Rockfall protection wall that can withstand multiple strikes without needing to be repaired

Abstract

In a hilly and congested urban environment, use of reinforced concrete barrier for hillslope protection is common. With some of these barriers, a layer of gabion is placed in front of the barrier to provide additional protection to avoid localised failure caused to the concrete surface as direct contact is made with a fallen boulder. In addition, the layer of gabion would also function as cushion which mitigates the transfer of momentum to the barrier wall behind it causing bending to occur. There has only been one study that targeted at modelling this cushioning mechanism, but it has only dealt with single boulder strike scenarios. Other studies on impact on gabions did not deal with momentum transfer, though they did investigate the effect of reducing the transmitted force and energy dissipation. This study presents a new design procedure which accounts for the cushioning mechanism of the gabion in multiple strike scenarios. Full-scale pendulum tests were conducted on a reinforced concrete barrier specimen which was fitted with a layer of gabions for validating the accuracy of the proposed predictive model. The design of a rockfall barrier wall taking into account multiple strike scenarios can significantly reduce the costs of maintaining reinforced concrete rockfall barriers during its service life.