Erosion Function Apparatus for Scour Rate Predictions
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VIEW THE REPLYPublication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 127, Issue 2
Abstract
Scour is the number one cause of bridge failures. Scour in coarse grained soils (sand, gravel) is relatively well known, but scour in fine grained soils (silt, clay) and weak rock is not. In coarse grained soils, scour takes place very rapidly and the scour rate is rarely an issue because one flood is likely to create the maximum scour depth. In fine grained soils, the scour process is much slower; as a result, even after a hundred years, a bridge may not experience the maximum depth of scour. Therefore, in fine grained soils it becomes necessary to predict the rate at which scour takes place. A new apparatus called the EFA (Erosion Function Apparatus; 〈http://tti.tamu.edu/geotech/scour〉) has been built and tested to measure the erosion rate of fine grained soils; the EFA can also be used to measure the erosion rate of coarse grained soils if necessary. The end of a Shelby tube sample from the bridge site is fitted through a tight opening at the bottom of a pipe with a rectangular cross section. Water flows through the pipe and erodes the soil sample, which protrudes 1 mm above the bottom of the pipe. The rate at which the sample erodes is measured, and the shear stress imposed by the water on the soil is calculated. The plot of erosion rate versus shear stress is the result of an EFA test. It indicates the critical shear stress at which erosion starts and the rate of erosion beyond that shear stress. This function can be used to predict the rate of scour at a bridge.
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References
1.
Apperly, L. W. ( 1968). “Effect of turbulence on sediment entrainment.” PhD thesis, University of Auckland, Auckland, New Zealand.
2.
Ariathurai, R., Arulanandan, K. (1978). “Erosion rates of cohesive soils.”J. Hydr. Div., ASCE, 104(2), 279–283.
3.
Arulanandan, K., Loganthan, P., and Krone, R. B. (1975). “Pore and eroding fluid influences on surface erosion of soil.”J. Geotech. Engrg. Div., ASCE, 101(1), 51–66.
4.
ASTM. ( 1999a). “Standard practice for thin-walled tube geotechnical sampling of soils.” ASTM-D1587,West Conshohocken, Pa.
5.
ASTM. ( 1999). “Standard test method for identification and classification of dispersive clay soils by the pinhole test.” ASTM-D4647, West Conshohocken, Pa.
6.
Briaud, J.-L., Chen, H. C., Nurtjahyo, P., Kwak, K., and Han, S. W. ( 1999a). “Bridge scour in cohesive materials.”Interim Rep. on NCHRP Project 24-15, NCHRP, Washington, D.C.
7.
Briaud, J.-L., Ting, F. C. K., Chen, H. C., Gudavalli, R., Perugu, S., and Wei, G. (1999b). “Sricos: prediction of scour rate in cohesive soils at bridge piers.”J. Geotech. and Geoenvir. Engrg., ASCE, 125(4), 237–246.
8.
Einstein, H. A., and El-Samni, E. S. A. ( 1949). “Hydrodynamic forces on a rough wall.” Review of Modern Phys., 21, 520–524.
9.
Gudavalli, R., Ting, F. C. K., Briaud, J.-L., Chen, H. C., Perugu, S., and Wei, G. ( 1997). “Flume tests to study scour rate of cohesive sails.” Res. Rep. Prepared for Texas Dept. of Transp., Dept.of Civ. Engrg., Texas A&M University, College Station, Tex.
10.
Kwak, K., Briaud, J.-L., Chen, H. C., Ting, F. C. K., and Han, S. W. ( 1999). “Generalized Sricos method and verification for prediction of scour depth versus time at bridge piers.” Res. Rep. Prepared for Texas Dept. of Transp., Dept. of Civ. Engrg., Texas A&M University, College Station, Tex.
11.
Lagasse, P. F., Schall, J. D., Johnson, F., Richardson, E. V., and Chang, F. ( 1995). “Stream stability at highway structures.” Rep. No. FHWA-IP-90-014 (HEC 20), Federal Highway Administration, Washington, D.C.
12.
Landers, M. N., and Mueller, D. S. ( 1996). “Channel scour at bridges in the United States.” Rep. No. FHWA-RD-95-184, Federal Highway Administration, Washington, D.C.
13.
Lee, S. C., and Mehta, A. J. ( 1994). “Cohesive sediment erosion,” Dredging Res. Program Contract Rep. DRP-94-6, University of Florida, Gainsville, Fla.
14.
Moody, L. F. ( 1944). “Friction factors for pipe flow.” Trans. Am. Soc. of Mech. Engrs., 66.
15.
Moore, W. L., and Masch, F. D. ( 1962). “Experiments on the scour resistance of cohesive sediments.”J. Geophys. Res., 67(4), 1437–1449.
16.
Munson, B. R., Young, D. F., and Okiishi, T. H. ( 1990). Fundamentals of fluid mechanics, Wiley, New York.
17.
Philogene, B., and Briaud, J.-L. ( 1996). “Scour of cohesive soils: a literature review.” Res. Rep. Prepared for Texas Dept. of Transp., Dept. of Civ. Engrg., Texas A&M University, College Station, Tex.
18.
Richardson, E. V., and Davis, S. R. ( 1995). “Evaluating scour at bridges,” Rep. No. FHWA-IP-90-017 (HEC 18), Federal Highway Administration, Washington, D.C.
19.
Rohan, K., Lefebvre, G., Douville, S., and Milette, J. P. ( 1986). “A new technique to evaluate erosivity of cohesive material.” Geotech. Testing J., 9(2), 87–92.
20.
Shields, A. ( 1936). “Anwendung der Aenlichkeitsmechanik und der Turbulenzforschung auf die Geschiebebewegung.” Mittleilungen der Preussischen Versuchsanstalt fur Wasserbau und Schiffbau, W. P. Ott and J. C. Van Uchelen, translators, California Institute of Technology, Pasadena, Calif.
21.
Shirole, A. M., and Holt, R. C. ( 1991). “Planning for a comprehensive bridge safety assurance program.” Transp. Res. Rec. 1290, Transportation Research Board, Washington, D.C., 137–142.
22.
Vanoni, V. A., ed. ( 1975). “Sedimentation engineering.” ASCE manuals and reports on engineering practice, ASCE, New York.
23.
White, C. M. ( 1940). “The equilibrium of grains on the bed of a stream.” Proc. Royal Soc. of London, London, 174(958), 322–338.
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Received: Sep 16, 1999
Published online: Feb 1, 2001
Published in print: Feb 2001
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