Application of Particle Swarm based Neural Network to Predict Scour Depth around the Bridge Pier

Abstract

Scour around the bridge pier is one of the major factors which affect the safety and stability of the bridge structure. Due to the presence of complexity in the scour mechanism, there is no common and simple method to estimate the scour depth. The present paper gives an idea of hybridizing two techniques such as an artificial neural network with swarm intelligence technique particle swarm optimization to estimate the scour depth around the bridge pier and abbreviated as PSO-ANN. The present discussion covers the estimation of scour depth for clear water and live bed scour condition around circular and rectangular pier shapes. The independent variables, Sediment size (d 50), sediment quantity (Sq), velocity (u) and time (t) are used as input to develop the models to estimate or quantify a dependent variable scour depth (ds). The efficiency and accuracy of the model are measured using model performances indicators such as Correlation Coefficient (CC), Normalized Root Mean Square Error (NRMSE), Nash Sutcliffe Error (NSE), and Normalized Mean Bias (NMB). The predicted results of both the models are compared with each other and also compared with measured scour depth. The study concludes that the proposed PSO-ANN model is suitable to estimate the scour depth in both the cases for circular and rectangular pier shapes.

The impact of cables on local scouring of bridge piers using experimental study and ANN, ANFIS algorithms

“…The results showed that the model produced estimates of scour equilibrium depth with many fewer constants compared to the hidden layer of neural networks. Sreedhara et al (2019) investigated the prediction of scour depths near a pier bridge by a swarming group of bees based on a neural network and found that for clear water conditions, the PSO-ANN model method outperforms the artificial neural network model. Azmatullah (2012) examined gene expression programming to estimate scour depth downstream of sills.…”