Advanced Design Method for Failure Control in Column‐Drilled Shaft Sockets: A Combined Experimental and Numerical Study

ABSTRACT Socket connections play a pivotal role in accelerating construction and improving bridges’ resilience in seismic‐prone regions. However, current design guidelines for reinforced concrete (RC) column‐drilled shaft socket connections (CDSSCs) may inadequately account for the required shaft transverse reinforcement (STR). This study proposes an improved design method to estimate the hoop tension demand and capacity of shafts and determine the optimal spacing of STR. The proposed method is validated through quasi‐static cyclic tests conducted on five CDSSCs with varying axial loads and column configurations. The tests highlighted different failure modes, including plastic hinges at the column bases, severe shaft cracking, debonding at the shaft‐steel corrugated tube interface, and eventual shaft failure. The study further highlighted the response of CDSSCs by analyzing the deformation patterns, hysteretic behavior, and shaft reinforcement strains. Finite element (FE) models were developed in ABAQUS to replicate the experimental results, including force‐drift responses, local responses, and failure modes. The validated ABAQUS models were used to perform a numerical parametric analysis by varying the STR spacing. For increasing STR spacings, the failure mode of the CDSSC progressively transitions from column to shaft failure, while the force transfer mechanism transitions from bending‐dominated action to prying‐dominated action. The results confirmed the effectiveness of the proposed method in controlling the failure modes of CDSSCs and designing the STR spacing.