Bearing capacity attenuation and energy response of end-anchored bodies under dynamic disturbance with different frequencies.

Dynamic disturbances significantly impact the stability of end-anchored systems, yet their bearing capacity attenuation and energy response evolution remain poorly understood. This study investigated sandstone end-anchored specimens with anchorage lengths of 300 mm and 600 mm. By conducting comparative static pull-out tests and pull-out tests following sinusoidal cyclic disturbances via a custom-designed apparatus, coupled with Particle Flow Code 2D (PFC2D) numerical simulations, the capacity attenuation, energy dissipation, and internal damage evolution were analyzed. Results reveal a negative correlation between bearing capacity and disturbance frequency. Low-frequency (10 Hz) disturbances cause severe damage, triggering extensive interfacial debonding, whereas 50-200 Hz disturbances induce highly localized damage. The failure process involves elastic, slip, debonding-slip, and complete detachment stages, governed by a tensile-shear mode. This is characterized by axial debonding along the cable-anchoring agent interface and radial or oblique tensile micro-cracking within the anchoring agent. Low-frequency energy propagates efficiently over long distances and continuously accumulates, whereas high-frequency energy dissipates rapidly. Furthermore, extending the anchorage length to 600 mm effectively enhances system rigidity and dynamic resistance. Numerical simulations confirm that lower frequencies accelerate tensile crack development, exacerbating internal damage and capacity degradation.