Process Parameters of HSCM Pile Formation in Marine Soft Soils

The Helix Stiffened Cement Mixing (HSCM) pile is a composite of a rigid helical pile and a flexible cement soil pile. These two types of piles are constructed simultaneously to form a strong composite pile with complementary enhancement. Based on existing field tests, this paper systematically designs indoor tests for HSCM piles. It considers the effects of rotational speed, drilling speed, grouting water-cement ratio, the number of helical blades, and grouting pressure process parameters, and analyzes their impacts on the pile formation and the strength of the surrounding cement soil. The results show that increasing the rotational speed during HSCM pile formation can substantially improve the uniformity of the surrounding cement soil strength. A significant increase in drilling speed can lead to a decrease in the cement content of the pile, thereby reducing its diameter and strength. The diameter of HSCM piles increases as the water-cement ratio decreases, with the trend slowing when the ratio is less than 0.7. Increasing grouting pressure can significantly increase the diameter of pile formation and the strength of the surrounding cement soil. An appropriate increase in the number of blades can improve the integrity and continuity of the hydromud pile. Additionally, increasing the number of helical blades can enhance the uniformity and integrity of the pile, thereby improving the bearing performance of the pile foundation. This paper provides a parametric design basis for the construction of HSCM piles in marine soft soil sites.