Comparison of CN Values between SNI 4153:2008 with Other Methods in Standard Penetration Test

This study investigates the variability of overburden pressure correction factors (CN) derived from SNI 4153:2008 and six widely used international methods based on Standard Penetration Test (SPT) data obtained from three investigation points. The objective is to evaluate how differences in CN values influence bearing capacity and settlement analyses for building foundations. The results reveal substantial variation among the correction methods, with CN values increasing from Peck et al. (1975) to Liao and Whitman (1986). The SNI 4153:2008 method consistently produces moderate CN values, positioned between conservative and aggressive correction schemes. Higher CN values lead to increased estimated bearing capacity but tend to underestimate soil settlement due to overestimation of stiffness. Conversely, lower CN values yield more conservative bearing capacity and larger settlement predictions. The findings demonstrate that SNI 4153:2008 provides a balanced correction approach, producing reliable bearing capacity estimates while maintaining realistic settlement predictions. This balance supports its applicability as a national standard aligned with contemporary international geotechnical design practice.