Anchoring performance of a novel two-section pressure-tension composite anchor for earthen sites conservation

Anchorage is the key technique to ensure the structural stability of earthen sites. However, the traditional anchor often fails to fully utilize the interfacial bond strengths, and may cause cracking damage, and not align with the “minimal intervention” principle. This study proposes an innovative two-section pressure-tension composite (P-T type) anchor. Pull-out tests were conducted to compare the anchoring performance of Tension type, Pressure type, P-T type anchor. The influence of the proportion of pressure section length (PPSL) on failure modes, bearing efficiency, and interfacial stress evolution was investigated. Finally, two improvement strategies of the P-T type anchor are proposed. The results indicate that bearing capacity shows a significant positive linear correlation with PPSL, which can provide superior anchoring forces with reduced anchorage lengths. However, higher PPSL is prone to cause cracking damage. It is therefore necessary to achieve an equilibrium between anchoring forces and site damage.