Safety Focus of the Week: Planning the Excavation (Revisited)
Planning is essential to the safety and success of all aspects of our work, including excavations. The first step is the Dig-Safe process that we discussed last week. Then the crew needs to plan for the excavation:
- Assess the following:
- Underground utility locations and depths; confirm by potholing
- Overhead wires and other clearance restrictions
- Adjacent structures that could be affected by excavation and dewatering
- Plan the excavation dimensions (Length x Width x Depth)
- Plan for dewatering and discharge
- Consider potential for boulders, bedrock, contamination, abandoned structures, etc.
- Layout limits of excavation to include trenchbox and/or slopes
- Select proper sized excavator and support equipment; Consider:
- Lifting and reach requirements for a trenchbox
- Clearance for overhead wires and obstructions
- Horizontal clearances; smaller excavator or backhoe boom?
- Plan for limitations on reach of equipment and stockpiling spoil
- Plan for trenchbox assembly
- Provide ladder(s) and consider excavation egress
- Plan for securing the excavation from traffic and pedestrians during the work and after hours
- Consider fall protection for workers
- Plan for access for and delivery of pipe, backfill, etc.
- Expect the unexpected.