Current Science

Open Access Open Access  Restricted Access Subscription Access

A Modification to The Indian Practice of Scour Depth Prediction Around Bridge Piers


Affiliations
1 Department of Civil Engineering, Indian Institute of Technology, Bombay, Mumbai 400 076, India
 

Estimation of the expected maximum scour depth is very crucial at the design stage of a bridge. In India, for design of a bridge pier, the guidelines given by the Indian Road Congress (IRC) code is generally followed. The IRC equation is generally used to estimate the mean scour depth with a factor of safety of two to obtain the maximum design scour depth. The IRC equation comprises of two factors pertaining to the flow characteristics and bed material characteristics respectively. However, pier geometry is one crucial attribute which contributes to the local scour, and it is not considered in the IRC equation. Due to this, the computed mean scour depth will be much less. In the present study, a modification to the IRC equation is suggested based on detailed experimental studies using different shapes of piers. The scour pattern is obtained on a sand bed for various shapes at different flow conditions. Based on the study, an empirical constant is introduced in the IRC equation, which attributes to the pier geometry. The proposed modified IRC (M-IRC) equation gives better scour prediction for all the shapes. The effectiveness of the proposed equation is verified by comparing with other equations available in literature. The proposed M-IRC equation will be very useful for the design of bridge foundation in Indian conditions.

Keywords

Bridge, Equilibrium Scour Depth, IRC Equation, Local Scour, Modified IRC Equation, Pier Geometry.
User
Notifications
Font Size

  • Breusers, H. N. C., Nicollet, G. and Shen, H. W., Local scour around cylindrical piers. J. Hydr. Res., 1977, 15(3), 211–252.

  • Raudkivi, A. J. and Ettema, R., Clear-water scour at cylindrical piers. J. Hydr. Eng., 1983, 109(3), 338–350.

  • Chiew, Y. M. and Melville, B. W., Local scour around bridge piers. J. Hydr. Res., 1987, 25(1), 15–26.

  • Melville, B. W. and Sutherland, A. J., Design method for local scour at bridge piers. J. Hydr. Eng., 1988, 114(10), 1210–1226.

  • Garde, R. J. and Kothyari, U. C., Scour around bridge piers. Proc. Indian Natl. Sci. Acad., 1998, 64A, 569–580.

  • Kothyari, U. C., Bridge scour: status and research challenges. ISH J. Hydr. Eng., 2008, 14(1), 1–27.

  • HEC-18., Evaluating scour at bridges: Federal Highway Administration Hydraulic Engineering Circular No. 18, FHWA, National Highway Institute, USA, 2012, 5th edn.

  • Qi, M., Li, J. and Chen, Q., Comparison of existing equations for local scour at bridge piers: parameter influence and validation. Nat. Haz., 2016, 82(3), 2089–2105.

  • Williams, P., Bolisetti, T. and Balachandar, R., Evaluation of governing parameters on pier scour geometry. Can. J. Civil Eng., 2016, 44(1), 48–58.

  • Pandey, M., Sharma, P. K., Ahmad, Z. and Singh, U. K., Evaluation of existing equations for temporal scour depth around circular bridge piers. Env. Fluid Mech., 2017, 17(5), 981–995.

  • Rady, R. A. E. H., Prediction of local scour around bridge piers: artificial-intelligence-based modeling versus conventional regression methods. Appl. Water Sci., 2020, 10(2), 57.

  • Kothyari, U. C., Garde, R. C. J. and Ranga Raju, K. G., Temporal variation of scour around circular bridge piers. J. Hydr. Eng., 1992, 118(8), 1091–1106.

  • Melville, B. W., Local scour at bridge abutments. J. Hydr. Eng., 1992, 118(4), 615–631.

  • IRC: 78-2000, Standard specifications and code of practice for road bridges. The Indian Roads Congress, New Delhi, India, 2000.

  • IRC: 89-1997, Guidelines for design and construction of river training and control works for road bridges. The Indian Roads Congress, New Delhi, India, 1997.

  • Borge, V. B. and Jangde, K. S., Innovative bridge foundations in weak soils-experiment and practice in Maharashtra. The Indian Roads Congress, 2005, pp. 455–484.

  • Kothyari, U. C., Indian practice on estimation of scour around bridge piers – a comment. Sādhanā, 2007, 32(3), 187–197.

  • Vijayasree, B. A., Eldho, T. I., Mazumder, B. S. and Viswanadham, B. V. S., Effectiveness of combinations of raft foundation with aprons as a protection measure against bridge pier scour. Sādhanā, 2018, 43(2), 21.

  • Al-Shukur, A. H. K. and Obeid, Z. H., Experimental study of bridge pier shape to minimize local scour. Int. J. Civil Eng. Tech., 2016, 7(1), 162–171.

  • Vijayasree, B. A. and Eldho, T. I., Experimental study of scour around bridge piers of different arrangements with same aspect ratio. In 8th International Conference on Scour and Erosion (ICSE 2016), Oxford, 12–15 September 2016.

  • Vijayasree, B. A., Eldho, T. I. and Mazumder, B. S., Turbulence statistics of flow causing scour around circular and oblong piers. J. Hydr. Res., 2019, 58(4), 673–686; doi:10.1080/00221686. 2019.1661292.

  • Vijayasree, B. A., Eldho, T. I., Mazumder, B. S. and Ahmad, N., Influence of bridge pier shape on flow field and scour geometry. Int. J. River Basin Mgmt., 2019, 17(1), 109–129.

  • Farooq, R. and Ghumman, A. R., Impact assessment of pier shape and modifications on scouring around bridge pier. Water, 2019, 11(9), 1761.

  • Wang, H., Tang, H., Liu, Q. and Wang, Y., Local scouring around twin bridge piers in open-channel flows. J. Hydr. Eng., 2016, 142(9), 06016008-1–06016008-8.

  • Wang, H., Tang, H., Xiao, J., Wang, Y. and Jiang, S., Clear-water local scouring around three piers in a tandem arrangement. Sci. China Tech. Sci., 2016, 59(6), 888–896.

  • Wang, H., Tang, H., Liu, Q. and Zhao, X., Topographic Evolution around Twin Piers in a Tandem Arrangement. KSCE J. Civil Eng., 2019, 23(7), 2889–2897.


Abstract Views: 174

PDF Views: 82




  • A Modification to The Indian Practice of Scour Depth Prediction Around Bridge Piers

Abstract Views: 174  |  PDF Views: 82

Authors

B. A. Vijayasree
Department of Civil Engineering, Indian Institute of Technology, Bombay, Mumbai 400 076, India
T. I. Eldho
Department of Civil Engineering, Indian Institute of Technology, Bombay, Mumbai 400 076, India

Abstract


Estimation of the expected maximum scour depth is very crucial at the design stage of a bridge. In India, for design of a bridge pier, the guidelines given by the Indian Road Congress (IRC) code is generally followed. The IRC equation is generally used to estimate the mean scour depth with a factor of safety of two to obtain the maximum design scour depth. The IRC equation comprises of two factors pertaining to the flow characteristics and bed material characteristics respectively. However, pier geometry is one crucial attribute which contributes to the local scour, and it is not considered in the IRC equation. Due to this, the computed mean scour depth will be much less. In the present study, a modification to the IRC equation is suggested based on detailed experimental studies using different shapes of piers. The scour pattern is obtained on a sand bed for various shapes at different flow conditions. Based on the study, an empirical constant is introduced in the IRC equation, which attributes to the pier geometry. The proposed modified IRC (M-IRC) equation gives better scour prediction for all the shapes. The effectiveness of the proposed equation is verified by comparing with other equations available in literature. The proposed M-IRC equation will be very useful for the design of bridge foundation in Indian conditions.

Keywords


Bridge, Equilibrium Scour Depth, IRC Equation, Local Scour, Modified IRC Equation, Pier Geometry.

References





DOI: https://doi.org/10.18520/cs%2Fv120%2Fi12%2F1875-1881