Finite Element Analysis of Bridge Deck Using MATLAB

Bridges are the most common types of structures generally adopted when there is a obstacle in the path such as water body, valley, road etc without closing the way underneath. Moving live load is one of the critical loading for which bridge superstructure need to be analysed by developing model as realistic as possible. Even though various conventional methods are present for the analysis of bridge superstructure but finite element analysis gives us more realistic behavior of structure. The objective of the thesis is to develop a finite element model of T-beam slab bridge ,bridge pier and pier footing and analyse to study behavior of bridge superstructure for moving live load as per Indian road congress standards given in IRC:6-2017 and IRC: 112-2011 and the dead load of the structure.
In my work, bridge deck is modelled as Mindlin-Reissner plate element which is two dimensional plate in which shear deformations effect is considered whereas longitudinal girders ,cross girders and diaphragms are modelled using Euler-Bernoulli’s grid element which are a one dimensional element . A MATLAB code is developed to model T-beam slab composite action in which beam elements is modelled in plane of plate element so that the nodes of beams are coincide to the nodes of the plate by doing such center of gravity of the beam coincides with the plate element ignoring offset present between them. Moving live load analysis is performed using step by step method in which load moves in longitudinal as well as transverse direction giving the worst case for maximum bending moments, shear forces and deflections. Then Moving live load analysis for 2 lane T-beam bridge is carried out for IRC Class 70R wheeled vehicle and compare the result by modeled in sap2000,2016 of same dimension and the effect of the number of cross girders in the deck span on bending moments, shear forces and deflections of longitudinal girders is presented.