Discussion on Design Stresses for Concrete Structures Subject to Multiaxial Stresses by D.W. Hobbs,

Whilst I am a firm believer in the economy obtained by the intelligent use of grade 50 steel, the submission by Mr. Needham that the present cost differential is an extra £3.50 per tonne compared with grade 43 steel is somewhat misleading. This figure is applicable only when comparing the cost of grade 43A steel with that of grade 50A steel, and is thus limited only to certain rolled sections. Significant economy by the use of grade 50 steel with rolled steel sections is doubtful, especially where deflection is the criterion. When using structural hollow sections in lattice construction, where the maximum economy in weight is possible, it is necessary to compare the cost differential between grade 43C and grade 40C. This is, I am given to understand, as much as 50 per tonne depending on the sections used. B.J. Jessup

。。备距离那棵树，C. G. H. H. Jofeh显然是一个关注自然保护的人。他写道：我利益读过A.Billingham先生（11月78日）的来信。有感兴趣的我不是建筑法规所做或不说的问题，而是作者的态度，我推断了他对树木所说的。Verulam.

提供了设计曲线和公式，用于计算钢筋混凝土弯曲构件中的偏转。这些基于CP110的附录A中给出的程序，用于直接计算由于短期和长期效应而导致的曲率和偏转。使用设计曲线作为基础，获得了目前用于偏转计算的简化假设引入的误差，并且定义了这些假设的有效性区域。通过最佳的设计示例说明了对对偏转的更现实评估和设计曲线的使用。通过考虑双加强构件，示出了设计公式的优点和偏转计算中的相关曲线。D.J.gunaratnam.