Comparative Study of Scouring Around Bridge Piers
269
also been evaluated. The important observations from the study are summarised as
follows:
1. It has been found that while using CSU equation, the grain size effect is not
influenced when diameter of the sediments is less than 2 mm.
2. Froehlich considers the effect of grain size when the diameter are less than 2 mm.
3. Jain and Fischer and Larsen and Toch does not considers the effect of grain size
of the sediments.
4. It has been also seen that by using Lacey’s equation over predicted values are
obtained compared to other formula.
From the numerical study, it has been noted that the scour depth increases with the
increase in approach flow depth and decreases at greater rate with decrease in flow
depth. The decrease in scour depth is due to the interference of the eddies formed
around the pier with the downward flow into the scour hole.
4.1 Future Scope of Work
Since the observed data for the scour depth was not available, the validation of the
results could not carry out. Study has to be carried out for improving Lacey’s equation
for using the same for scour determination in the case of cohesive soils.
References
1. Shen HW, Schneider VR, Karaki SS (1969) Local scour around bridge piers. J Hydraulics Div
95(HY6):1919–1940
2. Ghorbani B (2007) A field study of scour at bridges piers in flood plain rivers. Turkish J Eng
Environ Sci 32:1–11
3. Ahmed F, Rajaratnam N (1998) Flow around bridge piers. J Hydrau Eng 24(3):288–300
4. Chiew YM (2004) Local scour and riprap stability at bridge in a degrading channel. J Hydrau
Eng 130(3):218–226
5. Lacey G (1929) Stable channels in alluviums. J Inst Eng 4736:229
6. Laursen EM, Toch A (1956) Scour around bridge piers and abutments. Bull. No. 4, Iowa Hwy
Res Board, Ames, Iowa
7. Jain SC (1981) Maximum clear water scour around cylindrical piers. JHE 107(5):611–625
8. U.S. Army Corps of Engineers (2008) Hydrologic Engineering Center, HEC-RAS river analysis
system version 4.0.0, March 2008
9. Mueller DS (1996) Local scour at bridge piers in non uniform sediment under dynamic
conditions. Fort Collins, Colo., Colorado State University, Ph.D. dissertation, 212p
269
also been evaluated. The important observations from the study are summarised as
follows:
1. It has been found that while using CSU equation, the grain size effect is not
influenced when diameter of the sediments is less than 2 mm.
2. Froehlich considers the effect of grain size when the diameter are less than 2 mm.
3. Jain and Fischer and Larsen and Toch does not considers the effect of grain size
of the sediments.
4. It has been also seen that by using Lacey’s equation over predicted values are
obtained compared to other formula.
From the numerical study, it has been noted that the scour depth increases with the
increase in approach flow depth and decreases at greater rate with decrease in flow
depth. The decrease in scour depth is due to the interference of the eddies formed
around the pier with the downward flow into the scour hole.
4.1 Future Scope of Work
Since the observed data for the scour depth was not available, the validation of the
results could not carry out. Study has to be carried out for improving Lacey’s equation
for using the same for scour determination in the case of cohesive soils.
References
1. Shen HW, Schneider VR, Karaki SS (1969) Local scour around bridge piers. J Hydraulics Div
95(HY6):1919–1940
2. Ghorbani B (2007) A field study of scour at bridges piers in flood plain rivers. Turkish J Eng
Environ Sci 32:1–11
3. Ahmed F, Rajaratnam N (1998) Flow around bridge piers. J Hydrau Eng 24(3):288–300
4. Chiew YM (2004) Local scour and riprap stability at bridge in a degrading channel. J Hydrau
Eng 130(3):218–226
5. Lacey G (1929) Stable channels in alluviums. J Inst Eng 4736:229
6. Laursen EM, Toch A (1956) Scour around bridge piers and abutments. Bull. No. 4, Iowa Hwy
Res Board, Ames, Iowa
7. Jain SC (1981) Maximum clear water scour around cylindrical piers. JHE 107(5):611–625
8. U.S. Army Corps of Engineers (2008) Hydrologic Engineering Center, HEC-RAS river analysis
system version 4.0.0, March 2008
9. Mueller DS (1996) Local scour at bridge piers in non uniform sediment under dynamic
conditions. Fort Collins, Colo., Colorado State University, Ph.D. dissertation, 212p