نتایج جستجو برای: the maximum scour depth is observed in middle pier

تعداد نتایج: 21384246  

Journal: :Water 2022

Several bridge piers were visited, and their scour hole was characterized into three zones: scour, transition, mound zones. The observed onsite sorting scouring patterns recreated through flume experiments with varying pier aspect ratio (1:1, 1:2, 1:4 1:6) sediment geometric standard deviation (σg). showed that maximum depth decreased non-uniformity; 52.7 mm, 20.2 16.6 mm are the respective of ...

2007
A. M. Negm Y. A. Mohamed

Failures barrages or parts of them may be expected when excessive scour patterns are observed downstream of such structures. Severe and excessive scour may be largely due to unsymmetric operation of gates especially when a multi-vents barrage or regulator is being considered. Previous investigations proved that the scour patterns downstream hydraulic structures are functions of the bottom veloc...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده ادبیات و علوم انسانی 1392

in new management approaches, in the organizations with inflexible structure, existing of red tapes and interruptions caused by limitations and also non-compliance with environmental changes, create demotivation among staff. with regard to the influence of job motivational potential and its relationship to the type of organizational structure( enabling and dissuasive), the goal of this research...

Journal: :تحقیقات مهندسی کشاورزی 0
سیدمجتبی رضوی نبوی دانشجوی دکتری سازه های آبی محمود شفاعی بجستان استاد هیدرولیک، دانشکده مهندسی و علوم آب، دانشگاه شهید چمران سیدمحمود کاشفی پور استاد هیدرولیک، دانشکده مهندسی و علوم آب، دانشگاه شهید چمران

grade control structures are hydraulic structures used to stabilize a river bed. scour downstream of this structure is the main cause of its failure. studies have developed numerous empirical relations for scour depth prediction that designers must choose between to decide the most effective equation for a specific application. this study tested the condition of submerged jets over beds of sedi...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1387

boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - پژوهشکده ادبیات 1393

1.0 overview it seems that grammar plays a crucial role in the area of second and foreign language learning and widely has been acknowledged in grammar research. in other words, teaching grammar is an issue which has attracted much attention to itself, and a lot of teachers argue about the existence of grammar in language teaching and learning. this issue will remind us a famous sentence f...

2010
David Kosnik Steve Ng

Scour is by far the primary cause of bridge failures in the United States. Scour and other hydraulic effects are particularly threatening because the deterioration is often invisible , hidden beneath turbid water. Many scour monitoring methods attempt to measure the development of scour pockets themselves. However, this is difficult due to debris — both floating and submerged — and shifting str...

Journal: :Eng. Appl. of AI 2011
Mahesh Pal N. K. Singh N. K. Tiwari

This paper investigates the potential of support vector machines based regression approach to model the local scour around bridge piers using field data. A dataset of consisting of 232 pier scour measurements taken from BSDMS were used for this analysis. Results obtained by using radial basis function and polynomial kernel based Support vector regressionwere comparedwith four empirical relation...

ژورنال: علوم آب و خاک 2001
کوچک زاده, صلاح ,

Bridge abutments are usually located in the floodplain zone of rivers where velocity and shear stress are not uniformly distributed. The influence of channel geometry and lateral momentum transfer in compound flow field on the scouring phenomenon has not been fully investigated and understood yet. The impact of lateral momentum transfer on the local scour at abutments terminating in the floodpl...

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