Simulation of Scour Depth Around Twin and Three Piers Using Group Method of Data Handling

Document Type : Research Paper


1 Ph.D. Candidate, Department of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran

2 Department of Water Engineering, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran


Estimation and computation of scouring around structures such as piers has a significant importance. In this study, scour depth in the vicinity of twin and three piers was simulated using Group Method of Data Handling (GMDH). First, effective parameters on scour depth were identified and then four different GMDH models were defined. To verify the simulation results, some experimental measurements were applied and 70% of these data were utilized to train the GMDH models, whereas 30% of the data were employed to test the models. Subsequently, the best GMDH model and the most influencing input parameters were introduced by conducting a sensitivity analysis. The sensitivity analysis showed that the GMDH models estimated the scour depth with acceptable accuracy. For instance, the correlation coefficient (R), scatter index (SI), and variance accounted for (VAF) for the best GMDH model were respectively calculated to be 0.949, 0.212, and 90.129. In addition, the Froude number was detected as the most important input variable to estimate the scour depth through GMDH model. Moreover, the mean discrepancy ratio (DRave) for the superior GMDH model was computed to be 1.228. For different GMDH models, four equations were presented and lastly a computer code was provided to simulate scour depth by means of the GMDH model.


Anastasakis, L. and Mort, N. (2001). The development of self-organization techniques in modelling: a review of the group method of data handling (GMDH). Research Report-University of Sheffield.
Atashkari, K, Nariman-Zadeh, N, Gölcü, M, Khalkhali, A. and Jamali, A. (2007). Modelling and multi-objective optimization of a variable valve-timing spark-ignition engine using polynomial neural networks and evolutionary algorithms. Energy Conversion and Management, 48(3), 1029-1041.
Ataie-Ashtiani, B., Baratian-Ghorghi, Z., and Beheshti, A.A. (2010). Experimental investigation of clear-water local scour of compound piers. Journal of Hydraulic Engineering, 136(6), 343-351.
Azamathulla, H.M. (2012). Gene-expression programming to predict scour at a bridge abutment. Journal of Hydroinformatics, 14(2), 324-331.
Azimi, H., Bonakdari, H., Ebtehaj, I., Gharabaghi, B., and Khoshbin, F. (2018). Evolutionary design of generalized group method of data handling-type neural network for estimating the hydraulic jump roller length. Acta Mechanica, 229(3), 1197-1214.
Azimi, H., Bonakdari, H., Ebtehaj, I., Talesh, S. H. A., Michelson, D. G., and Jamali, A. (2017). Evolutionary Pareto optimization of an ANFIS network for modeling scour at pile groups in clear water condition. Fuzzy Sets and Systems, 319, 50-69.
Azimi, H., Bonakdari, H., Ebtehaj, I., Shabanlou, S., Talesh, S. H. A., and Jamali, A. (2019). A pareto design of evolutionary hybrid optimization of ANFIS model in prediction abutment scour depth. Sādhanā, 44(7), 169.
Bateni, S. M., and Jeng, D. S. (2007). Estimation of pile group scour using adaptive neuro-fuzzy approach. Ocean Engineering, 34(8), 1344-1354.
Firat, M., and Gungor, M. (2009). Generalized regression neural networks and feed forward neural networks for prediction of scour depth around bridge piers. Advances in Engineering Software, 40(8), 731-737.
Liriano, S. L., and Day, R. A. (2001). Prediction of scour depth at culvert outlets using neural networks. Journal of Hydroinformatics, 3(4), 231-238.
Noori, R., Hoshyaripour, Gh., Ashrafi, Kh., and Nadjar Araabi B. (2010). Uncertainty analysis of developed ANN and ANFIS models in prediction of carbon monoxide daily concentration. Atmospheric Environment, 44(4), 476-482.
Shamshirband, S., Mosavi, A., and Rabczuk, T. (2020). Particle swarm optimization model to predict scour depth around a bridge pier. Frontiers of Structural and Civil Engineering, 14(4), 855-866.
Sharafi, H., Ebtehaj, I., Bonakdari, H., and Zaji, A. H. (2016). Design of a support vector machine with different kernel functions to predict scour depth around bridge piers. Natural Hazards, 84(3), 2145-2162.
Trent, R., Gagarin, N., and Rhodes, J. (1993). Estimating pier scour with artificial neural networks. In Hydraulic Engineering (pp. 1043-1048). ASCE.
Wang, H., Tang, H.W., Xiao, J.F., Wang, Y., and Jiang, S. (2016a). Clear-water local scouring around three piers in a tandem arrangement. Science China Technological Sciences, 59(6), 888–896.
Wang, H., Tang, H., Liu, Q., and Wang, Y. (2016b). Local scouring around twin bridge piers in open-channel flows. Journal of Hydraulic Engineering, 142(9), 060160081-8.