Stability of Buildings BY INSTITUTE OF CIVIL ENGINEERS

Structural engineering is the science and an of designing and making mith economy and elegance buildings, bridges, frameworks and other similar stmcmres so that they can safely resist the forces to which they may be subjected This report confines itself to buildmgs_ : Structural safrty depend• on both material strength and stability. It is Vital that designers should distinguish be- tween the TIIIS report deals with stability not strength, and describes the actions to be considered at the design and c onstmctl on stages and subsequently so that the building remains stable throughout its life. Stability is essentially an inherent property, very largely independent of strength. Yet lack of stability has probably caused more stmctural problems than have shoncomings in material strength. Stability- is suscept1Me to numerical analysis only to a lunitedextent. Fig_l alms to convey at a glance the essence of stability. A house of cards is unstable, but the matenal is not seriously stressed. Those masonry buildings that fail do so mostly by Instability rather than by overstressmg. Slender beams, or columns may become unstable or buckle at loads well below those which the matenal itself can support ‘Lack of bracmg can allow Instability to occur leading to collapse. Ovelturnmg of a complete stmcture is an extreme example of instability.