Issue 14

A simple analysis of a cantilever subjected to uniform steady flow is outlined. The analysis includes the effect of material strain-rate and strain-hardening on the response. Accompanying this analysis is the result of an experimental investigation on the response of uniform circular cantilevers exposed to air-blast loading. The explosion test was conducted at the Woomera Prohibited Area, South Australia. Aluminium cantilever specimens were exposed to a 5t net equivalent TNT charge weight detonation. Details of the analysis and experimental work are presented. Comparison of results suggests that cantilevers could be used as a mechanical indicator to assess air-blast pressure. Eur-Ing. T.S. Lok, BSc(Hons), PhD, CEng, MIStructE, PEng, MASCE, SrMIES Associate Professor, Nanyang Technological University, School of Civil and Environmental Engineering, Nanyang Avenue, Singapore A. Kulkarni, BEng, MEng Research Scholar, Nanyang Technological University, School of Civil and Environmental Engineering, Nanyang Avenue, Singapore

Strut and waler are key components of the steel strutting system commonly found in steel temporary works for braced excavation in cut and cover tunnel, underground station and basement construction. In Singapore, the Nicoll Highway Collapse investigation has identified the stiffened strut–waler connection as a key cause of the catastrophic collapse of a section of the cut and cover tunnel construction for the Island’s Circle Line mass rapid transit system. This paper looks at the behaviour of the strut–waler connection formed typically from steel H-sections and influence of its various stiffening details. Finite element analyses of the stiffened connections comprising steel plates, channels and concrete infills are carried out, and their load resistances and post-peak behaviours are evaluated. It is concluded that conventional plate stiffeners are still the best for stiffening strut–waler connections. S. P. Chiew, PhD, FIStructE, MIES, MASCE Y. Yu, BEng, MEng School of Civil and Environmental Engineering, Nanyang Technological University, Singapore

Boon Lay Extension is an extension of the existing east-west railway line to the industrial estate in Singapore. It includes two elevated stations. The paper describes the design challenges of the station steel roof that is formed of single-layer gridshell structures. It covers the structural scheme, macro-buckling analysis, finite-element analysis for the connections and vibration isolation. These considerations have not been well documented. Siak Keong Song, CEng, MICE, MIStructE, PE(S) Land Transport Authority, Singapore Pui Ming Ho, PE(S) Land Transport Authority, Singapore Zeqin Guo, MIStructE, PE(S) Land Transport Authority, Singapore

This paper describes the design of the support structure for Singapore’s new Supreme Court Building. Most of the structure is exposed to view and this was a major driver in the adoption of precast composite steel members. Particular attention is given to fabrication and erection of the highest court house (both symbolically and physically) within a ‘disc’ set above the main building block. This disc is supported on a perimeter set of inclined columns that terminate in ball and socket joints. Dan Yap Tian Wee, BEng(Hons), MSc (Int’l Const Mgmt), PEng(Singapore) Tan Kheng Soon, BEng(Hons), MSc(Build Sci), PEng(Singapore), MACES Lai Hoke Sai, BSc (Hons), PhD, PEng(Singapore), MACES, MIES Lim Peng Hong, BEng(Civ), MSc (Civ Eng), MConcStruct DIC, PEng (Singapore), MACES, SMIES All CPG Consultants Pte. Ltd