نتایج جستجو برای: bridge piers and abutments

تعداد نتایج: 16836952  

ژورنال: Journal of Railway Research 2016
Ataei, S., Jahangiri, M., miri, A.,

A common practice for detailed assessment of masonry bridges is to use recorded deflection signature of mid-span of such structures due to predefined loading schemes. However, measuring the deflection of bridges with tall piers or those situated over deep valleys introduces certain difficulties, since common deflection-meters require a reference point relative to which the measureme...

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 ...

2003
Robert Ettema Tatsuaki Nakato

The paper describes the range of scour types that may occur at bridge abutments, and addresses the extensive attendant difficulties confronting accurate estimation of abutment-scour depth. The difficulties, which include similitude aspects of laboratory experiments on scour at bridge abutments, complicate the development of reliable scour-estimation relationships. In a practical sense, the diff...

A.A Dehghani S Kharaghani T Esmaeili

Local scouring around the bridges piers has always been considered as a problem, especially in rivers. If we do not take the necessary actions to avoid the occurrence of this phenomenon or to reduce its influence, then the bridge's piers will be destroyed. Placing the bridge piers' foundation far from the earth's surface will turn out in a plan which is not economic at all. Experimental studies...

Journal: :Water 2021

Local scour is a common threat to structures such as bridge piers, abutments, and dikes that are constructed on natural rivers. To reduce the risk of foundation failure, understanding local phenomenon around hydraulic important. The well-predicted depth can be used reference for structural design river management. Numerical simulation relatively efficient at studying these issues. Currently, tw...

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...

2010
Michael Pollino

The behavior and design of four-legged controlled rocking bridge steel truss piers to three components of seismic excitation are presented in this paper. The controlled rocking approach for seismic protection allows a pier to uplift from its base, limiting the force demands placed on the bridge pier and deck, and can allow the structure to remain elastic during an earthquake, preventing damage ...

ژورنال: علوم آب و خاک 2016
سبهانی, مرتضی , مسجدی, علیرضا ,

Riprap is used to control scouring around the bridge abutment. In order to study the stability of riprap around two bridge abutments with two different shapes, experiments were conducted in a laboratory flume made of Plexiglass in 180 degree bend.  In this research, several experiments were done by placing the two bridge abutments made of Plexiglas in a series of riprap. Experiments included tw...

2008
J. Liu X. Y. Huang N. S. He

In this paper, a forward-looking infrared (FLIR) video surveillance system is presented for collision avoidance of moving ships to bridge piers. An image pre-processing algorithm is proposed to reduce clutter noises by multi-scale fractal analysis, in which the blanket method is used for fractal feature computation. Then, the moving ship detection algorithm is developed from image differentials...

2005
Nasim Uddin Nadim Shehab Farhat

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