Issue 23/24

作者研究了数学的一个鲜为人知的分支，发现它非常适合在讲座剧院和从基本束理论到最棘手问题的数值解决方案的每个级别的结构理论的介绍，这可能是遭遇。在最坏的情况下，这对于验证计算机分析的输出很有用。充其量，它可以用更准确的解决方案替换计算机，而没有比准备输入数据和仔细阅读输出数据的劳动力更高的劳动力，并且有优势，结果易于可视化，给出有关残留错误的大小和还原的清晰信息that ‘hands-on’ feeling which has been lost with the advent of computer-aided design. This is achieved with low-level arithmetic. A brief introduction and a simple example are given in the hope of encouraging others to pursue the subject. J. M. Rolfe, BSc (Eng), PrEng, CEng, FIStructE

High-strength concrete is relatively brittle and its use in a reinforced concrete member might result in unacceptably low flexural ductility. One way of improving ductility is to provide confinement. However, in the case of beam design the effects of confinement are generally not considered due mainly to the lack of a suitable design method. In order to develop a design method for improving the flexural ductility of highstrength concrete members through the provision of confinement, the effects of confinement on the flexural behaviour of reinforced concrete beams have been evaluated in this study by complete moment-curvature analysis of beam sections with and without confinement provided. It was found that the provision of confinement significantly increases the ultimate concrete strain, balanced steel ratio and flexural ductility. Furthermore, design formulae for the flexural strength and ductility design of high-strength concrete beams with the effects of confinement taken into account have been developed. A. K. H. Kwan F. T. K. Au S. L. Chau Department of Civil Engineering, The University of Hong Kong, Hong Kong

This paper presents two new methodologies (one formal (NLFEM), the other approximate (CFPM)) which show clear differences – often quite considerable – with regard to code predictions needed to assess and rate existing concrete bridges. The work has obvious implications in terms of both economy and safety, and can assist the engineer in reaching more rational and accurate decisions on the true structural capacity and mode of failure of a structure. A. A. Mahdi, BSc, MSc, PhD, CEng, MICE Hyder Consulting, The Surrey Research Park, Guildford Prof M. D. Kotsovos, Dipl Ing, PhD, DSc, CEng Department of Civil Engineering, National Technical University of Athens, Prof M. N. Pavlovic, ,BEng, MEngSc, PhD, ScD, CEng, FIStructE, FICE, FConsE Department of Civil & Environmental Engineering, Imperial College, London