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1.
The Zagros fold‐and‐thrust belt of SW Iran represents deformation of the former Arabian passive margin since Permian–Triassic opening of the Neo‐Tethys ocean. The Zagros belt is characterized by a present‐day structural salient‐recess setting inherited from past marginal embayment‐promontory geometry, which was involved in discontinuous ophiolite obduction and diachronous continental collision. We examine outcrop‐scale Mesozoic extensional brittle tectonics, preserved as syn‐depositional normal faults within the folded strata, in terms of stress tensor inversion. The result is then integrated with belt‐scale isopach, seismic and topographical data to delineate the geometry of a major irregularity along the passive margin originating from oblique oceanic opening. The implication of this configuration within the tectonic framework of oceanic closure is discussed. 相似文献
2.
The Zagros fold-and-thrust belt of SW-Iran is among the youngest continental collision zones on Earth. Collision is thought to have occurred in the late Oligocene–early Miocene, followed by continental shortening. The High Zagros Belt (HZB) presents a Neogene imbricate structure that has affected the thick sedimentary cover of the former Arabian continental passive margin. The HZB of interior Fars marks the innermost part of SE-Zagros, trending NW–SE, that is characterised by higher elevation, lack of seismicity, and no evident active crustal shortening with respect to the outer (SW) parts. This study examines the brittle structures that developed during the mountain building process to decipher the history of polyphase deformation and variations in compressive tectonic fields since the onset of collision. Analytic inversion techniques enabled us to determine and separate different brittle tectonic regimes in terms of stress tensors. Various strike–slip, compressional, and tensional stress regimes are thus identified with different stress fields. Brittle tectonic analyses were carried out to reconstruct possible geometrical relationships between different structures and to establish relative chronologies of corresponding stress fields, considering the folding process. Results indicate that in the studied area, the main fold and thrust structure developed in a general compressional stress regime with an average N032° direction of σ1 stress axis during the Miocene. Strike–slip structures were generated under three successive strike–slip stress regimes with different σ1 directions in the early Miocene (N053°), late Miocene–early Pliocene (N026°), and post-Pliocene (N002°), evolving from pre-fold to post-fold faulting. Tensional structures also developed as a function of the evolving stress regimes. Our reconstruction of stress fields suggests an anticlockwise reorientation of the horizontal σ1 axis since the onset of collision and a significant change in vertical stress from σ3 to σ2 since the late stage of folding and thrusting. A late right-lateral reactivation was also observed on some pre-existing belt-parallel brittle structures, especially along the reverse fault systems, consistent with the recent N–S plate convergence. However, this feature was not reflected by large structures in the HZB of interior Fars. The results should not be extrapolated to the entire Zagros belt, where the deformation front has propagated from inner to outer zones during the younger events. 相似文献
3.
Jahangoshai Rezaee Mustafa Yousefi Samuel Eshkevari Milad Valipour Mahsa Saberi Morteza 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(1):201-218
Stochastic Environmental Research and Risk Assessment - Organizations are continuously endeavoring to provide a healthy work environment without any incident, by Health, Safety, and Environment... 相似文献
4.
Methods to simulate facies (or categorical) fields are numerous. However, calibration of simulated facies fields to large-scale or dynamic data still remains an important challenge due to the discrete nature of the fields, the non-linearity of the response with respect to the facies fields, and the non-derivability of the objective function used in calibration. A new gradual deformation method (GDM) is presented and tested for the calibration of facies realizations obtained by patch-multipoint simulation (MPS). The proposed method borrows ideas from pluriGaussian simulation, evolutionary algorithms, and GDM. Various test cases are considered: proportion maps, section of seismic amplitudes, inlet to outlet travel time along the shortest path, and water-cut curves obtained with a flow simulator. Both conditional/unconditional MPS simulations and 2D/3D problems are considered. In all studied test cases, the new GDM approach has provided excellent calibration to the target variables. The method is general as it can be used in conjunction with any facies simulator. 相似文献
5.
In this paper,dynamic simulation of a beam-like structure with a transverse open crack subjected to a random moving mass oscillator is investigated.The simultaneous effect of a crack and a random oscillator has not been addressed up to now.The crack in the beam at different locations and with different depths is considered as one group of damage,each as an individual imperfection.In addition,bearing immobility is considered as another type of problem in the beam.Mass, stiffness,damping and velocity of th... 相似文献
6.
Multiple-point geostatistical simulation of dykes: application at Sungun porphyry copper system,Iran 总被引：5，自引：3，他引：2
Hassan Rezaee Omid Asghari Mohammad Koneshloo Julián M. Ortiz 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(7):1913-1927
Variogram-based methods are not capable of capturing high (>2) order statistics since the variogram measures the relationship between two points at a time only. Multiple-point geostatistics (MPS) has brought new insights into many geological modeling problems. The application of MPS methods has been well documented in realizing complex geological patterns. These methods have often been used in reservoir characterization since their advent in recent decades. The frequent non-linear behaviors of geologic continuity are not limited to reservoirs, but mineral deposits bear complicated formations in many cases. Relying on the power of MPS methods and considering the complexity of geological scenarios in mineral deposits, we have applied MPS in the modeling of mineral deposits. A training image (TI) is produced using geological data from upper horizons of a porphyry copper ore deposit which have been mined out during the previous mining operations. In this study, the SNESIM algorithm has been used. A number of realizations are produced using this multiple-point geostatistical method. Extensive validation steps are performed considering the TI as the reference model. These validations first show that the TI is representative for the domain under study and also illustrates some degrees of similarity between the TI and the realizations. Despite simplifications made to the problem, the application of MPS in mineral deposit modeling still faces many challenges. 相似文献
7.
Rezaee Hassan Marcotte Denis Tahmasebi Pejman Saucier Antoine 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(3):893-913
Stochastic Environmental Research and Risk Assessment - This study presents a new approach of generating a set of alternative training images (ATI) to use in patch-based multiple-point simulation.... 相似文献
8.
Simulating urban growth under planning policies through parcel-based cellular automata (ParCA) model
Somaie Abolhasani Mohammad Taleai Mohammad Karimi Adel Rezaee Node 《International journal of geographical information science》2016,30(11):2276-2301
In recent decades, the cellular automata model, among the urban development prediction models, has been applied considerably. Studies show that the output of conventional cellular automata models is sensitive to cell size and neighborhood structure, and varies with changes in the size of these parameters. To solve this problem, vector-based cellular automata models have been introduced which have overcome the mentioned limitations and presented better results. The aim of this study was to present a parcel-based cellular automata (ParCA) model for simulating urban growth under planning policies. In this model, undeveloped areas are first subdivided into smaller parcels, based on some geometric parameters; then, neighborhood effect of parcels is defined in a radial structure, based on a weighted function of distance, area, land-use, and service level of irregular cadastral parcels. After that, neighborhood effect is evaluated using three components, including compactness, dependency and compatibility. The presented model was implemented and analyzed using data from municipal region 22 of Tehran. The obtained results indicated the high ability of ParCA model in allocating various land-uses to parcels in the appropriateness of the layout of different land-uses. This model can be used in decision-making and urban land-use planning activities, since it provides the possibility of allocating different urban land-use types and assessing different urban-growth scenarios. 相似文献
9.
ABSTRACTThe problem of estimation of suspended load carried by a river is an important topic for many water resources projects. Conventional estimation methods are based on the assumption of exact observations. In practice, however, a major source of natural uncertainty is due to imprecise measurements and/or imprecise relationships between variables. In this paper, using the Multivariate Adaptive Regression Splines (MARS) technique, a novel fuzzy regression model for imprecise response and crisp explanatory variables is presented. The investigated fuzzy regression model is applied to forecast suspended load by discharge based on two real-world datasets. The accuracy of the proposed method is compared with two well-known parametric fuzzy regression models, namely, the fuzzy least-absolutes model and the fuzzy least-squares model. The comparison results reveal that the MARS-fuzzy regression model performs better than the other models in suspended load estimation for the particular datasets. This comparison is done based on four goodness-of-fit criteria: the criterion based on similarity measure, the criterion based on absolute errors and the two objective functions of the fuzzy least-absolutes model and the fuzzy least-squares model. The proposed model is general and can be used for modelling natural phenomena whose available observations are reported as imprecise rather than crisp.
Editor D. Koutsoyiannis; Associate editor H. Aksoy 相似文献
10.
Payman Khalili-Tehrani Anoosh Shamsabadi Jonathan P. Stewart Ertugrul Taciroglu 《Bulletin of Earthquake Engineering》2016,14(11):3003-3023
Recent advances in performance-based seismic assessment and design of bridges call for the development of computationally efficient models with high fidelity for nonlinear static pushover and transient dynamic analyses. Response models of bridge abutment systems are significant ingredients of such analyses. Herein, we present closed-form relationships for lateral response of abutment backwalls with uniform backfills. These relationships are obtained by performing extensive parametric studies with a previously validated limit-equilibrium model coupled with hyperbolic soil stress–strain relations. The resulting “Generalized Hyperbolic Force–Displacement (GHFD)” backbone curve has explicit dependencies on the physical properties of the abutment system, including the backwall height. All input parameters to the GHFD relationships are measurable via standard geotechnical laboratory tests. We also perform a validation study using published measurements from several field and laboratory experiments. The GHFD equations are in closed form and can easily be implemented in a structural analysis package as a nonlinear spring that accounts for the bridge abutment–backfill interaction. 相似文献