Predicting the flexural collapse load of concrete slab bridges

This paper presents a new method for predicting the load which will cause a ductile reinforced concrete slab to collapse in flexure. The method is less conservative than elastic techniques, easier to use than nonlinear finite element analysis, and applicable to more general slab geometries than any plastic technique in common use. It allows engineers to verify the load-carrying capacity of existing concrete bridges and other structures, thus reducing the unnecessary strengthening or replacement of bridges currently deemed as inadequate using more conservative analysis methods. The method is based on the lower bound theory of plasticity and uses equilibrium finite elements and optimisation by conic programming. Extensions to previous researchers work include the ability to calculate a rigorous lower bound to the collapse load and to predict the critical collapse mechanism. The results can be checked by hand using yield line analysis to produce a complementary upper bound and hence fully bound the ideal plastic collapse load. The technique is applied to existing concrete slabs and is shown to produce results which are consistent with or improve upon previous analyses and experiments. (a) For the covering entry of this conference, please see IRRD abstract no. E218160.

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  • English

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  • Accession Number: 01144016
  • Record Type: Publication
  • Source Agency: TRL
  • Files: ITRD, ATRI
  • Created Date: Nov 16 2009 12:20PM