Bridges
- Publication no: ABC2017-099-17
- Published: 26 April 2017
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Roads and Maritime Services of NSW (RMS) design, accept and manage barriers for use on classified roads and bridges. Crash testing of a system of barrier units is infrequently performed due to high costs and a myriad of impact conditions that needs to be considered. The safety of these structural elements can be checked or greatly enhanced by carrying out explicit analysis, taking into account parametric variations in problem definition such as vehicle types, vehicle speed, impact angles and barrier geometry/material composition.
The paper describes the outcome of research work conducted through simulations to evaluate the effect on concrete barrier units subjected to impact from a 2 T truck. Three-dimensional finite element (FE) analyses for a system of barrier units have been carried out using commercial explicit software (MSC.SOL 700) for impact by a Chevrolet 2000 kg truck. As there was an interest in not just the barrier joints but in the behaviour of concrete in the barrier, advanced material models that take into account fracture and failure behaviour in the concrete was adopted. The predicted displacements and the structural behaviour of the vehicle, barrier and the connections for parametric variations in the speed, subgrade modulus and joint configuration are provided in this paper. In addition, checks for fidelity of the model and acceleration, energy and velocity data required for test analyses correlation are also provided. The physical test which was done subsequently showed good correlation in all identified parameters including fracture locations and progressive failure, with predicted deflections being within 10% of observed values.