SRICOS-EFA Method for Contraction Scour in Fine-Grained Soils
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 131, Issue 10
Abstract
Scour at bridges is the number-one cause of bridge collapse in the United States. Much research has been performed to improve the prediction of scour depths in coarse-grained soils, but little has been done for fine-grained soils. Starting in the early 1990s, the scour rate in cohesive soils-erosion function apparatus (SRICOS-EFA) method was developed for fine-grained soils. The first version of the method predicted the scour depth versus time curve for a cylindrical bridge pier in deep water subjected to a multiflood hydrograph and founded in a layered soil. Here, the SRICOS-EFA method is extended to the case of contraction scour, which is the lowering of the river bottom caused the narrowing of the river. Furthermore, the paper addresses clear-water scour only. The input to the new prediction method consists of the soil properties as tested in a special laboratory device called the EFA, the water parameters given by the velocity history over the design period considered, and the geometry of the contraction described by the contraction ratio, the contraction length, the contraction transition angle, and the water depth. This article focuses on the simpler case of a constant water velocity lasting for a limited time. The prediction equations are based on a combination of 14 model scale flume tests, 16 three-dimensional (3D) numerical simulations, and a verification (very limited). The step-by-step procedure is given, and a simple example is presented. The prediction process is automated by the program SRICOS-EFA, which can be downloaded free from http://ceprofs.tamu.edu/briaud/sricos-efa.htm. The advantages of the method are that it is based on site-specific soil testing (EFA), that it introduces the time effect in a simple manner, and that it therefore gives a more realistic prediction of the scour depth in cases where time effects significantly reduce the final scour depth. The drawback is that it requires soil testing.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This work is the partial result of NCHRP Project 24-15, sponsored by the National Academy of Sciences—Transportation Research Board. Thanks are extended to Tim Hess (contact with NCHRP) and the technical review panel: Steve Smith (Chair), Larry Arneson, Daryl Greer, Robert Henthorne, Melinda Luna, William Moore, Richard Phillips, Mehmet Tumay, Sterling Jones, and Jay Jayaprakash.
References
Briaud, J. L., Chen, H. C., Kwak, K. W., Han, S.-W., and Ting, F. C. K. (2001a). “Multiflood and multilayer method for scour rate prediction at bridge piers.” J. Geotech. Geoenviron. Eng., 127(2), 114–125.
Briaud, J.-L., Chen, H.-C., Li, Y., Nurtjahyo, P., and Wang, J. (2003). “Complex pier scour and contraction scour in cohesive soils.” NCHRP Rep. 24-15, Transportation Research Board, Washington D.C.
Briaud, J.-L., Ting, F., Chen, H. C., Cao, Y., Han, S.-W., and Kwak, K. (2001b). “Erosion function apparatus for scour rate predictions.” J. Geotech. Geoenviron. Eng., 127(2), 105–113.
Briaud, J.-L., Ting, F. C. K., Chen, H. C., Gudavalli, R., Perugu, S., and Wei, G. (1999). “SRICOS: Prediction of scour rate in cohesive soils at bridge piers.” J. Geotech. Geoenviron. Eng., 125(4), 237–246.
Chang, F., and Davis, S. (1999). “Maryland SHA procedure for estimating scour at bridge abutments. II: Clear water scour.” Stream stability and scour at highway bridges, E. V. Richardson and P. F. Lagasse, eds., ASCE, Reston, Va., 412–416.
Chen, H. C. (1995a). “Assessment of a Reynolds stress closure model for appendage hull junction flows.” J. Fluids Eng., 117, 557–563.
Chen, H. C. (1995b). “Submarine flows studied by second-moment closure.” J. Eng. Mech., 121(10), 1136–1146.
Chen, H. C. (2002). “Numerical simulation of scour around complex piers in cohesive soils.” Proc. 1st Int. Conf. on Scour of Foundations, College Station, Tex., 14–33.
Chen, H. C., Chen, M., and Davis, D. A. (1997). “Numerical simulation of transient flows induced by a berthing ship.” Int. J. Offshore Polar Eng., 7, 277–284.
Chen, H. C., and Korpus, R. A. (1993). “A multi-block finite-analytic Reynolds-average Navier–Stokes method for 3D incompressible flow.” Individual papers in fluids engineering, 150, ASME, New York, 113–121.
Chen, H. C., and Patel, V. C. (1988). “Near-wall turbulence models for complex flows including separation.” AIAA J., 26(6), 641–648.
Chen, H. C., and Patel, V. C. (1989). “The flow around wing-body Junctions.” Proc., 4th Symp. on Numerical and Physical Aspects of Aerodynamic Flows.
Chen, H. C., Patel, V. C., and Ju, S. (1990). “Solutions of Reynolds-averaged Navier-Stokes equations for three-dimensional incompressible flows.” J. Comput. Phys., 88(2), 305–336.
Flaxman, E. M. (1963). “Channel stability in undisturbed cohesive soils.” J. Hydraul. Div., Am. Soc. Civ. Eng., 89(HY2), 87–96.
Gill, M. A. (1981). “Bed erosion in rectangular long contraction.” J. Hydraul. Div., Am. Soc. Civ. Eng., 107(3), 273–284.
HEC-RAS River Analysis System. (1997). User’s manual, version 2.0, Hydrologic Engineering Center, U.S. Army Corps of Engineers, Davis, Calif.
Hjorth, P. (1975). “Studies on nature of local scour.” Bulletin Series A, No. 46, Dept. of Water Resources Engineering, Lund Institute of Technology/Univ. of Lund, Sweden.
Ivarson, W. R. (1999). “Scour and erosion in clay soils.” Stream stability and scour at highway bridges, E. V. Richardson and P. F. Lagasse, eds., ASCE, Reston, Va., 104–119.
Komura, S. (1966). “Equilibrium depth of scour in long contractions.” J. Hydraul. Div., Am. Soc. Civ. Eng., 92(5), 17–37.
Laursen, E. M. (1960). “Scour at bridge crossings.” J. Hydraul. Div., Am. Soc. Civ. Eng., 86(HY2), 93–118.
Laursen, E. M. (1963). “An analysis of relief bridge scour.” J. Hydraul. Div., Am. Soc. Civ. Eng., 89(HY3) 93–118.
Li, Y. (2003). “Pier scour and contraction scour in cohesive soils on the basis of flume tests.” PhD dissertation, Texas A&M Univ., Dept. of Civil Engineering, College Station, Tex.
Lim, S.-Y., and Cheng, N.-S. (1998). “Scouring in long contractions.” J. Irrig. Drain. Eng., 124(5), 258–261.
Melville, B. W., and Coleman, S. E. (1999). Bridge scour, Water Resources Publications, Fort Collins, Colo.
Munson, B. R., Young, D. F., and Okiishi, T. H. (1990). Fundamentals of fluid mechanics, Wiley, New York.
Neill, C. R. (1973). Guide to bridge hydraulic, Roads and Transportation Association of Canada, University of Toronto Press, Toronto.
Nurtjahyo, P. Y. (2002). “Numerical simulation of pier scour and contraction scour.” PhD dissertation, Dept. of Civil Engineering, Ocean Engineering Program, Texas A&M Univ., College Station, Tex.
Nurtjahyo, P. Y. (2003). “Numerical simulation of pier scour and contraction scour.” PhD dissertation, Dept. of Civil Engineering, Ocean Engineering Program, Texas A&M Univ., College Station, Tex.
Richardson, E. V., and Davis, S. M. (2001). “Evaluating scour at bridges.” Publication No. FHWA NHI 01-001, HEC No. 18, U.S. Dept. of Transportation, Washington, D.C.
Smith, C. D. (1967). “Simplified design for flume inlets.” J. Hydraul. Div., Am. Soc. Civ. Eng., 93(6), 25–34.
Straub, L. G. (1934). “Effect of channel contraction works upon regime of movable bed streams.” Trans., Am. Geophys. Union, 454–463.
Information & Authors
Information
Published In
Copyright
© 2005 ASCE.
History
Received: Jun 23, 2003
Accepted: Mar 4, 2005
Published online: Oct 1, 2005
Published in print: Oct 2005
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.