Design of sluice foundation treatment of Xinglong Hydrojunction Project on Hanjiang River

The thickness of the sluice foundation of Xinglong Hydrojunction Project on Hanjiang River, a deep fine sand layer, is 25 m. To solve the liquefaction problem of saturated sand and large settlement of the foundation, the foundation was treated by using cement-soil mixing pile rather than the dynamic consolidation or vibroflotation method through comparison. In the current cases of mixing pile, the viscous soft soil with small frictional resistance are treated; however, the treatment of fine sand layer with large frictional resistance and running groundwater are rare. Therefore, the laboratory experiment and in-situ test of cement-soil mixing pile was conducted, which proved that this mixing pile is suitable for the treatment of the sluice foundation of Xinglong Hydrojunction Project. The piles are arranged in grid with the replacement rate of 20%. The quality of the mixing pile meets the requirement and the deformation monitoring shows that the settlement control meets the design requirement.