V shaped gully method for controlling rockfall on high-steep slopes in China

Large, deep open-pit mining projects lead to rockfall, which becomes an engineering hazard second only to slope stability. The V shaped gully (V-gully) method introduced here was shown to have a significant effect on preventing rockfall through reduction of kinetic energy and rainfall discharge. The method, where a gravel cushion was laid on the V-gully surface, was applied in a typical open-pit mine. A drain dyke should be set at the bottom of the V-gully to discharge rainfall effectively. The slope stability analysis under different drainage rates was calculated by Modified Sarma (MSARMA) software. Slope stability, engineering activities and weathering condition of slope were taken into account to identify the rockfall prone areas. RocFall numerical software was used to calculate the effect of various angle V-gullies on the movements of various rockfall. A striking reduction in kinetic energy of rockfall was achieved, and the effects of V-gully protective measures were studied. Then, a system for controlling rockfall effectively and economically was designed for a particular slope according to the field situation. The effectiveness and reasonableness of design were evaluated through numerical simulations and field testing. This paper provides a theoretical and practical basis for a novel rockfall prevention technique on the high-steep slopes in similar engineering projects.