Fracture analysis of concrete gravity dam under earthquake induced loads

In this paper, seismic fracture behavior of the concrete gravity dam using finite element (2D) theory has been studied. Bazant model which is non-linear fracture mechanics criteria as a measure of growth and smeared crack was chosen to develop profiles of the crack. Behavior of stress - strain curves of concrete as a simplified two-line, dam and reservoir system using the formulation of the Euler - Lagrange was chosen. According to the above models, Koyna concrete gravity dam were investigated by the 1967 earthquake record. The results provide profiles of growth and expansion first with the effects of reservoir and second without it. Comparison of the obtained results shows good agreement with the works of the other researchers

Morphological changes in the southern coasts of the Caspian Sea using remote sensing and GIS

Coastal areas are continuously under the regional changing and interaction of land-sea resulting in the short and long terms deformation. Study of beach morphology has been one of the most important issues in coastal engineering research projects. Managing and controlling the shoreline changes and behavior are essential for all marine projects and integrated coastal zone management policy in such environments. In the present study, Guilan Province region was selected and an analysis of the coastal zone behavior was carried out based on the available satellite images. According to results, we estimated the bed level changes and also submerged area, resulting from a rise in sea level at different locations in the study area (from Anzali Port to Boujagh National Park) and compared them with those obtained from the satellite images. The results were presented graphically and changes in shorelines were estimated using ETM+ sensors and OLI images from 2002 to 2013 which can be used for site selection and design of marine structures and establishing a data base for the coastal zone in the study region. Laplacian filter was applied to satellite images to establish the shoreline and to clarify the effect of ports and coastal structures constructed in the study region on beach and shoreline morphological changes. This study is a combination of remote sensing and GIS systems with field surveys on the ground. The innovation of this work is the application of Laplacian filter for shoreline detection and estimation of the sediment deposition area by calculating the distance between the observed shorelines. This will lead to the better understanding of the effect of coastal structures on the beach morphology using satellite images. The results show the remarkable changes occurred in the shoreline due to the environmental and human-based effects during the eleven years period. The present study can be considered as a contribution to the existing knowledge of the coastal process in the study area and referred to as a basis for the future coastal research projects

Fracture analysis of concrete gravity dam under earthquake induced loads

In this paper, seismic fracture behavior of the concrete gravity dam using finite element (2D) theory has been studied. Bazant model which is non-linear fracture mechanics criteria as a measure of growth and smeared crack was chosen to develop profiles of the crack. Behavior of stress - strain curves of concrete as a simplified two-line, dam and reservoir system using the formulation of the Euler - Lagrange was chosen. According to the above models, Koyna concrete gravity dam were investigated by the 1967 earthquake record. The results provide profiles of growth and expansion first with the effects of reservoir and second without it. Comparison of the obtained results shows good agreement with the works of the other researchers

Beach profile evolution in front of a partially reflective structure

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN029631 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Southern Caspian Sea Coasts, Morphology, Sediment Characteristics, and Sea Level Change

As the world\u27s largest closed body of water, considerable changes in the Caspian Sea water level make it an unique laboratory to study all aspects of coastal zones. This research was aimed at evaluating the linkage between sea level changes and sediment characteristics of the south Caspian Sea coast. Initially, three field surveys were made along 700 km of the southern Caspian Sea coast. In addition to nearshore sampling, land forms were mapped. On the basis of the field reconnaissance, eight principal sampling stations were chosen. Sediments were sampled by divers along profiles at right angles to the coast at 5 depths (2, 4, 6, 8,10 meters). Hydrographic profiles also were surveyed. Laboratory tests on the sediment samples were made, and the sediment characteristics and morphological features were divided into distinct zones based on their response to sea level changes

Fracture analysis of concrete gravity dam under earthquake induced loads

In this paper, seismic fracture behavior of the concrete gravity dam using finite element (2D) theory has been studied. Bazant model which is non-linear fracture mechanics criteria as a measure of growth and smeared crack was chosen to develop profiles of the crack. Behavior of stress - strain curves of concrete as a simplified two-line, dam and reservoir system using the formulation of the Euler - Lagrange was chosen. According to the above models, Koyna concrete gravity dam were investigated by the 1967 earthquake record. The results provide profiles of growth and expansion first with the effects of reservoir and second without it. Comparison of the obtained results shows good agreement with the works of the other researchers

Beach evolution under random waves

This paper considers the evolution of steep mobile sediment beaches under random waves and results from a new experimental investigation are presented. Both hydrodynamic data obtained over fixed beds and the resulting profile evolution of fine, coarse and bimodal sediment beaches are discussed. Wave heights and undertow in the inner surf zone are found to be poorly predicted by commonly used numerical solutions. In addition, the undertow appears to be strongly influenced by wave grouping in the nearshore. The behaviour of the fine, coarse and bimodal sediment beaches are compared and contrasted. The fine sand beaches tend to erode in the inner surf and swash zones, with the sediment moving predominantly offshore to form a bar. In contrast, onshore sediment transport dominates over the coarse sand beaches, resulting in the formation of a berm above the initial still water level. The bimodal beaches show a similar evolution to the fine sand beaches. However, considerable sediment sorting occurs, with the swash zone largely denuded of fines and the coarser sediment deposited between the still water line and the bar. The data suggests that the stability of the coarse material is significantly reduced by the presence of fines, with little evidence of armouring effects under high incident energy conditions