1. Construction should preferably use soft-cutting full-casing drilling rigs.
2. For full-casing bored secant pile construction in sandy soil, corresponding technical measures to overcome sand piping should be adopted according to different piping conditions, and the dynamics of groundwater in the hole and the sand layer being crossed should be observed at all times; operations should follow the principle of taking less soil and pressing in more to ensure the casing stays ahead.
3. The bottom edge of the casing should always remain at least 2.5 m ahead of the excavation face. When the casing bottom cannot stay ahead, water may be injected into the casing to balance the pressure of the first-sequence pile concrete and prevent piping.