Auger Stall and Hole Sloughing in Gravel Fill
A crew is boring a 9 ft deep, 24 in diameter hole for a 45 ft pole in compacted gravel fill over clay. The utility locate is current and marks an 8 in water main 9 ft away. At 6 ft depth, the auger stalls and the boom gives a slight kick; the operator increases down pressure and reverses the auger while a ground hand stands near the spoil pile. The spoil pile is within 2 ft of the hole edge, and the hole has begun to slough near the top. The operator wants to use the boom to pry the auger sideways to free it, then continue boring without repositioning. The crew is working in a residential backyard with a fence 10 ft from the hole.
1. What should the operator do immediately after the stall and boom kick?
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Stop applying down pressure and stop rotation. A stall plus a boom kick can mean the auger hit a rock, a root, or a utility, or that the auger is binding in the hole. Reversing immediately while the auger is loaded can unload suddenly and drop spoil or damage the auger, so first raise the auger slightly to relieve torque and see whether the boom settles. Keep the ground hand away from the hole and spoil pile. Check the utility locate and the water main location; the mark is 9 ft away, but the auger diameter and spoil placement still matter. Do not use the boom to pry the auger sideways. Side loading the boom or auger can bend the flighting, damage the Kelly bar, or cause a sudden release. Assess the obstruction before restarting.
2. Which practices in the setup are unsafe, and what corrections are needed?
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The spoil pile within 2 ft of the hole edge is too close; spoil should be moved back so it does not load the hole edge or fall back in. The ground hand standing near the spoil pile during a stall is exposed to falling spoil, auger kickback, and hole collapse. The operator's plan to pry sideways with the boom is unsafe because digger derrick booms and augers are not designed for side loading. The sloughing at the top indicates the hole is unstable; continuing to bore without controlling the caving can enlarge the hole and undermine the outrigger or fence area. Corrections include moving spoil at least several feet back, barricading the hole, keeping personnel outside the swing and collapse zone, reducing down pressure, and using a shorter auger section or casing if the hole must be stabilized.
3. If the auger cannot be freed by controlled raising and rotating, what should the crew do next?
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Stop and reassess rather than increasing force. Confirm the auger is not tangled in a utility or obstruction, and check whether the hole is caving around the flighting. If the auger is bound by soil, try controlled rotation with the auger slightly raised, but do not pry with the boom or jerk the load. If it remains stuck, the crew may need to excavate around the auger by hand with proper protection, use a larger machine or extraction tool, or abandon and relocate the hole after approval. Because the hole is already sloughing, do not send a worker into it. Protect the opening, keep the area barricaded, and notify the supervisor. The pole setting should not proceed until the hole is stable and the auger is recovered safely.