Euler-Euler two-phase flow simulation of tunnel erosion beneath marine pipelines     

Abbas Yeganeh-Bakhtiary  Mohammad Hossein Kazeminezhad 《Applied Ocean Research》2011,33(2):137-146

In this study an Euler-Euler two-phase model was developed to investigate the tunnel erosion beneath a submarine pipeline exposed to unidirectional flow. Both of the fluid and sediment phases were described via the Navier-Stokes equations, i.e. the model was implemented using time-averaged continuity and momentum equations for the fluid and sediment phases and a modified k−ε turbulence closure for the fluid phase. The fluid and sediment phases were coupled by considering the drag and lift interaction forces. The model was employed to simulate the tunnel erosion around the pipeline laid on an erodible bed. Comparison between the numerical result and experimental measurement confirms that the numerical model successfully predicts the bed profile and velocity field during the tunnel erosion. It is evident that the sediments are transported as the sheet-flow mode in the tunnel erosion stage. Also the transport rate under the pipe increases rapidly at the early stage and then reduces gradually at the end of the tunnel erosion beneath pipelines.  相似文献   

Apportioning deformation among depth intervals in an aquifer system using InSAR and head data     

Smith  Ryan G.  Hashemi  Hossein  Chen  Jingyi  Knight  Rosemary 《Hydrogeology Journal》2021,29(7):2475-2486

Land surface subsidence due to excessive groundwater pumping is an increasing concern in California, USA. Interferometric Synthetic Aperture Radar (InSAR) is a remote sensing technique for measuring centimeter-to-millimeter surface deformation at 10–100 m spatial resolution. Here, a data-driven approach that attributes deformation to individual depth intervals within an aquifer system by integrating head data acquired from each of three screened intervals in a monitoring well with InSAR surface deformation measurements was developed. The study area was the Colusa Basin in northern Central Valley. To reconstruct the surface deformation history over the study area, 13 ALOS-PALSAR scenes acquired between 2006 and 2010 were processed. Up to ~3-cm year^?1 long-term subsidence and up to ~6 cm seasonal subsidence were observed using the InSAR technique. The technique developed in this paper integrates the InSAR-observed seasonal deformation rate and the co-located head measurements in multiple depth intervals to estimate the elastic skeletal storage coefficient, the time delay between the head change and the observed deformation, and subsequently the deformation of each depth interval. This technique can be implemented when hydraulic head measurements within each depth interval are not correlated with each other. Using this approach, the depth interval that contributed the most to the total subsidence, as well as storage parameters for all intervals, are estimated. The technique can be used for identification of the depth interval within the aquifer system responsible for deformation.

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Spatial prediction of flood-susceptible areas using frequency ratio and maximum entropy models   总被引：1，自引：0，他引：1  

Safura Siahkamari  Hossein Zeinivand  Naser Tahmasebipour  Omid Rahmati 《国际地球制图》2018,33(9):927-941

Modelling the flood in watersheds and reducing the damages caused by this natural disaster is one of the primary objectives of watershed management. This study aims to investigate the application of the frequency ratio and maximum entropy models for flood susceptibility mapping in the Madarsoo watershed, Golestan Province, Iran. Based on the maximum entropy and frequency ratio methods as well as analysis of the relationship between the flood events belonging to training group and the factors affecting on the risk of flooding, the weight of classes of each factor was determined in a GIS environment. Finally, prediction map of flooding potential was validated using receiver operating characteristic (ROC) curve method. ROC curve estimated the area under the curve for frequency ratio and the maximum entropy models as 74.3% and 92.6%, respectively, indicating that the maximum entropy model led to better results for evaluating flooding potential in the study area.  相似文献   

Effect of fault reactivation on deformation of off-fault fractures near a generic deep geological repository in crystalline rock in Canada     

Blanksma  Derrick  Hazzard  Jim  Damjanac  Branko  Lam  Tom  Kasani  Hossein A. 《Journal of Seismology》2022,26(5):987-1002

Journal of Seismology - In this study, fault rupture and its effect on the deformation of the off-fault fractures are numerically simulated. The purpose of the analysis is to determine the distance...  相似文献   

Biostratigraphy,Microfacies, Sedimentary Environments and Sequence Stratigraphy of the Late Devonian–Carboniferous Deposits at the Anarak Section,Central Iran     

Elaheh SATTARI  Ali BAHRAMI  Hossein VAZIRI-MOGHADDAM  Azizollah TAHERI  Iliana BONCHEVA 《《地质学报》英文版》2023,97(4):1038-1057

The Late Devonian–early Carboniferous deposits of the Anarak section in northeastern Isfahan, Central Iran, evaluated based on conodont biostratigraphy, sedimentary environment and sequence stratigraphy. According to the field observations, five lithological units were identified. Investigating the conodont fauna of the Late Devonian–Carboniferous(Mississippian–Pennsylvanian) deposits of Bahram, Shishtu, and Qaleh(Sardar 1) formations in Anarak section led to the identification of 67 species of ...  相似文献   

A new rating system approach for risk analysis of rock slopes     

Reza Nassirzadeh Goorchi  Mehdi Amini  Hossein Memarian 《Natural Hazards》2018,91(1):75-102

In this paper, an approach is presented to analyze the stability risk of rock slopes based on a new rating system. Three factors are used to estimate the risk level of rock slopes: (1) failure probability, (2) element at risk rating, and (3) vulnerability rating. Element at risk and vulnerability ratings are both given a range from 0 to 10, and the probability of failure is varied between 0 and 1, so the risk rating ranges between 0 and 100. This risk rating can be used to determine both the quantitative and qualitative risk levels of slopes at the same time. The method is tested on the western sector of the slopes facing Songun copper plant phase III, Iran, to clarify its procedures and assess its validity. Deterministic kinematic analyses showed that the slope has a potential for circular failure. Risk assessments revealed that the risk levels of the slope in both static and pseudo-static conditions are “very low” and “high,” respectively.  相似文献   

Porosity/(SiO<Subscript>2</Subscript> and Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Particles) Ratio Controlling Compressive Strength of Zeolite-Cemented Sands     

Hossein Mola-Abasi  Aghileh Khajeh  Safoura Naderi Semsani Semsani 《Geotechnical and Geological Engineering》2018,36(2):949-958

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A Critical Review on Filter Design Criteria for Dispersive Base Soils     

Amir Hossein Vakili  Mohamad Razip bin Selamat  Parsa Mohajeri  Hossein Moayedi 《Geotechnical and Geological Engineering》2018,36(4):1933-1951

Dispersive soils have become common materials for the construction industry. Highly susceptible to internal erosion and piping, dispersive soils must only be used with specific engineering measure in order to avoid failures that were often catastrophic. In an earth dam, clayey soils are used for the core and sandy materials are used for the filter to retain the eroded core soils and prevent their migration. In the absence of first-rate core material, dispersive soils have been used instead. This paper provides a review of the current knowledge and experiences regarding filtration of core soils, particularly the dispersive ones. The engineering problems associated with the use of dispersive soils are discussed and significant findings from previous studies on protective filters are summarized. It is worthy to note that the current review considers both, the conventional, rather empirical filter design criteria based on particle sizes and the current, quite theoretical state-of-the-art filter design criteria based on constriction sizes, with discussion given on the advantages and disadvantages of both. The information provided by this review should be handy for the study, design, construction, and operation of related geotechnical and geo-environmental projects.  相似文献   

A Risk-Based Technique to Analyze Flyrock Results Through Rock Engineering System     

Mahdi Hasanipanah  Danial Jahed Armaghani  Hassan Bakhshandeh Amnieh  Mohammadreza Koopialipoor  Hossein Arab 《Geotechnical and Geological Engineering》2018,36(4):2247-2260

Flyrock is an adverse effect produced by blasting in open-pit mines and tunneling projects. So, it seems that the precise estimations and risk level assessment of flyrock are essential in minimizing environmental effects induced by blasting. The first aim of this research is to model the risk level associated with flyrock through rock engineering systems (RES) methodology. In this regard, 62 blasting were investigated in Ulu Tiram quarry, Malaysia, and the most effective parameters of flyrock were measured. Using the most influential parameters on flyrock, the overall risk of flyrock was obtained as 32.95 which is considered as low to medium degree of vulnerability. Moreover, the second aim of this research is to estimate flyrock based on RES and multiple linear regression (MLR). To evaluate performance prediction of the models, some statistical criteria such as coefficient of determination (R²) were computed. Comparing the values predicted by the models demonstrated that the RES has more suitable performance than MLR for predicting the flyrock and it could be introduced as a powerful technique in this field.  相似文献   

Theoretical investigation of the neutron star in low-mass X-ray binary X1822-371 (V691 CrA)     

Sk. Monowar Hossein  Nur Farhad  Sajahan Molla  Mehedi Kalam 《Astrophysics and Space Science》2016,361(6):203

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