Abstract:Vibroflotation compaction is a comparably mature method for the improvement of cohesiveless soils,but it is seldom used to strengthen silty fine sands without additional stone aggregates because of some failure case histories. By means of innovative and modified construction techniques and parameters,the effectiveness of vibroflotation of saturated silty fine sands without additional backfill materials as well as related technical parameters are investigated. The aging effects of strength of sands after vibroflotation are also discussed. The in-situ test results indicate that the densification of silty fine sands have progressed to the state of medium compaction,and even to condense compaction state in some depths. Based on the successful in-situ experiment and large-scale practice of a container terminal in Shanghai,it is verified that vibroflotation compaction without the addition of stones is significantly efficient in strengthening silty fine sands with the new techniques and special construction process.