Prediction of hard rock TBM penetration rate using particle swarm optimization

The aim of this study is to predict the performance of tunnel boring machines (TBMS) using particle swarm optimization technique (PSO). With this aim, a database including intact rock parameters comprising of strength and brittleness, and rock mass properties such as distance between planes of weakness and orientation of discontinuities, together with field machine performance data, was established using data collected along a 7.5 km long hard rock mechanical tunnel. The particle swarm optimization technique was applied to develop new predictive model for TBM performance. Seven different PSO models were developed using the assortment of datasets having various percentages of rock type in the dataset. Additionally, the PSO model was developed using the entire dataset in random without paying attention to rock type to generalize the model. As a result of the developed models via a variety of generated testing and training datasets, it is concluded that Model 7 and its resultant equation are the most precise among the seven models tested. (C) 2011 Elsevier Ltd. All rights reserved.