Evaluation of soil improvement methods with the help of numerical analysis

During earthquakes, liquefaction-induced damages may occur in areas where there are loose-soft alluvial soils. Soil improvement applications may be required in these regions. In this study, the liquefaction potential of Adapazarı soils of alluvial origin was evaluated by different methods in a typical cross section and the effect of the improvement method was examined. Jet grout application has been selected as the improvement method against liquefaction in the soil section with high liquefaction potential. Besides the classical analysis of liquefaction, numerical analysis was performed by modeling natural soil, structure and jet-grout columns with UBC3D-PLM model in Plaxis 2D software. In order to see the liquefaction and the change in the cavity water pressure in the Plaxis 2D program, analysis was performed using the UBCSAND model. The behavior of the ground profile under earthquake load, determined by mentioning the material parameters and calibration stages to be used in the UBCSAND model, has been calibrated to exhibit a behavior that is close to reality in the numerical model. The building in the created model consists of 4 soils and a basement.the building, which is 10 meters wide and 15 meters high, is built on a loose sand with a high probability of liquefaction. The 1999 Marmara Earthquake was used as earthquake data. The model solution consists of five stages. The acceleration time changes obtained as a result of the analyses performed at the points determined in the cross section were compared with the 1999 Marmara Earthquake acceleration data. The results obtained in the UBC3D-PLM model showed acceleration-time behavior similar to the results of earthquake movement. When the maximum acceleration values were examined at some of the analysis points in question, it was observed that the analysis acceleration changes were up to 65% higher than the earthquake input. When the displacement-time changes were examined, it was observed that the improvement reduced the horizontal displacements by up to 59%. Improvement of pore water pressure variation over time is examined in the absence of pore water pressure and total stress reaches the scene of liquefaction in the case where the total stress pore water pressure are made to improve the liquefaction was observed that reached passed in front of.