9th International Black Sea Coastline Countries Scientific Research Conference, Ankara, Turkey, 10 - 11 August 2023, pp.176-183
The characteristics of peaty soils that are widely recognized include their high
compressibility and poor shear strength. The construction of any structure on these
cohesive soils requires careful consideration of stability and settlement, giving rise to
significant challenges. Geotechnical engineers have developed various strategies to
address these challenges in the past decade. These solutions encompass applications of
some remedial techniques such as vertical drains, preloading techniques, geosynthetics,
concrete piles, deep mixing columns, stone columns, and jet grout columns (JGC).
Contemporary
advancements in construction technology have led to significant progress
in enhancing the quality of soft soil. One such technique that has gained significant
popularity is jet grouting, which proves to be economically viable, technically efficient,
and widely adopted for reinforcing peaty soil. The structures constructed within the
boundaries of Kayseri Free Zone have encountered settlement issues attributed to the
presence of peat and organic soil layers. This study aims to examine the impact of
spacing between JGCs (Jet grout columns) on the performance of organic soil. The
researchers designed a square steel box to conduct undisturbed soil sampling and model
tests. The settlement of peat improved with end-bearing JGC was assessed using finite
element method (FEM), employing PLAXIS 3D software. A rigid-square plate was
subjected to vertical stress to simulate a single footing. The Mohr-Coulomb model was
applied in the analysis of JGC, whereas the soft soil model was employed to capture the
behavior of peat in the finite element simulation. The study's findings illustrated that the
improved soil showed a significant increase in bearing capacity, ranging from 3.5 to 4.0
times greater than its initial state. Furthermore, the settlement values obtained from the
software simulations were comparable to those observed in physical model tests.