Akademik Veri Yönetim Sistemi
Soil Dynamics and Earthquake Engineering, cilt.208, 2026 (SCI-Expanded, Scopus)
This study evaluates the instability and associated excessive displacements of reinforced concrete cantilever retaining walls located at the 36th km of the Sürgü-Malatya to Gölbaşı-Adıyaman highway, adjacent to the Göksu River, in southeastern Türkiye. The observed failure was induced by liquefaction of foundation alluvial soils initiated during the February 6, 2023, Pazarcık (Mw = 7.8) and Ekinözü-Elbistan (Mw = 7.7) earthquakes. Surface manifestations of liquefaction, including soil ejecta, excessive ground displacements and deformations, and sliding and rotational failures of the retaining wall segments were documented through post-earthquake reconnaissance. Site investigations involved in-situ testing, including standard penetration test (SPT) and cone penetration test (CPT), and soil sampling. The foundation soil profile consists of a 1-2 m thick loose to medium dense silty sand (SM) layer with an average fines content of approximately 14%, underlain by a thick very dense silty sand layer. Preliminary liquefaction initiation assessments were performed following the probabilistic framework of Moss et al. (2006). Peak ground acceleration (PGAs) at the site were estimated to range between 0.4 to 0.9 g and 0.06 to 0.20 g for the Pazarcık and Ekinözü events, respectively. For the more critical Pazarcık earthquake, the resulting factor of safety (FS) against liquefaction in the critical loose to medium dense silty sand layer ranged between 0.15 to 0.33, consistent with the observed surface manifestations of liquefaction. Lateral ground displacements were estimated using the semi-empirical procedures of Hamada et al. (1986) and Youd et al. (2002), yielding predictions of 51 cm and 886 cm, respectively. These estimates compare reasonably with field-mapped lateral displacements ranging from 105 to 250 cm. Volumetric settlements were evaluated using the procedure of Cetin et al. (2009), predicting approximately 4 to 5 cm, which are lower than the observed values ranging from 10 to 55 cm. The discrepancy is attributed to additional deviatoric (lateral spreading) displacements, which are not captured by volumetric-only settlement models. Back analyses of flow-liquefaction failure mechanisms yielded undrained residual shear strengths ranging from 4 to 11 kPa and representative excess pore water pressure ratios (ru) between 0.72 to 0.92 for rotational failure modes. For translational failures, residual shear strengths and ru values ranged from 4 to 9 kPa and 0.76 to 0.91, respectively. These results fall within the bounds of semi empirical model predictions, which suggest shear strengths of 3 to 43 kPa and ru values between 0.87 to 0.98.