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181.
Abbas Rajabifard Behnam Atazadeh Mohsen Kalantari 《International journal of geographical information science》2018,32(10):2098-2122
Three-dimensional (3D) spatial information models are increasingly being adopted to help communicate the spatial dimensions of complex built environments. Land administration practices in multi-owned developments include the subdivision, registration and management of legal interests associated with private, communal and public properties, which are often located along the vertical dimension. The spatial structure of each legal interest is normally composed of invisible spaces, defined as the inside and outside of multi-owned developments, as well as physically built structures. Additionally, a wide variety of legal boundary types mark out the spatial limits of the individual parts of each legal interest. These legal boundaries are typically delineated by either relying on fixed surveying measurements or referencing physically existent objects. This article provides a critical assessment of 3D spatial information models in terms of their capabilities for modelling legal interests and legal boundaries defined in the Victorian jurisdiction. We classify these models into three categories: purely legal, purely physical and integrated. This assessment provides the basis for developing a new 3D spatial information model, which would subsequently support a pathway towards realising the Victorian land administration system in a 3D digital environment. 相似文献
182.
In this work the interaction between adjacent rigid, surface foundations resting on a viscoelastic layered soil medium is studied. A 3-D frequency domain BEM formulation in conjunction with infinite space fundamental solutions and the so called `successive stiffness method', initially developed for elastostatics and adapted here for the solution of elastodynamic problems, are used for the simulation of a layered soil medium. As a result, a discretization of the soil-foundation interface and the surrounding free surface as well as the soil layers' interfaces is necessary. However, it is shown in this work that reasonably accurate results can be obtained by using a substantially reduced discretization scheme involving only a small portion of the free surface surrounding the foundation and the corresponding interfaces of the soil layers. The presented numerical results demonstrate the importance of the dynamic foundation-soil-foundation interaction phenomenon which becomes even more pronounced where the supporting soil medium is made up of relatively shallow layers close to its free surface. 相似文献
183.
Mark V. Trevorrow Tokuo Yamamoto Altan Turgut Dean Goodman Mohsen Badiey 《Marine Geophysical Researches》1989,11(2):129-152
Sources of very low frequency (0.01 to 1.0 Hz) ambient seismic noise in the shallow (<100 m) water continental margin sediments are investigated using Ocean Bottom Seismometers (OBS). The predominant seismic motions are found to be due to surface gravity (water) waves and water-sediment interface waves. Actual experimental measurements of seabed acceleration and hydrodynamic pressure are given, including side by side comparisons between buried and plate-mounted OBS units. OBS-sediment resonant effects are found to be negligible at the low frequencies under investigation. Wherever there exists relative motion between the seabed and the water, however, an exposed OBS is subject to added mass forces that cause it to move with the water rather than the sediments. Calculations based on measured seabed motions show that a neutral density, buried seismometer has superior sediment coupling charactersitics to any exposed OBS design. 相似文献
184.
Mohsen Kamalian Abdollah Sohrabi-Bidar Arash Razmkhah Amirata Taghavi Iraj Rahmani 《Journal of Earth System Science》2008,117(2):783
This paper presents the results of an extensive numerical parametric study on seismic behavior of 2D homogenous hills subjected to vertically propagating incident SV waves. It is shown that the amplification potential of these hills is strongly influenced by the wavelength, by the shape ratio, by the shape of the hill and in a less order of importance, by the Poisson ratio of the media. The 2D topography effect could be ignored, only if the hill has a shape ratio of less than 0.1 or if it is subjected to incident waves with predominant dimensionless periods of greater than 13 times the shape ratio. In incidence of waves with wavelengths longer than the width of the hill, the amplification curve usually finds its maximum at the crest and decreases towards the base of the hill. Else, some de-amplification zones would occur along the hill. Among hills with similar shape ratios, those with intermediate cross section areas show intermediate seismic behavior, too. Estimated seismic site coefficients for the crest of a 2D rocky hill depend on its shape ratio and could reach even 1.7, which encourages one to classify it according to standard site categorization procedures as soil profile types SC or SD instead of the conventional SB type. 相似文献
185.
M. Moayyed M. Moazzen A.A. Calagari A. Jahangiri M. Modjarrad 《Chemie der Erde / Geochemistry》2008,68(2):141-154
Eslamy peninsula in NW of Iran is formed by a strato-volcano with collapsed calderon, which is intruded by lamprophyric dykes with minette composition. Also trachytic and microsyenitic dykes have intruded the volcanic rocks. The oldest volcanic activity includes eruption of leucite basanite, leucite tephrite, basanite and tephrite, which are associated with pyroclastic rocks. Lamprophyric dykes are distinguishable with large mica phenocrysts. Mica-clinopyroxenite xenoliths can be found in the rocks. The source magma of the rocks had a ultrapotassic to shoshonitic nature, rich in LREE and LILE. Eslamy peninsula lamprophyres are between alkaline and calc-alkaline lamprophyres in terms of REE patterns and spider diagrams for trace elements, but are closer to clac-alkaline lamprophyres. The behaviour of trace elements studied by the means of spider diagrams show that the magma, producing the lamprophyres, is generated from deep-mantle probably from a garnet-bearing source (garnet lherzolite) with high CO2/H2O content. The resulted magma had interacted with crustal materials and had formed Eslamy peninsula lamprophyres in a post-collisional tectonic setting. Geochemistry of rare elements indicate an extensive rutile-rich metasomatism in the source magma of the lamprophyres. 相似文献
186.
The paper examines the effect on the structural response of the inevitable correlation which exists between the six earthquake components acting along a set of structural axes. The rotational components are expressed in terms of the spatial derivatives of the translational components. For the calculation of response, modal analysis is employed so that ground response spectra can also be used as seismic input. A methodology is developed to obtain the maximum mean square response which can occur in a structure, irrespective of its orientation with respect to the impinging seismic waves. The application of this methodology for the calculation of design response is advocated, especially for asymmetric structures. For the assumed model of seismic wave motion, the numerical results show a significant contribution to the response from the rotational components. This contribution is, however, expected to be reduced by structural foundation averaging and interaction effects. Further studies with more complete models of seismic wave motions, and their interaction with structural foundations, are thus warranted for a realistic evaluation and characterization of the rotational inputs for design purposes. 相似文献
187.
188.
189.
Federico Lucci Federico Rossetti John Charles White Hadi Shafaii Moghadam Alireza Shirzadi Mohsen Nasrabady 《Arabian Journal of Geosciences》2016,9(10):573
Calc-alkaline arc magmatism at convergent plate margins is volumetrically dominated by metaluminous andesites. Many studies highlighted the importance of differentiation via fractionation processes of arc magmas, but only in the last decades, it has been demonstrated that not all rock-forming minerals may affect the evolution of calc-alkaline suites. In particular, a major role exerted by Al-rich hornblende amphibole as fractionating mineral phase has been documented in many volcanic arc settings. The aim of this work is to understand the role of the Tschermak molecule (CaAlAlSiO6) hosted in the hornblende and plagioclase fractionation assemblage in driving magma differentiation in calc-alkaline magmatic suites. We explore this issue by applying replenishment–fractional crystallization (RFC) and rare earth element–Rayleigh fractional crystallization (REE-FC) modeling to the Sabzevar Eocene (ca. 45–47 Ma) calc-alkaline volcanism of NE Central Iran, where hornblende-controlled fractionation has been demonstrated. Major element mass balance modeling indicates RFC dominated by a fractionating assemblage made of Hbl52.0–52.5 + Pl44.1–44.2 + Ttn3.3–3.9 (phases are expressed on total crystallized assemblage). REE-FC modeling shows, instead, a lower degree of fractionation with respect to RFC models that is interpreted as due to hornblende and plagioclase resorption by the residual melt. Calculations demonstrate that fractionation of the Tschermak molecule can readily produce dacite and rhyolite magmas starting from a calc-alkaline andesite source (FC = ca. 30 %). In particular, the Tschermak molecule controls both the heavy rare earth elements (HREE) and light rare earth element (LREE) budgets in calc-alkaline differentiation trends. 相似文献
190.
Quantifying the uncertainty of semiarid flash floods using generalized likelihood uncertainty estimation 总被引:1,自引:0,他引:1
This paper aims to address the question of how the parameter uncertainty associated with a mixed conceptual and physical based rainfall-runoff model (AFFDEF) has influences on flood simulation of the semiarid Abolabbas catchment (284 km2), in Iran. AFFDEF was modified and coupled with the generalized likelihood uncertainty estimation (GLUE) algorithm to simulate four flash flood events. Analysis suggests that AFFDEF parameters showed non-unique posterior distributions depending on the magnitudes and duration of flash flood events. Model predictive uncertainty was heavily dominated by error and bias in soil antecedent moisture condition that led to large storage effect in simulation. Overall, multiplying parameter for the infiltration reservoir capacity and multiplying parameter for the interception reservoir capacity along with potential runoff contributing areas were identified the key model parameters and more influential on flood simulation. Results further revealed that uncertainty was satisfactorily quantified for the event with low to moderate flood magnitudes while high magnitude event exhibited unsatisfactory result. 相似文献