Dynamic response of a double-lined shield tunnel to train impact loads

摘要

A three-dimensional numerical finite element model was established by Abaqus to study the time history curves of train-to-tunnel impact forces for impacts at different velocities, train configurations and oblique-impact angles. A concrete plastic-damage model was used to study the dynamic responses of a double-lined shield tunnel to train impacts by the HI-IT time-integration scheme. Model simulations showed that the impact force was related to the velocity and angle of the train at impact, as well as the train configuration. Two categories of characteristic force vs. time curve were found for the train-to tunnel impact, and multi-peak Gaussian fitting was used to interpret the first category. The dynamic response increases with greater impact velocity and impact angle, while it greatly reduces when the thickness of the secondary lining is increased. Most of the tensile damage was seen ahead of the impact point (in the direction of travel), and compressive damage was concentrated behind, above and below the impact point. The average maximum tensile damage was found to exceed the compressive damage. (C) 2015 Elsevier Ltd. All rights reserved.