, magnetic susceptibility and remanent magnetization) reveals selective responses due to a strong lithologic control.In TCDP, two significant results are reported. On the one hand, comparison of magnetic and acoustic anisotropy showed a differential evolution of deformation between the matrix-rich rocks (siltstones) and those with coarser granular fraction (sandstone). On the other hand, the combined results of the anisotropy of P waves velocity, microstructural analysis and magnetic mineralogy, show a peculiar behavior of the samples located in the wall of the fault FZB1136, considered to be responsible of the Chi-Chi earthquake in 1999. A network of highly permeable dilatant structures allowed the circulation of fluids, neo-crystallization of calcite and neoformation of magnetic minerals. On the Nankai prism, an estimate of quantifying the deformation recorded by the samples of the prism is modeled using a simple March-type model and the parameters of magnetic susceptibility. The various work in this thesis show a direct coupling of physical properties measured with some aspect of deformation, each property characterizing a specific point of the fabric recorded in rocks.Keywords : Anisotropy, magnetic susceptibility, ultrasonic wave velocity, strain, fabric, microstructures, thrust fault, TCDP, NanTroSeiZE.

Depositional processes are the most critical, complicated conditions that govern sediment properties and their variations, which in turn significantly affect the geotechnical behavior of the sediment. The complexity of depositional and post-depositional processes, which results in a variety of depositional environments, makes constructing a plausible model for the consolidation process of sediments difficult. The mutual influence between the temporal and spatial variation of depositional environments with their resultant physical and mechanical properties cause several compression issues, such as consolidation settlement and land subsidence, which mostly occur in estuarine-riverine regions throughout the world. The first aim of this study is proposing a new grain-size based scheme to classify unconsolidated inorganic sediments that cover a wide range of natural depositional environments with a special emphasis on fine-grained deposits. The proposed classification depends on the linear relationship between percent Fines and the silt fraction. By combining grain size characteristics and plasticity, the proposed scheme provides further characterization of depositional environments. The proposed scheme extends the utility of the scheme beyond simply classifying the sediment class, towards inferring the potential mechanical behavior of sediments having various Grain Size Distribution (GSD) proportions and mineralogy. Addressing elastic wave properties as a geotechnical parameter, in particular, shear wave velocities to determine the mechanical behavior of sediments is because is strongly influenced by the change in those physical state properties during compression and cementation processes. This study presents a continuous function that explicitly uses shear wave velocity to predict the non-linear function of consolidation process (e -log p'), This approach also defines factors that describe the depositional environment, such as grain size and plasticity limits. These factors are shown to influence and control the e -log p' relationship. Thus, the resulting function is shown to be applicable to a variety of sedimentary materials. Also, in this dissertation, elastic shear-wave velocity under critical state framework was employed. A shear wave-based constitutive model was developed that is able to predict the stress-strain behavior of a normally consolidated sediments, under undrained loading. A new power-type relationship that predicts the shear strength behavior and critical stress paths of fine-grained sediments under undrained conditions. Also, it investigates the reliability of the link between input model parameters with the basic properties of a variety of fine-grained sediments. As importance of measuring of elastic wave velocities, a number of soil tests performed during particular construction stages can be reduced and compensated. This reduces the cost of evaluating the stability level, monitoring stress path distributions, and determining undrained shear strength behavior during particular stages of the construction process. The study also provides correlations that can be applied in various fine-grained depositional environments that have weak, fine-grained soil layers, on which the constructions are built.

Earthquakes are among the most destructive natural disasters affecting urban populations. Structural damage caused by the earthquakes varies depending not only on the seismic source and propagation properties but also on the soil properties. The amplitude and frequency content of seismic shear waves reaching the earth&rsquo / s surface is dependent on local soil conditions. It is well known that the soft sediments on top of hard bedrock can greatly amplify the ground motion and cause severe structural damage. When the fundamental period of the soil is close to the fundamental period of a structure, structural damage increases significantly. Estimation of the fundamental periods, amplification factors and types of soils is critical in terms of reduction of loss and casualties. For the reasons stated, estimation of dynamic behavior of soils has become one of the major topics of earthquake engineering. Studies for determining dynamic properties of soils depend fundamentally on the estimation of the S-wave velocity profiles, amplification factors and ground response. In this study first, the Multi-Mode Spatial Autocorrelation (MMSPAC) method is used to estimate the S-wave velocity profiles at the sites of interest. This method is different than the other ones in the sense that it works for the higher modes as well as the fundamental mode. In the second part, Horizontal to Vertical Spectral Ratio (HVSR) method will be used on both microtremor and ground motion data. Finally, the amplification factors from alternative methods are compared with each other. Consistent results are obtained in terms of both fundamental frequencies and amplification factors.

Enhanced Integration of Shear Wave Velocity Profiling in Direct-Push Site Characterization Systems Alexander V. McGillivray 370 Pages Directed by Dr. Paul W. Mayne Shear wave velocity (VS) is a fundamental property of soils directly related to the shear stiffness at small-strains. Therefore, VS should be a routine measurement made during everyday site characterization. There are several lab and field methods for measuring VS, but the seismic piezocone penetration test (SCPTu) and the seismic dilatometer test (SDMT) are the most efficient means for profiling the small-strain stiffness in addition to evaluating large-strain strength, as well as providing evaluations of the geostratigraphy, stress state, and permeability, all within a single sounding. Although the CPT and DMT have been in use for over three decades in the USA, they are only recently becoming commonplace on small-, medium-, and large-size projects as more organizations begin to realize their benefits. Regrettably, the SCPTu and the SDMT are lagging slightly behind their non-seismic counterparts in popularity, in part because the geophysics component of the tests has not been updated during the 25 years since the tests were envisioned. The VS measurement component is inefficient and not cost effective for routine use. The purpose of this research is to remove the barriers to seismic testing during direct-push site characterization with SCPTu and SDMT. A continuous-push seismic system has been developed to improve the integration of VS measurements with SCPTu and SDMT, allowing VS to be measured during penetration without stopping the progress of the probe. A new type of portable automated seismic source, given the name RotoSeis, was created to generate repeated hammer strikes at regularly spaced time intervals. A true-interval biaxial seismic probe and an automated data acquisition system were also developed to capture the shear waves. By not limiting VS measurement to pauses in penetration during rod breaks, it is possible to make overlapping VS interval measurements. This new method, termed frequent-interval, increases the depth resolution of the VS profile to be more compatible with the depth intervals of the near-continuous non-seismic measurements of the SCPTu and the SDMT.

Since 1976, the General Directorate of Disaster Affairs of Turkey has deployed several strong-motion accelerographs at selected sites. Within the framework of the project entitled Compilation of National Strong Ground Motion Database in Accordance with International Standards, initiated in 2006, site conditions at a total of 153 strong-motion sites were investigated within the uppermost 30 m depth through boreholes including Standard Penetration Testing and surface seismics by means of Multi-channel Analysis of Surface Waves (MASW). In this study, firstly, the assessment of the site characterization was held by making use NEHRP Provisions, EC-8 and Turkish Seismic Design Code. The corrected penetration resistances are calculated and observed how it affects the classification. In addition, the consistency of site classes obtained from either penetration resistance or shear wave velocity criteria is examined. Also the consistency of the boundaries of the site classes in terms of shear wave velocity and penetration resistance data pairs are investigated. Secondly, the liquefaction potential of these sites is examined. Thirdly and finally, the shear wave velocity profiles obtained from MASW technique are contrasted to other seismic tests.

Although blood viscosity is an important component in determining vascular function, it is often assumed constant. Emerging evidence linking individual differences in viscosity to cardiovascular disease casts doubt on this assumption. The purpose of this study was to determine the contribution of whole blood viscosity to key measures of vascular function. To address this aim as comprehensively as possible, first, whole blood viscosity was compared with traditional risk factors for cardiovascular disease. Then flow-mediated dilation (FMD), carotid-femoral pulse wave velocity (cfPWV), and carotid artery compliance were calculated either with or without blood viscosity taken into account. Lastly, we tested whether the removal of blood viscosity could influence well-established associations between age and vascular function. Blood viscosity and vascular function were measured in 97 adults ranging in age from 18-63 years. No significant differences were observed between whole blood viscosity and traditional risk factors for cardiovascular disease. Whole blood viscosity was not significantly correlated with FMD, cfPWV, and carotid compliance. As expected, age was positively correlated with cfPWV (r=0.65, p<0.001) and negatively correlated with FMD (r=-0.21, p<0.05) and carotid compliance (r=-0.45, p<0.01). Even after controlling for viscosity, these relationships remained statistically significant (cfPWV r=0.65, p<0.001; FMD r=-0.24, p<0.05; carotid compliance r=-0.44, p<0.05). These results indicate that whole blood viscosity does not appear to significantly impact measures of vascular function and that the rationale for including whole blood viscosity in the calculation of vascular function remains weak. / text

Vascular stiffening is defined as the reduced ability of the blood vessels to expand in response to an increase in blood pressure. Vascular stiffening is often not appreciated as a disease in and of itself but is important to recognize because it is considered a predictor of many cardiovascular disease states. Mechanisms of vascular stiffening remain largely unknown; however the immune system has been found to play major roles in cardiovascular disease and arterial remodeling. This dissertation therefore seeks to illustrate the role of the adaptive immune system in vascular stiffening. This has been done by modeling vascular stiffness in transgenic mice lacking an adaptive immune system as well as immunosuppression in normal mice using a novel method to stimulate regulatory T cells with a cytokine immune complex. We have found that inhibition of the immune system by the use of a genetic knockout (RAG 1 ⁻/⁻ mice) or suppression of an existing immune system with an IL-2/anti-IL-2 complex reduces the development of angiotensin II-induced vascular stiffening. This dissertation supports the role of the adaptive immune system, and particularly CD4⁺T cells, in the development of vascular stiffening as well as the protective roles of Tregs in the disease. It also highlights the use of the IL-2/anti-IL-2 complex as a new potential therapy for vascular stiffness. Therapeutics that suppress adaptive immune function may be beneficial in the treatment of vascular stiffening.