L1 Effective stress

Effective stress equation

London Basin geology

• previous artesian conditions w/out human activity

• industrial processes pumped water from basin → table became lower than hydrostatic conditions

• processes stopped needing this water but still need to pump this water today (even though it has no use) → low water table = low pore pressure → if we allowed it to increase back to artesian conditions we would produce an effective stress → swelling, loss of strength that was assumed in many designs

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