Selection of monitoring poles and key points in foundation construction

Pole height selection

Key parameters

• Wall thickness: Commonly used are 3~4mm (low pole) or 4~6mm (high pole). Insufficient wall thickness will cause significant shaking in strong winds. Leading to screen jitter and fatigue breakage.
• Material: Hot-dip galvanized steel pipe is the most common. It is recommended to use 304/316 stainless steel or strengthen anti-corrosion in coastal or chemical industry areas.
• Arm length: Generally 0.5~2.0 meters. The longer the cantilever arm, the higher the requirements for foundation and wall thickness.
• Wind load: Check based on the local basic wind pressure once in 50 years. Coastal and typhoon areas should focus on review.
• Hand holes and cable holes: Hand holes are reserved for inspection, and there is room for internal cables.

Basic construction

1. Foundation size: related to pole height, cantilever arm and soil quality. The common 6-meter pole is 600×600×800mm (length×width×depth), Weak foundations need to be reinforced or piled.
2. Embedded parts: Use anchor bolts + flange connections, and the bolt specifications and burial depths are implemented as designed. Check the positioning dimensions before pouring.
3. Concrete: C25/C30 is commonly used, and it must be cured for no less than 7 days after pouring before pole erection.
4. Grounding: The ground electrode is pre-embedded in the foundation, and the ground resistance meets the design requirements.
5. Drainage: The top surface of the foundation should be 100~150mm higher than the surrounding ground to avoid water accumulation.

Common security risks

• The basic size is reduced based on experience, and the pole tilts or topples after strong winds.
• The position deviation of the embedded bolts is too large and they must be forcibly bent or cut on site.
• The wiring holes are not sealed waterproofly, and rainwater enters the foundation and equipment box along the pipes.
• The equipment box is not fixed or has poor heat dissipation. High temperatures in summer cause the equipment to restart frequently.
• If grounding is not done or the grounding resistance is unqualified, equipment will be damaged in batches during thunderstorms.