Experimental study on the dynamic behavior of pile-anchor structures under impact loading of debris flow and rockfall

Abstract

The pile-anchor structure is widely used in slope/landslide reinforcement, and is also applicable to debris flow and rockfall barriers in mountainous areas. However, the impact behavior of this structure has not been studied. To promote the use of this retaining structure in the prevention of slope geological disasters, this study investigated the dynamic responses and impact behavior of pile-anchor structures through a set of impact experiments, wherein dry granular materials with different particle size and sliding blocks with different masses were adopted to simulate different impact loading scenarios of granular flow and rockfall. The impact pressure on the pile-anchor structure, the seismic signals induced inside the slope during the sliding and impact processes, and the deformation characteristics and failure modes of the piles and anchors were systematically investigated. The results indicate that the peak impact force and intensity of the seismic signal are affected by the particle size of the impact granular materials. As the impact loading increased, the tensile force of the anchor increased nonlinearly, the distribution pattern of the pile’s impact dynamic moment changed, and anchor prestress loss was observed. The preliminary results obtained by this study are expected to provide the theoretical basis for designing relevant barriers in areas prone to debris flow and rockfall, and promote the inclusivity of the impact behavior of slope retaining structures in existing design codes pertaining to retaining structures.