The effects of impact loading on integral barrier-retaining wall system

An integral barrier-retaining wall system is a reinforced concrete retaining wall with a fully integrated traffic barrier. When a vehicle hits the barrier, this collision impact must be resisted by the barrier, the retaining wall and the soil foundation. In fact, the vehicle collision is a very short transient dynamic loading over a small impact zone. However, for geotechnical design, when considering stability of the whole system, the establishment of equivalent uniformly distributed loads for the plane-strain case is perhaps more important than the ultimate dynamic loading. To obtain these equivalent loads, it is essential to understand fundamentally how the impact loading transmits/ram the impact point and time to the broader structure. Hence, in this paper, a full-scale Test Level 4 (TL-4, corresponding to regular traffic in AS5100.2) vehicle crash test on a 3-m-high concrete retaining wall integrated with a 1.2-m-high traffic barrier was performed numerically and the effects of the impact loading on such integral barrier-retaining wall system were studied. The magnitude and duration of the impact loading from vehicle collision were obtained from the model. An influence length, which is used to establish equivalent uniformly distributed loads, has been discussed. According to the numerical results, the maximum loads in the transverse, longitudinal and vertical (downwards) directions are 2 79. 65 kN, 7 8.44 kN and 71. 04 kN, respectively. These forces correspond to the design loads specified in AS 5100.2:2004.