Critical normal traffic loading for flexure of bridges according to TMH7

[摘要] ENGLISH ABSTRACT: Different types of live loading due to traffic may act on bridges. The focus of this study is onnormal traffic loading according to the South African specification of TMH7. Heavy vehicles are notincluded in normal traffic loading. TMH7 represents the code of practice for the design of highwaybridges and culverts in South Africa. The aim of the study is to provide an insight into the flexuralanalysis of skew bridges, under the effects of normal traffic loading.The need for the study arose since the specification of TMH7 does not explicitly specify applicationpatterns for normal traffic loading. Only the intensity of normal traffic loading is specified and itshould be applied to yield the most adverse effects. For these reasons, a set of so-called standardapplication patterns are investigated and developed through the course of this study. The envelopeof the values from the standard application patterns are compared to the most adverse applicationpattern for flexural effects in certain design regions of the bridge deck. Flexure, as in the context ofthis study, translates into the bending and twisting of the bridge deck under loads.A number of numerical experiments are performed for typical single span and multi-spancontinuous carriageways, where the standard application patterns are compared to the most adverseapplication patterns. The results from the numerical experiments are documented and compared asthe angle of skew of the bridge deck increases in plan-view. For this purpose, the development ofeffective and specialized software was necessary.It was found that the set of standard application patterns can be used as a preliminary approximationfor the most adverse effects of normal traffic loading, for specific flexural resultants in certaindesign regions of a bridge deck. However, for a large number of secondary flexural effects, the set ofstandard application patterns did not represent a good approximation for the most adverse values.

[发布机构] Stellenbosch University