Field Observation of Structures Damaged by Settlement

Settlement affects many structures and is usually the result of factors involving incorrect design and changed physical conditions caused by nature or the acts of man, or both. There are no formulas or rules that can define when the settlement reaches an intolerable limit as proven by the example of a silo that collapsed after a differential settlement of 2 in. as compared to public buildings that are useful after gross settlements of several feet and differential settlements of as much as 15 in. The use to which a structure is put is a factor in that structures housing special equipment can become obsolete after settlements of a fraction of an inch even though there is little structural damage. In almost all cases, the settlement can be arrested and the damage repaired by employing experienced qualified firms to plan the repairs and perform the work.