Dynamic responses of highway bridge subjected to heavy truck impact

Abstract

This study aims to numerically analyze the dynamic responses and damage/failure of bridge substructure during the vehicle-pier collisions, by employing the refined finite element (FE) models of a heavy truck and a simply-supported prototype highway bridge. Firstly, the adopted numerical algorithm and material model parameters to capture both the flexural and shear failures are validated through the simulations of two lateral flexible impactor crash tests. Then, the full-scale FE model of a typical four-span reinforced concrete (RC) bridge with two-pier bents is established, and a high-fidelity heavy truck FE model established previously is improved and further certified by comparisons with the eccentric and aligned full-scale crash test data. Furthermore, a series of numerical simulations are conducted to examine the heavy truck collision process and analyze the failure modes of bridge structure, as well as the parametric influences, including truck mass, impact velocity, and impact angle. Finally, the linear relationships of initial engine momentum, maximal vehicular impact force, 25-ms moving average, sectional force, and lateral displacement are proposed. It indicates that, (i) compared with the *MAT_CONCRETE_DAMAGE_REL3 and *MAT_WINFRITH_CONCRETE, *MAT_ CSCM_CONCRETE can well depict the flexural and shear failure modes of the pier subjected to heavy truck impact in actual accidents; (ii) the ultimate failure of the impacted pier is mainly caused by the impact of the cargo rather than the engine in the heavy truck; (iii) the impact angle significantly amplifies the possibilities of the T-girder falling off and the failure of bent cap, increasing the potential risk of overall collapse of the bridge superstructure.