Comparison of Seismic Performance of High Modulus Columns in Liquefiable Soils

Abstract

In this study, a series of numerical studies were carried out to compare the seismic performance of columns that have different rigidity in liquefaction mitigation. For this purpose, experimental results of two dynamic centrifuge test models were investigated through numerical analysis using an effective stress based model UBC3D-PLM. In order to evaluate the performance and effectiveness of columns that have different rigidity on the reduction of liquefaction risk, test models improved with stiff granular columns and soil-cement columns were analyzed numerically. The results of the numerical analysis were evaluated by going through the shear stress sharing mechanism that generate between granular column, soil-cement column, and surrounding liquefiable soil. For this purpose, shear stress reduction factor (K-G) and the ratio of shear strain (gamma(r)) were computed and the obtained numerical results showed that high modulus columns did not reduce seismic shear stress in the surrounding soils and the shear strain ratio between soil and column was found less than 1.0 which stands in for the shear strain compatibility assumption.