GMDH-GEP to predict free span expansion rates below pipelines under waves. Issue 3 (16th March 2019)

• Record Type: Journal Article
• Authors: Najafzadeh, Mohammad; Saberi-Movahed, Farid
• Is Part Of: Marine georesources & geotechnology. Volume 37:Issue 3(2019)
• Page Start: 375
• Page End: 392
• Publication Date: 2019-03-16
• Subjects: Free span expansion -- gene-expression programming -- group method of data handling -- pipeline -- scour rate; Marine mineral resources -- Periodicals; 551.46
• DOI: 10.1080/1064119X.2018.1443355
• Languages: English
• ISSNs: 1064-119X

Abstract

ABSTRACT: In this research, group method of data handling (GMDH) as a one of the self-organized approaches is utilized to predict three-dimensional free span expansion rates around pipeline due to waves. The GMDH network is developed using gene-expression programming (GEP) algorithm. In this way, GEP was performed in each neuron of GMDH instead of polynomial quadratic neuron. Effective parameters on the three-dimensional scour rates include sediment size, pipeline geometry, and wave characteristics upstream of pipeline. Four-dimensionless parameters are considered as input variables by means of dimensional analysis technique. Furthermore, scour rates along the pipeline, vertical scour rate, and additionally scour rates in the left and right of pipeline are determined as output parameters. Results of the proposed GMDH-GEP models for the training stages and testing ones are evaluated using various statistical indices. Performances of the GMDH-GEP models are compared with artificial neural network (ANN), GEP, GMDH, and traditional equations-based regression models. Moreover, sensitivity analysis and parametric study are conducted to perceive influences of different input parameters on the three-dimensional scour rates.