G MS THESIS_final version_Maxim Prokudin.pdf - Digital Repository ...

33The load carrying capacity was found to increase from 50 to 75 percent for partiallypenetrated columns and from 150 to 260 percent for fully penetrated columns when the meshwas utilized. The bulging effect of the column was noticed to be primarily within the top 300mm portion of the column. Upon excavation no splitting of the mesh was observed. Thebridge reinforcement was found to perform very well in terms of controlling load carryingcapacity of the column and initial stiffness modulus of the subbase reaction.In spite of the fact that the load transfer mechanism was the same for both the bridgingreinforcement and the concrete plug, the modulus of the subgrade reaction was found to belower for the concrete plug. Overall, the concluding remarks indicate potential forimprovement of peat soil with different types of design modification methods (mesh, rod,etc.). The bridging rod reinforcing method was found to be especially effective, however fullscaletests were suggested to be carried out to supplement the findings.The authors indicated a limited extent to which the tabular mesh could be constructed in thefield conditions. Also bridging reinforcement techniques must be modified in order to besuccessfully implemented in the field.Case 4 – Sivakumar et al., 2004 – Triaxial Tests on Model Sand Columns in Clay (Queen'sUniversity of Belfast, United Kingdom)This research study was completed at Queen's University of Belfast, United Kingdom. Thetesting was performed on compacted moist sand vibro-columns and frozen columns of thesame material. The sand material was categorized as uniformly graded fine crystal sand withd 10 = 0.2 mm and d 60 = 0.27 mm, mixed at 18 percent moisture content. The test soil wasclassified as kaolin soft clay mixed at 105 percent moisture content (1.5 times the liquidlimit) and consolidated to 200 kPa vertical pressure. The undrained shear strength of the claywas evaluated at 30 kPa. The moist sand columns were built at 32 mm in diameter and 80,120, 160, 200 mm in lengths, while the frozen columns were built at 120 mm and 200 mmlengths.