COMBINED BOUNDARY-ELEMENT FINITE STRIP ANALYSIS OF BRIDGES

In the present study, the boundary element method is employed to analyze the top slabs of rectangular or skewed composite slab-on-girder and box-girder bridges, while the finite strip method is used to analyze the girders. The boundary elements and the finite strips are connected by transition strips. One side of the transition strip coincides with the nodal line of the adjacent finite strip and has the same degrees of freedom; while on the opposite side, a number of nodes coincides with the nodes of the neighboring boundary elements. Within the transition strip the displacements are expressed in terms of the degrees of freedom of the finite strip nodal line and the boundary element nodes by their corresponding shape functions. In this way, a fully compatible connection between slab and girders is achieved. This combined analysis is very effective in calculating the local bending moments due to moving vehicle wheel loads.