Asked in US Civil WarCivil EngineeringThe Difference Between
What is the difference between ultimate and serviceability limit states in civil engineering?
February 17, 2010 9:18AM
The serviceability limit state is the point where a structure can no longer be used for it's intended purpose but would still be structurally sound. The tolerances for serviceability depend on the intended use of the structure and can vary significantly.
For example machine foundations often have extremely small tolerances for differential settlement which if it occurred would render the machines unusable (without causing any damage), whereas the same level of differential settlement on a road or embankment would have virtually no effect on its use.
The ultimate limit state is reached when the applied stresses actually exceed the strength of the structure or structural elements causing it to fail or collapse.