Spur dykes also known as Groynes are often used to either divert or attract the flow from the main structure to safeguard their life.Those structures may be bridge piers,abutments or any similar hydraulics structures....Spur dykes also known as Groynes are often used to either divert or attract the flow from the main structure to safeguard their life.Those structures may be bridge piers,abutments or any similar hydraulics structures.Spur dykes are also used to save the cutting of banks on concave side of stream.Lots of work have been done in recent past on spur dykes by many investigators in which various hydraulic and geometrical parameters of spur dykes such as discharge,sediment size,flow velocity,shear stress,spur dykes shape,size and submergence etc.are studied in detail.But mostly all the studies were pointed out in straight open channels.Very few studies were done in curved channel and only their similar effects were studied.In present thesis main emphasis is given to study the effect of orientation and location of spur dykes in meandering channel on the bed of downstream side.In the present study experimental work has been carried out in 80°bend and constant discharge(Q=4.5 l/s)is allowed to pass in channel without spur dyke.It is found that maximum scouring occurs at angular displacementθ=60°to 80°in the vicinity of outer bank.To minimize this scouring,spur dyke has been installed at angular displacementθ=20°,40°&60°by changing the dyke angleα=60°,90°&120°respectively.It is found that scouring atθ=60°is reduced by installing spur dyke at angular displacementθ=40°which is oriented atα=60°and scouring atθ=80°is reduced by installing spur dyke at angular displacementθ=60°which is oriented atα=60°.展开更多
have been done in the past by many researchers.Many factors which affect scour around piers such as shape of piers,size,positioning and orientation etc.have been studied in detail by them.However,similar studies in me...have been done in the past by many researchers.Many factors which affect scour around piers such as shape of piers,size,positioning and orientation etc.have been studied in detail by them.However,similar studies in meandering channels are scanty.Very few researchers have studied the effect of angular displacement which has considerable effects of scour around bridge piers.In this paper an attempt has been made to carry out a detailed study of angular displacement on scour.A constant diameter bridge pier of circular shape has been tested in a meandering channel bend with bend angle as 800.The test bed was prepared by using uniform sand having d50 as 0.27 mm and run was taken for a discharge of 2.5 l/s.展开更多
文摘Spur dykes also known as Groynes are often used to either divert or attract the flow from the main structure to safeguard their life.Those structures may be bridge piers,abutments or any similar hydraulics structures.Spur dykes are also used to save the cutting of banks on concave side of stream.Lots of work have been done in recent past on spur dykes by many investigators in which various hydraulic and geometrical parameters of spur dykes such as discharge,sediment size,flow velocity,shear stress,spur dykes shape,size and submergence etc.are studied in detail.But mostly all the studies were pointed out in straight open channels.Very few studies were done in curved channel and only their similar effects were studied.In present thesis main emphasis is given to study the effect of orientation and location of spur dykes in meandering channel on the bed of downstream side.In the present study experimental work has been carried out in 80°bend and constant discharge(Q=4.5 l/s)is allowed to pass in channel without spur dyke.It is found that maximum scouring occurs at angular displacementθ=60°to 80°in the vicinity of outer bank.To minimize this scouring,spur dyke has been installed at angular displacementθ=20°,40°&60°by changing the dyke angleα=60°,90°&120°respectively.It is found that scouring atθ=60°is reduced by installing spur dyke at angular displacementθ=40°which is oriented atα=60°and scouring atθ=80°is reduced by installing spur dyke at angular displacementθ=60°which is oriented atα=60°.
文摘have been done in the past by many researchers.Many factors which affect scour around piers such as shape of piers,size,positioning and orientation etc.have been studied in detail by them.However,similar studies in meandering channels are scanty.Very few researchers have studied the effect of angular displacement which has considerable effects of scour around bridge piers.In this paper an attempt has been made to carry out a detailed study of angular displacement on scour.A constant diameter bridge pier of circular shape has been tested in a meandering channel bend with bend angle as 800.The test bed was prepared by using uniform sand having d50 as 0.27 mm and run was taken for a discharge of 2.5 l/s.
