How are ground anchors designed and tested?

Ground anchor design involves: (1) Estimating ultimate bond stress in anchor zone (empirical correlations with soil type, SPT, or pressuremeter), (2) Calculating required anchor length for working load with FOS 2.0-2.5, (3) Selecting tendon size (strand or bar) for structural capacity, (4) Determining unbonded length for movement and corrosion protection, (5) Testing: proof test (1.33x design), performance test (with creep measurement at 1.5x), extended creep test for critical anchors. Post-tensioned anchors include long-term monitoring and re-stressing provisions.