Hole shrinkage in expansive soils often appears “necked,” with three-level prevention and control
measures:water well drilling rig
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Prevention stage:
Maintain mud density at 1.15–1.20 during drilling to form a dense mud cake.
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Monitoring stage:
Use a caliper to measure in real time; activate emergency response when shrinkage rate exceeds 5%.
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Treatment stage:
Employ a reaming bit (20mm larger than design diameter) with chemical consolidants.water well drilling rig
Bangxin drilling rig