Finite element analysis of cracking and delamination of concrete beam due to steel corrosion

This paper presents the analytical results to investigate cracking and delamination of concrete beam due to steel corrosion. A series of concrete beams were idealised as two dimensional models via their cross section and analysed using the finite element software – LUSAS. The corrosion of steel bars was simulated using a radial expansion. The FE results show that cracking of beam section due to steel corrosion can be clarified into four types, i.e., Internal Cracking, Internal Penetration, External Cracking (HS) and External Cracking (VB). The amount of corrosion in term of radial expansion required to causes Internal Cracking, Internal Penetration, External Cracking (HS) and External Cracking (VB) varies almost linearly with bar diameter d, bar clear distance s and concrete cover c, respectively. If the ratio s/c was less than the critical value of about 2.2, the delamination of concrete cover could occur before the cracks can be visualised on the concrete surface, which does concern engineers

Numerical modeling of wave-induced liquefaction around pipelines

This paper presents the results of a numerical modeling study of wave-induced liquefaction around offshore structures. The finite-element model was first validated against both analytical solutions and laboratory data and was shown to be able to reproduce the observed behavior of the pore pressure variations. The model includes a constitutive model that can predict both residual and momentary liquefaction. The model was used to study liquefaction around a buried pipeline under wave action. In the analysis, it was assumed that the soil in the trench was loose and therefore susceptible to residual liquefaction. The numerical modeling focused on some of the questions that were raised in the physical modeling studies of Sumer et al. in 2006 and Teh et al. in 2003. In particular the influence of pipe diameter, boundary conditions around the pipeline, trench depth, etc., have been assessed and the results are in general agreement with the experimental findings