<p>Subsoil liquefaction poses a significant risk of catastrophic failure in offshore infrastructure during both construction and service periods. The planned Jintang cross-sea tunnel, spanning the Jintang strait which is a seismically active region, necessitates a thorough evaluation of subsoil liquefaction potential. A series of tests, including piezocone penetration test (CPTU), standard penetration test (SPT), shear wave velocity (<i>V</i>_S) test, and cyclic triaxial test (CTX), were performed to assess the liquefaction resistance (CRR) of the seabed sediments, and the results were compared to determine the relative applicability of each method. The findings reveal discrepancies among the test results; notably, the CPTU-based CRR closely aligns with the CTX-based CRR, while the <i>V</i>s-based CRR for surficial sediments is significantly higher than those obtained from other methods. This phenomenon, referred to as apparent aging, is likely attributable to microstructural formations induced by wave loading and diagenetic processes at the seabed surface. Neglecting the influence of such microstructure may lead to an underestimation of the CRR in surficial soils. Consequently, this study proposes a procedure for identifying the microstructure in seabed soils and introduces a corresponding method for modifying the liquefaction resistance. These findings provide novel insights into offshore liquefaction evaluation in similar sedimentary environments.</p>