Application of Long-Short Term Memory and Convolutional Neural Networks for Real-Time Bridge Scour Prediction

TL;DR

This study evaluates deep learning models, specifically LSTM and CNN, for real-time prediction of bridge scour depth using sensor data, demonstrating their effectiveness and computational efficiency in diverse geological settings.

Contribution

The paper introduces the application of LSTM and CNN models for real-time scour prediction, including innovative hyperparameter tuning methods and feature analysis, advancing predictive capabilities in civil engineering.

Findings

LSTM achieved MAE of 0.1m to 0.5m for weekly predictions.

FCN outperformed other CNNs with lower computational costs.

Feature analysis highlighted the importance of historical scour data.

Abstract

Scour around bridge piers is a critical challenge for infrastructures around the world. In the absence of analytical models and due to the complexity of the scour process, it is difficult for current empirical methods to achieve accurate predictions. In this paper, we exploit the power of deep learning algorithms to forecast the scour depth variations around bridge piers based on historical sensor monitoring data, including riverbed elevation, flow elevation, and flow velocity. We investigated the performance of Long Short-Term Memory (LSTM) and Convolutional Neural Network (CNN) models for real-time scour forecasting using data collected from bridges in Alaska and Oregon from 2006 to 2021. The LSTM models achieved mean absolute error (MAE) ranging from 0.1m to 0.5m for predicting bed level variations a week in advance, showing a reasonable performance. The Fully Convolutional Network (FCN) variant of CNN outperformed other CNN configurations, showing a comparable performance to LSTMs with significantly lower computational costs. We explored various innovative random-search heuristics for hyperparameter tuning and model optimisation which resulted in reduced computational cost compared to grid-search method. The impact of different combinations of sensor features on scour prediction showed the significance of the historical time series of scour for predicting upcoming events. Overall, this study provides a greater understanding of the potential of Deep Learning algorithms for real-time scour prediction and early warning for bridges with distinct geology, geomorphology and flow characteristics.