Abstract: At present, the types of supporting soldier piles in excavation support engineering mainly include square and circular soldier piles. Square soldier piles have better stress forms and are more economical, but they need to be formed manually. Circular piles have poor stress forms and are less economical, but they can be mechanically formed. The current policies and regulations have increasingly strict restrictions on manual excavation, which leads to the fact that square piles with better support effects are often unable to be adopted, and circular piles with mechanical boreholes have high support costs due to poor stress distributions, which forms a general demand in support engineering. It is hoped that there is a soldier pile type that meets the safety and convenience of mechanical borehole forming and has high efficiency and economy like square piles. This article innovatively presents a new excavation support concept and method of “mechanical borehole forming oblong-shaped soldier pile” and makes a comparative analysis and research on the section characteristics, support effect and economy of oblong-shaped, square and circular soldier piles. The advantages and disadvantages of the relevant indexes of each soldier pile type are obtained, which provides a theoretical basis for the selection of the optimal support section, saves the support cost, improves the support effect, and increases the construction safety.

Key words: Oblong-Shaped Soldier Pile, Square Soldier Pile, Circular Soldier Pile, Excavation Support