Mechanical characterization of dry-stone walls for terraced slopes stability assessment

Mediterranean terraced slopes, commonly characterized by dry-stone walls, are often affected by instabilities. This study aims to develop a methodology for parametrizing the mechan-ical behavior of dry-stone walls for stability analyses and test it on a terraced vineyard in the Troodos Mountains (Cyprus). Dry-stone walls were characterized by treating them as frac-tured rock masses and applying an adapted version of the Geological Strength Index (GSI) classification. This approach focused on both the rock mass structure (i.e., the dry-stone wall, considering stones interlocking and wall homogeneity) and the conditions of discontinuities (i.e., stones surfaces, evaluating Joint Roughness Coefficient - JRC, weathering, in-filling material and Joint Wall Compressive Strength - JCS). GSI values were translated into Mohr-Coulomb strength pa-rameters; laboratory analyses characterized backfill soils (tex-ture, bulk density, shear strength). Stability was assessed us-ing limit equilibrium numerical analyses. Field-based geome-chanical characterization identified walls in good and poor condition. The former exhibited higher structural integrity and better surface conditions, with a mean JCS of 151 MPa com-pared to 142 MPa. Good-condition walls also had larger stone mean front surface areas than poor-condition ones (313 cm2 compared to 187 cm2). Stability analyses showed that good-condition walls favor stability for gentler slopes (≈ 20°) under saturated conditions, while poor-condition walls result in in-stability. Additionally, terraces with high riser (>= 2.0 m) and steep slopes (>= 50°) showed instability even when completely dry. These failure surfaces did not involve walls, suggesting that such terrace geometries are inappropriate for the local conditions.