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Precautions against tilt and shift of well

Short answer

Precautions: prepare a level firm base, build curb and steining truly vertical and symmetric, dredge evenly from centre, apply kentledge symmetrically, check tilt/shift regularly with plumb and levels, use guide frames, remove obstructions, avoid sudden sinking by not dredging far below the cutting edge, and take extra care at the final stage.

List out the precautionary measures that should be taken to prevent tilt and shift of well foundation.

To prevent tilt and shift of a well during sinking, the following precautions are taken.

  1. Level, firm base for sinking: the sand island or ground is made level and firm before the cutting edge is laid.
  2. Accurate construction of curb and steining: the well curb and steining are built truly vertical and symmetrical, with uniform thickness and equal lifts.
  3. Uniform dredging: dredging must be done evenly around the dredge hole, taking out the soil from the centre first and not from the sides.
  4. Even kentledge and loading: load must be placed symmetrically.
  5. Regular checks: check the tilt and shift at least once per shift with a plumb and levels, and keep records of the levels.
  6. Guide frames / dolphins to keep the well in position during the initial sinking.
  7. Obstructions: examine the soil first and remove boulders and tree trunks in advance, using divers and blasting.
  8. Avoid sudden sinking by controlling dredging and not dredging far below the cutting edge.
  9. Extra care in the final stage, when the well reaches the founding level.

✓ Answer checked by Claude Sonnet 5.5

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