Evaluation of Effectiveness of Ground Improvement for Liquefiable Deposits by Vibro-compaction from CPTU Data

Vibro-compaction is a new method for liquefaction ground treatment in China. To evaluate the geotechnical characterization of liquefaction foundation improved by the vibro-compaction, a series of field tests including piezocone penetration tests （CPTU） were performed before and after ground treatment in the construction activity of highway in Suqian, China. According to critical state theory, an approach to evaluate the improvement level in liquefiable soils treated by vibro-compaction was developed on the basis of the state parameter (Ψ) of sand soils. Some meaningful results were obtained through analyzing relative density (Dr), state parameter (Ψ), factor of safety (Fs) and probability of liquefaction （PL） before and after vibro-compaction. The high consistency of liquefaction evaluations indicate that the vibro-compaction could be used for ground improvement needed to mitigate liquefaction.