Deflection Theory for Self-Anchored Suspension Bridges under Live Load

Abstract

For self-anchored suspension bridges having the fabrication camber subjected to live loads, a new deflection theory is formulated after an optimized initial state solution is found under dead loads. Its analytical solution for three-span continuous suspension bridges is consistently derived by considering tower effects compared with that derived by the conventional deflection theory for earth-anchored bridges. On the other hand, the unstrained length method (ULM), which keeps all element lengths constant in the nonlinear iteration process, is extended and applied to the nonlinear finite-element analysis of suspension bridges under live loads. Finally, an earth-anchored and self-anchored bridge examples are analytically and numerically solved using the two methods. The numerical results are compared to verify the accuracy and effectiveness of both the proposed deflection theory and the ULM.