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Prediction of Local Scour Around Bridge Piers Using GEP Model

GEP 모형을 이용한 교각주위 국부세굴 예측

  • 김태준 (연세대학교 대학원 토목환경공학과) ;
  • 최병웅 (연세대학교 토목환경공학과) ;
  • 최성욱 (연세대학교 공과대학 토목환경공학과)
  • Received : 2014.06.03
  • Accepted : 2014.09.18
  • Published : 2014.12.01

Abstract

Artificial Intelligence-based techniques have been applied to problems where mathematical relations can not be presented due to complicatedness of the physical process. A representative example in hydraulics is the local scour around bridge piers. This study presents a GEP model for predicting the local scour around bridge piers. The model is trained by 64 laboratory data to build the regression equation, and the constructed model is verified against 33 laboratory data. Comparisons between the models with dimensional and normalized variables reveals that the GEP model with dimensional variables predicts better. The proposed model is now applied to two field datasets. It is found that the MAPE of the scour depths predicted by the GEP model increases compared with the predictions of local scours in laboratory scale. In addition, the model performance increases significantly when the model is trained by the field dataset rather than the laboratory dataset. The findings suggest that apart from the ANN model, GEP model is a sound and reliable model for predicting local scour depth.

물리현상의 난해성으로 인해 수학적인 관계식이 제시되기 어려운 경우 인공지능 기술에 근거한 다양한 기법이 적용되어 왔다. 수리학 분야의 대표적인 예로 교각주위 국부세굴 문제를 들 수 있다. 본 연구에서는 유전자 알고리즘의 진화된 방법인 GEP 기법을 이용하여 교각주위 국부세굴을 예측하는 방법을 제시하였다. 64개의 실험 자료를 이용하여 GEP 모형을 학습시켜 회귀식을 구축하였으며, 33개의 실험 자료를 이용하여 구축된 모형의 검증을 실시하였다. 평형세굴심 예측을 위하여 차원을 갖는 일반 변수와 표준화된 변수로 GEP 모형을 구축하여 예측 결과를 비교하였는데, 차원을 갖는 변수에 의한 GEP 모형이 세굴심을 더 잘 예측하는 것으로 나타났다. 구축된 GEP 모형을 두 가지 현장 실측자료에 적용하였다. 적용 결과, 실험 자료에 적용한 경우에 비해 예측의 정확도가 낮아지는 것을 확인하였다. 또한, 현장 실측자료를 이용하여 학습시킨 경우 실험 자료를 이용하는 경우 보다 예측 능력이 많이 향상되는 것으로 나타났다. GEP 모형의 적용성을 위해 ANN 모형과의 비교를 수행하였으며, 본 연구에서 사용된 GEP 모형이 교각주위 국부세굴 예측에 대하여 실내 및 현장 모두 ANN 모형보다 우수한 것으로 나타났다.

Keywords

References

  1. Azamathulla, H. Md. and Ghani, A. A. (2010). "Genetic programming to predict river pipeline scour." Journal of Pipeline Systems Engineering and Practice, ASCE, Vol. 1, No. 3, pp. 127-132. https://doi.org/10.1061/(ASCE)PS.1949-1204.0000060
  2. Azamathulla, H. Md., Ghani, A. A. and Guven, A. (2010). "Genetic programming to predict bridge pier scour." Journal of Hydraulic Engineering, ASCE, Vol. 136, No. 3, pp. 165-169. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000133
  3. Cater, J. E. and Williams, J. J. R. (2008). "Large eddy simulation of a long asymmetric compound channel." Journal of Hydraulic Research, IAHR, Vol. 46, No. 4, pp. 445-453. https://doi.org/10.3826/jhr.2008.3134
  4. Chabert, J. and Engeldinger, P. (1956). Etude des affouillements autour des piles des ponts, Laboratoire Nationale d'Hydraoulique, Chatou, France.
  5. Choi, S.-U. and Cheong, S. (2006). "Prediction of local scour around bridge piers using artificial neural networks." Journal of the American Water Resources Association, Vol. 42, No. 2, pp. 487-494. https://doi.org/10.1111/j.1752-1688.2006.tb03852.x
  6. Cui, J. and Neary, V. S. (2008). "LES study of turbulent flows with submerged vegetation." Journal of Hydraulic Research, IAHR, Vol. 46, No. 3, pp. 307-316. https://doi.org/10.3826/jhr.2008.3129
  7. Dey, S., Bose, S. K. and Sastry, G. L. N. (1995). "Clear water scour at circular piers: A Model." Journal of Hydraulic Research, IAHR, Vol. 15, No. 4, pp. 869-876.
  8. Ferreira, C. (2001). "Gene expression programming: A New Adaptive Algorithm for Solving Problems." Complex Systems, Vol. 13, No. 2, pp. 87-129.
  9. Gao, D., Posada, G. L. and Nordin, C. F. (1993). Pier scour equations used in the people's republic of China - Review and Summary, U.S. Department of Transportation, Federal Highway Administration, Publication FHWA-SA-93-076.
  10. Grega, L. M., Wei, T., Leighton, R. I. and Neves, J. C. (1995). "Turbulent mixed-boundary flow in a corner formed by a solid wall and a free surface." Journal of Fluid Mechanics, Vol. 294, pp. 17-46. https://doi.org/10.1017/S0022112095002795
  11. Guven, A. and Gunal, M. (2008). "Genetic programming approach for prediction of local scour downstream of hydraulic structures." Journal of Irrigation and Drainage Engineering, Vol. 134, No. 2, pp. 241-249. https://doi.org/10.1061/(ASCE)0733-9437(2008)134:2(241)
  12. Harlow, F. H. and Welch, J. E. (1965). "Numerical calculation of time-dependent viscous incompressible flow of fluid with free surface." Physics of Fluids, Vol. 8, p. 2182. https://doi.org/10.1063/1.1761178
  13. Holland, J. H. (1975). "Adaptation in natural and artificial systems: An Introductory Analysis with Applications to Biology, Control, and Artificial Intelligence." Oxford, England: University of Michigan Press.
  14. Hsu, T. Y., Grega, L. M., Leighton, R. I. and Wei, T. (2000). "Turbulent kinetic energy transport in a corner formed by a solid wall and a free surface." Journal of Fluid Mechanics, Vol. 410, pp. 343-366. https://doi.org/10.1017/S0022112099008125
  15. Issa, R. I., Gosman, A. D. and Watkins, A. P. (1986). "The computation of compressible and incompressible recirculating flows." Journal of Computational Physics, Vol. 62, No. 1, pp. 62-82.
  16. Jee, Y. G., Kim, S. J. and Kim, P. S. (2005). "Forecasting monthly inflow for the storage management of small dams." 2005' Conference of Korea Water Resources Association, pp. 85-89 (in Korean).
  17. Kim, K., Kim, S., Kim, T. and Heo, J.-H. (2007). "Theoretical derivation of IDF curve using probability distribution function of rainfall data." 2007' Conference of Korea Water Resources Association, pp. 1503-1506 (in Korean).
  18. Kim, S. J., Jee, Y. G. and Kim, P. S. (2004). "Parameter optimization of long and short term runoff models using genetic algorithm." 2004' Conference of Korea Water Resources Association, pp. 1117-1121 (in Korean).
  19. Kim, S., Heo, J.-H. and Choi, M. (2011). "Derivation of plotting position formulas considering the coefficients of skewness for the GEV distribution" Journal of Water Resources Association, KWRA, Vol. 44, No. 2, pp. 85-96 (in Korean). https://doi.org/10.3741/JKWRA.2011.44.2.085
  20. Kim, S., Heo, J.-H., Shin, H. and Kho, Y. W. (2009). "Comparison of plotting position formulas for gumbel distribution" Journal of Water Resources Association, KWRA, Vol. 42, No. 5, pp. 365-374 (in Korean). https://doi.org/10.3741/JKWRA.2009.42.5.365
  21. Lee, K. S., Kim, S. U. and Hong, I. P. (2005). "Automatic calibration of rainfall-runoff model using multi-objective function" Journal of The Korean Water Resources Association, Vol. 38, No. 10, pp. 861-869 (in Korean). https://doi.org/10.3741/JKWRA.2005.38.10.861
  22. Melville, B. W. and Chiew, Y. M. (1999). "Time scale for local scour at bridge piers." Journal of Hydraulic Engineering, ASCE, Vol. 125, pp. 59-65. https://doi.org/10.1061/(ASCE)0733-9429(1999)125:1(59)
  23. Melville, B. W. and Coleman, S. E. (2000). Bridge scour, Water Resources Publications, Highlands Ranch, Colorado.
  24. Ministry of Security and Public Administration. (1995-2003). Disaster annual report (in Korean).
  25. Mueller, D. S. and Wagner, C. R. (2005). Field observations and evaluations of streambed scour at bridges, Office of Engineering Research and Development, Federal Highway Administration, McLean, Virginia.
  26. Muzzammil, M. (2010). "ANFIS approach to the scour depth prediction at a bridge abutment." Journal of Hydroinformatics, Vol. 12, No. 4, pp. 474-485. https://doi.org/10.2166/hydro.2010.004
  27. Pagan-Ortiz, J. E. (2002). "Impact of the federal highway administration's scour evaluation program in the united states of north america's highway bridges." Proceedings of the First International Conference on Scour of Foundations, ICSF-1, Texas A&M University, College Station, Texas, U.S.A., Vol. 2. pp. 636-641.
  28. Richardson, E. V. and Davis, S. R. (1995). Evaluating scour at bridges, Report No. FHWA-IP-90-017, Hydraulic Engineering Circular No. 18 (HEC-18) (Third Edition), Office of Technology Applications, HTA-22, Federal Highway Administration, U.S. Department of Transportation, Washington, D.C.
  29. Sheppard, D. M., Melville, B. and Demir, H. (2014). "Evaluation of existing equations for local scour at bridge piers." Journal of Hydraulic Engineering, ASCE, Vol. 140, No. 1, pp. 14-23. https://doi.org/10.1061/(ASCE)HY.1943-7900.0000800
  30. Shin, J., Kim, S., Kim, T. and Heo, J.-H. (2007). "Parameter estimation of intensity-duration-frequency curve using genetic algorithm." 2007' Conference of Korea Water Resources Association, pp. 142-146 (in Korean).
  31. Shppard, D. M. and Melville, B. (2011). Scour at wide piers and long skewed piers, NCHRP Report 682, Transportation Research Board of the National Academies. Washington, D.C.
  32. Yang, W. and Choi, S.-U. (2002). "Three-Dimensional numerical simulation of local scour around the bridge pier using large eddy simulation." Journal of The Korean Society of Civil Engineers, Vol. 22, No.6-B, pp. 785-793 (in Korean).
  33. Yanmaz, A. M. and Altinbilek, H. D. (1991). "Study of time-dependent local scour around bridge piers." Journal of Hydraulic Engineering, ASCE, Vol. 117, No. 10, pp. 1247-1268. https://doi.org/10.1061/(ASCE)0733-9429(1991)117:10(1247)