{
  "schema": "footing-thrust-educational-screen/v1",
  "basis": "Historical preliminary analysis trigger only under adopted equipment/foundation conditions",
  "w": {
    "value": 500,
    "unit": "kN",
    "kind": "hypothetical total weight as force"
  },
  "distribution": {
    "channel_fraction": 0.6,
    "shell_fraction": 0.4,
    "kind": "stated preliminary normal-distribution assumption; not verified all equipment"
  },
  "trigger_fraction": 0.3,
  "results": {
    "channel_supported_kN": 300,
    "shell_supported_kN": 200,
    "channel_screen_kN": 90,
    "shell_screen_kN": 60
  },
  "formula": "F_screen = .30 * alpha * w",
  "limits": [
    "actual distribution/thrust direction/state/load combinations must agree",
    "not contact-friction coefficient",
    "not nozzle/material acceptance",
    "low-friction detail needs independent evaluation, not guaranteed remedy"
  ]
}