THE TORSION RULES IN THE AUSTRALIAN （扭转规则在澳大利亚）.pdf

THE TORSION RULES IN THE AUSTRALIAN BRIDGE DESIGN CODE AS5100 Joe Wyche, Director, Wyche Consulting SYNOPSIS The author is a member of the Standards Association BD002 Committee revising the AS3600 Concrete Structures Standard, and has submitted a proposal for revising the Shear and Torsion rules for that Standard. There are a number of errors and shortcomings in the present set of rules, which, whatever problems they may create in buildings, will be significantly worse for bridges. The Bridge Design Standard, AS5100 and AS3600 both contain errors and shortcomings at present, and the author believes both should be corrected, improved and made as compatible as possible. For bridges, in some instances the errors produce very conservative results, and in other instances unconservative results. This paper outlines the author’s proposed rule changes and discusses how they might affect bridge designs ranging from Super Ts through to large box girder bridges, using specific examples. It is a subject on which anyone designing any type of concrete box superstructure, including Super Ts should be informed. 1. INTRODUCTION While the focus of this paper is on the Torsion clauses of the Australian Bridge Design Standard (Ref 1), also referred to as the Bridge Code, some mention will also be made of the Shear clauses. It will be argued that essentially the Shear clauses as they stand are reasonably sensible and technically correct, although there is certainly still room for debate which is beyond the scope of this paper. The Torsion clauses by comparison contain a number of errors, which must be corrected, and the whole layout of the Torsion clauses should be reviewed to make them much