N. Labanda, A. Sfriso, D. Tsingas, R. Aradas, M. Martini
{"title":"EPB-TBM tunnel under internal pressure: Assessment of serviceability","authors":"N. Labanda, A. Sfriso, D. Tsingas, R. Aradas, M. Martini","doi":"10.1201/9780429321559-38","DOIUrl":"https://doi.org/10.1201/9780429321559-38","url":null,"abstract":"The Mantanza-Riachuelo basin recovery is one of the most ambitious environmental projects under construction in Argentina. In this context, the sanitary bureau of the metropolitan area of Buenos Aires (AySA) is building a sewage collection network to transport the waste water of the population in the southern area of the city, composed by almost five million people. The most complex tunnel in this big project is named textit{Lot 3}, an outfall EPB-TBM tunnel starting at a shaft located at the textit{Rio de la Plata} margin and running under the river 12 km to a discharge area. \u0000The tunnel runs through soft clay belonging to the textit{post-pampeano} formation and dense sands of the textit{Puelchese} formation. In operation, it will be pressurized by a pumping station which will produce a piezometer head that, in the first 2000 m, might be eventually higher than the confining pressure around the tunnel. \u0000This paper presents the numerical analysis of the structural forces acting on the tunnel rings using a risk-oriented approach that considers the stochastic nature of materials, stratigraphy and tunnel-ground interaction. The compression of the lining is evaluated and compared with field measurements in order to predict the structural forces and the risk of the rings going into tension beyond the structural capacity of the system.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132161298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
arXiv: GeophysicsPub Date : 2020-09-09DOI: 10.1002/ESSOAR.10504235.1
J. Behura, Shayan Mehrani, F. Forghani
{"title":"The Episodically Buckling and Collapsing Continental Crust in Subduction Zones","authors":"J. Behura, Shayan Mehrani, F. Forghani","doi":"10.1002/ESSOAR.10504235.1","DOIUrl":"https://doi.org/10.1002/ESSOAR.10504235.1","url":null,"abstract":"We discover a remarkable correlation between the inter-tremor time interval and the slenderness ratio of the overriding plate in subduction zones all over the world. In order to understand this phe...","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":" 46","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114053286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vishnu Viswanathan, E. Mazarico, S. Merkowitz, Xiaoli Sun, T. Eubanks, David E. Smith
{"title":"Next-Generation Geodesy at the Lunar South Pole: An Opportunity Enabled by the Artemis III Crew","authors":"Vishnu Viswanathan, E. Mazarico, S. Merkowitz, Xiaoli Sun, T. Eubanks, David E. Smith","doi":"10.13016/M2AXJS-ZIQG","DOIUrl":"https://doi.org/10.13016/M2AXJS-ZIQG","url":null,"abstract":"Lunar retro-reflector arrays (LRAs) consisting of corner-cube reflectors (CCRs) placed on the nearside of the Moon during the Apollo era have demonstrated their longevity, cost-effectiveness, ease of deployment, and most importantly their interdisciplinary scientific impact through the ongoing lunar laser ranging (LLR) experiment. The human exploration of the lunar south polar region provides a unique opportunity to build on this legacy and contribute to the scientific return of the Artemis, for many decades to come. Here we outline the extended science objectives realizable with the deployment of geodetic tracking devices by the Artemis III crew.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125077103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fault slip in hydraulic stimulation of geothermal reservoirs: Governing mechanisms and process-structure interaction","authors":"I. Berre, Ivar Stefansson, E. Keilegavlen","doi":"10.1190/tle39120893.1","DOIUrl":"https://doi.org/10.1190/tle39120893.1","url":null,"abstract":"Hydraulic stimulation of geothermal reservoirs in basement or crystalline igneous rock can enhance permeability by reactivation and shear-dilation of existing fractures. The process is characterized by interaction between fluid flow and the fractured structure of the formation. The flow is highly affected by the fracture network, which in turn is deformed because of hydromechanical stress changes caused by the fluid injection. This process-structure interaction is decisive for the outcome of a stimulation and, in analysis of governing mechanisms, physics-based modeling has potential to complement field and experimental data. \u0000Here, we show how recently developed simulation technology is a valuable tool to understand governing mechanisms of hydro-mechanical coupled processes and the reactivation and deformation of faults. The methodology fully couples flow in faults and matrix with poroelastic matrix deformation and a contact mechanics model for the faults, including dilation because of slip. Key elements are high aspect ratios of faults and strong nonlinearities in highly coupled governing equations. Example simulations illustrate direct and indirect hydraulic fault reactivation and corresponding permeability enhancement.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121796274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Miner, P. Mayewski, S. Baidya, K. Broad, H. Clifford, A. Gajurel, Bibek Giri, M. Hubbard, Corey Jaskolski, H. Koldewey, Wei Li, T. Matthews, I. Napper, Baker Perry, M. Potocki, J. Priscu, A. Tait, Richard C. Thompson, Subash Tuladhar Climate Change Institute, U. Maine, Usa Jet Propulsion Lab, C. I. O. Technology., Usa Department of Environmental Sciences, Montana State University, U. Geology, Tribhuvan University, Nepal Dept. of Geography, Environment, Loughborough University, UK Dept. of Geography, Planning, A. S. University, Usa International Marine Litter Research Unit, U. Plymouth, Uk London, London, U. Earth, Climate Sciences, Usa National Geographic Society, DC Washington, Usa Department of Hydrology, Meteorology, Kathmandu, Nepal Abess Center for Ecosystem Science, Policy., University of Miami, Usa Dept. of Land Resources, E. Sciences, Usa Virtual Wonders, Llc, Wisconsin., Usa
{"title":"Emergent risks in the Mt. Everest region in the time of anthropogenic climate change","authors":"K. Miner, P. Mayewski, S. Baidya, K. Broad, H. Clifford, A. Gajurel, Bibek Giri, M. Hubbard, Corey Jaskolski, H. Koldewey, Wei Li, T. Matthews, I. Napper, Baker Perry, M. Potocki, J. Priscu, A. Tait, Richard C. Thompson, Subash Tuladhar Climate Change Institute, U. Maine, Usa Jet Propulsion Lab, C. I. O. Technology., Usa Department of Environmental Sciences, Montana State University, U. Geology, Tribhuvan University, Nepal Dept. of Geography, Environment, Loughborough University, UK Dept. of Geography, Planning, A. S. University, Usa International Marine Litter Research Unit, U. Plymouth, Uk London, London, U. Earth, Climate Sciences, Usa National Geographic Society, DC Washington, Usa Department of Hydrology, Meteorology, Kathmandu, Nepal Abess Center for Ecosystem Science, Policy., University of Miami, Usa Dept. of Land Resources, E. Sciences, Usa Virtual Wonders, Llc, Wisconsin., Usa","doi":"10.5281/ZENODO.3972343","DOIUrl":"https://doi.org/10.5281/ZENODO.3972343","url":null,"abstract":"In April and May 2019, as a part of the National Geographic and Roxel Perpetual Planet Everest Expedition, the most interdisciplinary scientific ever was launched. This research identified changing dynamics, including emergent risks resulting from natural and anthropogenic change to the natural system. We have identified compounded risks to ecosystem and human health, geologic hazards, and changing climate conditions that impact the local community, climbers, and trekkeers in the future. This review brings together perspectives from across the biological, geological, and health sciences to better understand emergent risks on Mt. Everest and in the Khumbu region. Understanding and mitigating these risks is critical for the ~10,000 people living in the Khumbu region, as well as the thousands of visiting trekkers and the hundreds of climbers who attempt to summit each year.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128913165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Near-surface characterization using a roadside distributed acoustic sensing array","authors":"S. Yuan, A. Lellouch, R. Clapp, B. Biondi","doi":"10.1190/tle39090646.1","DOIUrl":"https://doi.org/10.1190/tle39090646.1","url":null,"abstract":"Thanks to the broadband nature of the Distributed Acoustic Sensing (DAS) measurement, a roadside section of the Stanford DAS-2 array can record seismic signals from various sources. For example, it measures the earth's quasi-static distortion caused by the weight of cars (<0.8 Hz), and Rayleigh waves induced by earthquakes (<3 Hz) and by dynamic car-road interactions (3-20 Hz). We directly utilize the excited surface waves for shallow shear-wave velocity inversion. Rayleigh waves induced by passing cars have a consistent fundamental mode and a noisier first mode. By stacking dispersion images of 33 passing cars, we obtain stable dispersion images. The frequency range of the fundamental mode can be extended by adding the low-frequency earthquake-induced Rayleigh waves. Thanks to the extended frequency range, we can achieve better depth coverage and resolution for shear-wave velocity inversion. In order to assure clear separation from Love waves and aligning apparent velocity with phase velocity, we choose an earthquake that is approximately in line with the array. The inverted models match those obtained by a conventional geophone survey performed by a geotechnical service company contracted by Stanford University using active sources from the surface until about 50 meters. In order to automate the Vs inversion process, we introduce a new objective function that avoids manual dispersion curve picking. We construct a 2-D Vs profile by performing independent 1-D inversions at multiple locations along the fiber. From the low-frequency quasi-static distortion recordings, we invert for a single Poisson's ratio at each location along the fiber. We observe spatial heterogeneity of both Vs and Poisson's ratio profiles. Our approach is dramatically cheaper than ambient field interferometry and reliable estimates can be obtained more frequently as no lengthy cross-correlations are required.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125653758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SWinvert: a workflow for performing rigorous 1-D surface wave inversions","authors":"J. Vantassel, B. Cox","doi":"10.1093/gji/ggaa426","DOIUrl":"https://doi.org/10.1093/gji/ggaa426","url":null,"abstract":"SWinvert is a workflow developed at The University of Texas at Austin for the inversion of surface wave dispersion data. SWinvert encourages analysts to investigate inversion uncertainty and non-uniqueness in shear wave velocity (Vs) by providing a systematic procedure and open-source tools for surface wave inversion. In particular, the workflow enables the use of multiple layering parameterizations to address the inversion's non-uniqueness, multiple global searches for each parameterization to address the inverse problem's non-linearity, and quantification of Vs uncertainty in the resulting profiles. To encourage its adoption, the SWinvert workflow is supported by an open-source Python package, SWprepost, for surface wave inversion pre- and post-processing and an application on the DesignSafe-CyberInfracture, SWbatch, that enlists high-performance computing for performing batch-style surface wave inversion through an intuitive and easy-to-use web interface. While the workflow uses the Dinver module of the popular open-source Geopsy software as its inversion engine, the principles presented can be readily extended to other inversion programs. To illustrate the effectiveness of the SWinvert workflow and to develop a set of benchmarks for use in future surface wave inversion studies, synthetic experimental dispersion data for 12 subsurface models of varying complexity are inverted. While the effects of inversion uncertainty and non-uniqueness are shown to be minimal for simple subsurface models characterized by broadband dispersion data, these effects cannot be ignored in the Vs profiles derived for more complex models with band-limited dispersion data. The SWinvert workflow is shown to provide a methodical procedure and a powerful set of tools for performing rigorous surface wave inversions and quantifying the uncertainty in the resulting Vs profiles.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128825627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
arXiv: GeophysicsPub Date : 2020-05-01DOI: 10.20944/PREPRINTS202007.0323.V1
Huijing He
{"title":"Multiple Scattering Theory for Strong Scattering Heterogeneous Elastic Continua with Triaxial Inhomogeneities: Theoretical Fundamentals and Applications","authors":"Huijing He","doi":"10.20944/PREPRINTS202007.0323.V1","DOIUrl":"https://doi.org/10.20944/PREPRINTS202007.0323.V1","url":null,"abstract":"The geometry of mesoscopic inhomogeneities plays an important role in determining the macroscopic propagation behaviors of elastic waves in a heterogeneous medium. Non-equiaxed inhomogeneities can lead to anisotropic wave velocity and attenuation. Developing an accurate scattering theory to describe the quantitative relation between the microstructure features and wave propagation parameters is of fundamental importance for seismology and ultrasonic nondestructive characterization. This work presents a multiple scattering theory for strongly scattering elastic media with general tri-axial heterogeneities. A closed analytical expression of the shape-dependent singularity of the anisotropic Green’s tensor for the homogeneous reference medium is derived by introducing a proper non-orthogonal ellipsoidal coordinate. Renormalized Dyson’s equation for the coherent wave field is then derived with the help of Feynman’s diagram technique and the first-order-smoothing approximation. The exact dispersion curves and the inverse Q-factors of coherent waves in several representative medium models for the heterogeneous lithosphere are calculated numerically. Numerical results for small-scale heterogeneities with the aspect ratio varying from 1 to 7 show satisfactory agreement with those obtained from real earthquakes. The results for velocity dispersion give rise to a novel explanation to the formation mechanism of different seismic phases. The new model has potential applications in seismology and ultrasonic microstructure characterization.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115183776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
arXiv: GeophysicsPub Date : 2020-04-22DOI: 10.1002/essoar.10502774.1
B. Apostol
{"title":"Bath's law, correlations and magnitude distributions","authors":"B. Apostol","doi":"10.1002/essoar.10502774.1","DOIUrl":"https://doi.org/10.1002/essoar.10502774.1","url":null,"abstract":"The empirical Bath's law is derived from the magnitude-difference statistical distribution of earthquake pairs. The pair distribution related to earthquake correlations is presented. The single-event distribution of dynamically correlated earthquakes is derived, by means of the geometric-growth model of energy accumulation in the focal region. The dynamical correlations may account, at least partially, for the roll-off effect in the Gutenberg-Richter distributions. The seismic activity which accompanies a main shock, including both the aftershocks and the foreshocks, can be viewed as fluctuations in magnitude. The extension of the magnitude difference to negative values leads to a vanishing mean value of the fluctuations and to the standard deviation as a measure of these fluctuations. It is suggested that the standard deviation of the magnitude difference is the average difference in magnitude between the main shock and its largest aftershock (foreshock), thus providing an insight into the nature and the origin of the Bath's law. It is shown that moderate-magnitude doublets may be viewed as Bath partners. Deterministic time-magnitude correlations of the accompanying seismic activity are also presented.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129596904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"AstroSeis: A 3D Boundary Element Modeling Code for Seismic Wavefields in Irregular Asteroids and Bodies","authors":"Yuan Tian, Yingcai Zheng","doi":"10.1785/0220200145","DOIUrl":"https://doi.org/10.1785/0220200145","url":null,"abstract":"We developed a 3-D elastic Boundary Element Method (BEM) computer code, called AstroSeis, to model seismic wavefields in a body with an arbitrary shape, such as an asteroid. Besides the AstroSeis can handle arbitrary surface topography, it can deal with a liquid core in an asteroid model. Both the solid and liquid domains are homogenous in our current code. For seismic sources, we can use single forces or moment tensors. The AstroSeis is implemented in the frequency domain and the frequency-dependent Q can be readily incorporated. The code is in MATLAB and it is straightforward to set up the model to run our code. The frequency-domain calculation is advantageous to study the long-term elastic response of a celestial body due to a cyclic force such as the tidal force with no numerical dispersion issue suffered by many other methods requiring volume meshing. Our AstroSeis has been benchmarked with other methods such as normal modes summation and the direct solution method (DSM). This open-source AstroSeis will be a useful tool to study the interior and surface processes of asteroids.","PeriodicalId":390991,"journal":{"name":"arXiv: Geophysics","volume":"53 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123435935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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