The effect of soil improvement in limited area on general soil behavior of field

Frequently soil improvement by jet-grout method can be preferred for the insufficient in concerning with behaviors like bearing capacity, settlement and liquefaction phenomenon. The subject of this study is the effect of soil improvement with jet-grout on one-dimensional ground response analysis. For this purpose, a soil improvement with jet-grout method at within about 15 m depth from the foundation base of a structure planned to be built on a thick alluvial deposit was investigated. The thickness of alluvium in the study area is around 150 m. In the study, two one-dimensional soil profiles were formed to represent pre-improvement and post-improvement soils. Then, 12 earthquake acceleration records selected for analysis were applied as input motions at the bedrock level. As a result of the analyses, the spectrums for the soils which unimproved and improved with jet-grout were obtained at the foundation base level and compared. As a result of the comparisons, it was observed that there were somewhat differences in the spectrums determined at the foundation base level. When these observed differences are evaluated in terms of the proposed design spectra for the soil classes in the literature; It was concluded that it would not be appropriate to define as a better soil class in terms of design spectrums in order to the new soil profiles formed after the jet-grout applications.