Sharif Digital Repository

Rubble-mound breakwaters are common marine structures that provide a safe area for human coastal activities. The stability of these structures against sea-waves requires their seaward slope to be protected by an armor layer consisting of natural rock or concrete units. To provide a safe breakwater, it is reasonable to establish a relation between the exerted wave loads and the stability of the armor units. However, up to now, the empirical design equations, derived from model tests, relate wave parameters to armor weight, and keeps the effect of wave loads in a black box. In this paper, a new approach, based on numerically-derived wave loads on the armor, is presented to evaluate the... 

Impulsive water waves generated by landslides impose severe damage on coastal areas. Very large mass ows in the ocean can generate catastrophic tsunamis. Preventing damage to dams and coastal structures, and saving the lives of local people against landslide-generated waves, has become an increasingly important issue in recent years. Numerical modeling of landslide-generated waves is a challenging subject in CFD. The reason lies in the difficulty of determining the interaction between the moving solids and sea water, which causes complicated turbulent regimes around the moving mass and at the water surface. Submarine or aerial types of landslide can further complicate the problem. Up to now,... 

Free Trade Zones (FTZs) around the world offer special advantages to investors and facilitate import/export of goods in order to boost the regional economy. Integrated coastal management in these areas faces special challenges in addition to what ordinary ICZMs usually encounter. For a successful ICZM plan, the very strong business orientation in FTZs has to be taken into account, while other important aspects such as environmental, social, and cultural issues should not be overlooked. The problem becomes more difficult where the free zone is situated in sensitive and valuable environmental circumstances.Kish Island, a free trade zone in the Persian Gulf region, has recently been the focus... 

Geotextiles are one of the most widely used synthetic materials in filtration and drainage applications. Since in real applications, geotextiles are subjected to various hydraulic gradients and confining stresses, hydraulic behavior of geotextiles under different circumstances is of great practical importance. In this study filtration and drainage properties of several nonwoven needle-punched geotextiles with different properties and unit mass per area of 200g/m2, 400g/m2, 500g/m2 and 800g/m2, under various confining stresses and hydraulic gradients, were studied using standard permittivity and transmissivity equipments. Prepared samples were subjected to hydraulic heads in the range of 10cm... 

Creating hydraulically induced fractures in oil/gas reservoirs is one of the methods for Enhanced Oil Recovery (EOR) that has been applied extensively in petroleum industry in recent years. Despite its popularity, the design process of Hydraulic Fracture treatment is mostly empirical based on the previous experiences gained in the oil-rich formation. The reason lies in the complexities involved in the Hydraulic Fracture process including interacting effects of fluid(s) flowand solid deformations, injection of non-Newtonian fluids in the porous media, leak-off of the injected fluid into the formation, complex geometry of the induced fracture in the intact or naturally fractured rock,... 

Self-weight consolidation and desiccation phenomena of ultra soft soils and slurries have important implications in mining, coastal, and environmental engineering. Disposal of mine tailings behind tailings impoundments, transportation of dredged materials and land reclamation, and disposing of sludge in water/wastewater treatment facilities are some of the engineering applications where self-weight consolidation and desiccation of slurries are of concern. Numerical modeling of desiccation phenomenon is a relatively new subject that enables geotechnical engineers to better manage the large volume of mine tailings, dredged materials, and other slurries that are disposed in confined disposal... 

The stability of tailings dams is affected by seepage characteristics such as the location of the phreatic surface inside the dam, the effects of the capillary fringe, and the unsaturated zone above the zero pore pressure level. In this study, the performance of drainage systems in tailings dams was investigated by analyzing saturated and unsaturated seepage in the dam, considering the effects of the construction method, tailings properties, and the type of drainage systems. First, general seepage characteristics in tailings dams were studied and the effects of non-homogeneity were investigated. Our results show that in a silty tailings dam with a height of 15 m, unsaturated plus capillary... 

Iran, having two separate coastlines at its north and south of about 3000 km length, with very different characteristics, suffers from various coastal problems. While its northern coastal area is over-populated and its sensitive and unique habitats must be protected from destruction, most of its southern coastal areas are undeveloped and deserted. Intense oil and gas exploitation activities in the Caspian Sea region and occurrence of two wars in the Persian Gulf during the last two decades have rendered hydrocarbon pollution a major issue for this country's marine and coastal environment. Biodiversity is under threat in some areas and natural resources are deteriorating. To overcome the...