نتایج جستجو برای: scour depth for first pier is more than single pier

تعداد نتایج: 12563502  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

in this study, scour of mashkid bridge pier located in mashkid river of saravan county has been studied and to measure the scour rate, the numerical model hec-ras 4.0 has been used. upon selection of mashkid river as the case study and whereas the studied zone is important with respect to the climatic conditions and showery monsoon raining and flowing the great and destructive floodwaters, ther...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی عمران 1391

today, scouring is one of the important topics in the river and coastal engineering so that the most destruction in the bridges is occurred due to this phenomenon. whereas the bridges are assumed as the most important connecting structures in the communications roads in the country and their importance is doubled while floodwater, thus exact design and maintenance thereof is very crucial. f...

Journal: :تحقیقات آب و خاک ایران 0
سید محمد علی زمردیان دانشیار دانشگاه شیراز مجتبی عقلی دانشجوی کارشناسی ارشد، دانشگاه شیراز

a large number of authors have studied to find out how to control scouring around a pier along direct stream. the objective of this research is then to study a scour pattern around such piers on curves rivers due to the fact that there may be a difference between a flow pattern on a direct line and the meander. thus, this study tries to check whether the use of cable and collar alone and in a c...

ژورنال: علوم آب و خاک 2009
حیدرپور, منوچهر, موسوی, فرهاد , کیخایی, ملیحه,

Ripraps are placed around bridge piers to prevent scour and secure the piers from failure. Proper riprap cover is essential to be economical. The present study examines using of riprap for reduction of local scour in piers group and the results are compared with data from riprap on a single pier. The models consist of two and three circular-shaped piers in line with the flow, with the diameter ...

ژورنال: علوم آب و خاک 2017

Flood currents are considered threatening factors by creating local scour along bridge piers. One method for decreasing local scour is to strengthen the bed against imposed tensions. Among methods which can directly be appropriate in decreasing and controlling local scour of bridge piers is to employ geotextile around bridge piers. In the present study, the effect of geotextile layer in decreas...

حسین افضلی مهر, , محسن نادری بنی, , منوچهر حیدرپور, ,

The use of slot through a pier is a new method proposed to control local scour at bridge piers. In this study, control of local scour at bridge pier is studied using 20 pier models under clear water conditions. The models consist of one circular pier without slot, three round-nosed piers without slot, and 16 piers with slot. Two slot lengths were chosen (yl=b and yl=2b, where y1 is the length o...

An experimental study has been conducted on the effectiveness of two types of flow-altering countermeasures placed around a cylindrical pier under clear water condition, which include sacrificial piles and submerged vanes. Their arrangements follow the optimal configurations recommended in the published articles with some modification. The temporal evolution of maximum scour depth and its equil...

2014
Afshin Jahangirzadeh Hossein Basser Shatirah Akib Hojat Karami Sareh Naji Shahaboddin Shamshirband

The scour phenomenon around bridge piers causes great quantities of damages annually all over the world. Collars are considered as one of the substantial methods for reducing the depth and volume of scour around bridge piers. In this study, the experimental and numerical methods are used to investigate two different shapes of collars, i.e, rectangular and circular, in terms of reducing scour ar...

ژورنال: علوم آب و خاک 2003
حسین افضلی مهر, , محسن نادری بنی, , منوچهر حیدرپور, ,

The use of slot through a pier is a new method proposed to control local scour at bridge piers. In this study, control of local scour at bridge pier is studied using 20 pier models under clear water conditions. The models consist of one circular pier without slot, three round-nosed piers without slot, and 16 piers with slot. Two slot lengths were chosen (yl=b and yl=2b, where y1 is the length o...

2012
Sabita Madhvi Singh P. R. Maiti

Local scour around a cylindrical pier in a channel with an erodible bed or natural bed is a common problems in bridge or pile supported structure. The highly unsteady complex flow field around a circular pier produces scour hole mainly for the presence of vortices. The main mechanism that drives the formation and evolution of the scour hole around bridge pier is horse shoe vortex motion. In the...

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