This paper presents an experimental research on the distribution of local friction factor, fb, and global friction factor, f, over the cross-section of a channel with V-shaped bottom, which typically occurs in sewers and culverts. Several series of experiments were conducted for measuring velocity and boundary shear stress. It is found that, Darcy-Weisbach, f, is more sensitive than other resis...

The process of wave equation continuation (migration) is adapted for refraction data in order to produce velocity-depth models directly from the recorded data. The procedure consists of two linear transformations: a slant stack of the data produces a wave field in the p T plane which is then downward continued using T = 0 as the imaging condition. The result is that the data wave field is linea...

Submarine pipelines are appropriate method for transmission of oil and gas from sea bed. Free spans may occur due to the natural uneven seabed or by under-scouring. Vortex Induced Vibration (VIV) can happen in such free spans at high Reynolds number. Resonance occurs if the frequency of vortex shedding is close to the pipeline’s natural frequency leading to its fatigue that can break the pipeli...

in this paper, two formulas were chosen among those that estimate the suspendedsediment discharge in rivers. these two formulas were lane and kalinske and bagnold. forstudying and knowing the correlation between input parameters and calculated suspendedsediment discharge (cssd), the spss17 software was used. input parameters in these twoformulas were as: water velocity, water discharge, suspend...

tehran, the capital of iran, is under the threat of large magnitude earthquakes (above 7) located on known active faults. previous studies on the effect of local surface geology on earthquake ground motion using 1d calculation of sh transfer function (jafari et al., 2001; jica & cest, 2000) and using experimental methods (haghshenas, 2005) based on earthquake and ambient noise vibration recordi...