Hole shrinkage in expansive soils often appears “
necked,”
with three-level prevention and control measures:Plate-forme de forage de puits d’eau
-
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 (20
mm larger than design diameter)
with chemical consolidants.water well drilling rig