Improvement of Organic Soil Using Jet Grout Columns

The characteristics of peaty soils that are widely recognized include their high compressibility and poor shear strength. The construction of any structure on thesecohesive soils requires careful consideration of stability and settlement, giving rise tosignificant challenges. Geotechnical engineers have developed various strategies toaddress these challenges in the past decade. These solutions encompass applications ofsome remedial techniques such as vertical drains, preloading techniques, geosynthetics,concrete piles, deep mixing columns, stone columns, and jet grout columns (JGC).Contemporaryadvancements in construction technology have led to significant progressin enhancing the quality of soft soil. One such technique that has gained significantpopularity is jet grouting, which proves to be economically viable, technically efficient,and widely adopted for reinforcing peaty soil. The structures constructed within theboundaries of Kayseri Free Zone have encountered settlement issues attributed to thepresence of peat and organic soil layers. This study aims to examine the impact ofspacing between JGCs (Jet grout columns) on the performance of organic soil. Theresearchers designed a square steel box to conduct undisturbed soil sampling and modeltests. The settlement of peat improved with end-bearing JGC was assessed using finiteelement method (FEM), employing PLAXIS 3D software. A rigid-square plate wassubjected to vertical stress to simulate a single footing. The Mohr-Coulomb model wasapplied in the analysis of JGC, whereas the soft soil model was employed to capture thebehavior of peat in the finite element simulation. The study's findings illustrated that theimproved soil showed a significant increase in bearing capacity, ranging from 3.5 to 4.0times greater than its initial state. Furthermore, the settlement values obtained from thesoftware simulations were comparable to those observed in physical model tests.