Experimental research on treatment of silty-fine sand foundation with impaction and grind method (IGM)

Based on a coastal tourism highway of Hainan Province, an experimental research was made into the treatment of silty-fine sand foundation with impaction and grind method (IGM). In-situ tests (SPTs, DPTs), compaction test, deflection test and real-time monitoring data of groundwater level, pore water pressure and surface settlement were adopted to discuss the effectiveness and construction technology of the silty-fine sand foundation with the impact roller compaction method. The results show that the key to an effective treatment of silty-fine sand foundation with impaction and grind method is to take the excess pore water pressure dissipation rate at least 70% in saturated silty-fine sand shallow foundation as the control standard of next round of the impact roller compaction. The reasonable construction technology not only can effectively improve the strength of silty-fine sand foundation, but also can eliminate liquefaction shallow silty-fine sand foundation. After the treatment, the subsoil up to the depth of 2 m is well improved.