Theory 212/Bridges/Threshold lens
Damage Needs a Seizure Threshold
The claim
Structural damage occurs above a threshold in the ratio of restrained movement to joint tolerance, so a seized joint transfers force into the deck.
01Mechanism
A joint that cannot move converts thermal strain into stress; the threshold determines whether the structure can absorb it.
02Prediction
Damage should track the ratio.
03Refutation
Damage tracking temperature would remove restraint.