Analytical Nonlinear Rollover Behavior of Cambered Precast Concrete Beams on Flexible Supports

Abstract

Precast prestressed concrete beams present camber after prestressing and early-age imperfections like initial sweep and rotations. Because there have been many reported cases of collapse with this type of element when supported only by bearing pads and during transport, its nonlinear behavior must be understood for a possible improvement in safety during handling and erection. From this observation, it should be pointed out that there have been no analytical studies on the nonlinear response of the problems. Also, no analytical solution accounts for the initial rotation of the elements on stability analysis. Thus, the purpose of the present research is to present nonlinear solutions for prestressed concrete beams resting on elastomeric bearing pads as well as truck and trailer during transport while considering initial imperfections and camber. The equations are obtained by using the Rayleigh-Ritz variational method. From the results, the nonlinear study demonstrates that the problem is highly sensitive to initial imperfections due to the unstable trajectory after peak load. The most critical imperfection for rollover of beams is the initial rotation, compared with initial camber and initial sweep. However, all misalignments influenced the maximum load. Furthermore, the proposed formulation can determine the nonlinear rollover behavior combining all these factors.