Analytical Model for Load-Transfer Mechanism of Rock-Socketed Drilled Piles: Considering Bond Strength of the Concrete–Rock Interface

Abstract

The mobilization of side resistance has a significant effect on load-transfer characteristics and the ultimate bearing capacity of rock-socketed piles. A good understanding of the shear mechanism of a concrete–rock interface has a critical part in analytical load-transfer solutions of rock-socketed piles. However, most of the existing analytical solutions have ignored the effect of bond strength, which constrains the concrete–rock interface. The present analytical model is distinguished by adopting a modified shear constitutive law of bonded concrete–rock interface. It also considers the wear model of asperity roughness to calculate the critical shear displacement. The accuracy of the analytical formulation is verified by comparison with field cases. Parameters analysis results indicate that the peak shear stress would be improved due to contact bonding. The residual shear stress displays a marked reduction with increasingly unconfined compressive strength of rock under the condition of bond strength consideration.