Design, Construction and Monitoring of a Permanent Soil-Nailed Wall in Karstic Limestone, and its Performance During the 2023 Kahramanmaras Earthquakes-PPT Presentation

PPT Presentation

Pdf Summary

The presentation describes the design, construction, monitoring and earthquake performance of a permanent soil-nailed wall in weak, highly variable karstic limestone at a large residential development in southeastern Türkiye. The wall retained heights of up to 15.5 m beside roads and nearby tower foundations.<br /><br />Extensive ground investigation—including 93 boreholes, pressuremeter and laboratory testing, and geophysics—identified fractured, weathered limestone with dissolution cavities and locally variable strength. Design parameters were based on rock-mass behaviour rather than intact rock strength, using several independent methods and conservative assumptions.<br /><br />The system used corrosion-protected, encapsulated reinforcing-bar nails, temporary shotcrete facing and a permanent reinforced-concrete facing. A conservative ultimate grout-to-ground bond resistance of 200 kPa was adopted and checked through field pull-out testing. Stability and deformation were assessed using limit-equilibrium and finite-element analyses. Predicted movements at critical sections were generally about 8–15 mm. Eight inclinometers recorded movements consistent with predictions, which stabilised after construction.<br /><br />The wall was subsequently exposed to the February 2023 Kahramanmaraş earthquake sequence, including the Mw 7.8 and Mw 7.5 events. At a nearby matched rock station, recorded shaking was approximately 0.16 g—close to the project’s 0.20 g design peak ground acceleration and above its adopted pseudo-static coefficient. Post-earthquake inspection found no observable structural damage, cracking or spalling, and no serviceability problems.<br /><br />The presentation attributes this performance to intensive investigation of karst variability, conservative and verified nail bond design, staged construction, monitoring, robust detailing, and the flexibility and redundancy of the soil-nailed system. It concludes that permanent soil-nailed walls can be viable in weak karstic rock when design assumptions are verified through testing, construction records, monitoring and post-event assessment.

Keywords

soil-nailed wall

karstic limestone

earthquake performance

Türkiye

ground investigation

pressuremeter testing

reinforced-concrete facing

pull-out testing

inclinometer monitoring

pseudo-static design