Second Order Effects and Elastic Critical Loads of Plane, Multistorey, Unbraced Frames

Pythagoras It may have seemed as though every member of the Institution has submitted a solution of Pythagoras in this column, but we have two late entries from areas of the world that were coloured red in our old school atlas. Verulam

Mr. E. F. Glover (DTp): I have one question for Mr Hulme concerning the importance of the time element before the erection of temporary or permanent lining. Some experiments were made by the Building Research Establishment on the Kielder Dam Scheme, as part of the preliminary works, to establish how long it took to obtain a balance between the maximum pressure on the lining using minimum materials.

Among the most important conclusions of the joint committees which prepared reports on the fire resistance of concrete structures were those stating that: (i) ‘Full appreciation of ultimate limit states of concrete structures at normal temperatures is the essential prerequisite for being able to predict reliably their behaviour in fire.’ (ii) ‘The concept of “nominal shear stress” is not appropriate for a cracked section.’ (iii) Enough information is available to recommend guidelines based on: ‘Analytical procedures, which may be necessary only in some cases, to determine the limit state of collapse when the performance of the structures is largely controlled by the behaviour of the steel reinforcement.’