71.2 Limit State Design(Design to BS 8110) 1.2.1 Introduction •The design of engineering structures must ensure: oThe structure is safeunder the worstloading. oThe deformation of the members does not detract from the appearance, durability or performance of the structure during normal working conditions. •Design purpose – to achieve acceptable probabilities that a structure will not become unfit for its intended use– i.e., that will not reach a limit state. •Two principal types of limit state: oUltimate limit state−relating to safety: The whole structure or its components should not collapse, overturn or buckle when subjected to design loads. oServiceability limit state- relating to satisfactory performance: The structure should not become unfit for use due to excessive deflection and cracking. oOther limit states that may be reached include excessive vibration, fire resistance, fatigue, etc. 1.2.2 Characteristic material strengths (fk) •Concrete strength —it is based on the mean cube crushing strength (cube strength)
has intentionally blurred sections.
Sign up to view the full version.