(01) It avoids the phenomenon of concrete piping in adjacent holes that easily occurs when super-retarding concrete secant piles complete the cutting and interlocking process; at the same time, since conventional concrete is used, the requirements for concrete are reduced and costs are saved.

(02) Because the hard-cutting process is adopted, the drawback of being unable to carry out the interlocking construction of Pile B due to excessively long pile-forming time of a single pile and excessively high concrete strength of Pile A will not occur.

(03) When encountering relatively hard large-area underground obstacles, the full-rotation drilling rig can directly remove underground rock layers and obstacles during pile formation, achieving one-pass pile formation.

(04) The full-casing full-rotation drilling rig itself has a water-stop and wall-protection function, requiring no additional wall-protection measures; it is an energy-saving and environmentally friendly construction process.

(05) According to the grab bucket's soil extraction depth, the soil layers can be accurately distinguished and a suitable pile-end bearing layer can be selected.

(06) The soil extracted from the hole has low water content, is convenient for outward transport, and there is no concern about mud polluting the environment; the construction site is clean and civilized, making it extremely suitable for construction within urban areas.

(07) Settlement and displacement are easy to control, enabling construction adjacent to nearby buildings and underground pipelines.

(08) The full-rotation follow-up casing drilling and other excavation methods effectively prevent quicksand and mud surges in the hole, and can also perform rock socketing, ensuring pile quality.

(09) The second-constructed pile performs cutting and interlocking between the two already-completed first piles; the full-casing hole protection method ensures tight interlocking between piles, with the pile concrete setting into one body to form a good, integral continuous structure.

(10) The reinforcement ratio is relatively low, because bored secant piles can adopt an arrangement in which reinforced concrete piles and plain concrete piles are arranged alternately;

(11) The seepage resistance is stronger, because bored secant piles are constructed continuously, with no construction joints between piles, whereas the construction joints at the panel joints of diaphragm walls are often the weak points for seepage prevention;

(12) Construction is flexible, because during the construction of bored secant piles, the line can be turned and changed as needed, making it more suitable for constructing foundation pits with geometrically varied plan shapes or various arc shapes.