Numerical analysis of axial load effects on RC bridge columns under blast loading

Abstract

Blast load and its effects on transportation infrastructure especially bridge structures have received considerable attention in recent years. The RC bridge columns are considered as the most critical structural members because their failure leads to collapse of the bridge. Although RC bridge columns are typical axial load-carrying components, the studies on blast-resistant capacity of RC bridge columns usually neglect the axial load effect since it is commonly assumed that neglecting the axial load leads to conservative predictions of column responses. This assumption is true when column failure is governed by flexural response since axial compressive load generates a prestress in column which compensates concrete tensile stress induced by bending response. When subjected to blast loads, column response however could be governed by shear response. In this case neglecting axial loading effect does not necessarily lead to conservative predictions of column responses. In this study, high-fidelity finite element (FE) models for both non-contact explosion and contact explosion were developed in LS-DYNA. The FE models were validated with field blast test data. Subsequently, intensive simulations of the RC bridge columns with and without axial load subjected to a wider range of blast loading scenarios, including far-field, near-field and contact explosion were conducted. The influence of axial load on the dynamic performance of RC bridge columns corresponding to different blast loading scenarios was discussed.

Dynamic Response of a Box Multistage Stiffened Beam under the Coupling of Vehicle Load and Air Blast Load

“…Buildings 2023, 13,2733 that when the blasting distance is 1 m, the critical charge of the box beam in th state is 500 g, and the critical proportional blasting distance is Z0 = 1.26 m/kg 1/3 .…”

“…In recent years, there have been many studies on the maneuverability of such beams in complex environments [7][8][9]. In particular, with the development of computer technology, more and more scholars have begun to use the finite element method to simulate the structural response of bridges, and numerical simulations have also been shown to be effective in predicting structural responses [10][11][12][13].…”

Blast Loaded Columns—State of the Art Review

“…The damage of the columns is shown in Figure 21. Yuan et al [77] investigated the effect of axial load on RC bridge columns subjected to far-field, close-in, and contact explosion. Columns in the far-field have mainly a flexure response, and the axial load affects the reduction in the maximum displacement in the middle of the column.…”

Comparative nonlinear seismic analysis of an existing RC bridge designed with obsolete codes

“…In contrast, an explicit integration scheme offers advantages over traditional finite element solvers by avoiding numerical deadlocks due to convergence problems. Explicit models have been widely used for bridges subjected to impact (Do et al, 2019; Tran, 2009) or blast loadings (Yuan et al, 2017, 2021), whose duration is very short compared to earthquakes. Seismic analysis of structures through explicit modeling is less frequent.…”