Helical pile is a pile foundation structure that is widely used in various environments. Mainly used in:

1. Construction engineering: Screw piles have a wide range of applications in construction engineering. They can be used to enhance the foundation stability of buildings, increase load-bearing capacity, and reduce soil liquefaction. Screw piles are particularly suitable for working with weak foundations, such as sand and clay.

2. Road works: Screw piles can be used to stabilize the roadbed of the road, especially in mountainous areas or areas with poor ground conditions. They are able to provide better support and reduce soil slippage and settlement, thereby improving the safety and longevity of the road.

3. Hydraulic engineering: In hydraulic engineering, screw piles can be used to strengthen the stability of river banks, prevent river erosion, and protect embankments and flood control facilities. They can also be used in the infrastructure of hydraulic buildings, such as sluices and pumping stations.

4. Bridge engineering: In bridge engineering, screw piles can be used as supporting structures to provide a stable foundation for the bridge. They can be used to fix piers, support the bridge deck, and improve the overall stability of the bridge.

5. Underground engineering: In underground engineering, screw piles can be used to reinforce the surrounding rock of tunnels and underground caverns to improve their stability. They can also be used to prevent problems such as landslides and soil liquefaction.

6. Environmental protection engineering: Screw piles also have an important application in environmental protection engineering. They can be used to prevent soil erosion and landslides, and to protect vegetation and the ecological environment. At the same time, the construction of screw piles has less impact on the environment, which is conducive to environmental protection and sustainable development.

In general, screw piles have a wide range of applications and can play an important role in various geological conditions and engineering projects. However, in practice, design and construction need to be carried out on a case-by-case basis to ensure the best results and safety.