Effects of Operating Parameters of the NSV System on Field Soilcrete Characteristics in the Mekong Delta, Vietnam

Unconfined compressive strength (UCS) and uniformity of soilcrete are strongly influenced by deep mixing equipment and its operating parameters. Soil cement mixing was applied to reinforce the two sections of earth levees (1) 60 m long in An Giang and (2) 30 m long in Dong Thap using a mini light-weight soil-cement wet mixing system, named as a NSV system. Core boring was employed to take field soilcrete samples and UCS tests were conducted to investigate soilcrete characteristics. The operating parameters were save in the built-in memory of the NSV system during construction. This paper instigated the proper operating parameters such as mixing energy, penetrating/lifting speeds, rotation speed, and mixing duration to optimize the NSV system for the Mekong Delta conditions. The results indicate that the field soilcrete achieved high UCS and uniformity along soilcrete columns with the mixing time of 800 times/m, mixing duration of 2.5–3.5 min/m, rod rotations of 40–50 times/m (penetration) and 70–80 times/m (lift), penetrating speed of 0.5 m/min and lifting speed of 1.2 m/min.