A comprehensive Activity Hazard Analysis (AHA) for steel erection, in accordance with EM 385-1-1, should address several key areas to ensure worker safety. Here's a breakdown of the hazards and control measures to consider:

1. Pre-Erection Planning and Site Conditions:

• Hazards: Unstable ground conditions for cranes, inadequate foundation strength, and lack of proper site-specific erection plans 10, 15.
• Control Measures: Ensure the controlling contractor provides written notification and documentation confirming that concrete footings and mortar have reached the required strength 10, 15. Conduct pre-shift inspections of cranes, checking ground conditions and ensuring the equipment is level 5, 19. Develop a site-specific erection plan addressing the sequence of erection, crane selection and placement, and coordination with other trades 9, 10, 16.

2. Hoisting and Rigging:

• Hazards:吊Loads falling due to improper rigging, crane malfunctions, or failure to use tag lines [1].
• Control Measures: Pre-plan all hoisting operations to ensure compliance with safety requirements 10, 16. Visually inspect cranes before each shift, paying attention to control mechanisms, safety devices, and hydraulic lines 5, 12. Use tag lines to control loads unless a qualified rigger determines they create a greater hazard [1]. Ensure that routes for suspended loads are pre-planned to avoid employees working directly below them, except for those engaged in initial connection or load hooking/unhooking [2].

3. Structural Steel Assembly:

• Hazards: Loss of structural stability during erection, leading to collapses; tripping hazards from shear connectors 7, 8.
• Control Measures: Maintain structural stability throughout the erection process [3]. Install permanent floors as erection progresses, limiting the number of stories between the erection floor and the uppermost permanent floor [3]. Ensure a fully planked or decked floor is maintained within two stories or 30 feet directly under erection work [3]. Prevent tripping hazards by attaching shear connectors after metal decking is installed [4].

4. Fall Protection:

• Hazards: Falls from heights, especially from unprotected sides or edges [5].
• Control Measures: Provide fall protection for employees on walking/working surfaces with unprotected sides or edges more than 15 feet above a lower level, using guardrail systems, safety net systems, personal fall arrest systems, or fall restraint systems [5]. Ensure connectors are protected from fall hazards of more than two stories or 30 feet above a lower level [5]. In Controlled Decking Zones (CDZ), limit access to trained employees engaged in leading-edge work and clearly mark boundaries 6, 20.

5. Falling Object Protection:

• Hazards: Workers being struck by falling tools, equipment, or materials [5].
• Control Measures: Secure all materials, equipment, and tools against accidental displacement when aloft [5]. Bar other construction processes below steel erection unless overhead protection is provided [5].

6. Personal Protective Equipment (PPE):

• Hazards: Injuries due to lack of appropriate PPE [6].
• Control Measures: Personnel employed in steel erection must wear hard hats and protective footwear while on the job site [6]. Gloves, special protective clothing, and respirators should be worn as necessary [6].

7. Miscellaneous Hazards:

• Hazards: Exposure to weather conditions, such as high winds or extreme temperatures.
• Control Measures: Monitor weather conditions and halt operations if conditions become unsafe. Provide adequate shelter and hydration for workers in extreme temperatures.

8. Training and Competency:

• Hazards: Lack of training leading to unsafe practices.
• Control Measures: Ensure all employees, including connectors and those working in CDZs, have completed the necessary training [5]. Maintain records of qualified and competent persons on site [6].

By addressing these hazards and implementing the appropriate control measures, a steel erection project can be executed more safely and efficiently. Regular monitoring and review of the AHA are essential to adapt to changing site conditions and ensure continued safety.